Inkjet recording apparatus

Abstract

An inkjet recording apparatus includes a conveyance section, a carriage, at least one pre-treatment head, at least one ink head, and at least one post-treatment head, wherein the conveyance section conveys a recording medium in a prescribed conveyance direction, the carriage moves back and forth in a main scanning direction intersecting the conveyance direction, the at least one pre-treatment head is mounted on the carriage, and ejects a non-pigmented pre-treatment liquid, the at least one ink head is mounted on the carriage, and ejects ink, the at least one post-treatment head is mounted on the carriage, and ejects a non-pigmented post-treatment liquid, and the at least one pre-treatment head, the at least one ink head, and the at least one post-treatment head are arranged so as to be staggered in the conveyance direction.

Description

TECHNICAL FIELD

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

[0002] An inkjet recording apparatus such as an inkjet printer is provided with an ink head that ejects ink for image formation toward a recording medium.

[0003] In the case where the recording medium is wide, the above-described ink head is mounted on a carriage that reciprocates in a main scanning direction. At the time of recording processing, the recording medium is intermittently conveyed in a prescribed conveyance direction (sub-scanning direction), and in the case where the recording medium is stopped, the carriage reciprocates in the main scanning direction. At the time of carriage movement, ink (colored ink) is ejected from the ink head.

[0004] Patent Document 1 discloses a technique in which a pre-treatment liquid is applied to a recording medium before colored ink is ejected toward the recording medium, and on the other hand, a post-treatment liquid is applied to the recording medium after the colored ink is ejected toward the recording medium. The pre-treatment liquid is, for example, a treatment liquid for improving the fixing property of ink to a recording medium and the coagulation property of ink pigments. Further, the post-treatment liquid is, for example, a treatment liquid for improving the fastness of a printed image. On the carriage of the inkjet recording apparatus, in addition to the ink head, a pre-treatment head that ejects a pre-treatment liquid and a post-treatment head that ejects a post-treatment liquid are provided.

[0005] PRIOR ART DOCUMENT

[0006] PATENT DOCUMENT

[0007] Patent Document 1: Japanese Patent Publication No. 2017-094673 SUMMARY

[0008] One aspect of the present application relates to an inkjet recording apparatus including a conveyance section, a carriage, at least one pre-treatment head, at least one ink head, and at least one post-treatment head. The conveyance section conveys a recording medium in a prescribed conveyance direction. The carriage reciprocates in a main scanning direction that intersects the conveyance direction. The at least one pre-treatment head is mounted on the carriage and ejects a non-colored pre-treatment liquid. The at least one ink head is mounted on the carriage and ejects ink. The at least one post-treatment head is mounted on the carriage and ejects a non-colored post-treatment liquid. The at least one pre-treatment head, the at least one ink head, and the at least one post-treatment head are arranged so as to be staggered in the conveyance direction. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a perspective view showing the overall structure of an inkjet recording apparatus according to an embodiment of the present application.

[0010] Figure 2 is Figure 1 a schematic cross-sectional view of the II-II line.

[0011] Figure 3 is Figure 1 an enlarged perspective view of the carriage shown in

[0012] Figure 4 is a schematic view showing a serial printing method employed in an embodiment of the present application.

[0013] Figure 5A is a schematic view showing the printing condition of the carriage in the forward path and the backward path.

[0014] Figure 5B is a schematic view showing the printing condition of the carriage in the forward path and the backward path.

[0015] Figure 6 is a plan view schematically showing Figure 3 the arrangement of the ink head and the processing head on the carriage shown in

[0016] Figure 7 is a block diagram of an inkjet recording apparatus to which an embodiment of the present application relates.

[0017] Figure 8 is a plan view showing the relationship between the pre-treatment liquid landing area and the ink landing area on a recording medium in an inkjet recording apparatus to which an embodiment of the present application relates.

[0018] Figure 9 is a plan view showing the relationship between the pre-treatment liquid landing area and the ink landing area on a recording medium in an inkjet recording apparatus to which an embodiment of the present application relates.

[0019] Figure 10 is a schematic view showing the landing of ink on the surface of a recording medium in association with the movement of the carriage. DETAILED DESCRIPTION

[0020] In the following, inkjet recording apparatuses to which the embodiments of the present application relate will be described with reference to the drawings. In these embodiments, as a specific example of an inkjet recording apparatus, an inkjet printer provided with an ink head that ejects ink for image formation toward a wide and long recording medium is exemplified. The inkjet printer is suitable for digital textile printing that prints images such as characters and patterns on a recording medium formed of cloth such as woven fabric and knitted fabric by an inkjet method. Of course, the inkjet recording apparatus to which the present application relates can also be used for the purpose of printing various inkjet images on recording media such as paper and resin sheets.

[0021] [Overall structure of inkjet printer]

[0022] Figure 1 is a perspective view showing the overall structure of an inkjet printer 1 to which the first embodiment of the present application is applied, Figure 2 is Figure 1 a schematic cross-sectional view of II-II line of FIG. 1. The inkjet printer 1 is a printer that prints an image on a wide and long workpiece W (recording medium) by an inkjet method, and includes a device frame 10, a workpiece conveying section 20 (conveying section) assembled to the device frame 10, and a carriage 3. In addition, in the present embodiment, the right-left direction is a main scanning direction S (direction of arrow A in FIG. 1) at the time of printing the workpiece W, and the rearward direction is a sub scanning direction (conveying direction F of the workpiece W). Figure 3

[0023] The device frame 10 forms a skeleton for mounting various constituent components of the inkjet printer 1. The workpiece conveying section 20 is a mechanism that intermittently feeds (conveys) the workpiece W in such a manner that the workpiece W passes through a printing region (image forming position) where the inkjet printing process is performed along the conveying direction F from the rearward direction. The carriage 3 mounts the ink head 4, the pre-treatment head 5, the post-treatment head 6, and the sub tank 7, and reciprocally moves along the main scanning direction S (right-left direction) intersecting the conveying direction F of the workpiece W when the inkjet printing process is performed.

[0024] The device frame 10 includes a central frame 111, a right frame 112, and a left frame 113. The central frame 111 forms a skeleton for mounting various constituent components of the inkjet printer 1, and has a right-left width corresponding to the workpiece conveying section 20. The right frame 112 and the left frame 113 are respectively erected on the right side and the left side of the central frame 111. Between the right frame 112 and the left frame 113 is a printing region 12 where the printing process is performed on the workpiece W.

[0025] The right frame 112 forms a maintenance region 13. The maintenance region 13 is a region where the carriage 3 is evacuated when the printing process is not performed. In the maintenance region 13, cleaning process, removal process, and the like of the nozzles (discharge holes) of the ink head 4, the pre-treatment head 5, and the post-treatment head 6 are performed, and are covered with a cover. The left frame 113 forms a folding-back region 14 of the carriage 3. The folding-back region 14 is a region where the carriage 3 temporarily enters when performing reverse main scanning, which is performing main scanning from right to left on the printing region 12 in the printing process.

[0026] ​A carriage guide 15 for reciprocating the carriage 3 in the left-right direction is assembled above the device frame 10. The carriage guide 15 is a flat plate-like member long in the left-right direction, and is disposed above the work conveying section 20. A timing belt 16 (moving member) is assembled on the carriage guide 15 in a manner rotatable in the left-right direction (main scanning direction). The timing belt 16 is an endless belt, and is rotated in the left direction or the right direction by a carriage drive section 3S described later.

[0027] An upper and lower pair of rails 17 (holding members) for holding the carriage 3 in a state reciprocable in the main scanning direction S is provided on the carriage guide 15 in a manner extending in parallel in the left-right direction. The carriage 3 is engaged with the rails 17. Further, the carriage 3 is fixed to the timing belt 16. The carriage 3 is guided by the rails 17 and moved in the left direction or the right direction along the carriage guide 15 in conjunction with the rotation of the timing belt 16 in the left direction or the right direction.

[0028] Referring mainly to Figure 2 , the work conveying section 20 includes a feed-out roller 21 for feeding out the work W before printing and a take-up roller 22 for taking up the work W after printing. The feed-out roller 21 is disposed at the lower rear portion of the device frame 10, and is a winding shaft of a winding body of the work W before printing, i.e., a feed-out roll WA. The take-up roller 22 is disposed at the lower front portion of the device frame 10, and is a winding shaft of a winding body of the work W after printing processing, i.e., a take-up roll WB. The first motor Ml is attached to the take-up roller 22, and rotates the take-up roller 22 about the shaft and performs a take-up operation of the work W.

[0029] A path between the feed-out roller 21 and the take-up roller 22 and passing through the printing region 12 becomes a conveying path of the work W. In the conveying path, a first tension roller 23, a work guide 24, a conveying roller 25 and a pinch roller 26, a return roller 27, and a second tension roller 28 are disposed in this order from the upstream side. The first tension roller 23 applies a predetermined tension to the work W at the upstream side of the conveying roller 25. The work guide 24 changes the conveying direction of the work W from the upward direction to the front direction, and causes the work W to enter the printing region 12.

[0030] The conveying roller 25 is a roller that generates a conveying force for intermittently conveying the work W in the printing region 12. The conveying roller 25 is rotated about the shaft by the second motor M2, and intermittently conveys the work W in the front direction (predetermined conveying direction F) at a predetermined conveying pitch in such a manner that the work W passes through the printing region 12 (image forming position) facing the carriage 3. The pinch roller 26 is disposed facing the conveying roller 25 from above, and forms a conveying nip portion together with the conveying roller 25.

[0031] The turn-back roller 27 changes the conveyance direction of the work W that has passed through the printing region 12 from the forward direction to the downward direction, and guides the work W after the printing process to the take-up roller 22. The second tension roller 28 applies a prescribed tension to the work W on the downstream side of the conveyance roller 25. A platen 29 is disposed below the conveyance path of the work W in the printing region 12.

[0032] The carriage 3 is supported in a cantilevered state by the guide rail 17, and reciprocates in the main scanning direction S (in this embodiment, the left-right direction) that intersects (in this embodiment, is perpendicular to) the conveyance direction F in the printing region (image forming position). The carriage 3 includes a carriage frame 30, an ink head 4 mounted on the carriage frame 30, a pre-processing head 5, a post-processing head 6, and a plurality of sub-tanks 7. The carriage frame 30 includes a head support frame 31 and a rear frame 32 (engagement portion).

[0033] 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. Further, the guide rail 17 is engaged with the rear frame 32. That is, in this embodiment, the rear frame 32 is an engagement portion that is held in a cantilevered state by the guide rail 17. The head support frame 31 is a horizontal plate whose rear end side is supported in a cantilevered state by the guide rail 17 via the engagement portion.

[0034] In addition, the cantilevered state indicates that, in the carriage 3, the engagement portion (rear frame 32) exists only on one side of the upstream side or the downstream side from the center of the carriage 3 in the conveyance direction F, and no other engagement portion exists on the opposite side of the side on which the engagement portion exists. The engagement portion is a portion that is held by the guide rail 17 that is a holding member. The engagement portion can also be disposed outside the range in which the ink head 4 and the processing heads are disposed in the conveyance direction F. That is, the engagement portion can also be disposed only on the upstream side or the downstream side with respect to the range in which the ink head 4 and the processing heads are disposed in the conveyance direction F.

[0035] [Detailed structure of carriage]

[0036] The carriage 3 will be described further. Figure 3 is Figure 1 An enlarged perspective view of the carriage 3 is shown. Figure 3 The conveyance direction F (sub-scanning direction) of the work W and the main scanning direction S that is the moving direction of the carriage 3 are shown in FIG. Figure 3 An example in which a plurality of ink heads 4 that eject an image forming ink for the work W, a pre-processing head 5 and a post-processing head 6 that eject a non-pigmented processing liquid, and a plurality of sub-tanks 7 that supply the ink and the processing liquid to these heads 4 to 6 are mounted on the carriage 3 is shown in FIG.

[0037] Each printhead 4 includes: multiple nozzles (ink ejection orifices) that eject ink droplets by means of, for example, piezoelectric ejection using a piezoelectric element or thermal ejection using a heating element; and an ink channel that guides the ink to the nozzles. As ink, for example, an aqueous pigment ink containing an aqueous solvent, pigment, and binder resin can be used. Alternatively, the ink can contain dye instead of pigment. Therefore, the concept of containing pigment and dye is sometimes referred to as pigment below. The multiple printheads 4 in this embodiment include first to sixth printheads 4A to 4F that eject six different colors of ink from each other. For example, the first printhead 4A ejects orange ink, the second printhead 4B ejects green ink, the third printhead 4C ejects yellow ink, the fourth printhead 4D ejects red ink, the fifth printhead 4E ejects blue ink, and the sixth printhead 4F ejects black ink.

[0038] The printheads 4A to 4F of each color are mounted on the head support frame 31 of the carriage 3 in an arrangement along the main scanning direction S. Each printhead 4A to 4F of each color has one head.

[0039] The pre-processing head 5 and the post-processing head 6 are positioned differently from the printhead 4 in the transport direction F. The pre-processing head 5 is positioned upstream of the printhead 4 in the transport direction F. Figure 3 An example is shown where a pre-processing head 5 is positioned near the right end of the printhead 4 array. Similarly, a post-processing head 6 is positioned downstream of the printhead 4 in the transport direction F. Figure 3 The illustration shows an example where one post-processing head 6 is disposed at the right end of the printhead 4 assembly. In other embodiments, multiple pre-processing heads 5 or multiple post-processing heads 6 may also be disposed. That is, at least one pre-processing head 5 and at least one post-processing head 6 are respectively provided on the carriage 3.

[0040] The pretreatment head 5 ejects a pretreatment liquid for performing a prescribed pretreatment on the workpiece W. The pretreatment liquid is ejected from the pretreatment head 5 towards a position on the workpiece W from the printhead 4 where ink has not yet been ejected from the printhead 4. The pretreatment liquid is a non-coloring treatment liquid that does not exhibit color even when adhering to the workpiece W; for example, it is a treatment liquid that improves the fixing properties of the ink on the workpiece W and the aggregation properties of the ink pigment. Such a pretreatment liquid can be a treatment liquid in which a binding resin is mixed with a solvent, or a treatment liquid in which a positively charged cationic resin is mixed with a solvent.

[0041] The post-processing head 6 sprays a post-processing liquid onto the ink-coated workpiece W to perform the prescribed post-processing. The post-processing liquid is sprayed from the post-processing head 6 towards the workpiece W from the position after ink is ejected from the printhead 4. The post-processing liquid is also a non-coloring liquid that does not impart color even when adhering to the workpiece W; it is designed to improve the fixing properties and adhesion (resistance to friction and scratching) of the ink image printed on the workpiece W by the printhead 4. Silicone-based post-processing liquids can be used as such post-processing liquids. Furthermore, the post-processing liquid and the pre-processing liquid are different liquids. Specifically, the post-processing liquid and the pre-processing liquid contain different components.

[0042] Here, "non-coloring processing fluid" refers to a processing fluid that, when printed alone on a recording medium, cannot be perceived by the naked eye as having any color. This includes colors with a chromaticity of 0, such as black, white, and gray. Non-coloring processing fluid is essentially a transparent liquid; however, when observing 1L of processing fluid in its liquid state, it is not completely transparent and sometimes appears slightly whitish. This color is very faint, and when printed alone on a recording medium, it cannot be perceived by the naked eye. Additionally, depending on the type of processing fluid, when printed alone on a recording medium, the recording medium may sometimes exhibit changes such as gloss, but this is not considered coloring.

[0043] In this embodiment, the pretreatment liquid and posttreatment liquid can be sprayed onto almost the entire surface of the workpiece W, or the pretreatment liquid and posttreatment liquid can be selectively sprayed out in the same way as ink, depending on the image being printed.

[0044] Next, we will explain the case where pretreatment and posttreatment solutions are selectively ejected. As described above, for workpiece W where the color is printed according to the image, the pretreatment solution, ink, and posttreatment solution are ejected in the order of image. In this case, the ink can be one color or multiple colors. For parts where no color is printed, i.e., parts where no ink is ejected, the pretreatment and posttreatment solutions are also generally not ejected. Furthermore, to adjust the quality of the printed image, the texture of workpiece W, etc., the selection of the ejection of the pretreatment and posttreatment solutions can differ from the ejection of the ink.

[0045] An opening 31H is provided at each head configuration location of the head support frame 31. Figure 3 The printheads 4A to 4F, the pre-processing head 5, and the post-processing head 6 are assembled on the head support frame 31 by being embedded in each of the openings 31H. The nozzles disposed on the lower end faces of each of the heads 4, 5, and 6 protrude from each of the openings 31H.

[0046] The sub-tanks 7 are supported by the carriage 3 above the side of the heads 4, 5, 6 through a holding frame not shown. The sub-tanks 7 are provided corresponding to the heads 4, 5, 6, respectively. Ink or a treatment liquid is supplied from an ink cartridge or a main tank, which houses ink and a treatment liquid, to each of the sub-tanks 7. Each of the sub-tanks 7 supplies the ink or the treatment liquid to each of the heads 4, 5, 6. Each of the sub-tanks 7 and the heads 4, 5, 6 are connected through a pipe not shown. Figure 3 The pipe not shown is omitted.

[0047] As described above, the inkjet printer 1 according to the present embodiment is a multifunctional integrated printer in which the ink head 4, the pre-treatment head 5, and the post-treatment head 6 are mounted on one carriage 3. According to the inkjet printer 1, for example, in a printing step of performing inkjet printing on a cloth in digital printing, the ejection step of the pre-treatment liquid and the ejection step of the post-treatment liquid can be integrally performed. Therefore, it is possible to achieve simplification of the printing step and miniaturization of a printing device.

[0048] [Printing method]

[0049] Next, a printing method performed by the inkjet printer 1 according to the present embodiment will be described. The inkjet printer 1 performs printing processing on a work W in a serial printing method. Figure 4 is a schematic view showing the serial printing method. In Figure 4 , the carriage 3 is schematically drawn with omission of the pre-treatment head 5 and the post-treatment head 6.

[0050] In a case where the work W has a wide size, it is not possible to perform printing while continuously feeding out the work W. The serial printing method is a printing method in which reciprocating movement of the carriage 3 on which the ink head 4 of each color is mounted in the main scanning direction S and intermittent feeding of the work W in the feeding direction F are repeated. 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 substantially equal to the arrangement range of the ink ejection nozzles of the ink head 4. In addition, in Figure 4 and the following Figure 5A , Figure 5B , the width of each head in the feeding direction F and the printing width Pw are drawn to be substantially equal. Actually, the width of each head in the feeding direction F is larger than the printing width Pw and the arrangement range of the ejection nozzles.

[0051] Figure 4The state in which the carriage 3 moves in the departure direction SA of the main scanning direction S and the printing of the band-shaped image G1 of the printing width Pw ends is shown in FIG. 12. When the main scanning is performed in the departure direction SA, the conveyance of the work W is stopped. After the band-shaped image G1 is printed, the work W is fed by a distance corresponding to the printing width Pw in the conveyance direction F. At this time, the carriage 3 waits at the return region 14 on the left end side. After the work W is fed, the carriage 3 is returned in the return direction SB in conjunction with the reverse rotation of the timing belt 16. The work W is in a stopped state. Then, as shown in FIG. 13, the carriage 3 moves in the return direction SB and prints the band-shaped image G2 having the printing width Pw on the upstream side of the band-shaped image G1. Thereafter, the same operation is repeated. Figure 4

[0052] Figure 5A Figure 5B are schematic diagrams showing the printing states of the carriage 3 in the departure direction and the return direction. Here, the ink head 4, the pre-treatment head 5, and the post-treatment head 6 mounted on the carriage 3 are simply shown. The ink head 4 includes first, second, third, and fourth ink heads 4A, 4B, 4C, 4D for ejecting inks of first, second, third, and fourth colors different from each other, and these first to fourth ink heads 4A to 4D are arranged in a line in the main scanning direction S. The pre-treatment head 5 is arranged on the upstream side in the conveyance direction F of the ink head 4, and the post-treatment head 6 is arranged on the downstream side. Further, as in the case explained in FIG. 10, the work W is fed in the conveyance direction F between the printing in the departure direction and the printing in the return direction. At this time, the moving distance in the conveyance direction F is the interval pitch (head pitch) between the heads adjacent in the conveyance direction F. Further, this moving distance is also the printing width Pw of each head 4, 5, 6. Figure 4

[0053] Figure 5A The state in which the carriage 3 moves in the departure direction SA of the main scanning direction S and the printing of the band-shaped image G1 of the printing width Pw ends is shown in FIG. 12. When the main scanning is performed in the departure direction SA, the conveyance of the work W is stopped. After the band-shaped image G1 is printed, the work W is fed by a distance corresponding to the printing width Pw in the conveyance direction F. At this time, the carriage 3 waits at the return region 14 on the left end side. After the work W is fed, the carriage 3 is returned in the return direction SB in conjunction with the reverse rotation of the timing belt 16. The work W is in a stopped state. Then, as shown in FIG. 13, the carriage 3 moves in the return direction SB and prints the band-shaped image G2 having the printing width Pw on the upstream side of the band-shaped image G1. Thereafter, the same operation is repeated.

[0054] The region A3 is a region which is 1 head pitch of distance toward the downstream side from the region A4, is a region faced by the ink head 4. On the region A3, the pre-treatment layer Lpre has been formed on the entire length range in the main scanning direction by the previous return direction main scanning. In this time's departure direction main scanning, on the pre-treatment layer Lpre of the region A3, the first, second, third, and fourth ink layers LCA, LCB, LCC, LCD are formed by the inks of the first to fourth colors ejected in this order in accordance with the arrangement order of the first to fourth ink heads 4A to 4D. In addition, for the sake of easy understanding, Figure 5A ​​​The illustration shows the fourth to first ink layers (LCD to LCA) being stacked sequentially, but in reality, they are not stacked. Furthermore, the aforementioned pre-processing layer Lpre and the post-processing layer Lpos, described later, are not formed on the workpiece W.

[0055] Region A2 is a region located downstream of region A3 by a distance of one head pitch, and is the region faced by the post-processing head 6 mounted on the downstream side of the carriage 3. On region A2, a pre-processing layer Lpre formed by the previous outgoing main scan and first to fourth ink layers LCA to LCD formed by the previous return main scan have been formed along the entire length of the main scanning direction. In this outgoing main scan, a post-processing layer Lpos is formed on the first to fourth ink layers LCA to LCD in region A2 using post-processing liquid ejected from the post-processing head 6.

[0056] Region A1 is a region located downstream of region A2 by a distance of one head pitch, and is the region where the printing process ends after the carriage 3 has passed through. That is, in region A1, the pre-processing layer Lpre, the first to fourth ink layers LCA to LCD, and the post-processing layer Lpos are formed along the entire length of the main scanning direction.

[0057] Figure 5B Indicates the end Figure 5A After the outgoing main scan, the carriage 3 folds back and moves towards the return path direction SB while performing the return main scan. Before this folding-back movement, the workpiece W is conveyed in the transport direction F by a distance of one head pitch. Region A5 on the workpiece W is the region one head pitch upstream of region A4, and is the region faced by the pretreatment head 5 during this return main scan. On region A5, a pretreatment layer Lpre is formed by the pretreatment liquid sprayed from the pretreatment head 5.

[0058] In regions A4 and A3, the first to fourth ink layers LCA to LCD and the post-processing layer Lpos are formed on the existing layers, respectively. Specifically, in region A4, the first to fourth ink layers LCA to LCD are formed on the pre-processing layer Lpre. In region A3, the post-processing layer Lpos is formed on the first to fourth ink layers LCA to LCD. Region A2 becomes the region where printing processing ends after region A1.

[0059] The reason why printing can be performed in both the outgoing and returning main scans as described above is that the pre-processing head 5 and the post-processing head 6 are offset relative to the printhead 4 in the transport direction F. Assuming that the pre-processing head 5, printhead 4, and post-processing head 6 are arranged in this order along the main scan direction S in the carriage 3, printing that allows the pre-processing fluid and post-processing fluid to land in the desired order can only be achieved in one of the outgoing or returning main scans. To enable bidirectional printing, a pair of pre-processing heads 5 and a pair of post-processing heads 6 must be arranged on each side of the printhead 4 array. In this case, the width of the carriage 3 in the main scan direction S becomes larger. Since such a configuration is not required in this embodiment, the width of the carriage 3 in the main scan direction S can be reduced.

[0060] Furthermore, by setting multiple columns of printheads 4, the amount of ink applied to the workpiece W can be increased. For example, when there are two columns of printheads 4, printing can be performed as follows: After the first to fourth ink layers LCA to LCD are formed by the first column of printheads 4 as described above, the workpiece W is transported in the transport direction F a distance equal to one printhead pitch, and the first to fourth ink layers LCA to LCD are formed by the second column of printheads 4. By operating in this way, two layers of ink can be printed onto the workpiece W.

[0061] Figure 6 Is it a top view that roughly represents the head configuration on the carriage 3 according to this embodiment, or is it a plan view that represents... Figure 3 The diagram shows the configuration of the printhead 4, preprocessing head 5, and postprocessing head 6 (multiple processing heads) on the carriage 3. As described, the carriage 3 is equipped with first to sixth printheads 4A to 4F, preprocessing head 5, and postprocessing head 6, each ejecting six different colors of ink. One printhead 4A to 4F, one preprocessing head 5, and one postprocessing head 6 are provided for each color. The group of first to sixth printheads 4A to 4F constituting the printhead 4 is arranged in a manner that it is aligned along the main scanning direction S in the central region of the carriage 3 in the transport direction F. Furthermore, when viewed along the main scanning direction S, the downstream end of the preprocessing head 5 in the transport direction F is arranged to overlap with the upstream end of the printhead 4 in the transport direction F. Similarly, when viewed along the main scanning direction S, the downstream end of the printhead 4 in the transport direction F is arranged to overlap with the upstream end of the postprocessing head 6 in the transport direction F.

[0062] In addition, unless otherwise specified, in the following areas Figure 6 In all the diagrams, the spacing between adjacent heads (the spacing between the centers of each head) in the main scanning direction S is the same. Similarly, the distance between adjacent heads (the spacing between the centers of each head) in the transport direction F is the same.

[0063] Figure 6 The nozzle region of each head is schematically illustrated with a broken line inside the appearance shape of each head. The nozzle region is a region defined by nozzles arranged in the lower surface of each head that eject liquid when printing is performed. In each head, a plurality of nozzles are arranged in the nozzle region along the main scanning direction S and the conveyance direction F.

[0064] Further, the upstream side end portion and the downstream side end portion of the nozzle region of the first to sixth heads 4A to 4F in the conveyance direction F are arranged at the same position in the conveyance direction F as each other. In addition, the upstream side end portion of the nozzle region of the first to sixth heads 4A to 4F in the conveyance direction F and the downstream side end portion of the nozzle region of the pre-treatment head 5 in the conveyance direction F are continuously arranged (connected, adjacent) in the conveyance direction F. In addition, the upstream side end portion of the nozzle region of the post-treatment head 6 in the conveyance direction F and the downstream side end portion of the nozzle region of the first to sixth heads 4A to 4F in the conveyance direction F are continuously arranged in the conveyance direction F.

[0065] The arrangement region of each nozzle is arranged in such a manner that ink and each treatment liquid land adjacent to each other in units of resolution. Therefore, the landing region of the pre-treatment liquid and the ink landing region of the first to sixth heads 4A to 4F are continuous (abutted) at the pre-treatment / ink head boundary line Ll, and the ink landing region of the nozzle region of the first to sixth heads 4A to 4F and the landing region of the post-treatment liquid are continuous at the ink / post-treatment head boundary line L2.

[0066] Figure 7 is a block diagram of the inkjet printer 1 to which the present embodiment relates. The inkjet printer 1 further includes a control section 90 that generally controls the operation of each section of the inkjet printer 1, a carriage drive section 3S, an I / F 91, and an image memory 92. The control section 90 is constituted by a CPU (Central Processing Unit), a ROM (ReadOnly Memory) that stores a control program, a RAM (Random Access Memory) that serves as a work area of the CPU, and the like. Further, not only the above-described first motor Ml and second motor M2, the ink head 4, the pre-treatment head 5, and the post-treatment head 6, but also the carriage drive section 3S, the I / F 91, the image memory 92, and the like are electrically connected to the control section 90. The carriage drive section 3S includes a not-shown motor and the like that rotates the timing belt 16 in the circumferential direction in order to reciprocally move the carriage 3 along the main scanning direction S.

[0067] The image memory 92 temporarily stores print image data provided from an external device such as a personal computer, for example.

[0068] The I / F 91 is an interface circuit for realizing data communication with an external device, for example, generates a communication signal in accordance with a communication protocol of a network to which the inkjet printer 1 and the external device are connected, and converts a communication signal from the network side into data in a format processable by the inkjet printer 1. A print instruction signal transmitted from a personal computer or the like is supplied to the control section 90 via the I / F 91, and image data is stored in the image memory 92 via the I / F 91.

[0069] The control section 90 has the functions of a drive control section 901, an ejection control section 902, an ejection pattern designation section 903, and a storage section 904 by executing a control program stored in the ROM by the CPU.

[0070] The drive control section 901 controls the conveyance operation of the work W by controlling the first motor Ml and the second motor M2 of the work conveyance section 20. Further, the drive control section 901 controls the reciprocating movement of the carriage 3 in the main scanning direction S by controlling the carriage drive section 3S.

[0071] The ejection control section 902 inputs a prescribed command signal to the ink head 4, the pre-treatment head 5, and the post-treatment head 6, and controls the ejection operation of each color of ink, pre-treatment liquid, and post-treatment liquid.

[0072] The ejection pattern designation section 903 designates the ejection pattern of each head in order to cause ink to land on a prescribed position on the work W in accordance with image information accepted from the I / F 91 or the image memory 92. More specifically, the ejection pattern designation section 903 designates the ink ejection amount (ejection pattern) of each color of ink head 4, and inputs a signal corresponding to the ejection amount and the ejection timing thereof to the ejection control section 902. The ejection pattern designation section 903 also performs the same control as described above with respect to the pre-treatment head 5 that ejects pre-treatment liquid and the post-treatment head 6 that ejects post-treatment liquid.

[0073] The storage section 904 stores various threshold values, parameters, and the like that are referred to by the drive control section 901, the ejection control section 902, and the ejection pattern designation section 903 of the control section 90 in advance.

[0074] In addition, the structure of the control section 90 is not limited to the structure described above, and can be different from the structure described above in accordance with the structure of the device and the program, and the like. In other words, each function of the drive control section 901, the ejection control section 902, the ejection pattern designation section 903, and the storage section 904 described above can be executed by the control section 90.

[0075] <Regarding the Ejection of Each Treatment Liquid and Ink>

[0076] As Figure 6As shown, in the head configuration of the present embodiment, one pre-treatment head 5 is arranged on the upstream side of the ink head 4 in the conveyance direction F, and one post-treatment head 6 is arranged on the downstream side. That is, a multifunctional integrated inkjet printer 1 in which the three heads of the pre-treatment liquid, the ink, and the post-treatment liquid are mounted on one carriage 3 can be provided. Further, since the pre-treatment head 5, the ink head 4, and the post-treatment head 6 are arranged in this order in the conveyance direction F, the pre-treatment liquid, the ink, and the post-treatment liquid can be ejected in the desired landing order on both the forward pass main scan and the return pass main scan.

[0077] As described above, in the present embodiment, the inkjet printer 1 includes: a workpiece conveyance unit 20 that conveys a workpiece W in a predetermined conveyance direction F; a carriage 3 that reciprocates in a main scan direction S that intersects the conveyance direction F; a pre-treatment head 5 that is mounted on the carriage 3 and ejects a non-pigmented pre-treatment liquid; an ink head 4 that is mounted on the carriage 3 and ejects ink; and a post-treatment head 6 that is mounted on the carriage 3 and ejects a non-pigmented post-treatment liquid. When the ejection control unit 902 controls the ejection of each head in accordance with the movement of the carriage 3 in the main scan direction S, the pre-treatment head 5 ejects the pre-treatment liquid onto a predetermined recording region (pixel) on the workpiece W in association with a first movement of the carriage 3 in the main scan direction S, then the workpiece conveyance unit 20 conveys the workpiece W in the conveyance direction F at a predetermined pitch in association with a second movement of the carriage 3 in the main scan direction S, further, the ink head 4 ejects the ink onto the recording region in association with a third movement of the carriage 3 in the main scan direction S, then the workpiece conveyance unit 20 further conveys the workpiece W in the conveyance direction F, and the post-treatment head 6 ejects the post-treatment liquid onto the recording region in association with a fourth movement of the carriage 3 in the main scan direction S, thereby forming an ink image including the pre-treatment liquid, the ink, and the post-treatment liquid on the recording region. Thus, in the present embodiment, the pre-treatment head 5, the ink head 4, and the post-treatment head 6 are arranged in this order in the conveyance direction F. Therefore, the pre-treatment liquid, the ink, and the post-treatment liquid can be reliably and stably applied to the workpiece W in this order. As a result, high-quality printing can be reliably performed on the workpiece W. In addition, as an example, the first movement of the carriage 3 is in one direction in the main scan direction S (from right to left), the second movement is in the other direction in the main scan direction S (from left to right), and the third movement is in the one direction in the main scan direction S. Figure 6 Figure 6 Figure 6 Figure 6

[0078] ​​​​That is, in the present embodiment, if the movement of the carriage 3 when the pre-treatment head 5 is arranged to spray the pre-treatment liquid while moving relative to a prescribed region on the workpiece W along the main scanning direction S is a first scan, the movement of the carriage 3 when the ink head 4 is arranged to spray ink while moving relative to the prescribed region along the main scanning direction S is a second scan, and the movement of the carriage 3 when the post-treatment head 6 is arranged to spray the post-treatment liquid while moving relative to the prescribed region along the main scanning direction S is a third scan, the first scan, the second scan, and the third scan are different scans from each other, and the first scan, the second scan, and the third scan are each performed at least once in that order. As a result, the pre-treatment liquid, the ink, and the post-treatment liquid can be reliably applied to the workpiece W in that order. In addition, the prescribed region on the workpiece W is a region that is equal to or smaller than the region printed in one scan.

[0079] In addition, the present application is not limited to the arrangement in which one row of ink heads 4 is arranged along the main scanning direction S as in the present embodiment, but can also be an arrangement in which two or more rows of ink heads 4 are arranged along the conveyance direction F and the ink heads 4 of each row are arranged along the main scanning direction S. Furthermore, the ink heads 4 are not limited to ink heads that form images in multiple colors, but can also be an ink head 4 that sprays ink in a single color mounted on the carriage 3. In this case, the pre-treatment head 5, the ink head 4, and the post-treatment head 6 can also be arranged offset in that order in the conveyance direction F.

[0080] Furthermore, in the present embodiment, the carriage 3 has a rear frame 32 (engagement portion) held in a cantilevered state by the guide rail 17 (holding member). By supporting the carriage 3 in a cantilevered state by the timing belt 16, the structure can be simplified. Furthermore, by supporting in a cantilevered state, the structure can be easily arranged to open the downstream side of the carriage 3, and maintenance of the ink head 4 and the treatment heads 5, 6 can be easily performed.

[0081] In the carriage 3 supported in a cantilevered state in this way, the pre-treatment head 5 is arranged on the proximal end side 311 (the side close to the engagement portion) of the head support frame 31, and the post-treatment head 6 is arranged on the distal end side 312 (the side away from the engagement portion). Unlike the proximal end side 311 close to the rear frame 32 fixed to the timing belt 16, the distal end side 312, which is a free end, is estimated to have a lower positional accuracy. However, the post-treatment head 6, which does not require a high degree of spraying accuracy, is mounted on the distal end side 312. Since the post-treatment liquid is applied to the ink image printed on the workpiece W, even if the landing position deviates, the relative degree of influence on the image quality can be reduced compared to the same degree of landing position deviation of the pre-treatment liquid. Therefore, even in the case of using a carriage 3 supported in a cantilevered state, it is difficult to reduce the image quality.

[0082] <Problems in Carriage Scanning>

[0083] Figure 10 is a schematic view showing a case where the ink 4M lands on the surface of the work W accompanying the movement of the carriage 3. When the work W is formed of cloth such as woven fabric or knitted fabric, or paper composed of paper fibers, various irregularities exist on the surface thereof. In the case of cloth, irregularities exist between adjacent yarns depending on the undulations of the surface resulting from the weaving process or the knitting process, the thickness of the yarn, and the twisting method. Generally, these irregularities are larger than the ink dot diameter of several tens of micrometers, and even if not, they are of a size that cannot be ignored with respect to the ink dot diameter. Further, in the case of paper, fine irregularities exist due to the random distribution of paper fibers on the surface, and depending on the kind of paper, irregularities of a size that cannot be ignored with respect to the ink dot diameter also exist. In other words, the recording medium such as cloth or certain paper sometimes has irregularities of a period on the surface thereof that is of a size that cannot be ignored with respect to the dot diameter of the ejected ink.

[0084] In Figure 10 , when the ink head 4 moves along the paper surface from the right to the left in the main scanning direction SI while ejecting the ink 4M by the movement of the carriage not shown, the moving speed of the ink head 4 and the ejection speed of the ink 4M are added, so that each ink 4M lands on the work W obliquely in the direction indicated by the arrow of Figure 10 At this time, for example, if the work W has an irregularity shape in which a first face Kl and a second face K2 that are inclined respectively exist alternately, as shown in Figure 10 , the landing amount (coating amount) of the ink 4M per unit area becomes relatively less on the first face Kl that is approximately parallel to the ejection direction of the ink 4M, and the landing amount of the ink 4M per unit area becomes relatively more on the second face K2 that is approximately perpendicular to the ejection direction of the ink 4M. This phenomenon is because the area on which the same amount of ink 4M lands is larger on the first face Kl than on the second face K2.

[0085] Further, before the landing of the ink 4M as described above, the pre-treatment head 5 moves along the main scanning direction SI while ejecting the pre-treatment liquid, as shown in Figure 10 The landing amount of the pre-treatment liquid per unit area becomes relatively less on the first face Kl, and the landing amount of the pre-treatment liquid per unit area becomes relatively more on the second face K2. As a result, a small amount of ink lands on a small amount of pre-treatment liquid on the first face Kl, and a large amount of ink lands on a large amount of pre-treatment liquid on the second face K2.

[0086] As described above, the pretreatment solution improves the fixing properties of ink on the surface of workpiece W. For example, when the ink used has high permeability, the pretreatment solution inhibits its penetration and causes it to solidify on the surface (increasing the amount of ink used for fixing). Furthermore, when the ink used has low permeability, the pretreatment solution helps the ink remain on the surface. As mentioned above, the characteristics of the pretreatment solution vary depending on the characteristics of the ink used, but in any case, the pretreatment solution exhibits the function of improving the fixing properties of ink on the surface of workpiece W.

[0087] Furthermore, the pretreatment solution has this function and in Figure 10 When the pretreatment solution and ink are both low on the first surface K1, the amount of ink fixed on the surface decreases, resulting in a relatively lower concentration on the workpiece W. As a result, the relative concentration difference between the first surface K1 and the second surface K2, which has more pretreatment solution and ink, becomes significant, leading to uneven concentration on the workpiece W.

[0088] Similarly, in such Figure 10 After the ink 4M landed, the post-processor head 6 followed along Figure 10 As the main scanning direction S1 moves while spraying post-processing liquid, the amount of post-processing liquid landing per unit area on the first surface K1 becomes relatively less, while the amount of post-processing liquid landing per unit area on the second surface K2 becomes relatively more. As a result, on the first surface K1, a small amount of post-processing liquid lands on a small amount of ink, while on the second surface K2, a large amount of post-processing liquid lands on a large amount of ink.

[0089] When the post-treatment liquid has the function of improving the fixing and adhesion (resistance to friction and scratching, abrasion resistance) of the ink image printed on the workpiece W, if both the ink and post-treatment liquid on the first surface K1 are insufficient, the amount of ink coated will be less and the abrasion resistance will be low. Therefore, if a long time has passed since the ink was printed on the workpiece W, its concentration will be relatively lower compared to other parts such as the second surface K2, resulting in uneven concentration on the workpiece W. The concentration reduction mentioned above can also be exacerbated by washing, friction, wind, rain, etc.

[0090] In this embodiment, as described above, in order to solve the problem of concentration differences between areas with less and more ink due to the scanning direction of each head, the printhead 4, the pre-processing head 5, and the post-processing head 6 are appropriately arranged on the carriage 3, and the control unit 90 appropriately controls the timing of liquid ejection from each printhead.

[0091] That is, in this embodiment, as described above, when the movement of the carriage 3 while the pre-processing head 5 moves along the main scanning direction S and ejects pre-processing liquid is considered the first scan, the movement of the carriage 3 while the printhead 4 moves along the main scanning direction S and ejects ink is considered the second scan, and the movement of the carriage 3 while the post-processing head 6 moves along the main scanning direction S and ejects post-processing liquid is considered the third scan, the movement directions of the carriage 3 are different in the consecutive first and second scans. As a result, for example, in... Figure 6 A small amount of pretreatment liquid and a large amount of ink are coated on the first surface K1, while a large amount of pretreatment liquid and a small amount of ink are coated on the second surface K2. Therefore, as described above, areas with both low and high amounts of pretreatment liquid and ink on the workpiece W are prevented from occurring due to the scanning directions of the pretreatment head 5 and the printhead 4, thus preventing concentration differences between them. In particular, by reducing the areas with extremely low ink amounts on the surface of the workpiece W, the ink amount on the workpiece W is made uniform, reducing concentration unevenness. As a result, the image quality of the workpiece W can be improved. Furthermore, when there are two or more rows of printheads 4, the printheads 4 immediately downstream (immediately following) of the pretreatment head 5 and the pretreatment head 5 can satisfy the above relationship. The same applies when there are two or more rows of pretreatment heads 5. That is, the movement directions of the carriage 3 can be different in one scan of the first scan and one scan of the second scan that are consecutive to each other.

[0092] Similarly, in this embodiment, the movement directions of the carriage 3 are different during the second and third scans that are consecutive to each other. At this time, also... Figure 6 A small amount of ink and a large amount of post-processing liquid are coated on the first surface K1, while a large amount of ink and a small amount of post-processing liquid are coated on the second surface K2. Therefore, as described above, areas with both low ink and high post-processing liquid levels are prevented from occurring due to the scanning directions of the printhead 4 and the post-processing head 6, thus preventing a concentration difference between them. In particular, since the occurrence of areas with low ink volume and low abrasion resistance is reduced, areas where the concentration drops drastically compared to other areas after a long period of time are reduced. As a result, uneven concentration over a long period of time after printing is reduced, a stable image can be maintained for a long time, and the quality of the printed matter can be improved. Furthermore, when there are two or more rows of printheads 4, the printheads 4 immediately upstream (immediately before) and the post-processing head 6 need to satisfy the above relationship. The same applies when there are two or more rows of post-processing heads 6. That is, the movement directions of the carriage 3 need to be different in one scan of the second scan and one scan of the third scan, which are consecutive to each other.

[0093] exist Figure 10The example illustrates how the amount of liquid falling varies depending on the direction of the main scan due to the tilt of the landing surface of the workpiece W. In fabrics, for example, besides the case where the landing surface is merely tilted, the amount of liquid falling sometimes varies depending on the direction of the main scan due to the deformation of the protrusions and recesses. Even in this case, the improvement can be achieved as described above by making the scanning direction of the carriage 3 in the first movement (first scan) opposite to the scanning direction of the carriage 3 in the second movement (second scan). Similarly, the improvement can also be achieved as described above by making the scanning direction of the carriage 3 in the second movement opposite to the scanning direction of the carriage 3 in the third movement (third scan).

[0094] In addition, such as Figure 6 As shown, in this embodiment, the pre-processing head 5 has a pre-processing nozzle region 5Z, each ink head 4 has an ink nozzle region 4Z, and the post-processing head 6 has a post-processing nozzle region 6Z. The pre-processing nozzle region 5Z is an area defined by a plurality of pre-processing nozzles that are positioned facing the workpiece W at the image forming position and eject pre-processing liquid according to the first movement of the carriage 3. Similarly, the ink nozzle region 4Z is an area defined by a plurality of ink nozzles that are positioned facing the workpiece W at the image forming position and eject ink according to the second movement of the carriage 3. Furthermore, the post-processing nozzle region 6Z is an area defined by a plurality of post-processing nozzles that are positioned facing the workpiece W at the image forming position and eject post-processing liquid according to the third movement of the carriage 3. And, in Figure 6 In the process, when viewed along the main scanning direction S, the pre-processing nozzle area 5Z, the ink nozzle area 4Z, and the post-processing nozzle area 6Z are configured in a non-overlapping manner and are configured continuously (connected, adjacent) along the transport direction F.

[0095] Furthermore, in this embodiment, the lengths of the pretreatment nozzle region 5Z, the ink nozzle region 4Z, and the posttreatment nozzle region 6Z in the conveying direction F are each set to be greater than or equal to the maximum value (maximum conveying distance) of the conveying distance of the workpiece W.

[0096] With this configuration, even when the workpiece transport section 20 intermittently transports the workpiece W at the maximum transport interval, no image gap will be formed on the workpiece W, thus enabling the formation of a high-quality image in a short time.

[0097] Furthermore, it is preferable that the distance from the downstream end of the ink nozzle region 4Z in the conveying direction F to the downstream end of the post-processing nozzle region 6Z in the conveying direction F is set to be greater than or equal to the length of the ink nozzle region 4Z in the conveying direction F.

[0098] According to this configuration, since the post-treatment liquid can be reliably printed at the pitch of the printable ink, omission of the post-treatment liquid does not occur, and high-quality printing can be performed in a short time. In this case, the post-treatment nozzle region 6Z can also be extended further to the upstream side or the downstream side of the conveyance direction F than the range of the ink nozzle region 4Z. Figure 6 Moreover, in the case where the ink head 4 has a plurality of rows, the distance in the conveyance direction F from the downstream side end portion in the conveyance direction F of the ink nozzle region 4Z in the ink head 4 on the most downstream side in the conveyance direction F to the downstream side end portion in the conveyance direction F of the post-treatment nozzle region 6Z can be set to be longer than the length of the ink nozzle region 4Z in the conveyance direction F. In other words, the distance in the conveyance direction F from the downstream side end portion in the conveyance direction F of the ink nozzle region 4Z of the plurality of ink heads 4 to the downstream side end portion in the conveyance direction F of the post-treatment nozzle region 6Z can be set to be longer than the length of the ink nozzle region 4Z in the conveyance direction F.

[0099] In Figure 6 , the pre-treatment head 4 and the post-treatment head 6 are disposed at the same position in the main scanning direction S. By being disposed as above, the length of the carriage 3 in the main scanning direction S can be shortened. The positions of the pre-treatment head 4 and the post-treatment head 6 in the main scanning direction S can be any positions with respect to the first to sixth ink heads 4A to 4F. In Figure 6 , the pre-treatment head 4 and the post-treatment head 6 are disposed at the right end of the first to sixth ink heads 4A to 4F arranged in the main scanning direction S. If disposed at the right end as described above, or at the opposite left end, when using a pre-treatment liquid or a post-treatment liquid that reacts with ink, it is difficult to cause a case where the mist adhering to the carriage 3 reacts and solidifies, and the like.

[0100] Figure 8 and Figure 9 are plan views each showing the relationship between the pre-treatment liquid landing region and the ink landing region on the work W in the inkjet printer 1 to which the present embodiment is applied. In the present embodiment, the ejection timing of the pre-treatment head 5 and the ink head 4 is specified by the ejection pattern specifying section 903 (control section 90) according to the image information in such a manner that the region where the pre-treatment liquid lands in correspondence with the prescribed image information is larger than the region where the ink lands.

[0101] As Figure 8 shown, when an ink image is formed over a large range on the work W, a pre-treatment liquid landing region 5H is set in advance over a range larger than the ink image, and the pre-treatment liquid ejected from the pre-treatment head 5 lands in this region. Then, the ink ejected from the ink head 4 lands in the ink landing region 4H corresponding to the ink image. On the other hand, as Figure 9As shown, when forming an ink image locally on the work W, the pre-treatment liquid landing area 5H can also be set larger than the ink landing area 4H. With this control, the pre-treatment liquid can be reliably applied to the entire area where ink is applied, so that the effects of the pre-treatment liquid and the ink are stably exerted, and the print quality can be improved.

[0102] In particular, in the present embodiment, the ejection pattern designation section 903 (control section 90) designates the ejection timing of the pre-treatment head 5 and the ink head 4 so that the pre-treatment liquid landing area 5H is contained in the ink landing area 4H as shown. Figure 8 Figure 9 As a result, the pre-treatment liquid can be reliably applied to the entire area where ink is applied.

[0103] In addition, the manner in which the pre-treatment liquid landing area 5H is set larger than the ink landing area 4H is not limited to the manner of being contained around as described above, but can be set so that the pre-treatment liquid landing area 5H is larger than the ink landing area 4H only in the conveyance direction F, or so that the pre-treatment liquid landing area 5H is larger than the ink landing area 4H only in the main scanning direction S. Further, in the case where the ink landing area 4H is annular, the pre-treatment liquid landing area 5H can be annular and larger. Further, the ink landing area 4H and the pre-treatment liquid landing area 5H formed by ejecting ink and pre-treatment liquid from the ink head 4 and the pre-treatment head 5 can be set by previously editing a print pattern (print image information), or the ejection timing of each head can be set so as to be advanced or delayed in accordance with the print pattern.

[0104] In addition, as described above, the structure in which the pre-treatment liquid is printed to the entire surface of a larger area than ink regardless of the size of the ink image can also reduce the amount of pre-treatment liquid used compared to the case in which the entire work W is previously dipped in the pre-treatment liquid.

[0105] Further, in the manner of selectively printing the pre-treatment liquid as described above, the pre-treatment liquid is sometimes printed to a larger area than ink in correspondence with an ink print pattern in which bleeding needs to be further suppressed. At this time, if the ink landing area 4H and the pre-treatment liquid landing area 5H are set to the same range, printing can sometimes not be performed on the desired portion, so it is preferable to expand the print range of the pre-treatment liquid as described above.

[0106] Further, in the present embodiment, the conveyance speed of the work W and the scanning speed of the carriage 3 are set so that the time from the landing of the pre-treatment liquid to a prescribed pixel on the work W until the landing of the post-treatment liquid is contained in the range of 0.5 (seconds) or more and 10 (seconds) or less on the entire work W.

[0107] ​According to this configuration, it is possible to ensure high printing quality over the entire printing range of the work W. In particular, when the time from the landing of the pre-treatment liquid to the landing of the post-treatment liquid is shorter than 0.5 (seconds), the image quality such as coloring, texture, and firmness is likely to decrease. Further, when the time from the landing of the pre-treatment liquid to the landing of the post-treatment liquid exceeds 10 (seconds), the difference in image quality between the lower limit value and the upper limit value of the time, that is, the unevenness in image quality is likely to increase.

[0108] The above describes the inkjet printer 1 according to the embodiment of the present application, but the present application is not limited thereto, and for example, the following modified embodiment can be adopted.

[0109] In the above embodiment, the configuration in which the pre-treatment head 5 has a pre-treatment nozzle region 5Z, each of the ink heads 4 has an ink nozzle region 4Z, and the post-treatment head 6 has a post-treatment nozzle region 6Z is described, but the present application is not limited thereto. For example, as shown in FIG. 8, the pre-treatment nozzle region 5Z, the ink nozzle region 4Z, and the post-treatment nozzle region 6Z can be configured in a manner in which they are arranged so as not to overlap each other when viewed along the main scanning direction S. In this case, it is preferable that the nozzle regions of the respective heads be arranged so as to partially overlap each other at the ends thereof when viewed along the main scanning direction S. At this time, it is preferable that the nozzles (actual ejection nozzles) controlled by the ejection control section 902 to eject ink or each of the treatment liquids during printing be controlled so as not to overlap each other when viewed along the main scanning direction S. That is, in the present application, the plurality of nozzles (pre-treatment nozzles, ink nozzles, and post-treatment nozzles) that eject each of the liquids (pre-treatment liquid, ink, and post-treatment liquid) in association with the movement (first movement, second movement, and third movement) of the carriage 3 refers to the nozzles that actually eject each of the liquids during printing. Figure 6 That is, among the nozzles of the respective heads, it is not limited to ejecting the liquid from all of the nozzles set in advance, but can be controlled to eject the liquid from a part of the nozzles thereof. Further, it is preferable that the length of the region having the shortest length in the conveyance direction F among the pre-treatment nozzle region, the ink nozzle region, and the post-treatment nozzle region be longer than half the length of the region having the longest length. According to this control, it is possible to achieve high-quality printing in a short time. In addition, in each of the heads, a plurality of nozzles can be arranged in at least the conveyance direction F, and the number of nozzles arranged in the main scanning direction S is not limited.

[0110] Further, a part or all of the control section 90 of the inkjet printer 1 can be a personal computer or the like that transmits print image information to the inkjet printer 1.

[0111] Symbol Explanation

[0112] 1 Inkjet printer

[0113] 3 Carriage

[0114] 3 Carriage

[0115] 4 ink head

[0116] 4H ink landing area

[0117] 4M ink

[0118] 5 pre-treatment head

[0119] 5H pre-treatment liquid landing area

[0120] 6 post-treatment head

[0121] 7 sub-tank

[0122] 10 device frame

[0123] 12 printing area

[0124] 13 maintenance area

[0125] 14 folding-back area

[0126] 20 workpiece conveying section

[0127] 90 control section

[0128] 901 drive control section

[0129] 902 ejection control section

[0130] 903 ejection mode designation section (ejection condition designation section)

[0131] 904 storage section

[0132] 91 I / F

[0133] 92 image storage

[0134] F conveying direction

[0135] K1 first face

[0136] K2 second face

[0137] L1 pre-treatment / ink head boundary line

[0138] L2 ink / post-treatment head boundary line

[0139] M1 first motor

[0140] M2 second motor

[0141] S main scanning direction

[0142] W workpiece

Claims

1. An inkjet recording apparatus characterized by comprising: including: a conveyance section that conveys a recording medium in a prescribed conveyance direction; a carriage that reciprocates in a main scanning direction intersecting the conveyance direction; at least one pre-treatment head that is mounted on the carriage and that ejects a non-pigmented pre-treatment liquid; at least one ink head that is mounted on the carriage and that ejects ink; and, at least one post-treatment head that is mounted on the carriage and that ejects a non-pigmented post-treatment liquid, wherein the at least one pre-treatment head, the at least one ink head, and the at least one post-treatment head are arranged so as to be staggered in the conveyance direction, the at least one pre-treatment head has a pre-treatment nozzle region defined by a plurality of pre-treatment nozzles that respectively eject a pre-treatment liquid in conjunction with movement of the carriage, the at least one ink head has an ink nozzle region defined by a plurality of ink nozzles that respectively eject ink in conjunction with movement of the carriage, the at least one post-treatment head has a post-treatment nozzle region defined by a plurality of post-treatment nozzles that respectively eject a post-treatment liquid in conjunction with movement of the carriage, the pre-treatment nozzle region, the ink nozzle region, and the post-treatment nozzle region are arranged so as not to overlap each other when viewed along the main scanning direction, the conveyance section conveys the recording medium intermittently at a prescribed conveyance pitch, the length in the conveyance direction of each of the pre-treatment nozzle region, the ink nozzle region, and the post-treatment nozzle region is set to be greater than or equal to the maximum value of the conveyance pitch.

2. An inkjet recording apparatus characterized by including: a conveyance section that conveys a recording medium in a prescribed conveyance direction; a carriage that reciprocates in a main scanning direction intersecting the conveyance direction; at least one pre-treatment head that is mounted on the carriage and that ejects a non-pigmented pre-treatment liquid; at least one ink head that is mounted on the carriage and that ejects ink; and, at least one post-treatment head that is mounted on the carriage and that ejects a non-pigmented post-treatment liquid, wherein the at least one pre-treatment head, the at least one ink head, and the at least one post-treatment head are arranged so as to be staggered in the conveyance direction, the at least one pre-treatment head has a pre-treatment nozzle region defined by a plurality of pre-treatment nozzles that respectively eject a pre-treatment liquid in conjunction with movement of the carriage, the at least one ink head has an ink nozzle region defined by a plurality of ink nozzles that respectively eject ink in conjunction with movement of the carriage, the at least one post-treatment head has a post-treatment nozzle region defined by a plurality of post-treatment nozzles that respectively eject a post-treatment liquid in conjunction with movement of the carriage, the pre-treatment nozzle region, the ink nozzle region, and the post-treatment nozzle region are arranged so as not to overlap each other when viewed along the main scanning direction, the distance in the conveyance direction from the downstream side end portion of the ink nozzle region in the conveyance direction to the downstream side end portion of the post-treatment nozzle region in the conveyance direction is set to be greater than or equal to the length in the conveyance direction of the ink nozzle region.

3. The inkjet recording apparatus according to claim 2, wherein the conveyance section conveys the recording medium intermittently at a prescribed conveyance pitch, The lengths of the pre-treatment nozzle region, the ink nozzle region, and the post-treatment nozzle region in the conveyance direction are set to be greater than the maximum value of the conveyance pitch.

4. An inkjet recording apparatus characterized by Including: a conveyance section that conveys a recording medium in a prescribed conveyance direction; a carriage that reciprocates in a main scanning direction that intersects the conveyance direction; at least one pre-treatment head that is mounted on the carriage and that ejects a non-pigmented pre-treatment liquid; at least one ink head that is mounted on the carriage and that ejects ink; and at least one post-treatment head that is mounted on the carriage and that ejects a non-pigmented post-treatment liquid, wherein the at least one pre-treatment head, the at least one ink head, and the at least one post-treatment head are arranged so as to be staggered in the conveyance direction, the inkjet recording apparatus further includes: a control section that specifies the ejection timing of the pre-treatment head and the ink head in such a manner that the region on which the pre-treatment liquid lands corresponding to prescribed image information is larger than the region on which ink lands and includes the region on which ink lands, based on the image information. Including:

5. An inkjet recording apparatus characterized by a conveyance section that conveys a recording medium in a prescribed conveyance direction; a carriage that reciprocates in a main scanning direction that intersects the conveyance direction; at least one pre-treatment head that is mounted on the carriage and that ejects a non-pigmented pre-treatment liquid; at least one ink head that is mounted on the carriage and that ejects ink; and at least one post-treatment head that is mounted on the carriage and that ejects a non-pigmented post-treatment liquid, wherein the at least one pre-treatment head, the at least one ink head, and the at least one post-treatment head are arranged so as to be staggered in the conveyance direction, the conveyance speed of the recording medium and the scanning speed of the carriage are set so that the time from the landing of the pre-treatment liquid to the landing of the post-treatment liquid with respect to a prescribed pixel on the recording medium is included in a range of 0.5 seconds or more and 10 seconds or less over the entire recording medium. Including: a conveyance section that conveys a recording medium in a prescribed conveyance direction; 6. An inkjet recording apparatus characterized by a carriage that reciprocates in a main scanning direction that intersects the conveyance direction; at least one pre-treatment head that is mounted on the carriage and that ejects a non-pigmented pre-treatment liquid; at least one ink head that is mounted on the carriage and that ejects ink; and at least one post-treatment head that is mounted on the carriage and that ejects a non-pigmented post-treatment liquid, wherein the at least one pre-treatment head, the at least one ink head, and the at least one post-treatment head are arranged so as to be staggered in the conveyance direction, the at least one pre-treatment head has a pre-treatment nozzle region that is demarcated by a plurality of pre-treatment nozzles that respectively eject a pre-treatment liquid in conjunction with movement of the carriage, the at least one ink head has an ink nozzle region that is demarcated by a plurality of ink nozzles that respectively eject ink in conjunction with movement of the carriage, the at least one post-treatment head has a post-treatment nozzle region that is demarcated by a plurality of post-treatment nozzles that respectively eject a post-treatment liquid in conjunction with movement of the carriage, of the pre-treatment nozzle region, the ink nozzle region, and the post-treatment nozzle region, the length of the region that is shortest in the conveyance direction is longer than half the length of the region that is longest. ​ ​ ​ 7. The inkjet recording apparatus according to any one of claims 1 to 6, wherein when the pre-treatment head moves relative to a prescribed region on the recording medium while ejecting the pre-treatment liquid along the main scanning direction, the movement of the carriage is a first scan, when the ink head moves relative to the prescribed region while ejecting the ink along the main scanning direction, the movement of the carriage is a second scan, and when the post-treatment head moves relative to the prescribed region while ejecting the post-treatment liquid along the main scanning direction, the movement of the carriage is a third scan. the first scan, the second scan, and the third scan are different from each other. the first scan, the second scan, and the third scan are each performed at least once in that order.

8. The inkjet recording apparatus according to claim 7, wherein in the first scan and the second scan which are consecutive to each other, the moving direction of the carriage is different from each other.

9. The inkjet recording apparatus according to claim 7, wherein in the second scan and the third scan which are consecutive to each other, the moving direction of the carriage is different from each other.

10. The inkjet recording apparatus according to claim 8, wherein in the second scan and the third scan which are consecutive to each other, the moving direction of the carriage is different from each other. ​

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