Recording device

Abstract

The present invention comprises a plurality of liquid discharge parts each having a first nozzle region and a second nozzle region. A first treatment liquid discharge part (51) that discharges a first treatment liquid from the first nozzle region and the second nozzle region is disposed at the center in a main scanning direction (S). A plurality of ink discharge parts (41-46) that each discharge ink from the first nozzle region and the second nozzle region are arranged on both sides of the first treatment liquid discharge part in the main scanning direction (S). Ink for a first color is discharged from both sides of the first treatment liquid discharge part in the main scanning direction (S).

Description

Recording device

[0001] The present disclosure relates to a recording device.

[0002] As described in Patent Document 1, inkjet printers and other recording devices are known that include a printing unit that prints on a recording medium. The printing unit has an ink head (ink ejection unit) that ejects ink for forming an image toward the recording medium. When the recording medium is wide, the ink head is mounted on a carriage that moves back and forth in the main scanning direction. During printing, the recording medium is intermittently fed in a predetermined direction (sub-scanning direction), and while the recording medium is stationary, ink is ejected from the ink head while the carriage moves back and forth in the main scanning direction.

[0003] Japanese Patent Application Laid-Open No. 2012-20536

[0004] The object of the present disclosure is to provide a recording device that can mount a treatment liquid ejection unit that ejects treatment liquid and multiple ink ejection units that eject ink on a carriage, while preventing the ink and treatment liquid from adhering to each other around the ejection units.

[0005] a carriage that moves back and forth in a main scanning direction that intersects with the transport direction; and a plurality of liquid ejection units that are arranged side by side on the carriage in the main scanning direction, the plurality of liquid ejection units including a first nozzle region from which each liquid ejection unit is capable of ejecting a predetermined liquid, and a second nozzle region that is arranged side by side with the first nozzle region in the main scanning direction and is capable of ejecting a liquid different from that of the first nozzle region, the plurality of liquid ejection units having a first treatment liquid ejection unit that is arranged in a center portion in the main scanning direction and ejects a first treatment liquid from the first nozzle region and the second nozzle region, and a plurality of ink ejection units that are arranged on both sides of the first treatment liquid ejection unit in the main scanning direction and eject ink from the first nozzle region and the second nozzle region, the plurality of ink ejection units having a nozzle region that ejects ink of a first color that is arranged closer to one end in the main scanning direction than the first treatment liquid ejection unit, and the nozzle region that ejects ink of the first color that is arranged closer to the other end in the main scanning direction than the first treatment liquid ejection unit.

[0006] FIG. 1 is a perspective view showing the overall configuration of a recording apparatus according to an embodiment of the present disclosure. FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. 1. FIG. 3 is an enlarged perspective view of a carriage shown in FIG. 1. FIG. 4 is a schematic diagram showing a serial printing method employed in an embodiment of the present disclosure. FIG. 5 is a plan view showing the general arrangement of ink heads and treatment liquid heads on a carriage according to a first embodiment of the present disclosure. FIG. 6 is a schematic diagram for explaining nozzle regions within an ink head according to the first embodiment of the present disclosure. FIG. 7 is a schematic plan view showing the arrangement of ink heads and treatment liquid heads on a carriage according to a second embodiment of the present disclosure. FIG. 8 is a schematic plan view showing the arrangement of ink heads and treatment liquid heads on a carriage according to a third embodiment of the present disclosure. FIG. 9 is a schematic plan view showing the arrangement of ink heads and treatment liquid heads on a carriage according to a fourth embodiment of the present disclosure. FIG. 10 is a schematic plan view showing the arrangement of ink heads and treatment liquid heads on a carriage according to a fifth embodiment of the present disclosure. FIG. 11 is a schematic plan view showing the arrangement of ink heads and treatment liquid head liquid on a carriage according to a sixth embodiment of the present disclosure. FIG. 12 is a schematic plan view showing the nozzle region of an ink head on a carriage according to a seventh embodiment of the present disclosure. FIG. 13 is a schematic plan view showing the distribution of ink and treatment liquid ejected from an ink head and a treatment liquid head on a carriage. FIG. 14 is a schematic plan view showing the distribution of ink and treatment liquid ejected from an ink head and a treatment liquid head on a carriage. FIG. 15A is a schematic plan view showing the nozzle region of an ink head on a carriage according to a modified embodiment of the present disclosure. FIG. 15B is a schematic plan view showing the nozzle region of an ink head on a carriage according to a modified embodiment of the present disclosure. FIG. 16 is a schematic plan view showing the nozzle region of an ink head on a carriage according to a modified embodiment of the present disclosure. FIG. 17 is a schematic plan view showing the arrangement of ink heads and treatment liquid heads on a carriage according to a form compared to each embodiment of the present disclosure.

[0007] A printing unit according to each embodiment of the present disclosure will be described below with reference to the drawings. In these embodiments, an inkjet printer (recording device) equipped with an ink head that ejects ink for forming an image onto a wide, long recording medium is exemplified as a specific example of an apparatus equipped with a printing unit. Inkjet printers are suitable for digital textile printing, which uses an inkjet method to print images such as letters and patterns onto a recording medium made of fabric such as woven or knitted fabric. Of course, the printing unit according to the present disclosure can also be used to print various images on recording media such as paper sheets and resin sheets.

[0008] First Embodiment Fig. 1 is a perspective view showing the overall configuration of an inkjet printer 1 according to a first embodiment of the present disclosure, and Fig. 2 is a schematic cross-sectional view taken along line II-II in Fig. 1. The inkjet printer 1 is a printer that prints images on a wide and long workpiece W (recording medium) using an inkjet method, and includes a device frame 10, and a workpiece transport unit 20 (transport unit) and carriage 3 that are incorporated into this device frame 10. Note that in this embodiment, the left-to-right direction is the main scanning direction S (Fig. 3) when printing on the workpiece W, and the direction from rear to front is the sub-scanning direction (the transport direction F of the workpiece W, which intersects with the main scanning direction S).

[0009] The device frame 10 forms a framework for mounting various components of the inkjet printer 1. The work transport unit 20 is a mechanism that intermittently feeds (transports) the work W so that the work W progresses in a transport direction F from rear to front in a printing area where inkjet printing processing is performed. The carriage 3 is equipped with an ink head 4 as well as a pre-treatment liquid head, a post-treatment liquid head, and a sub-tank 7, which will be described later, and moves back and forth in a main scanning direction S (left and right direction) that intersects with the transport direction F of the work W during the inkjet printing processing.

[0010] The device frame 10 includes a central frame 111, a right frame 112, and a left frame 113. The central frame 111 forms a framework for mounting various components of the inkjet printer 1, and has a left-to-right width corresponding to the work transport section 20. The right frame 112 and left frame 113 are erected to the right and left of the central frame 111, respectively. Between the right frame 112 and the left frame 113 is the printing area 12 where printing processing is performed on the work W.

[0011] The right frame 112 forms the maintenance area 13. The maintenance area 13 is an area where the carriage 3 is retracted when the printing process is not being performed. In the maintenance area 13, cleaning processes, purging processes, etc. are performed on the nozzles (ejection holes) of the ink heads 4, pre-treatment liquid heads, and post-treatment liquid heads, and caps are also fitted. The left frame 113 forms a turn-around area 14 for the carriage 3. The turn-around area 14 is an area where the carriage 3 temporarily enters when it performs a main scan in the opposite direction after performing a main scan in the opposite direction across the printing area 12 from right to left during the printing process.

[0012] A carriage guide 15 for moving the carriage 3 back and forth in the left-right direction is attached to the upper side of the device frame 10. The carriage guide 15 is a flat plate-shaped member that is long in the left-right direction, and is disposed above the work transport unit 20. A timing belt 16 is attached to the carriage guide 15 so as to be able to move in a circular motion in the left-right direction (main scanning direction). The timing belt 16 is an endless belt that is driven to move in a circular motion in the left or right direction.

[0013] The carriage guide 15 is equipped with a pair of upper and lower guide rails 17 that extend parallel to the left and right and that hold the carriage 3 in a state that allows it to move back and forth in the main scanning direction S. The carriage 3 is engaged with the guide rails 17. The carriage 3 is also fixed to a timing belt 16. As the timing belt 16 moves orbitally leftward or rightward, the carriage 3 moves leftward or rightward along the carriage guide 15 while being guided by the guide rails 17.

[0014] Referring primarily to Figure 2, the work transport section 20 includes a feed roller 21 that pays out the work W before printing, and a take-up roller 22 that takes up the work W after printing. The feed roller 21 is located at the rear lower part of the device frame 10, and is a take-up shaft for a feed roll WA that is a roll of the work W before printing. The take-up roller 22 is located at the front lower part of the device frame 10, and is a take-up shaft for a take-up roll WB that is a roll of the work W after the printing process. A first motor M1 is attached to the take-up roller 22, which drives the take-up roller 22 to rotate about its axis and perform the operation of winding up the work W.

[0015] The path between the delivery roller 21 and the take-up roller 22 and passing through the printing area 12 is the transport path for the workpiece W. Arranged on this transport path, in order from upstream, are a first tension roller 23, a work guide 24, a transport roller 25 and a pinch roller 26, a turn-back roller 27, and a second tension roller 28. The first tension roller 23 applies a predetermined tension to the workpiece W on the upstream side of the transport roller 25. The work guide 24 changes the transport direction of the workpiece W from upward to forward, allowing the workpiece W to enter the printing area 12.

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

[0017] The turn-back roller 27 changes the transport direction of the workpiece W that has passed through the printing area 12 from forward to downward, and guides the workpiece W after printing processing to the take-up roller 22. The second tension roller 28 applies a predetermined tension to the workpiece W downstream of the transport roller 25. A platen 29 is disposed below the transport path of the workpiece W in the printing area 12.

[0018] The carriage 3 is cantilevered on the guide rails 17 and moves back and forth in a main scanning direction S (left and right in this embodiment) that intersects (orthogonal in this embodiment) with the transport direction F. The carriage 3 includes a carriage frame 30, and an ink head 4, a pre-treatment liquid head, a post-treatment liquid head, and a sub-tank 7 that are mounted on the carriage frame 30. The carriage frame 30 includes a head support frame 31 and a back frame 32.

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

[0020] Note that the cantilevered state refers to a state in which the guide rail 17 that holds the carriage 3 is present only on one side of the carriage 3, either upstream or downstream from the center of the carriage 3 in the conveying direction F, and the side opposite the side where the guide rail 17 is present is not held.

[0021] [Details of Carriage] The carriage 3 will now be further described. FIG. 3 is an enlarged perspective view of the carriage 3 shown in FIG. 1. FIG. 3 shows the transport direction F (sub-scanning direction) of the workpiece W and the main scanning direction S, which is the direction of movement of the carriage 3. FIG. 3 shows an example in which a plurality of ink heads 4 that eject ink for image formation onto the workpiece W and a plurality of sub-tanks 7 that supply the ink to these heads 4 are mounted on the carriage 3. As described below, at least one of a pre-treatment liquid head and a post-treatment liquid head that eject a non-color-forming treatment liquid is mounted on the carriage 3. The carriage 3 and the plurality of heads (liquid ejection units) mounted thereon constitute a liquid ejection unit of the present disclosure. The liquid ejection unit moves back and forth in the main scanning direction S to eject liquid onto the workpiece W.

[0022] Each ink head 4 has a number of nozzles (ink ejection holes) that eject ink droplets using an ejection method such as a piezoelectric method using a piezoelectric element or a thermal method using a heating element, and ink passages that guide the ink to the nozzles. For example, a water-based pigment ink containing a water-based solvent, pigment, and binder resin can be used as the ink. The multiple ink heads 4 in this embodiment are each capable of ejecting different inks. Each head is mounted on a head support frame 31 of the carriage 3. The detailed arrangement of each head will be described later.

[0023] A series of heads along the main scanning direction S, which are made up of the ink heads 4, pre-treatment liquid heads, and post-treatment liquid heads described below, is referred to as a row of heads, or simply as a row. Also, a series of heads along the transport direction F, which are made up of the ink heads 4, pre-treatment liquid heads, and post-treatment liquid heads, is referred to as a row of heads, or simply as a row.

[0024] The ink ejected from the ink head 4 is not particularly limited, and can be one containing a pigment or a dye. For example, an ink containing a pigment and an aqueous medium can be used. The ink may further contain at least one selected from the group consisting of surfactants, polyols, and binder resin particles, as needed. Examples of pigments include yellow pigments, orange pigments, red pigments, blue pigments, purple pigments, and black pigments. The ink may also contain an anionic pigment. In such cases, the cationic polymer and anionic pigment contained in the post-treatment liquid electrically react and aggregate on the surface of the recording medium, thereby preventing the binder resin contained in the ink from penetrating into the recording medium. This prevents the binder resin from penetrating into the gaps between fibers and bonding the fibers together when the recording medium is fabric. This can improve the texture (feel, etc.) of the fabric to be printed.

[0025] Specifically, anionic pigments having anionic groups such as a carboxyl group, a sulfonic acid group, a phosphate group, a phosphonic acid group, a phenylsulfonic acid group, or a phenylcarboxyl group are more preferred as anionic pigments. The aqueous medium contained in the ink is a medium containing water as its main component. The aqueous medium may function as a solvent or a dispersion medium. Specific examples of aqueous media include water and mixtures of water and polar solvents. Examples of polar solvents contained in aqueous media include methanol, ethanol, isopropyl alcohol, butanol, and methyl ethyl ketone. Furthermore, the ink contains a surfactant, which improves the wettability of the ink to the recording medium.

[0026] The binder resin particles contained in the ink exist in a dispersed state in an aqueous medium. The binder resin particles function as a binder that bonds the subject to be printed with the pigment. Therefore, by including binder resin particles in the ink, it is possible to obtain a printed item with excellent pigment fixation. Examples of resins contained in the binder resin particles include urethane resin, (meth)acrylic resin, styrene-(meth)acrylic resin, styrene-maleic acid copolymer, vinylnaphthalene-(meth)acrylic acid copolymer, and vinylnaphthalene-maleic acid copolymer. Urethane resin is preferred as the resin contained in the binder resin particles.

[0027] The binder resin content may be 1% by weight or more and 20% by weight or less, or 2% by weight or more and 10% by weight or less, based on the total weight of the ink. When the binder resin particle content is 1% by weight or more, a recording medium with excellent pigment fixation can be obtained. On the other hand, when the binder resin particle content is 20% by weight or less, the ink can be stably ejected onto the recording medium.

[0028] The pretreatment liquid head ejects a pretreatment liquid for performing a predetermined pretreatment on the workpiece W. The pretreatment liquid is ejected from the ink head 4 onto a position on the workpiece W where ink has not yet been ejected from the ink head 4.

[0029] The post-treatment liquid head ejects post-treatment liquid for performing a predetermined post-treatment on the ink-adhered workpiece W. The post-treatment liquid is ejected from the post-treatment liquid head onto the position on the workpiece W after the ink has been ejected from the ink head 4.

[0030] Any pretreatment liquid can be used. For example, a pretreatment liquid that aggregates the pigment of the ink to improve color development and fixation, as described below, can be used. The pretreatment liquid may also be used to suppress the penetration of the ink into the recording medium, or conversely, to promote the penetration, to print thickly to create a three-dimensional shape, or to impart gloss.

[0031] The pretreatment liquid may contain, for example, a water-soluble cationic polymer, an organic acid salt, and an aqueous medium. Such a pretreatment liquid reacts with and aggregates the pigment contained in the ink to be subsequently printed, improving color development. It can also improve washing fastness and the texture of the fabric. The content of the water-soluble cationic polymer may be 0.1 wt % or more and less than 10 wt % of the total pretreatment liquid. By making the content of the water-soluble cationic polymer less than 10 wt %, sufficient wet rub fastness can be obtained. The aqueous medium contained in the pretreatment liquid can be the same as that of the ink.

[0032] Any post-treatment liquid can be used. For example, a post-treatment liquid that improves texture can be used, as described below. The post-treatment liquid may also be used to provide a coating for protecting the printed ink, to thickly print a three-dimensional shape, or to impart gloss. It may also be used to perform a treatment not directly related to ink printing, such as imparting water repellency to the recording medium.

[0033] The post-treatment liquid may contain, for example, emulsified particles containing silicone oil, a surfactant, and an aqueous medium. That is, the post-treatment liquid is an emulsion in which emulsified particles are dispersed in an aqueous medium, more specifically, an oil-in-water (O / W) emulsion. The silicone oil may contain unmodified silicone oil. Examples of unmodified silicone oil include dimethylpolysiloxane, methylphenylsilicone oil, and methylhydrogensilicone oil. Such a post-treatment liquid can improve the texture.

[0034] The surfactant may include a first surfactant containing an alkyl group having 12 to 14 carbon atoms and a second surfactant containing an alkyl group having 16 to 18 carbon atoms. Polyoxyethylene alkyl ether may be used for both surfactants.

[0035] The aqueous medium contained in the post-treatment liquid can be the same as that of the ink. The post-treatment liquid is basically a non-color-forming treatment liquid that does not develop color even when attached to the workpiece W. The post-treatment liquid and the pre-treatment liquid are basically different treatment liquids. Specifically, the components contained in the post-treatment liquid and the pre-treatment liquid are different.

[0036] The processing liquid is basically a non-coloring processing liquid that does not develop color even when adhered to the workpiece W. Here, a non-coloring processing liquid refers to a processing liquid that, when printed alone on a recording medium, is not perceived as having developed color by the naked eye. Color here includes colors with a saturation of zero, such as black, white, and gray. A non-coloring processing liquid is basically a transparent liquid, but when viewed in its liquid state, for example, 1 liter of processing liquid may not be completely transparent and may appear slightly white. Such colors are very light, so when printed alone on a recording medium, they cannot be perceived as having developed color by the naked eye. Note that, depending on the type of processing liquid, when printed alone on a recording medium, changes such as gloss may occur on the recording medium, but such a state is not considered to be coloring.

[0037] In this embodiment, the pre-treatment liquid and the post-treatment liquid may be ejected onto almost the entire surface of the workpiece W, or the pre-treatment liquid and the post-treatment liquid may be ejected selectively in accordance with the image to be printed, similar to ink.

[0038] Here, a case where the pretreatment liquid and the posttreatment liquid are selectively ejected will be described. As described above, the pretreatment liquid, ink, and posttreatment liquid are ejected in this order onto the portion of the workpiece W where a color is to be printed in accordance with the image. In this case, the ink may be of one color or multiple colors. In portions where no color is to be printed, i.e., portions where no ink is ejected, the pretreatment liquid and the posttreatment liquid are basically not ejected either. Note that, in order to adjust the image quality of the printed image and the texture of the workpiece W, the selection of the ejection of the pretreatment liquid and the posttreatment liquid may be made to differ from the ejection of the ink. For example, the pretreatment liquid and the posttreatment liquid may be printed in an area slightly larger (for example, the area of ​​a few pixels) than the area printed with ink.

[0039] 3, openings 31H are provided at the locations where the heads are arranged in the head support frame 31. The ink heads 4, the pre-treatment liquid heads, and the post-treatment liquid heads are assembled to the head support frame 31 so as to be fitted into the respective openings 31H. Nozzles arranged on the bottom end surface of each head are exposed from each opening 31H.

[0040] The subtanks 7 are supported by the carriage 3 above each head via a holding frame (not shown). A subtank 7 is provided corresponding to each head. Each subtank 7 is supplied with ink or treatment liquid (sometimes collectively referred to as liquid) from a cartridge (not shown) or main tank containing ink and treatment liquid, and supplies these to each head. Each subtank 7 and each head are connected by a conduit (not shown in FIG. 3).

[0041] Each subtank 7 may have a supply subtank and a recovery subtank. The supply subtank supplies liquid to the corresponding head. The recovery subtank recovers liquid that was not ejected from the corresponding head. The supply and recovery of liquid are achieved, for example, by applying pressure to the liquid via gas (air) present above the liquid contained in the supply subtank and the recovery subtank. The supply and recovery of liquid are achieved by the pressure difference between the pressure applied to the supply subtank and the pressure applied to the recovery subtank. The pressures applied to each subtank are controlled so that the pressure at the nozzle of each head is approximately 0 (zero, the same as atmospheric pressure) or slightly negative or positive. This allows the nozzle to maintain a meniscus and remain capable of ejecting liquid.

[0042] Liquid may be transferred between the supply subtank, recovery subtank, and main tank as follows: When the liquid in the supply subtank falls below a predetermined level, the liquid in the recovery subtank is transferred to the supply subtank by a pump or the like. This allows the liquid to circulate within the supply subtank, head, and recovery subtank. When the liquid in the recovery subtank falls below a predetermined level, the liquid from the main tank is supplied to the recovery subtank by a pump or the like.

[0043] Supplying liquid adjusted to a constant temperature to the head can stabilize the temperature of the head. The liquid supplied to the head reaches the individual flow paths in which the nozzles are provided via a common flow path (manifold) within the head. When recovering liquid from the head, it is not necessary to recover the liquid supplied to the individual flow paths, and it is also possible to recover only the liquid that has passed through the common flow path. Liquid may be supplied to and recovered from the individual flow paths in which the nozzles are provided, so that the liquid is less likely to stagnate in and around the nozzles. In this case, the liquid recovered from the individual flow paths is recovered, for example, via the common flow path.

[0044] As described above, the inkjet printer 1 according to this embodiment is an all-in-one printer in which the ink head 4, the treatment liquid heads exemplified by the pre-treatment liquid head and the post-treatment liquid head are mounted on a single carriage 3. With this inkjet printer 1, for example, in the printing process of performing inkjet printing on fabric in digital textile printing, the pre-treatment liquid ejection process and the post-treatment liquid ejection process can be carried out in an integrated manner. This makes it possible to simplify the textile printing process and make the textile printing device more compact.

[0045] [Printing Method] Next, the printing method executed by the inkjet printer 1 according to this embodiment will be described. The inkjet printer 1 performs printing processing on the workpiece W using a serial printing method. Fig. 4 is a schematic diagram showing the serial printing method. In Fig. 4, the carriage 3 is depicted in a simplified manner, with the pre-treatment liquid head and post-treatment liquid head omitted.

[0046] If the workpiece W is wide, it is not possible to print while continuously feeding the workpiece W. The serial printing method is a printing method in which a carriage 3 carrying ink heads 4 of each color moves back and forth in the main scanning direction S, and intermittently feeds the workpiece W in the transport direction F. Here, the ink heads 4 are assumed to have a predetermined printing width Pw in the transport direction F. The printing width Pw is approximately equal to the length in the transport direction F of the arrangement area of ​​the ink ejection nozzles of the ink heads 4. Note that in Figure 4, the length in the transport direction F of each head is drawn as approximately equal to the printing width Pw, but in reality, the length in the transport direction F of each head is greater than the printing width Pw and the length in the transport direction F of the arrangement area of ​​the ejection nozzles.

[0047] FIG. 4 shows the state in which the carriage 3 moves in the forward direction SA in the main scanning direction S and has completed printing of a band-shaped image G1 with a printing width Pw. During this main scanning in the forward direction SA, feeding of the workpiece W is stopped. After printing the band-shaped image G1, the workpiece W is sent out in the transport direction F by a pitch corresponding to the printing width Pw. At this time, the carriage 3 waits in the turn-back area 14 on the left end side. After sending out the workpiece W, the carriage 3 turns back in the return direction SB as the timing belt 16 moves in the reverse direction. The workpiece W is in a stopped state. Then, as shown in FIG. 4, the carriage 3 moves in the return direction SB and prints a band-shaped image G2 with a printing width Pw upstream of the band-shaped image G1. Similar operations are repeated thereafter.

[0048] The workpiece W after printing with the inkjet printer 1 may be heated and dried by a heater (not shown) or the like provided in the inkjet printer 1. Alternatively, the printed portion of the workpiece W may be transported to a dryer separate from the inkjet printer 1 and dried therein, rather than being wound around the take-up roller 22. The heating temperature is, for example, 120°C or higher and 180°C or lower. The heating time is, for example, 1 minute or higher and 10 minutes or lower. Heating dries the volatile components contained in the ink and treatment liquid, promoting fixation of the ink and treatment liquid to the printing target P. In other words, the pretreatment liquid, ink, and posttreatment liquid are not dried during printing, but are dried all at once after printing is completed. Furthermore, the pretreatment liquid, ink, and posttreatment liquid are printed on workpiece W that has not been subjected to other processing, such as applying and drying other pretreatment liquids, before printing.

[0049] [Detailed Arrangement of Heads] FIG. 5 is a plan view schematically illustrating the arrangement of ink heads and treatment liquid heads on a carriage 3 according to this embodiment. FIG. 6 is a schematic diagram for explaining nozzle regions within an ink head according to this embodiment. Meanwhile, FIG. 17 is a schematic plan view illustrating the arrangement of ink heads and treatment liquid heads on a carriage according to another aspect that is compared to the embodiments of the present disclosure. In this embodiment, a plurality of heads are arranged in a row along the main scanning direction S on the carriage 3, and are arranged in the following order from left to right: first ink head 41, second ink head 42, third ink head 43, pretreatment liquid head 51, fourth ink head 44, fifth ink head 45, and sixth ink head 46. Each head includes two nozzle regions (first nozzle region and second nozzle region) aligned in the main scanning direction S.

[0050] As the two nozzle regions, from left to right in FIG. 5 , the first ink head 41 includes a blue ink nozzle region BI and a red ink nozzle region RI. The second ink head 42 includes a green ink nozzle region GI and a yellow ink nozzle region YI. The third ink head 43 includes a magenta ink nozzle region MI and a black ink nozzle region KI. The pretreatment liquid head 51 includes two pretreatment liquid nozzle regions P1. The fourth ink head 44 includes a black ink nozzle region KI and a magenta ink nozzle region MI. The fifth ink head 45 includes a yellow ink nozzle region YI and a green ink nozzle region GI. The sixth ink head 46 includes a red ink nozzle region RI and a blue ink nozzle region BI. Hereinafter, each nozzle region may be referred to by its reference symbol only.

[0051] Referring to FIG. 6 , two ink nozzle regions will be described using the third ink head 43 in FIG. 5 as an example. Note that FIG. 6 illustrates the transport direction F at a reduced scale. Each head has a substantially rectangular parallelepiped shape, with a rectangular head outline H appearing on its underside. Two ink nozzle regions MI and KI are arranged inside this head outline H. FIG. 5 simply illustrates only the relevant nozzle regions of each head. The magenta ink nozzle region MI is an area where multiple nozzles capable of ejecting magenta ink are arranged, and the black ink nozzle region KI is an area where multiple nozzles capable of ejecting black ink are arranged. In this embodiment, as shown in FIG. 6 , each nozzle region has two rows of nozzles arranged in a zigzag pattern along the transport direction F. In this case, the dimension of each nozzle group in the transport direction F corresponds to 300 npi (nozzles per inch). As shown by the reference line RL in FIG. 6 , the nozzles in the magenta ink nozzle region MI and the corresponding nozzles in the black ink nozzle region KI are arranged at the same position in the transport direction F, i.e., overlapping in the main scanning direction S. When using the third ink head 43 with this nozzle arrangement to print at 600 dpi with the inkjet printer 1, for example, a 300 dpi image can be printed in one main scanning pass, and then a 300 dpi image can be printed in another main scanning pass, with the pixel position shifted by one 600 dpi pixel in the transport direction F from the previously printed 300 dpi image. Alternatively, the fourth ink head 44 may be arranged to be shifted by one 600 dpi pixel in the transport direction F relative to the third ink head 43, and a 600 dpi image can be printed using two heads. Note that, as described below, the nozzles of the two colors may be arranged offset in the transport direction F. This has the advantage of eliminating the need for a different nozzle arrangement than a head capable of printing at 600 dpi with a single head. With such an arrangement, if ink of the same color is ejected from two nozzle areas, a 600 dpi image can be printed with one head.

[0052] 6 is formed with an ink flow path (also simply referred to as a flow path) (not shown) for receiving magenta ink ejected from the magenta ink nozzle region MI from outside the third ink head 43 and discharging it via the nozzles to outside the third ink head 43. Similarly, the third ink head 43 is formed with an ink flow path (not shown) for receiving black ink ejected from the black ink nozzle region KI from outside the third ink head 43 and discharging it via the nozzles to outside the third ink head 43. These two ink flow paths are configured independently of each other.

[0053] 6, the two nozzle regions provided in one head (liquid ejection unit) form one nozzle surface on the underside of the carriage 3, and the relationship between them can be expressed as follows: The first nozzle region and the second nozzle region are arranged side by side and in close proximity at least in the main scanning direction S. In this case, being arranged side by side or in close proximity as described above means that they are in a relative positional relationship such that, if liquid remains on the nozzle surface due to a nozzle ejection failure or the like, there is a possibility that one liquid will come into contact with the other liquid.

[0054] Furthermore, being arranged side by side or adjacent to each other as described above can be said to be a relative positional relationship such that when the nozzle regions are wiped with a wiper (not shown) or when liquid is pushed out of the nozzles by purging, one liquid may come into contact with the other liquid on the nozzle surface. In this case, the liquid spreads widely across the nozzle surface, so as long as the first nozzle region and the second nozzle region are on the same surface, regardless of the distance between the nozzles, this positional relationship is included. Even if the two nozzle regions are separated by a groove or the like, if it is expected that the liquid will be able to overcome the groove (for example, a width or depth of approximately 1 mm), this positional relationship is included.

[0055] The other heads in Fig. 5 also have the same nozzle arrangement as in Fig. 6. That is, in this embodiment, the multiple heads have the same shape and structure, and by arranging such common heads side by side on the carriage 3, it is possible to form multiple heads (regions) that eject different liquids.

[0056] As described above, in this embodiment, each of the multiple heads (liquid ejection units) mounted on the carriage 3 is arranged side by side on the carriage 3 at least in the main scanning direction S, and includes a first nozzle region capable of ejecting a predetermined liquid, and a second nozzle region arranged side by side with the first nozzle region at least in the main scanning direction S and capable of ejecting a liquid different from that of the first nozzle region. Note that, as described above, the fact that the liquids ejected are different can be said to mean that the flow paths, including the liquid receiving flow paths and the liquid discharging flow paths, are independent of each other between the first nozzle region and the second nozzle region. Furthermore, the ability to eject different liquids is not necessarily limited to ejecting different liquids; each of the heads may eject the same type of liquid, provided that the heads are configured to be able to eject different liquids.

[0057] Furthermore, the plurality of heads on the carriage 3 include a pretreatment liquid head 51 (first treatment liquid ejection unit) and a plurality of ink heads (ink ejection units) including the first ink head 41 to the sixth ink head 46. Here, the pretreatment liquid head 51 is arranged in the center of the plurality of heads lined up in a row in the main scanning direction S, and ejects the pretreatment liquid (first treatment liquid) from the first nozzle region and the second nozzle region.

[0058] The ink heads 41 to 46 are arranged on both sides of the pretreatment liquid head 51 in the main scanning direction S, and eject ink from the first nozzle region and the second nozzle region.

[0059] In this embodiment, because each head has two nozzle regions as described above, it is possible to reduce the number of heads required to eject multiple colors of ink and treatment liquid. As a result, it is possible to make the carriage 3, and ultimately the inkjet printer 1, smaller. Furthermore, by making the carriage (head placement area) smaller, the placement accuracy of each head increases, which also makes it possible to improve printing accuracy.

[0060] In this embodiment, as shown in FIG. 5, the ink heads and the nozzle areas of the respective colors included therein, which are arranged on both sides of the centrally arranged pretreatment liquid head 51, are arranged in line symmetry with respect to each other in the main scanning direction S.

[0061] In the case of such a head arrangement, as an example, while the carriage 3 makes one scan in the right direction, ink is ejected in order from the sixth ink head 46, the fifth ink head 45, and the fourth ink head 44. After the pretreatment liquid is ejected from the two nozzle regions of the pretreatment liquid head 51, ink can be ejected in order from the third ink head 43, the second ink head 42, and the first ink head 41. When the carriage 3 then makes one scan in the left direction, ink and pretreatment liquid can be ejected in the same order. The pretreatment liquid may be ejected from one of the two nozzle regions of the pretreatment liquid head 51. Furthermore, if the pretreatment liquid should land on the workpiece W before the ink due to its characteristics, the sixth ink head 46, the fifth ink head 45, and the fourth ink head 44 are not ejected during one scan in the right direction of the carriage 3 in FIG. 5 , and the pretreatment liquid may be ejected onto the workpiece W first from the pretreatment liquid head 51.

[0062] In a conventional configuration in which multiple ink ejection units are mounted on a carriage, attempting to mount an additional treatment liquid ejection unit that ejects treatment liquid poses a problem of ink and treatment liquid mixing and solidifying around the ejection unit. Specifically, because the pretreatment liquid and ink are likely to mix and solidify when mixed on the nozzle surface of one head, it is desirable not to arrange the pretreatment liquid and ink in two nozzle regions of one head. Furthermore, if the nozzle region for the pretreatment liquid is arranged at only one end of the multiple heads aligned in the main scanning direction S, the landing order of the ink and pretreatment liquid changes between the forward and backward passes of the carriage 3 in the main scanning direction S. Therefore, for example, as shown in FIG. 17 , if the nozzle regions for the pretreatment liquid (pretreatment liquid nozzle regions P1) are arranged at both ends in the main scanning direction S, the landing order of the ink and pretreatment liquid can be made the same between the forward and backward passes, but the number of heads (nozzle regions) increases.

[0063] In order to solve this problem, in this embodiment, the pretreatment liquid head 51 including the pretreatment liquid nozzle region P1 capable of ejecting the pretreatment liquid is positioned in the center, thereby preventing the ink and pretreatment liquid from adhering to each other in the nozzle region of one head, while suppressing an increase in the number of nozzle regions, and furthermore, the order in which the ink and pretreatment liquid land on the workpiece W can be kept the same in both directions.

[0064] In the above description, the pretreatment liquid is mainly exemplified as one that causes ink to aggregate on the workpiece W, but the pretreatment liquid may also contain a resin component in a larger amount than the ink and have the property of binding the fabric and the pigment. In this case, too, the pretreatment liquid is more likely to clog the ink nozzles or adhere to the nozzle surface, so the arrangement of the head and nozzle region as described above is desirable.

[0065] In other words, the arrangement of the heads and nozzle regions in FIG. 5 is such that, in the plurality of ink heads (ink ejection units), the nozzle region that ejects ink of the first color is arranged closer to one end in the main scanning direction S than the pretreatment liquid head 51, and the nozzle region that ejects ink of the first color is also arranged closer to the other end in the main scanning direction S than the pretreatment liquid head 51.

[0066] Furthermore, in FIG. 5 , in the plurality of ink heads, the nozzle region that ejects ink of a second color different from the first color is disposed closer to the one end in the main scanning direction S than the pretreatment liquid head 51, and the nozzle region that ejects ink of the second color is disposed closer to the other end in the main scanning direction S than the pretreatment liquid head, and at both the one end and the other end in the main scanning direction S, the nozzle region that ejects ink of the second color is disposed closer to the pretreatment liquid head 51 than the nozzle region that ejects ink of the first color.

[0067] 5, the ink nozzle regions for black and yellow are arranged in the order of yellow ink first, then black ink, from right to left on the right side of the pretreatment liquid head 51, and the ink nozzle regions for black ink first, then yellow ink, from right to left on the left side of the pretreatment liquid head 51. This makes it possible to keep the printing order (landing order) constant for these two colors, regardless of the main scanning direction S. In other words, in either the left or right direction of the main scanning of the carriage 3, the yellow ink nozzle region YI, the black ink nozzle region KI, the pretreatment liquid nozzle region P1, the pretreatment liquid nozzle region P1, the black ink nozzle region KI, and the yellow ink nozzle region YI are arranged in this order.

[0068] In addition, in FIG. 5 , nozzle regions that eject ink of the same color for three or more different colors including the first color are arranged on one end side and the other end side of the pretreatment liquid head 51 in the main scanning direction S, and the relationship in magnitude of the distance from each of the nozzle regions of the three or more colors on the one end side to the pretreatment liquid head 51 in the main scanning direction S is the same as the relationship in magnitude of the distance from each of the nozzle regions of the three or more colors on the other end side to the pretreatment liquid head 51.

[0069] In FIG. 5 , for all the colors of ink in the multiple ink heads, nozzle regions that eject ink of the same color are arranged on one end side and the other end side of the pretreatment liquid head 51 in the main scanning direction S, and the relationship in magnitude of the distance from each of the nozzle regions of all the colors on the one end side to the pretreatment liquid head 51 in the main scanning direction S is the same as the relationship in magnitude of the distance from each of the nozzle regions of all the colors on the other end side to the pretreatment liquid head 51.

[0070] In other words, the ink heads have at least two or more pairs of same-color ink ejection units that are arranged on one end side and the other end side of the center of the ink heads in the main scanning direction S, and eject ink of the same color. For each pair of colors of the at least two or more pairs of same-color ink ejection units, the relationship in magnitude of the distance from the pretreatment liquid head 51 to the color of each pair at the one end is the same as the relationship in magnitude of the distance from the pretreatment liquid head 51 to the color of each pair at the other end.

[0071] 5 and other figures, the spacing between adjacent heads in the main scanning direction S (the spacing between the closest parts of each head, or the spacing between the centers of each head) is the same. Similarly, in the case of a head arrangement with multiple rows described below, the spacing between adjacent heads in the transport direction F (the spacing between the centers of each head) is the same.

[0072] The distance between heads, the distance between nozzle regions, and the distance between heads and nozzle regions are, for example, the distance along the main scanning direction S, and refers to the distance between the closest points between the heads. Alternatively, the distance along the main scanning direction S between the centers of gravity of the areas occupied by each head when viewed in a plane may also be considered.

[0073] 7 is a schematic plan view showing the arrangement of ink heads and treatment liquid heads on a carriage according to a second embodiment of the present disclosure. Note that in the following embodiments, differences from the previous embodiment will be mainly described, and descriptions of commonalities will be omitted.

[0074] 7, the plurality of heads further includes a pair of post-treatment liquid heads 61 (second treatment liquid ejection units) in comparison with the heads shown in FIG. 5. Each post-treatment liquid head 61 has two nozzle regions, similar to the pre-treatment liquid head 51, and in the present embodiment, the first post-treatment liquid is ejected from the two first post-treatment liquid nozzle regions P2. In this manner, the pair of post-treatment liquid heads 61 are disposed on both outer sides of the plurality of ink heads in the main scanning direction S, and eject a first post-treatment liquid (second treatment liquid) different from the pre-treatment liquid (first treatment liquid) from at least the outer nozzle region in the main scanning direction S.

[0075] With this configuration, for all liquids, including ink, pretreatment liquid, and the first posttreatment liquid, the landing order of each liquid on the workpiece W can be the same between the forward pass and the backward pass, regardless of the main scanning direction S. Note that the ejection order of each liquid may be set to, for example, ink, pretreatment liquid, pretreatment liquid, ink, first posttreatment liquid, or may be set to the order of first posttreatment liquid, ink, pretreatment liquid, pretreatment liquid, ink, first posttreatment liquid.

[0076] Third Embodiment FIG. 8 is a schematic plan view showing the arrangement of ink heads and treatment liquid heads on a carriage 3 according to a third embodiment of the present disclosure. In the previous second embodiment, a pair of post-treatment liquid heads 61 arranged at both left and right ends ejects the second post-treatment liquid from both of the two first post-treatment liquid nozzle regions P2. However, the present disclosure is not limited to this. In FIG. 8 , a pair of post-treatment liquid heads 63, 64 is arranged on both outer sides of the plurality of heads 42, 43, 51, 44, 45 in the main scanning direction S. In each post-treatment liquid head 63, a first post-treatment liquid (second treatment liquid) different from the pre-treatment liquid is ejected from the first post-treatment liquid nozzle region P2 on the outer side in the main scanning direction S. Meanwhile, red ink is ejected from the red ink nozzle region on the outer side in the main scanning direction S. Even in this case, the same effects as those of the second embodiment can be achieved.

[0077] Fourth Embodiment FIG. 9 is a schematic plan view showing the arrangement of ink heads and treatment liquid heads on a carriage 3 according to a fourth embodiment of the present disclosure. In FIG. 9 , nozzle regions formed on the undersides of the heads are indicated by patterns, while white areas on the upstream and downstream sides of each head in the transport direction F indicate areas where no nozzles are arranged. This also applies to other figures described below. In this embodiment, two of each of the first ink head 41, second ink head 42, third ink head 43, pretreatment liquid head 51, fourth ink head 44, fifth ink head 45, and sixth ink head 46 of the first embodiment are arranged. In other words, the head rows of the first embodiment are arranged in two rows at different positions in the transport direction F. Furthermore, these two head rows are also arranged at different positions in the main scanning direction S. Specifically, the first ink head 41 of the row on the downstream side in the transport direction F is arranged so that a portion of the first ink head 41 extends between the first ink head 41 and the second ink head 42 of the row on the upstream side in the transport direction F. In this case, the nozzle regions are arranged so as to be continuous with each other in the transport direction F, and the nozzle regions on the upstream and downstream sides do not overlap when viewed along the main scanning direction S. The same is true for the other heads.

[0078] Furthermore, in this embodiment, the multiple heads (liquid ejection units) have a pair of posttreatment liquid heads 61. As in the second embodiment, each posttreatment liquid head 61 has two first posttreatment liquid nozzle regions P2 capable of ejecting a first posttreatment liquid. The pair of posttreatment liquid heads 61 are arranged further downstream in the transport direction F than the two rows of heads. Specifically, as shown in FIG. 9 , the left posttreatment liquid head 61 is located at the same position in the main scanning direction S as the first ink head 41 on the upstream side in the transport direction F, and is arranged so that a portion of the left posttreatment liquid head 61 overlaps with the first ink head 41 on the downstream side in the transport direction F further downstream in the transport direction F. Meanwhile, the right posttreatment liquid head 61 is arranged so that a portion of the right posttreatment liquid head 61 extends between the fifth ink head 45 and the sixth ink head 46 on the downstream side in the transport direction F.

[0079] In this configuration, after ink and pretreatment liquid are ejected from the first row of heads in the first main scan, the workpiece W is transported by one pitch in the transport direction F, and ink and pretreatment liquid are ejected from the second row of heads in the second main scan. After that, the workpiece W is further transported by one pitch, and the first posttreatment liquid is ejected onto the workpiece W from the pair of posttreatment liquid heads 61 in the third main scan.

[0080] According to this configuration, after the reaction between the ink and the pretreatment liquid has progressed to a certain extent to fix it on the workpiece W, the final first posttreatment liquid can be deposited on the workpiece W. As an example, the liquids can be deposited on the workpiece W in the following order: In the first main scan in which the carriage 3 moves rightward, the sixth ink head 46, the fifth ink head 45, and the fourth ink head 44 in the first row eject each ink, the pretreatment liquid is ejected in order from the two pretreatment liquid nozzle regions P1 of the pretreatment liquid head 51, and the inks are ejected from the third ink head 43, the second ink head 42, and the first ink head 41. Thereafter, during a second main scan in which the workpiece W is transported one pitch in the transport direction F and the carriage 3 moves leftward, inks are ejected from the first ink head 41, the second ink head 42, and the third ink head 43 in the second row, pretreatment liquid is ejected in order from the two pretreatment liquid nozzle regions P1 of the pretreatment liquid head 51, and inks are ejected from the fourth ink head 44, the fifth ink head 45, and the sixth ink head 46. Thereafter, during a third main scan in which the workpiece W is transported one pitch in the transport direction F and the carriage 3 moves rightward, the first posttreatment liquid is ejected from a total of four first posttreatment liquid nozzle regions P2 of the pair of posttreatment liquid heads 61.

[0081] Fifth Embodiment Fig. 10 is a schematic plan view showing the arrangement of ink heads and treatment liquid heads on a carriage 3 according to a fifth embodiment of the present disclosure. In this embodiment, two of each of the posttreatment liquid head 63, second ink head 42, third ink head 43, pretreatment liquid head 51, fourth ink head 44, fifth ink head 45, and posttreatment liquid head 64 in the third embodiment (Fig. 8) are arranged. In other words, two rows of heads in the third embodiment are arranged at different positions in the transport direction F. Furthermore, these two rows of heads are also arranged at different positions in the main scanning direction S. More specifically, the posttreatment liquid head 63 in the row on the downstream side in the transport direction F is arranged so that a portion of the posttreatment liquid head 63 in the row on the upstream side in the transport direction F extends between the posttreatment liquid head 63 and the second ink head 42. The same applies to the other heads in the second row.

[0082] Furthermore, in this embodiment, seven posttreatment liquid heads 61 are arranged in a row downstream of the second head row in the transport direction F. These posttreatment liquid heads 61 are arranged at the same position as the first head row in the main scanning direction S, and are arranged so as to partially extend toward the second head row in the transport direction F. The structure of the posttreatment liquid heads 61 is the same as in the third embodiment. For example, in cases where it is necessary to increase the amount of the first posttreatment liquid depending on the characteristics of the image to be formed on the workpiece W or the characteristics of the ink, as in this embodiment, a head row of posttreatment liquid heads 61 can be arranged in the third row, and nozzle regions of posttreatment liquid heads 61 can also be arranged on both ends of the first and second rows in the main scanning direction S.

[0083] In this configuration, for example, the liquids can be made to land on the workpiece W in the following order: During the first main scan in which the carriage 3 moves rightward, the first posttreatment liquid is ejected from the first posttreatment liquid nozzle region P2 ( FIG. 8 ) of the first row of posttreatment liquid heads 64, red ink is ejected from the red ink nozzle region of the posttreatment liquid head 64, then the inks are ejected from the fifth ink head 45 and the fourth ink head 44, pretreatment liquid is ejected in order from the two pretreatment liquid nozzle regions P1 of the pretreatment liquid head 51, inks are ejected from the third ink head 43, the second ink head 42, and the red ink nozzle region RI ( FIG. 8 ) of the posttreatment liquid head 63, and the first posttreatment liquid is ejected from the first posttreatment liquid nozzle region P2 of the posttreatment liquid head 63. Furthermore, during a second main scan in which the carriage 3 moves leftward, the first posttreatment liquid is ejected from the first posttreatment liquid nozzle region P2 of the posttreatment liquid head 63 in the second row, inks are ejected from the red ink nozzle region RI, the second ink head 42, and the third ink head 43 of the posttreatment liquid head 63, pretreatment liquid is ejected in order from the two pretreatment liquid nozzle regions P1 of the pretreatment liquid head 51, inks are ejected from the fourth ink head 44, the fifth ink head 45, and the red ink nozzle region RI of the posttreatment liquid head 64, and the first posttreatment liquid is ejected from the first posttreatment liquid nozzle region P2 of the posttreatment liquid head 64. Thereafter, during a third main scan in which the carriage 3 moves rightward, the first posttreatment liquid is ejected from a total of eight first posttreatment liquid nozzle regions P2 of the seven posttreatment liquid heads 61.

[0084] In the fourth and fifth embodiments described above, the plurality of liquid ejection units are arranged downstream of the plurality of ink ejection units in the transport direction F, and further include at least one second treatment liquid ejection unit that ejects a second treatment liquid different from the first treatment liquid.

[0085] Sixth Embodiment FIG. 11 is a schematic plan view showing the arrangement of ink heads and treatment liquid head liquid on a carriage 3 according to a sixth embodiment of the present disclosure. This embodiment corresponds to a modified example of the head arrangement in the fourth embodiment ( FIG. 9 ). Specifically, a head row composed of five treatment liquid heads is arranged in the third row. A pair of post-treatment liquid heads 61 is arranged on both sides of the first ink heads 41 in the second row in the main scanning direction S. Similarly, a pair of post-treatment liquid heads 61 is arranged on both sides of the fifth ink heads 45 in the second row in the main scanning direction S. Furthermore, a post-treatment liquid head 65 is arranged between the third ink heads 43 in the second row and the pre-treatment liquid head 51. The post-treatment liquid head 65 has two second post-treatment liquid nozzle regions P3 for ejecting a second post-treatment liquid, which is a liquid different from the first post-treatment liquid ejected from the post-treatment liquid head 61. Also in this embodiment, the heads in the third row are arranged so that a portion of each head extends between adjacent heads in the second row in the main scanning direction S.

[0086] The second post-treatment liquid ejected from the post-treatment liquid head 65 basically has the function of softening the workpiece W (cloth). In addition, the second post-treatment liquid may also have the effect of deepening the color on the workpiece W. In light of this function, it is basically desirable that the first post-treatment liquid land on the workpiece W after the ink fixing action by the pre-treatment liquid has finished.

[0087] On the other hand, the first post-treatment liquid ejected from the post-treatment liquid head 61 has the function of imparting durability to the ink and the workpiece W (cloth). Therefore, the first post-treatment liquid may be used not only to make it difficult for the ink to peel off from the workpiece W, but also to increase the amount of the first post-treatment liquid that hits the print surface, thereby raising the print surface and creating a three-dimensional shape.

[0088] Due to the characteristics of the first post-treatment liquid, it may be necessary to increase the amount of the first post-treatment liquid ejected onto the workpiece W. Therefore, instead of the first ink head 41 and the sixth ink head 46 in FIG. 11, the post-treatment liquid head 63 and the post-treatment liquid head 64 in FIG. 10 may be arranged, and the nozzle area of ​​the first post-treatment liquid may be arranged in the same row as the ink.

[0089] Furthermore, the durability and flexibility of the finished product may be adjusted by changing the ratio between the first and second post-treatment liquids while keeping the total amounts of the first and second post-treatment liquids that land substantially the same.

[0090] In this embodiment, the multiple liquid ejection sections are arranged downstream of the multiple ink ejection sections in the transport direction F, and further include at least one third treatment liquid ejection section that ejects a third treatment liquid that is different from the first treatment liquid and the second treatment liquid.

[0091] Seventh Embodiment Fig. 12 is a schematic plan view showing nozzle regions of an ink head on a carriage 3 according to a seventh embodiment of the present disclosure. In the first embodiment, as shown in Fig. 7, one head is provided with two nozzle regions, but the present disclosure is not limited to this. As shown in Fig. 12, one head may be provided with four nozzle regions, for example, a magenta ink nozzle region MI, a yellow ink nozzle region YI, a blue ink nozzle region BI, and a black ink nozzle region KI. In this case, each nozzle region is provided with nozzles equivalent to 150 dpn in the transport direction F. Furthermore, as an example, the nozzles of different colors are arranged with a shift in the transport direction F.

[0092] 13 and 14 are schematic plan views showing the distribution of ink and treatment liquid ejected from the ink head and treatment liquid head on the carriage 3. In each of the previous embodiments, when printing with a nozzle arrangement density of 300 npi, liquid is sequentially ejected onto the workpiece W in accordance with the order of the multiple nozzle regions while the carriage 3 moves in one direction. The workpiece W is then transported in the transport direction F a distance (one transport pitch) equivalent to the length of each ink nozzle region in the transport direction F. Because the multiple nozzles included in each nozzle region are arranged in the same position in the transport direction F between colors, the ejected inks are sequentially ejected onto the workpiece W so as to overlap one another, as shown in FIG.

[0093] On the other hand, in each of the previous embodiments, when printing at 600 dpi, i.e., twice the density of the nozzle arrangement, as described above, while the carriage 3 moves in one direction (first scan), liquid lands on the workpiece W in sequence according to the order of the multiple nozzle regions in the first row. The workpiece W is then transported in the transport direction F a distance (one transport pitch) equivalent to the length of each nozzle region in the transport direction F. Then, while the carriage 3 moves in the other direction (second scan), liquid lands on the workpiece W in sequence according to the order of the multiple nozzle regions in the second row. As shown in FIG. 14 , if the nozzle regions in the first and second rows are arranged in the same position, liquid can be deposited regularly on the workpiece W. Furthermore, because the multiple nozzles included in each nozzle region are arranged in the same position in the transport direction F between colors, the ejected ink droplets lands on the workpiece W in a sequentially overlapping manner, as shown in FIG. 14 .

[0094] In the above, the multiple nozzles included in each nozzle region are described as being arranged at the same position in the transport direction F between colors, but even if the nozzle positions are shifted in the transport direction F between colors, when averaged over the workpiece W, the droplets will land with a predetermined regularity, thereby achieving the same effect as the previous embodiments.

[0095] <Regarding Modified Nozzle Regions> FIGS. 15A and 15B are schematic plan views showing nozzle regions of an ink head on a carriage 3 according to a modified embodiment of the present disclosure. In the first embodiment, as shown by the reference line RL in FIG. 6 , the nozzles in the magenta ink nozzle region MI and the corresponding nozzles in the black ink nozzle region KI are arranged at the same position in the transport direction F, i.e., overlapping when viewed along the main scanning direction S. This disclosure is not limited to this arrangement. As shown in FIG. 15A , the nozzles in the nozzle regions between the two colors may be arranged offset from each other in the transport direction F. This has the advantage that the nozzle arrangement does not need to be different from that of the 600 dpn nozzle arrangement. Furthermore, when nozzles ejecting different liquids are located nearby, mist that may be generated during ejection may drift in the air or adhere to the nozzle surface and spread or flow, potentially mixing with the liquid in the nozzle ejecting the different liquid. The arrangement described above reduces the likelihood of this occurring. 15B , within the head, one color (black ink nozzle region KI) may be arranged at one end in the main scanning direction S, and the other color (magenta ink nozzle region MI) may be arranged at the other end in the main scanning direction S, with the two regions partially overlapping. In the example of Figure 15B , two rows of nozzles for each color are arranged alternately in the main scanning direction S. Even in this arrangement, the two nozzle regions KI and MI are arranged side by side in the main scanning direction S.

[0096] FIG. 16 is a schematic plan view showing nozzle regions of ink heads on a carriage 3 according to another modified embodiment of the present disclosure. In the first embodiment, each head is generally rectangular and has two color ink nozzle regions aligned in the main scanning direction S within the head outline H. However, the present disclosure is not limited to this. As shown in FIG. 16 , the magenta ink nozzle region MI and the black ink nozzle region KI may be offset in both the transport direction F and the main scanning direction S. Alternatively, in each of the magenta ink nozzle region MI and the black ink nozzle region KI shown in FIG. 16 , other nozzle arrangements may be used, in which the magenta ink nozzles and the black ink nozzles are aligned in two rows.

[0097] The combination of ink colors ejected from each head is arbitrary, but a specific combination may be selected taking the following into consideration: The difference in time it takes for different colored inks ejected from one head to land on the workpiece W is smaller than the difference in time it takes for different colored inks ejected from different heads to land on the workpiece W. This is because the distance between the nozzle region ejecting a first ink and the nozzle region ejecting a second ink different from the first ink within one head (more specifically, the distance along the main scanning direction S between the centers of the respective regions) is shorter than the distance between the nozzle region ejecting the first ink and the nozzle region ejecting a third ink different from the first ink between different heads (more specifically, the distance along the main scanning direction S between the centers of the respective regions).

[0098] If the time difference between landings is small, ink color mixing is likely to occur because the later ink lands before the earlier ink has penetrated much into the workpiece W. Therefore, for inks ejected from one head that are relatively prone to color mixing, it is possible to use a combination of inks that make color mixing less noticeable, or a combination of inks that make color mixing less likely to occur.

[0099] When the inks used are arranged on a color wheel, if the inks ejected from one head are a pair of adjacent colors, color mixing can be made less noticeable. When counting the types of heads with different color combinations, if more than half of the color combinations are adjacent on the color wheel, color mixing can be made less noticeable. If the color combinations in all heads are adjacent on the color wheel, color mixing can be made even less noticeable.

[0100] Note that, because black, white, gray, and the like are not colors on the color wheel, heads that combine these colors together or with colors on the color wheel are excluded from the count of head types with different color combinations. Also, in the case of heads that eject three or more colors of ink, if the combination of colors ejected by one head is adjacent on the color wheel, color mixture can be made less noticeable. Furthermore, within one head, the order of colors in the main scanning direction S may be the same as the order of colors on the color wheel.

[0101] In the first embodiment, the first ink head 41 and the sixth ink head 46 are a combination of blue and red, and the second ink head 42 and the fifth ink head 45 are a combination of green and yellow, resulting in two color combinations. In the blue, red, green, and yellow colors, blue and red are adjacent to each other on the color wheel, and green and yellow are adjacent to each other on the color wheel. Therefore, this arrangement makes color mixing less noticeable. As mentioned above, the third ink head 43 and the fourth ink head 44, which are combined with black, are not considered.

[0102] In addition to this, due to human characteristics, yellow is a color that is perceived as brighter even with the same amount of ink, so it is more noticeable when mixed with black, which is perceived as dark, so yellow and black can be placed on different heads.

[0103] Furthermore, because black appears dark, color mixing when mixed with other colors is relatively noticeable. When the third ink head 43 and the fourth ink head 44, which are adjacent to the pretreatment liquid head 51, are arranged on the pretreatment liquid head 51 side of the black ink head, one side of the nozzle area adjacent to the black ink head becomes a pretreatment liquid nozzle area, so the distance between the nozzle areas of other colors on one side can be increased. Furthermore, since the next nozzle area across the pretreatment liquid head 51 becomes a black nozzle area, the distance between the nozzle areas of other colors on one side can be further increased. Furthermore, since the black ink nozzle areas of the third ink head 43 and the fourth ink head 44 are arranged adjacent to each other with the pretreatment liquid nozzle area sandwiched between them, black ink can be deposited continuously with high accuracy, making it difficult for color mixing with other colors due to the influence of misaligned deposition.

[0104] Furthermore, like yellow, white is a color that humans perceive as bright, so if the ink contains white, white and yellow may be placed on one head. This makes it possible to make the mixture of white and other colors less noticeable. In addition to being used as a color on the image to be printed, white is also often used as the background color (base) of the image. Placing white and yellow on one head is more necessary when white is used as a color on the image to be printed than when it is printed as a base.

[0105] Furthermore, even with the same amount of ink, cyan appears relatively dark. Placing cyan in the same head as black can make the mixed colors less noticeable. However, doing so can make the cyan less noticeable compared to the black when the colors are mixed, and it can be difficult to recognize it as cyan on an image. Placing cyan and black on different heads, or arranging the nozzle areas at a greater distance, can make the cyan more noticeable on an image.

[0106] Specifically, as described above, the black nozzle region may be disposed adjacent to the pretreatment liquid head 51, and the cyan nozzle region may be located in the first ink head 41 and the sixth ink head 46 at both ends in the direction along the main scanning direction S. The cyan nozzle region may further be disposed outside the main scanning direction S in the first ink head 41 and the sixth ink head 46. This means that the cyan nozzle region is disposed at both ends in the main scanning direction S among the nozzle regions that eject ink. In the fifth embodiment, the cyan nozzle region may be disposed in the posttreatment liquid head 63 and the posttreatment liquid head 64. That is, the posttreatment liquid nozzle region and the cyan nozzle region may be disposed adjacent to each other.

[0107] Furthermore, even with the same amount of ink, cyan appears relatively dark. This is due not only to human characteristics but also to the tendency of the colorants used in practice. Placing cyan in the same head as black can make color mixing less noticeable. However, doing so may make cyan less noticeable compared to black, making it difficult to recognize as cyan on an image. In other words, the recognized image may deviate from the original image. Placing cyan and black on different heads or increasing the distance between their nozzle regions can make cyan more noticeable on an image. Specifically, as described above, the black nozzle region may be positioned adjacent to the pretreatment liquid head 51, and the cyan nozzle region may be located in the first ink head 41 and the sixth ink head 46 at both ends along the main scanning direction S. The cyan nozzle region may also be positioned outside the main scanning direction S within the first ink head 41 and the sixth ink head 46. This means that the cyan nozzle region is positioned at both ends of the main scanning direction S within the nozzle region that ejects ink. In the fifth embodiment, a cyan nozzle region may be arranged in the post-treatment liquid head 63 and the post-treatment liquid head 64. That is, the post-treatment liquid nozzle region and the cyan nozzle region may be adjacent to each other.

[0108] The arrangement of inks may be determined taking into consideration the surface tension of the ink. When different inks that have landed come into contact, the greater the difference in surface tension, the more likely color mixing will occur, and the smaller the difference in surface tension, the less likely color mixing will occur. If a pair of inks with the largest difference in surface tension among the inks are arranged in different heads, the possibility of color mixing can be reduced. Furthermore, a pair of inks with the second largest difference in surface tension among the inks may be arranged in a different head. Furthermore, a pair of inks with the third largest difference in surface tension among the inks may be arranged in a different head. Furthermore, inks arranged in the same head may be adjacent inks when the inks are arranged in order of the magnitude of their surface tension.

[0109] Furthermore, the surface tension of the pre-treatment liquid or post-treatment liquid may also be taken into consideration. Although they do not mix with the ink, it is thought that mixing will proceed more easily if the difference in surface tension is large, and that mixing will proceed more slowly if the difference in surface tension is small. Ideally, the pre-treatment liquid and post-treatment liquid would act on each ink in the same way, but there is a possibility that the effect on ink that lands temporally close to the pre-treatment liquid or post-treatment liquid will be stronger than the effect on other inks.

[0110] If the ink ejected from the nozzle region arranged adjacent to the pretreatment liquid head 51 is an ink having a small difference in surface tension from the pretreatment liquid, the effect of the pretreatment liquid on ink that lands temporally close to the pretreatment liquid is weakened, and the effect of the pretreatment liquid on other inks can be made to be similar to that of the pretreatment liquid. As such an ink, when the inks are arranged in order of the difference in surface tension from the pretreatment liquid, an ink that falls in the half with the smallest difference may be used. Furthermore, an ink having a surface tension closest to that of the pretreatment liquid may be used.

[0111] For example, when the post-treatment liquid and ink are disposed in the same head as in the fifth embodiment, if the ink disposed has a small difference in surface tension from the post-treatment liquid, the effect of the post-treatment liquid on ink that lands temporally close to the post-treatment liquid will be weakened, and the effect of the treatment liquid on other inks can be made to be similar. As such an ink, when the inks are arranged in order of the difference in surface tension from the post-treatment liquid, an ink that falls in the half with the smallest difference may be used. Furthermore, an ink with a surface tension closest to that of the post-treatment liquid may be used.

[0112] The present disclosure is not limited to the above-described embodiments, and may take the following forms.

[0113] (1) The ink heads 4 are not limited to being arranged in one or two rows on the carriage 3. The ink heads 4 may be arranged in three or more rows.

[0114] (2) In the above embodiment, the multiple heads each including multiple nozzle regions have the same structure and the same shape. However, such heads (liquid ejection units) having substantially the same shape may have the following relationships. That is, the longitudinal lengths of the nozzle arrangement ranges of each liquid ejection unit may be approximately the same. The lateral lengths of the nozzle arrangement ranges of each liquid ejection unit may be approximately the same. The shapes of the nozzle arrangement ranges of each liquid ejection unit may be approximately the same. Furthermore, the planar external shapes of each liquid ejection unit and head may be approximately the same. The nozzle arrangements of each liquid ejection unit may be approximately the same.

[0115] (3) In the above embodiments, multiple heads are mounted on the carriage 3, and multiple nozzle regions are formed. However, a single head may be mounted on the carriage 3, and multiple nozzle regions may be formed on the underside of the head. In this case, one nozzle region including a first nozzle region and a second nozzle region may be arranged next to other nozzle regions including other first nozzle regions and other second nozzle regions. In other words, the liquid ejection unit, ink ejection unit, etc. in the present disclosure do not necessarily have to be on a head-by-head basis.

[0116] (4) In each of the above embodiments, the relationship between the first nozzle region and the second nozzle region capable of ejecting a different liquid from the first nozzle region can be expressed as follows: The second nozzle region is capable of independently ejecting a different liquid from the liquid ejected by the first nozzle region. Here, independently ejecting different liquids means that different liquids (inks) can be ejected from the first nozzle region and the second nozzle region during the printing process, for example, during one scan of the carriage 3.

[0117] Furthermore, the second nozzle region ejects liquid held in a second liquid holding portion that exists independently of the first liquid holding portion that holds the liquid to be ejected from the first nozzle region. The first liquid holding portion corresponds to a flow path formed within the head. That is, the head structure has the same number of common flow paths as the number of nozzle regions, and inlet and outlet holes connected to these common flow paths, making it possible to eject the same number of different liquids as the number of nozzle regions. Note that the first liquid holding portion and the second liquid holding portion may include the aforementioned sub-tank or may be limited to flow paths within the head. For example, if one head includes a first nozzle region and a second nozzle region and ejects the same liquid from these two nozzle regions during printing, liquid may be supplied to two common flow paths from a single sub-tank 7. Therefore, the sub-tanks 7 corresponding to the two nozzle regions may be independent or may be a common one. Note that, as mentioned above, the above description is not limited to two nozzle regions provided in one head; multiple nozzle region sets including a first nozzle region and a second nozzle region may be arranged in one head.

[0118] REFERENCE SIGNS LIST 1 Inkjet printer (recording device) 3 Carriage 4 Ink head 10 Device frame 12 Printing area 13 Maintenance area 14 Turning area 20 Work transport section H Head placement area W Work

Claims

a carriage that reciprocates in a main scanning direction that intersects with the transport direction; and a plurality of liquid ejection units that are arranged on the carriage side by side in the main scanning direction, each liquid ejection unit including a first nozzle region capable of ejecting a predetermined liquid, and a second nozzle region that is arranged side by side with the first nozzle region in the main scanning direction and is capable of ejecting a liquid different from that of the first nozzle region, wherein the plurality of liquid ejection units include: a first treatment liquid ejection unit that is arranged in a center portion in the main scanning direction and ejects a first treatment liquid from the first nozzle region and the second nozzle region; and a plurality of ink ejection units that are arranged on both sides of the first treatment liquid ejection unit in the main scanning direction and eject ink from the first nozzle region and the second nozzle region, wherein among the plurality of ink ejection units, a nozzle region that ejects ink of a first color is arranged closer to one end in the main scanning direction than the first treatment liquid ejection unit, and the nozzle region that ejects ink of the first color is arranged closer to the other end in the main scanning direction than the first treatment liquid ejection unit.

2. The recording device according to claim 1, wherein, in the plurality of ink ejection units, a nozzle region that ejects ink of a second color different from the first color is disposed closer to the one end in the main scanning direction than the first treatment liquid ejection unit, and a nozzle region that ejects ink of the second color is disposed closer to the other end in the main scanning direction than the first treatment liquid ejection unit, and at both the one end and the other end in the main scanning direction, the nozzle region that ejects ink of the second color is disposed closer to the first treatment liquid ejection unit than the nozzle region that ejects ink of the first color.

3. A recording device as described in claim 1, wherein nozzle areas ejecting ink of the same color for three or more different colors including the first color are arranged at one end and the other end in the main scanning direction of the first treatment liquid ejection unit, and the relationship in magnitude of the distance from each of the nozzle areas of the three or more colors at the one end to the first treatment liquid ejection unit in the main scanning direction is the same as the relationship in magnitude of the distance from each of the nozzle areas of the three or more colors at the other end to the first treatment liquid ejection unit.

4. A recording device as described in claim 1, wherein nozzle areas ejecting ink of the same color for all colors of ink in the plurality of ink ejection sections are respectively arranged on one end side and the other end side in the main scanning direction of the first treatment liquid ejection section, and the relationship in magnitude of the distance from each of the nozzle areas of all colors on the one end side to the first treatment liquid ejection section in the main scanning direction is the same as the relationship in magnitude of the distance from each of the nozzle areas of all colors on the other end side to the first treatment liquid ejection section.

5. The recording device according to claim 1, wherein the plurality of ink ejection sections are respectively arranged on one end side and the other end side in the main scanning direction with respect to the center of the plurality of liquid ejection sections in the main scanning direction, and have at least two pairs of same-color ink ejection sections that eject ink of the same color, and for the colors of each pair of the at least two pairs of same-color ink ejection sections, the relationship in magnitude of the distance from the first treatment liquid ejection section to the color of each pair at the one end is the same as the relationship in magnitude of the distance from the first treatment liquid ejection section to the color of each pair at the other end.

6. A recording device as described in claim 1, wherein the plurality of liquid ejection units further include a pair of second treatment liquid ejection units arranged on both outer sides of the plurality of ink ejection units in the main scanning direction, and which eject a second treatment liquid different from the first treatment liquid from nozzle regions on the outer sides in the main scanning direction.

7. A recording device according to any one of claims 1 to 6, wherein the plurality of liquid ejection sections further comprises at least one second treatment liquid ejection section that is arranged downstream in the transport direction of the plurality of ink ejection sections and ejects a second treatment liquid that is different from the first treatment liquid.

8. A recording apparatus according to claim 7, wherein the plurality of liquid ejection sections further comprises at least one third treatment liquid ejection section that is arranged downstream of the plurality of ink ejection sections in the transport direction and that ejects a third treatment liquid different from the first treatment liquid and the second treatment liquid.

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