Ink jet printer and method for cleaning head unit

Abstract

This ink jet printer comprises: a processing liquid head for discharging a processing liquid; an ink head for discharging an ink; a first member for cleaning a nozzle placement surface of the processing liquid head; and a second member for cleaning a nozzle placement surface of the ink head, the second member differing from the first member in constituent material, cleaning method, or properties.

Description

How to clean an inkjet printer and its head unit

[0001] The present disclosure relates to an inkjet printer having a treatment liquid head that ejects a treatment liquid and an ink head that ejects ink, and a method for cleaning a head unit that has the treatment liquid head and the ink head.

[0002] Inkjet printers are equipped with a head having a large number of nozzles that eject ink or a predetermined treatment liquid. In such heads, the nozzle arrangement surface needs to be cleaned at predetermined intervals to unclog the nozzles and remove dirt and other contaminants from the nozzle arrangement surface.

[0003] Patent Literature 1 discloses an inkjet printer in which the nozzle arrangement surface of a single head equipped with treatment liquid ejection nozzles and ink ejection nozzles is cleaned with a wiping member supported by a pressing member. Patent Literature 2 discloses an inkjet printer in which the nozzle arrangement surface of the head is cleaned with different wiping members: a wipe blade made of a porous material and a wipe blade made of an elastic material.

[0004] JP 2022-161141 A JP 2016-32930 A

[0005] An inkjet printer according to one aspect of the present disclosure includes a treatment liquid head that ejects treatment liquid, an ink head that ejects ink, a first member that cleans the nozzle arrangement surface of the treatment liquid head, and a second member that cleans the nozzle arrangement surface of the ink head and has a different configuration or constituent material, cleaning method, or characteristics from the first member.

[0006] A method for cleaning a head unit according to another aspect of the present disclosure is a method for cleaning a head unit having a treatment liquid head that ejects treatment liquid and an ink head that ejects ink, in which a nozzle arrangement surface of the treatment liquid head is cleaned with a first member, and a nozzle arrangement surface of the ink head is cleaned with a second member that has a different configuration or constituent material, cleaning method, or characteristics from the first member.

[0007] FIG. 1 is a front view showing the overall configuration of an inkjet printer according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1 , with a printing machine added. FIG. 3 is an enlarged perspective view of the carriage shown in FIG. 1 . FIG. 4 is a perspective view of a blade wiping device (first device) installed in the printer for cleaning the treatment liquid head and the ink head. The upper view of FIG. 5 is a plan view of the blade wiping unit, and the lower view of FIG. 5 is a plan view showing the arrangement of the heads mounted on the carriage. FIG. 6 is a perspective view of an ink blade provided in the blade wiping unit. FIG. 7 is a schematic cross-sectional view of the carriage and the blade wiping unit. FIG. 8 is a perspective view of a cloth wiping device (second device) installed in the printer for cleaning the ink head, showing the cleaning status of the nozzle arrangement surface. FIG. 9A is a left side view of the cloth wiping device. FIG. 9B is a side view of the moving unit. FIG. 10 is a perspective view of the cloth wiping unit. FIG. 11 is a left side view of the cloth wiping device, showing the cloth wiping unit in the cleaning position. Fig. 12 is a block diagram showing part of the control configuration of an inkjet printer. Fig. 13 is a flowchart showing an example of the cleaning operation of the ink head and treatment liquid head in an inkjet printer. Fig. 14A is a diagram showing the procedure for cleaning the ink head using a blade wipe unit. Fig. 14B is a diagram showing the procedure for cleaning the ink head using a blade wipe unit. Fig. 14C is a diagram showing the procedure for cleaning the ink head using a blade wipe unit. Fig. 15 is a flowchart showing another example of the cleaning operation of the ink head and treatment liquid head. Fig. 16 is a front view showing the overall configuration of an inkjet printer according to a modified embodiment.

[0008] An embodiment of the present disclosure will be described below with reference to the drawings. In this embodiment, an inkjet printer according to the present disclosure is exemplified as a printer equipped with an ink head that ejects ink for forming an image onto a wide, long recording medium. The head unit cleaning method according to the present disclosure is applied to a head unit included in the printer. The inkjet printer according to this embodiment is suitable for digital textile printing, which uses an inkjet method to print images such as letters and patterns on a recording medium (workpiece) made of fabric such as woven or knitted fabric. Of course, the inkjet printer and cleaning method according to the present disclosure can also be used to print various inkjet images on recording media such as paper sheets and resin sheets.

[0009] [Overall Configuration of Inkjet Printer] First, the overall configuration of an inkjet printer 1 according to an embodiment of the present disclosure will be described. Figure 1 is a front view showing the overall configuration of the inkjet printer 1 according to an embodiment, and Figure 2 is a schematic cross-sectional view taken along line II-II in Figure 1. In Figures 1 and 2 and subsequent figures, directional indications such as up / down, front / rear, and left / right are provided, but these are merely for the convenience of explanation and are not intended to limit the directions.

[0010] The inkjet printer 1 is a printer that prints images on a wide and long workpiece W using an inkjet method, and includes a device frame 10, a workpiece transport unit 2 and a carriage 3 incorporated into this device frame 10, and a dryer 19 disposed in front of the device frame 10. Note that the dryer 19 is not shown in Figure 1. In this embodiment, the left-to-right direction is the main scanning direction when printing on the workpiece W, and the direction from rear to front is the sub-scanning direction, which is the transport direction F of the workpiece W.

[0011] The device frame 10 forms a framework for mounting various components of the inkjet printer 1. The work transport unit 2 is a mechanism that intermittently feeds the work W so that the work W progresses in a transport direction F from rear to front through a printing area where inkjet printing processing is performed. The carriage 3 is equipped with an ink head 4, a pre-processing head 5, a post-processing head 6, and a sub-tank (not shown), and moves back and forth in the left and right direction during the inkjet printing processing.

[0012] 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 unit 2. 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 a printing area 12 where printing processing is performed on the work W. The printing area 12 is an area in which the carriage 3 moves back and forth in the width direction perpendicular to the transport direction F of the work W, i.e., in the main scanning direction.

[0013] The right frame 112 forms the blade wipe area 13. The blade wipe area 13 is also an area where the carriage 3 is retracted when the printing process is not being performed. For maintenance purposes, the heads 4, 5, and 6 are purged, and blade cleaning of the nozzle arrangement surfaces 40 (FIGS. 7 and 14A-14C) of the heads 4, 5, and 6 exposed on the underside 3A of the carriage 3 is performed at required intervals. The blade wipe area 13 is equipped with a blade wiper device 7 (first device) that performs the blade cleaning. The blade wiper device 7 includes a blade wipe unit 70 having a blade BL (first member) that wipes the nozzle arrangement surface 40. In practice, the underside 3A of the carriage 3 and the nozzle arrangement surface 40 are wiped with the blade BL. The purging process is a process of forcibly ejecting ink or treatment liquid from the nozzles of the ink heads 4, pre-treatment head 5, and post-treatment head 6, for the purpose of removing air bubbles from each head. The blade cleaning is a process of wiping with a blade BL the nozzle arrangement surfaces 40 of the heads 4, 5, and 6. The blade wiping device 7 also functions as a cap to prevent the heads 4, 5, and 6 from drying out when they are at rest.

[0014] The left frame 113 forms the cloth wiping area 14. The cloth wiping area 14 is an area where cloth wiping cleaning is performed, cleaning the nozzle arrangement surface 40 using a cloth sheet. A cloth wiping device 8 (second device) that performs the cloth wiping cleaning is located in the cloth wiping area 14. The cloth wiping device 8 includes a cloth wiping unit 80 having a cloth sheet FS (second member). The cloth wiping area 14 also serves as a return area for the carriage 3. After scanning the printing area 12 from right to left during the printing process, the carriage 3 temporarily enters the cloth wiping area 14 before scanning in the opposite direction. During maintenance, the carriage 3 is stopped in the cloth wiping area 14, and cloth wiping cleaning is performed by the cloth wiping device 8. The cloth wiping device 8 is configured to be relatively small compared to the cloth wiping area 14. Therefore, when the carriage 3 is moved to the cloth wiping area 14, the underside 3A (nozzle arrangement surface 40) of the carriage 3 can be visually observed. This improves the ease of maintenance of the inkjet printer.

[0015] As described above, the inkjet printer 1 of this embodiment is equipped with two different wiping members, the blade BL and the cloth sheet FS, for cleaning the heads. This allows cleaning of each nozzle arrangement surface according to the different types of heads—the ink head 4, the pre-processing head 5, and the post-processing head 6—i.e., according to the characteristics of the liquid ejected from each head. Cleaning with the blade BL is applied to at least the pre-processing head 5 and the post-processing head 6. Cleaning with the cloth sheet FS is applied only to the ink head 4. In this embodiment, cleaning with the blade BL is applied to all heads 4, 5, and 6. These points will be described in more detail below. While "wiping" is used below as an example of "cleaning," the form of "cleaning" is not limited to "wiping." Note that a member with a high cleaning effect can be used for heads where the impact on ejection is greatest due to the drying, solidification, or thickening of the liquid. For example, if the ink head 4, the pre-processing head 5, and the post-processing head 6 have the greatest impact on ejection, in that order, the member with the highest cleaning effect can be used accordingly.

[0016] The blade wiper 7 is located in a blade wipe area 13 located on the right side (one side) of the printing area 12, and the cloth wiper 8 is located in a cloth wipe area 14 located on the left side (the other side) of the printing area 12. The blade wipe area 13 and the cloth wipe area 14 are spaces that are essentially necessary for the printer 1 as evacuation space and return space for the carriage 3 that moves back and forth within the printing area 12. By utilizing such spaces to install the blade wiper 7 and the cloth wiper 8, the printer 1 can be prevented from becoming larger even when equipped with two different types of wiping members.

[0017] A single-axis robot 15 is mounted near the top of the device frame 10 to move the carriage 3 back and forth in the left-right direction, i.e., the main scanning direction during the printing process. The single-axis robot 15 is disposed above the workpiece transport unit 2 so as to extend in the left-right direction. The single-axis robot 15 includes a linear motor 16 and a pair of upper and lower guide rails 17. As shown in FIG. 2 , the linear motor 16 includes a stator 161 disposed in the extension direction of the single-axis robot 15 and a mover 162 that moves along the guide rails 17. The pair of guide rails 17 extend parallel to the left-right direction and are engaged with a moving block 163 carrying the mover 162. The carriage 3 is mounted on the moving block 163 and moved leftward or rightward by the single-axis robot 15.

[0018] The work transport section 2 includes a feed roller 21 that pays out the work W before printing in the transport direction F, a take-up roller 22 that takes up the work W after printing, and a transport unit 20 arranged in the printing area 12. The feed roller 21 is a take-up shaft of a feed roll WA that is a roll of the work W before printing. The take-up roller 22 is a take-up shaft of a take-up roll WB that is a roll of the work W after the printing process. The feed roller 21 is arranged upstream of the printing area 12, and the take-up roller 22 is arranged downstream of the dryer 19.

[0019] 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 work W. On this transport path, a tension roller 23, a work guide 24, a transport roller 25, a pinch roller 26, a transport unit 20, a peeling roller 27, a carry-in roller 28, a dryer 19, and a folding roller 29 are arranged in this order from the upstream side.

[0020] The tension roller 23 applies a predetermined tension to the workpiece W upstream of the transport roller 25. The work guide 24 changes the transport direction F of the workpiece W from upward to forward, and transports the workpiece W into the printing area 12. The transport roller 25 generates a transport force that intermittently feeds the workpiece W in the printing area 12. The pinch roller 26 forms a transport nip with the transport roller 25. The pair of the transport roller 25 and pinch roller 26 unwinds the workpiece W from the feed roll WA and transports the workpiece W intermittently in the transport direction F so that it passes through the printing area 12.

[0021] The transport unit 20 is arranged to transport the workpiece W stably in the printing area 12 without causing it to float or shake. The transport unit 20 includes a drive roller 201 and a driven roller 202 arranged at a distance in the front-to-rear direction, and a transport belt 203 stretched over these rollers 201 and 202. The workpiece W is transported in the transport direction F while being in close contact with the surface of the transport belt 203. A platen 204 is arranged between the rollers 201 and 202 and on the back side of the transport belt 203. In the printing area 12, ink and treatment liquid are ejected onto the workpiece W from the ink head 4, pre-treatment head 5, and post-treatment head 6, respectively.

[0022] The peeling roller 27 is disposed diagonally above and in front of the drive roller 201, and serves to peel the printed workpiece W, which is in close contact with the surface of the conveyor belt 203, from said surface. The workpiece W is peeled from the conveyor belt 203 at a peeling section Bk at a predetermined peeling angle, and is sent to the downstream carry-in rollers 28. Between the peeling roller 27 and the carry-in rollers 28, the workpiece W becomes loose. The printed workpiece W is sent from the carry-in rollers 28 to the dryer 19. The dryer 19 dries the wet workpiece W by blowing hot air on it, for example. The return roller 29 changes the transport direction F of the dried workpiece W from the forward direction to a downward direction, and guides the workpiece W to the take-up roller 22.

[0023] The carriage 3 is cantilevered by the moving block 163 and moves back and forth in the main scanning direction (left and right direction) that intersects with the transport direction F. The carriage 3 includes a carriage frame 30 that mounts the ink head 4, pre-processing head 5, post-processing head 6, and a sub-tank (not shown). The carriage frame 30 includes a head support frame 31 and a back frame 32. The head support frame 31 is a horizontal plate that holds the heads 4, 5, and 6. The back frame 32 is a vertical plate that extends upward from the rear edge of the head support frame 31. The back frame 32 is fixed to the moving block 163.

[0024] [Details of the 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 illustrates an example in which the carriage 3 is equipped with multiple ink heads 4 that eject ink for image formation onto the workpiece W, and a pre-treatment head 5 and a post-treatment head 6 that eject non-color-forming treatment liquid. In other words, in this embodiment, the carriage 3 is a head unit having the ink head 4 and treatment heads 5 and 6. The actual carriage 3 also includes multiple sub-tanks that supply the ink and treatment liquid to these heads 4, 5, and 6. Note that the ink head 4, which is simply depicted in FIG. 1, is depicted more specifically in FIG. 3.

[0025] Each of the ink heads 4 has a number of nozzles that eject ink droplets using an ejection method such as a piezo method using a piezo element or a thermal method using a heating element, and ink passages that guide the ink to the nozzles. The pre-treatment head 5 and post-treatment head 6 are similar. For example, a water-based pigment ink containing a water-based solvent, pigment, and binder resin can be used as the ink. In this embodiment, the multiple ink heads 4 include first to eighth ink heads 4A to 4H that each eject eight different colors of ink.

[0026] The ink heads 4A to 4H of each color are mounted on the head support frame 31 of the carriage 3 so as to be aligned in the main scanning direction S. Each of the ink heads 4A to 4H of each color has two heads. For example, the first ink head 4A is composed of an upstream head 4A1 located upstream in the transport direction F, and a downstream head 4A2 located downstream of the upstream head 4A1 and shifted to the left in the main scanning direction S. The ink heads 4B to 4H of the other colors are similar. Each upstream head of these ink heads 4B to 4H is aligned in the main scanning direction S at the same position as the upstream head 4A1 in the transport direction F, and each downstream head is aligned in the main scanning direction S at the same position as the downstream head 4A2 in the transport direction F.

[0027] The pre-treatment head 5 and post-treatment head 6 are disposed at different positions from the ink heads 4 in the transport direction F. The pre-treatment head 5 is disposed upstream of the ink heads 4 in the transport direction F. Figure 3 shows an example in which one pre-treatment head 5 is disposed near the left end of the array of ink heads 4. The pre-treatment head 5 is located to the left of the upstream head 4A1 of the first ink head 4A, and is aligned front-to-back with the downstream head 4A2 at the same position in the main scanning direction S. In contrast, the post-treatment head 6 is disposed downstream of the ink heads 4 in the transport direction F. Figure 3 shows an example in which one post-treatment head 6 is disposed near the right end of the array of ink heads 4. The post-treatment head 6 is located to the right of the downstream head 4H2 of the eighth ink head 4H, and is aligned front-to-back with the upstream head 4H1 at the same position in the main scanning direction S.

[0028] The pretreatment head 5 ejects a pretreatment liquid for performing a predetermined pretreatment on the workpiece W. The pretreatment liquid is ejected from the pretreatment head 5 onto a position on the workpiece W where ink has not yet been ejected from the ink head 4. The pretreatment liquid is a non-color-forming treatment liquid that does not develop color even when attached to the workpiece W, and is a treatment liquid that exhibits functions such as improving the fixation of ink to the workpiece W or the coagulation of ink pigments. As such a pretreatment liquid, a treatment liquid in which a positively charged cationic resin is blended into a solvent can be used.

[0029] The post-processing head 6 ejects a post-processing liquid to perform a predetermined post-processing on the workpiece W to which ink has adhered. The post-processing liquid is ejected from the post-processing head 6 onto the position of the workpiece W after the ink has been ejected from the ink head 4. The post-processing liquid is a non-coloring processing liquid that does not develop color even when it adheres to the workpiece W, and exhibits the function of improving the fixation and durability of the ink image printed on the workpiece W by the ink head 4, such as resistance to rubbing and abrasion. For example, a silicone-based processing liquid can be used as such a post-processing liquid. Because the post-processing head 6 ejects a different target than the pre-processing head 5, different cleaning members may be used to clean the nozzle arrangement surfaces 40 of the two heads.

[0030] Openings 31H are provided at the locations where the heads are arranged in the head support frame 31. The ink heads 4A to 4F, pre-processing head 5, and post-processing head 6 are assembled to the head support frame 31 so as to fit into the respective openings 31H. The nozzle arrangement surface 40 located on the lower end surface of each of the heads 4, 5, and 6 is exposed from each opening 31H.

[0031] As described above, the inkjet printer 1 according to this embodiment is an all-in-one printer in which three types of heads - the ink head 4, the pre-treatment head 5, and the post-treatment head 6 - are mounted on a single carriage 3. With this printer 1, for example, in the printing process of inkjet printing onto fabric in digital textile printing, the process of ejecting the pre-treatment liquid and the process of ejecting the post-treatment liquid 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.

[0032] [Head Maintenance] As described above, the inkjet printer 1 includes a blade wiper device 7 that cleans the nozzle arrangement surface 40 (see FIG. 7 ) using a blade BL and a cloth wiper device 8 that cleans the nozzle arrangement surface 40 using a cloth sheet FS for maintenance of the heads 4, 5, and 6. The nozzle arrangement surface 40 is a surface on which a large number of nozzle openings that eject ink and treatment liquid are arranged in a predetermined pattern in each of the heads 4, 5, and 6, and is exposed on the underside 3A of the carriage 3. The difference between the inks exemplified above and the pre-treatment liquid and post-treatment liquid is the presence or absence of a binder resin. That is, the ink must contain a pigment that corresponds to the color to be developed, and a binder resin that serves to bind the pigment. On the other hand, the pre-treatment liquid and post-treatment liquid do not contain a pigment, and a binder resin is not essential. The physical properties of the ink, pre-treatment liquid, and post-treatment liquid differ depending on whether or not they contain a pigment and a binder resin. Taking into consideration this difference in physical properties, the blade wiping device 7 and the cloth wiping device 8 are used appropriately to clean the heads 4, 5, and 6.

[0033] Blade cleaning using the blade wiping device 7 is performed periodically based on printing time, printing area, number of operating days, etc. During blade cleaning, the carriage 3 is moved to the blade wiping area 13 by the operation of the single-axis robot 15. Prior to blade cleaning, a purge is performed, forcing ink or processing liquid to be ejected from the ink heads 4, pre-treatment head 5, and post-treatment head 6. After the purge, the blade BL of the blade wiping device 7 performs a non-contact wipe (first cleaning) to wipe away droplets hanging from the nozzle arrangement surfaces 40 of the heads 4, 5, and 6, and a contact wipe (second cleaning) to wipe the nozzle arrangement surfaces 40 by abutting the cleaning blade. In this embodiment, the second wipe differs from the first wipe in terms of whether or not contact with the wiped portion is possible. Contact and non-contact wiping will be described in detail with reference to Figures 14A to 14C.

[0034] Cloth wiping cleaning using the cloth wiping device 8 is performed on the ink head 4 only after the blade cleaning. That is, while the pre-processing head 5 and post-processing head 6 are wiped only with the blade BL, the ink head 4 is wiped with the blade BL and then with the cloth sheet FS, a two-stage wiping process. This is because the ink head 4 ejects a liquid (ink) containing a pigment and a binder resin, and blade cleaning alone may not be sufficient to clean the nozzle arrangement surface. For accurate ink ejection and dot formation, it is essential that a predetermined meniscus be formed at the nozzle opening of the ink head 4. If the nozzles become clogged, even after the purging and blade cleaning, it is difficult to form the desired meniscus at the nozzle opening. Wiping the nozzle arrangement surface with the cloth sheet FS after blade cleaning enables the formation of an appropriate meniscus at the nozzle opening. On the other hand, if wiping with the cloth sheet FS is performed immediately after purging, the cloth sheet FS will absorb excessive liquid droplets and immediately lose its cleaning function, so wiping with the blade BL is performed first.

[0035] Since the pre-treatment head 5 and the post-treatment head 6 are heads that eject liquid that does not contain pigment or binder resin, cloth wipe cleaning may be omitted. Note that there is also a case where only cloth wipe cleaning is performed on the ink head 4 without performing the above-mentioned purging (described later with reference to FIG. 15). During cloth wipe cleaning, the carriage 3 is moved to the cloth wipe area 14, as shown in FIG. 4.

[0036] In the above, the blade BL is exemplified as the first member that cleans both the ink head 4 and the processing heads 5 and 6, and the cloth sheet FS is exemplified as the second member that cleans only the ink head 4. The role of the first member is solely to wipe away most of the liquid present on the nozzle arrangement surface 40 of the heads 4, 5, and 6 after purging. On the other hand, the role of the second member is to wipe away any liquid remaining on the nozzle arrangement surface 40 and the nozzle openings after the previous wiping. Note that cleaning with the first and second members may be performed while supplying liquid to the nozzle arrangement surface 40. The liquid may be water or the like, and the liquid may be supplied to the nozzle arrangement surface 40 by spraying it from a specified supply port or by allowing it to seep out from a permeable part.

[0037] In consideration of the above-mentioned role, the first member can be a non-absorbent wiper or a solid wiper without any gaps. The blade BL is one example. Like a wiper that wipes raindrops off a car window, the first member only needs to be able to push away droplets present on the nozzle arrangement surface 40. For this reason, the first member does not necessarily need to have the absorbency to absorb droplets; it can be a spatula-shaped solid member. Generally, the nozzle arrangement surfaces 40 of the heads 4, 5, and 6 are coated with a water-repellent film. To minimize damage to this water-repellent film, it is desirable to use a non-absorbent solid member made of a rubber or resin material with a predetermined rigidity as the first member, rather than a metal member.

[0038] On the other hand, the second member may be an absorbent wiper or a porous wiper. An absorbent / porous wiper can absorb droplets remaining on the nozzle arrangement surface 40 and excess droplets from the nozzle openings. The cloth sheet FS is one example. For example, a woven fabric woven with ultrafine fibers can be used as the cloth sheet FS. Foam with small bubble diameters, sponge, or sponge can also be used as the second member. Among these, it is desirable to use a cloth sheet FS that has low sliding resistance to the underside 3A of the carriage 3 and excellent absorbency. As such, in this embodiment, the first sweeping member and the second member differ in their constituent materials or configurations.

[0039] [Details of Blade Wiping Device] Next, specific examples of the blade wiping device 7 will be described with reference to FIGS. 4 to 7. FIG. 4 is a perspective view of a specific example of the blade wiping device 7 shown in FIG. 1. The blade wiping device 7 includes a container unit 50 and a blade wiping unit 70. The upper view of FIG. 5 is a plan view of the blade wiping unit 70, and the lower view of FIG. 5 is a plan view showing the arrangement of the heads 4, 5, and 6 mounted on the carriage 3. FIG. 6 is a perspective view of an ink blade 72 provided in the blade wipe unit 70. The ink blade 72 corresponds to the blade BL (first wiping member) shown in FIG. 1. FIG. 7 is a schematic cross-sectional view of the carriage 3 and the blade wipe unit 70.

[0040] As described above, when cleaning the blades, the purging operation is first performed on the heads 4, 5, and 6. The container unit 50 is a container for collecting the ink, pre-treatment liquid, and post-treatment liquid ejected from the heads 4, 5, and 6 during the purging operation. The blade wiping unit 70 is a unit that cleans the blades on the nozzle arrangement surface 40.

[0041] The container unit 50 has a structure for separately collecting the pre-treatment liquid, ink, and post-treatment liquid. The pre-treatment liquid is a treatment liquid that improves the fixability of the ink and the coagulation of the ink pigment. Therefore, if the pre-treatment liquid and the ink are mixed, the mixture will coagulate, which may hinder collection into the waste liquid tank. On the other hand, the post-treatment liquid will not coagulate even when mixed with the ink. This is the reason for the above-mentioned separate collection in the container unit 50.

[0042] The container unit 50 includes an ink container 51 and a pretreatment liquid container 52 arranged on the front side of the frame structure 500, and a cleaning liquid tray 53 arranged on the rear side of the frame structure 500. The frame structure 500 includes a pair of left and right side frames 501 extending in the front-to-rear direction, and a front frame 502 connecting the front ends of the side frames 501. A handle 503 for pulling out the container unit 50 is attached to the front frame 502. A plurality of waste liquid hoses 504 extend from below the front frame 502. In addition, the frame structure 500 is equipped with a slider 505 that allows the container unit 50 to be pulled out, and a chain protector 506 that houses electrical cables and hoses.

[0043] The ink container 51 is a container that collects the ink and post-treatment liquid ejected from the ink head 4 and the post-treatment head 6, respectively, during the purging operation, and is provided with a first opening 51H on its top surface that receives the ink and post-treatment liquid. The ink container 51 includes a rectangular bottom surface 511 that is long in the left-right direction, four tapered surfaces 512 that extend upward from each of the four edges of the bottom surface 511, and an upper end flange 508 formed on the periphery of the first opening 51H. The ink container 51 also collects the ink and post-treatment liquid wiped from the nozzle arrangement surfaces 40 ( FIG. 7 ) of the ink head 4 and the post-treatment head 6 that are exposed on the underside 3A of the carriage 3 during the blade cleaning.

[0044] The pre-treatment liquid container 52 is disposed in a position that covers a portion of the upper part of the first opening 51H. The pre-treatment liquid container 52 is a container that collects the pre-treatment liquid ejected from the pre-treatment head 5 during the purging operation, and is provided with a second opening 72H on its upper surface that receives the pre-treatment liquid. The pre-treatment liquid container 52 also collects the pre-treatment liquid wiped from the nozzle arrangement surface 40 of the pre-treatment head 5 during the blade cleaning. The cleaning liquid tray 53 is a container that collects cleaning liquid CL ( FIG. 7 ) used to clean the blade wipe unit 70 that has become contaminated during the blade cleaning operation.

[0045] The container unit 50 is equipped with an overflow passage 541, a treatment liquid passage 542, and a relay passage 543 for the circulation of the recovered liquid. The overflow passage 541 has a start opening on the bottom surface 511 of the ink container 51 and a terminal end leading to a waste liquid container (not shown). The treatment liquid passage 542 has a start opening near the bottom surface of the pretreatment liquid container 52 and a terminal end leading to the waste liquid container. The relay passage 543 has a start opening on the bottom surface of the cleaning liquid tray 53 and a terminal opening near the bottom surface 511 of the ink container 51.

[0046] A cap rubber 55 is attached to the upper surface 50A of the container unit 50. The cap rubber 55 is arranged to surround the periphery of the first opening 51H of the ink container 51. The carriage 3 is capable of moving up and down as shown by arrow A1 in FIG. 7 . When the carriage 3 is in standby mode in the blade wipe area 13 or when the printer 1 is at rest, the carriage 3 is lowered and the lower surface 3A of the head support frame 31 comes into contact with the cap rubber 55. This seals the nozzle arrangement surfaces 40 of the heads 4, 5, and 6.

[0047] A cleaning unit 56 that sprays cleaning liquid CL from the blade wipe unit 70 is disposed above the cleaning liquid tray 53. The cleaning unit 56 includes a nozzle holding plate 561 and a plurality of cleaning nozzles 562 held by the nozzle holding plate 561. The cleaning nozzles 562 spray the cleaning liquid CL in a fan-shaped spray onto each of the blades 72, 73, and 74 of the blade wipe unit 70, which will be described below. The cleaning nozzles 562 are supplied with cleaning liquid CL from a cleaning liquid tank (not shown) via a cleaning liquid hose 563.

[0048] The blade wiping unit 70 includes a blade support plate 71 and a group of blades supported by the blade support plate 71: an ink blade 72, a pretreatment liquid blade 73, and a posttreatment liquid blade 74. The blade wiping unit 70 is movable in the front-rear direction as indicated by arrow A2 in FIG. 7 . The blade support plate 71 is a flat member that moves in the front-rear direction between the carriage 3 and the cleaning unit 56 and the container unit 50. The ink blade 72 wipes the nozzle arrangement surface 40 of the ink head 4 exposed on the lower surface 3A by moving backward while in contact with the nozzle arrangement surface 40. Similarly, the pretreatment liquid blade 73 and the posttreatment liquid blade 74 wipe the nozzle arrangement surface 40 of the pretreatment head 5 and the posttreatment head 6, respectively. That is, the blade wiping unit 70 can simultaneously wipe the nozzle arrangement surfaces 40 of all the heads 4, 5, and 6 with a single backward movement.

[0049] The structure of the blade wipe unit 70 will be described in further detail. The upper diagram of Fig. 5 shows a plan view of the blade support plate 71 that holds the blades 72, 73, and 74. The lower diagram of Fig. 5 shows the arrangement of the heads 4, 5, and 6 mounted on the carriage 3 and their corresponding relationships with the blades 72, 73, and 74. The arrangement of the heads 4, 5, and 6 shown in the lower diagram of Fig. 5 is the same as the arrangement shown in Fig. 3.

[0050] The blade support plate 71 includes a plurality of rectangular convex plates 711. The convex plates 711 protrude rearward, which is the direction of movement during wiping. A recess 712 is formed between adjacent convex plates 711, recessed toward the front. Ink blades 72 for wiping the nozzle arrangement surface 40 of the ink head 4 are attached to the rear edges (rear ends) of the convex plates 711 and the edges of the recesses 712. The ink blades 72 arranged on the edges of the convex plates 711 are used to wipe the upstream heads of the ink heads 4 of each color, such as the ink blade 72A1 arranged for the upstream head 4A1 of the first ink head 4A. Meanwhile, the ink blades 72 arranged on the edges of the recesses 712 are used to wipe the downstream heads of the ink heads 4 of each color, such as the ink blade 72A2 arranged for the downstream head 4A2.

[0051] The pretreatment liquid blade 73 that wipes the nozzle arrangement surface 40 of the pretreatment head 5 is attached to the edge (rear end) of a protruding piece 714 that protrudes further rearward than other areas of the blade support plate 71. The protruding piece 714 extends further rearward from the rear end of the leftmost protruding plate 711. A window 715 corresponding to the recess 712 is provided on the front side of the protruding piece 714. By arranging the pretreatment liquid blade 73 at the position on the blade support plate 71 that protrudes most in the movement direction, the pretreatment liquid wiped by the pretreatment liquid blade 73 is less likely to adhere to other parts of the blade support plate 71.

[0052] The post-treatment liquid blade 74, which wipes the nozzle arrangement surface 40 of the post-treatment head 6, is attached near the front of the right end of the blade support plate 71. The post-treatment head 6 is arranged alongside the upstream head 4H1 of the eighth ink head 4H, on the upstream and downstream sides in the transport direction F. In accordance with this head arrangement, the blade support plate 71 is provided with a retaining piece 716 and a window 717 near its right end. The retaining piece 716 supports, at its rear edge, an ink blade 72H1 that wipes the upstream head 4H1. An ink blade 72H2 that wipes the downstream head 4H2 is supported at the edge of the recess 712 adjacent to the left side of the retaining piece 716. The window 717 is an opening arranged in front of the retaining piece 716. The post-treatment liquid blade 74 is supported at the opening edge on the front side of the window 717.

[0053] The blade support plate 71 has a plurality of protrusions 713 arranged corresponding to each of the blades 72, 73, and 74. The protrusions 713 are connected to the rear end of the protrusion plate 711, the base edge of the recess 712, the rear end of the protrusion piece 714, and the base edge of the window portion 717. When viewed from above, these protrusions 713 are small projections that protrude in the direction of movement during wiping. The blades 72, 73, and 74 are arranged on the protrusions 713 that correspond to them. This arrangement makes it difficult for ink or treatment liquid adhering to the blades 72, 73, and 74 to adhere to the blade support plate 71.

[0054] 6 shows a detailed structure of the ink blade 72, which corresponds to the blade BL (first member) in FIG. 1. The pretreatment liquid blade 73 and the posttreatment liquid blade 74 have similar structures. The ink blade 72 includes a blade body 721, a first holder 722, and a second holder 723. The blade body 721 is a spatula-shaped plate that actually comes into contact with the nozzle arrangement surface 40 to perform a wiping operation. The upper end of the blade body 721 is located at a position that protrudes upward from the upper surface of the blade support plate 71.

[0055] The first holder 722 and the second holder 723 are members that sandwich and hold the blade body 721. The first holder 722 is fitted into a recess provided in the protrusion 713 and fixed with screws, supporting the lower back surface of the blade body 721. The second holder 723 is attached to the lower front surface of the blade body 721. The second holder 723 has a pair of openings 724, and the blade body 721 also has through holes at the same positions as the openings 724. Meanwhile, the first holder 722 has a pair of claws 725. The claws 725 are inserted through the through holes and the openings 724 and lock the second holder 723 at the periphery of the opening 724. This locking force causes the blade body 721 to be sandwiched between the first holder 722 and the second holder 723.

[0056] [Details of the Cloth Wiping Device] Next, a specific example of the cloth wiping device 8 will be described with reference to Figs. 8 to 11. Fig. 8 is a perspective view of the cloth wiping device 8, illustrating a state of cloth wiping cleaning. The cloth wiping device 8 includes a moving unit 60 and a cloth wiping unit 80. Fig. 9A is a left side view of the cloth wiping device 8, and Fig. 9B is a side view of the moving unit 60. Fig. 10 is a perspective view of the cloth wiping unit 80, and Fig. 11 illustrates a state in which the cloth wiping unit 80 is in the cleaning position.

[0057] The cloth wiping unit 80 includes a cloth sheet roll FSR, which is a stack of cloth sheets for cloth wiping. The moving unit 60 moves the cloth wiping unit 80 in the front-to-rear direction. During cloth wiping cleaning, a wiping area 8W formed by a cloth sheet FS unwound from the cloth sheet roll FSR is pressed against the nozzle arrangement surface 40 of the ink head 4, which is exposed on the underside 3A of the carriage 3. Figure 8 shows this pressed state, and when the moving unit 60 moves the cloth wiping unit 80 rearward from this state, the nozzle arrangement surface 40 is wiped by the cloth sheet FS in the wiping area 8W.

[0058] The cloth wiping unit 80 is the unit that actually performs the cloth wiping cleaning. The moving unit 60 moves the cloth wiping unit 80 between a cleaning position where it cleans the lower surface 3A (nozzle arrangement surface 40) and a retracted position where no cleaning is performed. The cloth wiping unit 80 shown in FIG. 9A is in a state where it has moved to the retracted position, and the cloth wiping unit 80 shown in FIG. 11 is in a state where it has moved to the cleaning position. The moving unit 60 includes a moving plate 61, a linear guide 62, a ball screw 63, a nut 64, a cloth wiper moving motor 65, and a position changing guide 66.

[0059] The moving plate 61 is a flat plate that is approximately rectangular in side view and is movable in the front-to-rear direction along the linear guide 62. A cloth wiping unit 80 is mounted on the moving plate 61. A pivot pin 81P that protrudes to the left is attached to the rear end of the moving plate 61 near the corner of the upper end. The pivot pin 81P is a pin that serves as a pivot axis for the cloth wiping unit 80. The cloth wiping unit 80 is mounted on the moving plate 61 so as to be rotatable around the axis of the pivot pin 81P.

[0060] The linear motion guide 62 includes a guide base 620, a guide rail 621, and a block 622. The guide base 620 is a flat plate member that serves as a mounting base for the guide rail 621, the ball screw 63, the cloth wiper movement motor 65, and the position change guide 66. The illustration of the guide base 620 is omitted in FIG. 9A . The guide rail 621 is a rail that extends linearly in the front-to-rear direction. The block 622 is fitted into the guide rail 621 and is movable in the front-to-rear direction along the guide rail 621. The moving plate 61 is fixed to the block 622.

[0061] The ball screw 63 is journaled on the guide base 620 so as to extend in the front-rear direction parallel to the guide rail 621. A nut 64 is threadedly engaged with the ball screw 63 and attached to the moving plate 61. The cloth wiper moving motor 65 is disposed so that its motor shaft is connected to the rear end of the ball screw 63, and drives the ball screw 63 to rotate forward or backward around its axis. The rotation of the ball screw 63 moves the nut 64 in the front-rear direction, and accordingly, the moving plate 61 moves in the front-rear direction while being guided by the guide rail 621.

[0062] The position change guide 66 is a member that abuts against the abutment portion 812 of the cloth wiping unit 80 when the moving plate 61 moves. The position of the abutment portion 812 against the position change guide 66 changes the rotational position of the cloth wiping unit 80 around the axis of the pivot pin 81P. The position change guide 66 includes a first horizontal portion 661, a second horizontal portion 662, and an inclined portion 663. The first horizontal portion 661 extends horizontally in the extension direction of the linear motion guide 62 at a predetermined height. The second horizontal portion 662 is located a predetermined height higher than the first horizontal portion 661 and extends horizontally in the front-to-rear direction at a position spaced rearward from the first horizontal portion 661. The inclined portion 663 connects the first horizontal portion 661 and the second horizontal portion 662, which are at different heights.

[0063] The cloth wiping unit 80 includes a base plate 81, a payout section 82, a take-up section 83, a pressure roller 84, a transport roller 85, and a transmission belt 86. The base plate 81 is a flat plate that is larger than the movable plate 61 and has a substantially square shape in side view. A bearing bush 811 protrudes from the right surface of the base plate 81 near the rear and upper corner. The bearing bush 811 has a rotation shaft hole 81A through which a pivot pin 81P of the movable plate 61 is inserted. The base plate 81 is rotatable relative to the movable plate 61, with the bearing bush 811, which is journaled by the pivot pin 81P, serving as a pivot point.

[0064] An abutment portion 812 protrudes from the left surface of the base plate 81 near the front and lower corner. The abutment portion 812 is, for example, a roller that is rotatable about an axis extending in the left-right direction. The corner where the abutment portion 812 is located is located diagonally from the corner where the bearing bush 811 is located. The abutment portion 812 abuts against the position change guide 66. FIG. 9A shows a state in which the abutment portion 812 abuts against the first horizontal portion 661 of the position change guide 66, causing the base plate 81 to assume a horizontal position. FIG. 11 shows a state in which the abutment portion 812 abuts against the second horizontal portion 662, which is located higher than the first horizontal portion 661. The base plate 81 rotates about the axis of the pivot pin 81P, causing the front side to be raised.

[0065] A payout unit 82 and a take-up unit 83 are attached to the base plate 81. The payout unit 82 pays out the cloth sheet FS used for cloth wiping cleaning. The payout unit 82 includes an unwinding roller 821 that holds a cloth sheet roll FSR, which is a roll of unused cloth sheet FS. A torque limiter 82L is attached to the rotation shaft of the unwinding roller 821. The take-up unit 83 takes up the cloth sheet FS after use in cloth wiping cleaning. The take-up unit 83 includes a take-up roller 831 around which the used cloth sheet FS is wound. A torque limiter 83L is also attached to the rotation shaft of the take-up roller 831.

[0066] A wiping area 8W using the cloth sheet FS is provided between the payout unit 82 and the take-up unit 83. The wiping area 8W is an area where the cloth sheet portion of the long cloth sheet FS in the form of a cloth sheet roll FSR is pressed against the underside 3A of the carriage 3 and actually performs cloth wiping cleaning of the nozzle arrangement surface 40 is located. Unused cloth sheets FS are successively paid out from the cloth sheet roll FSR of the payout unit 82 to the wiping area 8W. The cloth sheets FS used for cloth wiping cleaning in the wiping area 8W are successively taken up by the take-up unit 83.

[0067] The pressure roller 84 is made of an elastic roller and supports the cloth sheet FS in the wiping area 8W. The pressure roller 84 serves to press the cloth sheet FS in the wiping area 8W against the lower surface 3A. The pressure roller 84 is axially supported near the upper edge of the base plate 81 so that a portion of the pressure roller 84 protrudes upward from the upper edge of the base plate 81. With the cloth sheet FS supported from below by the pressure roller 84, the cloth sheet FS in the wiping area 8W also protrudes upward from the upper edge of the base plate 81.

[0068] A one-way clutch (not shown) is attached to the rotation shaft of the pressure roller 84. The one-way clutch rotates the pressure roller 84 only in the feeding direction of the fabric sheet FS. A pair of pulleys 842 is attached to both ends of the rotation shaft of the pressure roller 84. The pressure roller 84 is an elastically deformable roller, whereas the pulley 842 is made of a hard material that is substantially not elastically deformable. The pair of pulleys 842 is pressed against the lower surface 3A, thereby determining the positional relationship between the pressure roller 84 and the nozzle arrangement surface 40. Therefore, the amount of pressing of the fabric sheet FS by the pressure roller 84 against the nozzle arrangement surface 40 can be made constant and uniform in the axial direction.

[0069] In the payout direction of the cloth sheet FS, a first guide roller 843 is disposed upstream of the pressure roller 84, and a second guide roller 844 is disposed downstream. A transport roller 85 and a tension roller 845 are disposed downstream of the second guide roller 844. The transport roller 85 sends the cloth sheet FS from the payout section 82 through the wiping area 8W toward the take-up section 83. A one-way clutch 851 is incorporated into the rotation shaft of the transport roller 85. The tension roller 845 applies tension to the cloth sheet FS being taken up by the take-up section 83.

[0070] A gear (not shown) is attached to the shaft end of the transport roller 85. When the base plate 81 rotates relative to the moving plate 61 with the bearing bush 811 as a pivot point, a driving force is applied to the gear, causing the transport roller 85 to rotate. The cloth sheet FS is sent downstream by the rotation of the transport roller 85. The rotation of the transport roller 85 also causes the used cloth sheet FS to be taken up by the take-up section 83. As shown in FIG. 10 , a transmission belt 86 is stretched between the transport roller 85 and a take-up roller 831. When the transport roller 85 rotates by a certain amount in response to a change in the position of the cloth wipe unit 80, the rotation is transmitted to the take-up roller 831 by the transmission belt 86. As a result, the take-up roller 831 takes up the cloth sheet FS by the rotation of the transport roller 85.

[0071] A spray unit 87 is disposed between the first guide roller 843 and the pressure roller 84. The spray unit 87 has a spray gun 871 that sprays cleaning liquid, which is pure water or a liquid containing a cleaning component. The spray unit 87 is attached to the left side plate of the device frame 10. The spray gun 871 sprays cleaning liquid onto the cloth sheet FS in the wiping area 8W upstream of the pressure roller 84. Wetting the cloth sheet FS with cleaning liquid immediately before cloth wiping cleaning can improve the cleaning effect of the nozzle arrangement surface 40.

[0072] 9A shows the retracted position in which the cloth wiping unit 80 does not clean the nozzle arrangement surface 40, and FIG. 11 shows the cleaning position in which the cloth wiping unit 80 cleans the nozzle arrangement surface 40. When the cloth wiper movement motor 65 is driven from the state in FIG. 9A and the moving plate 61 is moved rearward, the cloth wiping unit 80 also moves rearward. The contact portion 812, which had been in contact with the first horizontal portion 661 ( FIG. 9B ) of the position change guide 66, comes into contact with the inclined portion 663. As the contact portion 812 rises up the inclined portion 663, the base plate 81 rotates with the bearing bush 811 inserted in the pivot pin 81P as the rotation fulcrum, so that the front end portion is lifted.

[0073] 11 shows the state in which the contact portion 812 has climbed the inclined portion 663 and reached the second horizontal portion 662. The contact portion 812 is raised by the height difference between the first horizontal portion 661 and the second horizontal portion 662, and the base plate 81 rotates about the axis of the pivot pin 81P by a rotation angle corresponding to the amount of lift. This rotation also raises the wiping area 8W, and the portion of the cloth sheet FS supported by the pressure roller 84 abuts against the lower surface 3A (nozzle arrangement surface 40). In other words, the cloth sheet FS in the wiping area 8W is now ready to perform cloth wiping cleaning of the lower surface 3A.

[0074] By driving the cloth wiper movement motor 65, the moving plate 61 is moved further rearward, and the nozzle arrangement surface 40 is cleaned by the cloth sheet FS in the wiping area 8W. In this embodiment, as shown in FIG. 3, the ink heads 4 of each color are arranged in two rows, one behind the other. The width of the cloth sheet FS is sufficient to cover the two ink heads 4 arranged in the main scanning direction S. Therefore, it is desirable to move at least the wiping area 8W by a stroke equivalent to the two rows. For this reason, the length of the second horizontal portion 662 of the position change guide 66 in the front-to-rear direction is set longer than the stroke.

[0075] When the wiping area 8W has been moved to the rear end and cloth wiping cleaning is complete, the carriage 3 is raised slightly, separating the wiping area 8W from the underside 3A. The cloth wiper movement motor 65 is then driven to return the moving plate 61 to the front. Eventually, the contact position of the contact portion 812 changes from the second horizontal portion 6622 to the inclined portion 663, and then from the inclined portion 663 to the first horizontal portion 661. This causes the base plate 81 to rotate around the axis of the pivot pin 81P, and the cloth wiping unit 80 returns to a horizontal position, i.e., the retracted position. The carriage 3 is then moved in the main scanning direction S by the distance of two heads, and the cloth wiping cleaning of the next ink head 4 is repeated in the above-described procedure.

[0076] 12 is a block diagram showing part of the control configuration of the printer 1. The printer 1 includes a controller 33, a carriage drive motor 34, a carriage lift motor 35, a head drive unit 36, a work transport motor 37, a work take-up motor 38, a blade drive unit 75, and the cloth wiper movement motor 65 described above, whose operation is controlled by the controller 33.

[0077] The carriage drive motor 34 generates a driving force that moves the carriage 3 left and right between the blade wiping area 13 and the fabric wiping area 14 through the printing area 12. The carriage drive motor 34 corresponds to the linear motor 16 shown in FIG. 1. The carriage lift motor 35 generates a driving force that moves the carriage 3 up and down in the blade wiping area 13 and the fabric wiping area 14. The head drive unit 36 ​​executes the ejection operations of ink, pre-treatment liquid, and post-treatment liquid from the heads 4, 5, and 6. The work transport motor 37 is a motor that serves as a driving source for transporting the workpiece W in the transport direction F in the printer 1. In the example of FIG. 2, the drive motors for the transport roller 25, the drive roller 201 of the transport unit 20, and the like correspond to the work transport motor 37. The work take-up motor 38 is a motor that serves as a driving source for rotating the take-up roller 22 that takes up the workpiece W after printing.

[0078] Under the control of the controller 33, the blade driving unit 75 operates the blade wiping device 7 to perform maintenance including purging processing and blade cleaning of the heads 4, 5, and 6. Specifically, as the purging processing, the blade driving unit 75 ejects high-pressure ink, pre-treatment liquid, and post-treatment liquid from the heads 4, 5, and 6 to clean the nozzles. Furthermore, as the blade cleaning, the blades 72, 73, and 74 of the blade wiping unit 70 are moved in close proximity to the nozzle arrangement surfaces 40 of the heads 4, 5, and 6 in the case of non-contact wiping, which will be described later, or in contact with the nozzle arrangement surfaces 40 in the case of contact wiping.

[0079] Under the control of the controller 33, the cloth wiper movement motor 65 moves the moving plate 61 on which the cloth wiping unit 80 is mounted, and performs cloth wiping cleaning of the ink head 4. The controller 33 sets a cleaning sequence for the nozzle arrangement surface 40 by the cloth wiping unit 80, and controls the cloth wiper movement motor 65, the carriage drive motor 34, and the like based on the cleaning sequence.

[0080] The controller 33 is made up of a processor and the like that operates according to a program, and comprehensively controls the operation of each part of the printer 1. With regard to cleaning control of the heads 4, 5, and 6, the controller 33 controls the blade wiping device 7 (first device) and the cloth wiping device 8 (second device) to perform the required blade cleaning and cloth wiping cleaning.

[0081] For the ink head 4, the controller 33 executes two-stage wiping (two-stage cleaning) in which the nozzle arrangement surface 40 is wiped by both the blade wiper device 7 and the cloth wiper device 8. The wiping order is as follows: first, the blade wiper device 7 wipes the nozzle arrangement surface 40, and then the cloth wiper device 8 wipes the nozzle arrangement surface 40. Furthermore, for wiping the ink head 4 by the blade wiper device 7, the controller 33 sequentially executes a first wiping (first cleaning) in which the ink blade 72 does not contact the nozzle arrangement surface 40, and a second wiping (second cleaning) in which the ink blade 72 contacts the nozzle arrangement surface 40. Meanwhile, for the pre-treatment head 5 and the post-treatment head 6, the controller 33 executes wiping of the nozzle arrangement surface 40 only by the blade wiper device 7. Note that, before blade cleaning by the blade wiper device 7, the controller 33 executes a purge in which ink and treatment liquid are forcibly ejected from each of the heads 4, 5, and 6.

[0082] [Specific Example of Head Cleaning Control] A specific example of the cleaning control by the controller 33 described above will be described with reference to the flowcharts shown in FIGS. 13 and 15. FIG. 13 is a flowchart showing an example of the cleaning operation for the heads 4, 5, and 6 in the printer 1. The controller 33 determines whether the current time is for cleaning (step S1). Whether it is time for cleaning is determined based on the accumulated printing time and print area since the previous head cleaning, the number of operating days, and other factors. Note that the determination of whether it is time for cleaning may also take into account non-periodic factors, such as when high-density printing is performed continuously or when a non-ejecting head is detected, in addition to the periodic factors mentioned above. If it is not time for cleaning (NO in step S1), the controller 33 puts the blade wiping device 7 and the cloth wiping device 8 into standby mode.

[0083] If it is time for cleaning (YES in step S1), it is determined (step S2) whether the carriage 3 is present in the blade wipe area 13. If the carriage 3 is not present in the blade wipe area 13 (NO in step S2), the controller 33 controls the carriage drive motor 34 to move the carriage 3 to the blade wipe area 13 (step S3).

[0084] If the carriage 3 is present in the blade wipe area 13 (YES in step S2), the controller 33 executes blade cleaning. The controller 33 controls the blade drive unit 75 to first execute a purge, which forcibly ejects ink and treatment liquid from the heads 4, 5, and 6 (step S4). The role of the purge is to expel air bubbles trapped in the nozzles of the heads 4, 5, and 6, and to blow away solid matter adhering to the nozzle arrangement surface 40 with a purge flow. For the ink head 4, the ink purge flow also softens solid matter derived from the ink, making it easier to peel off.

[0085] The purge amount can be set in the range of approximately 3 ml to 60 ml per head. It is also possible to execute purging only on the ink head 4. Furthermore, if only a specific ink head 4 has clogged nozzles, it is also possible to execute purging on only that specific head. In this case, to prevent adverse effects on the heads (damage to the water-repellent film) due to empty wiping, it is desirable to eject a small amount of ink or treatment liquid (approximately 0.2 ml to 1.0 ml) from heads other than the specific ink head 4.

[0086] Next, the controller 33 causes the blade wipe unit 70 to perform non-contact wiping (first cleaning) of the heads 4, 5, and 6 (step S5). In non-contact wiping, a gap of approximately 0.2 mm to 0.8 mm is provided between the blade body 721 of the ink blade 72 and the nozzle arrangement surface 40 of the ink head 4, and the wiping operation is performed. The same applies to the pre-treatment head 5 and the post-treatment head 6. The controller 33 controls the carriage lift motor 35 to lower the carriage 3 so that the gap is formed. This non-contact wiping wipes away droplets hanging from the nozzle arrangement surface 40 of the heads 4, 5, and 6 after purging. The movement speed of the blade wipe unit 70 in non-contact wiping can be selected from a range of approximately 10 mm / s to 100 mm / s.

[0087] Next, the controller 33 causes the blade wipe unit 70 to perform contact wiping (second cleaning) of the heads 4, 5, and 6 (step S6). In contact wiping, the blade body 721 of the ink blade 72 is pressed against the nozzle arrangement surface 40 of the ink head 4 to perform a wiping operation. The same applies to the pre-treatment head 5 and the post-treatment head 6. The pressing force (linear pressure) of the pressing can be set to approximately 0.1 N / m to 10 N / m. The controller 33 lowers the carriage 3 so that the pressing force is achieved. The movement speed of the blade wipe unit 70 in contact wiping can also be selected from a range of approximately 10 mm / s to 100 mm / s.

[0088] 14A to 14C are diagrams that schematically illustrate the cleaning procedures of steps S4 to S6. One ink head 4 and one ink blade 72 for wiping the head 4 are shown here. Figure 14A illustrates the purging operation of step S4. Purging liquid PA, i.e., ink, is ejected from the nozzle arrangement surface 40 of the ink head 4.

[0089] 14B is a diagram showing the execution status of the non-contact wiping in step S5. The gap described above exists between the ink blade 72 (blade body 721) and the nozzle arrangement surface 40. The blade support plate 71 on which the ink blade 72 is mounted is moved relative to the carriage frame 30. The ink blade 72 wipes away the droplets DR adhering to the nozzle arrangement surface 40.

[0090] FIG. 14C illustrates the execution status of the contact wiping in step S6. The ink blade 72 is in contact with the nozzle arrangement surface 40 and is deformed by the pressing force. In this state, the blade support plate 71 is moved relative to the carriage frame 30. As a result, the nozzle arrangement surface 40 itself is wiped by the ink blade 72. This two-stage wiping, non-contact and contact, cleans the nozzle arrangement surface 40. Because the ink blade 72 and the nozzle arrangement surface 40 do not come into contact with each other during non-contact wiping, the water-repellent film coated on the nozzle arrangement surface 40 is not affected. Relying entirely on contact wiping of the blade to remove the droplets DR can easily damage the water-repellent film. By pre-wiping the droplets DR using a non-contact wipe, as in this embodiment, the cleaning performance of the nozzle arrangement surface 40 can be improved while minimizing damage to the water-repellent film.

[0091] 13 , after completing the blade cleaning in steps S4 to S6, the controller 33 drives the carriage lift motor 35 to raise the carriage 3 so that the nozzle arrangement surface 40 is separated from the ink blade 72. The controller 33 then controls the carriage drive motor 34 to move the carriage 3 to the cloth wiping area 14 (step S7). After the movement, the controller 33 lowers the carriage 3 so that the nozzle arrangement surface 40 is at a predetermined height. Next, the controller 33 drives the cloth wiper movement motor 65 to cause the cloth wiping unit 80 to perform cloth wiping cleaning of the nozzle arrangement surface 40 of the ink head 4 (step S8).

[0092] That is, the moving plate 61 of the moving unit 60 is moved relative to the carriage frame 30, and the nozzle arrangement surface 40 is wiped by the cloth sheet FS. Before this wiping, a cleaning liquid is sprayed onto the cloth sheet FS from the spray unit 87. It is desirable that the cleaning liquid contains a surfactant that reduces surface tension in order to protect the water-repellent film on the nozzle arrangement surface 40. The pressing force of the pressing roller 84 on the cloth sheet FS to the nozzle arrangement surface 40 is 0.02 N / mm ２ ~0.20N / mm ２ , more preferably 0.05 N / mm ２ ~0.15N / mm ２ The relative movement speed of the fabric sheet FS can be selected from the range of about 10 mm / s to 100 mm / s.

[0093] 13 is a so-called "full wipe operation" that is performed in the following order: purging of heads 4, 5, and 6, non-contact and contact wiping of heads 4, 5, and 6 by blades 72, 73, and 74, and wiping of ink head 4 by cloth sheet FS. This full wipe operation does not need to be performed all the time, and may be performed only when necessary.

[0094] 15 is a flowchart showing an example of control for selectively executing a full wipe operation. The controller 33 checks whether the current mode of the printer 1 is "normal mode" (step S11). "Normal mode" is a state in which no accidents such as non-ejecting nozzles have been detected, and no events such as continuous high-density printing have occurred. In "normal mode," only cloth wiping of the ink heads 4 is performed periodically.

[0095] If the mode is "normal mode" (YES in step S11), the controller 33 determines whether the current time is cleaning timing (step S12). If the current time is cleaning timing (YES in step S12), the controller 33 moves the carriage 3 to the cloth wiping area 14 and operates the cloth wiping device 8 to wipe the ink head 4 with the cloth sheet FS (step S13). If the current time is not cleaning timing (NO in step S12), the controller 33 puts the blade wiping device 7 and the cloth wiping device 8 into standby mode.

[0096] On the other hand, if the mode is not "normal mode" (NO in step S11), the controller 33 operates the blade wiping device 7 and the cloth wiping device 8 in a timely manner to perform a "full wiping operation" as shown in Fig. 13 (step S14). Note that if a non-ejecting nozzle occurs in the ink head 4, a sequence may be set in which the cloth wiping device 8 first performs cloth wiping cleaning on the ink head 4, and if the non-ejection state is not resolved, the "full wiping operation" is performed.

[0097] 1 shows an example in which the blade wiping device 7 is arranged in the blade wiping area 13 located to the right of the printing area 12, and the cloth wiping device 8 is arranged in the cloth wiping area 14 located to the left of the printing area 12. Alternatively, both the blade wiping device 7 and the cloth wiping device 8 may be arranged on one side of the printing area 12.

[0098] 16 is a front view showing the overall configuration of an inkjet printer 1A according to a modified embodiment. A right frame 112A that defines a maintenance area 13A is located on the right side of the printing area 12. The maintenance area 13A houses a blade wiping device 7 and a cloth wiping device 8. In other words, with the printer 1A, both blade cleaning and cloth wiping cleaning can be performed in the maintenance area 13A.

[0099] The layout of the printer 1 shown in FIG. 1 has the advantage of enabling a more compact printer 1 because the left and right areas of the printing area 12 required for the reciprocating movement of the carriage 3 are utilized as the blade wiping area 13 and the fabric wiping area 14, respectively. However, after blade cleaning in the blade wiping area 13, it is necessary to move the carriage 3 to the fabric wiping area 14 to perform fabric wiping cleaning. On the other hand, with the printer 1A of the modified embodiment, both blade cleaning and fabric wiping cleaning can be performed in the maintenance area 13A simply by moving the carriage 3 slightly. This reduces maintenance time. Another advantage is that accessories required for head cleaning, such as cleaning liquid supply pipes, waste liquid pipes, and tanks, can be concentrated near the maintenance area 13A, simplifying and streamlining the arrangement of accessories.

[0100] In addition, the printer of the present disclosure can take on various modified embodiments. In the above embodiment, an example was shown in which the components are made of different materials, such as a blade BL as the first member and a cloth sheet FS as the second member, and the cleaning method is wiping. The meaning of "different" between the first member and the second member is not limited to different materials, but is ambiguous. For example, the first member and the second member may have different configurations, (2) different cleaning methods for the first member and the second member, or (3) different characteristics for the first member and the second member.

[0101] Examples of (1) above include (a) the first member and the second member having different shapes, (b) different positional relationships with respect to the nozzle arrangement surface, and (c) different numbers of members arranged. Specific examples of (a) above include an embodiment in which the shapes of the surfaces of the first member and the second member facing the nozzle arrangement surface (for example, one is smooth and the other is rough), the contact areas, and the tangential surface widths are different from each other. Specific examples of (b) above include an embodiment in which the first member is positioned in the main scanning direction with respect to the nozzle arrangement surface and the second member is positioned in the sub-scanning direction, or vice versa, or an embodiment in which the inclination angles with respect to the nozzle arrangement surface are different. Specific examples of (c) above include an embodiment in which multiple first members are arranged on one treatment liquid head, while one second member is arranged on one ink head.

[0102] Examples of (2) above include (d) different cleaning modes between the first member and the second member, (e) different cleaning directions, (f) different cleaning pressures or cleaning speeds, and (g) different cleaning frequencies. A specific example of (d) above is adopting different cleaning modes for the first member and the second member from cleaning modes such as wiping the nozzle arrangement surface, applying a fluid such as compressed air, inert gas, or liquid to the nozzle arrangement surface, or transferring, adsorbing, or suctioning dirt from the nozzle arrangement surface. For example, water or the like can be used as the liquid, and the liquid can be supplied to the nozzle arrangement surface by spraying it from a predetermined supply port or by allowing it to seep out from a permeable component. A specific example of (e) above is setting the movement directions of the first member and the second member when wiping the nozzle arrangement surface to different movement directions from options such as the main scanning direction, the sub-scanning direction, a diagonal direction, and the nozzle arrangement direction. The above example (f) includes an embodiment in which the pressure with which the first member and the second member are pressed against the nozzle arrangement surface differs from each other, an embodiment in which the first member and the second member are in contact with or not in contact with the nozzle arrangement surface, or an embodiment in which the cleaning speed of one of the members is faster than the other. The above example (g) includes an embodiment in which the first member and the second member clean the nozzle arrangement surface differently from each other. For example, an example can include an embodiment in which the first member cleans the treatment liquid head in a reciprocating motion (two cleanings), and the second member cleans the ink head only on its outward or return path (one cleaning).

[0103] Examples of the above (3) include making the first member and the second member different in liquid absorption, water repellency, strength such as rigidity and hardness, elastic modulus, electrical properties such as conductivity and capacitance, etc. In addition to an embodiment in which the first member and the second member are made of different materials and have different properties, an embodiment in which both are made of the same or similar materials but have different properties may also be used.

[0104] Furthermore, the above (1) to (3) may be appropriately combined to realize "different" first and second members.

[0105] Furthermore, instead of the above-described embodiment, components with the above-described "different" configurations, materials, cleaning methods, or characteristics may be used for each ink head color or each treatment liquid in the treatment liquid head. For example, the configuration, materials, cleaning methods, or characteristics of components may be different between the black ink head 4 and the ink heads 4 of colors other than black, or the configuration, materials, cleaning methods, or characteristics of components may be different between the pre-treatment head 5 and the post-treatment head 6. In this case, the components used to clean the nozzle arrangement surface of the black ink head 4 may be different from the components used to clean the nozzle arrangement surface of the ink heads 4 of colors other than black. Furthermore, the components used to clean the nozzle arrangement surface of the pre-treatment head 5 may be different from the components used to clean the nozzle arrangement surface of the post-treatment head 6. In this case, it goes without saying that the "different" components can be realized by appropriately combining the above (1) to (3).

[0106] In the above embodiment, the ink head 4 is wiped with the blade BL and the cloth sheet FS. Instead of wiping multiple times with the same wiping member, various combinations of wiping members can be used when wiping multiple times using "different" wiping members.

[0107] The combination of the first member and the second member may be selected as appropriate. That is, the combination is not limited to the following: when the first member is a blade, the second member is a cloth sheet; when the first member is a non-absorbent wiper, the second member is an absorbent wiper; or when the first member is a solid wiper, the second member is a porous wiper. For example, when the second member is a cloth sheet, an absorbent wiper, or a solid wiper, the first member may be selected from the configurations, constituent materials, cleaning methods, and characteristics exemplified in (1) to (3) above.

[0108] REFERENCE SIGNS LIST 1 inkjet printer 12 printing area 13 blade wiping area (one side) 14 cloth wiping area (other side) 3 carriage (head unit) 33 controller 4 ink head 40 nozzle arrangement surface 5 pre-treatment head (treatment liquid head) 6 post-treatment head (treatment liquid head) 7 blade wiping device (first device) 70 blade wiping unit 72 ink blade (blade) 73 pre-treatment liquid blade (blade) 74 post-treatment liquid blade (blade) 8 cloth wiping device (second device) 80 cloth wiping unit BL blade FS cloth sheet W work (recording medium)

Claims

1. a treatment liquid head that ejects a treatment liquid; An ink head that ejects ink; a first member for cleaning a nozzle arrangement surface of the treatment liquid head; an ink jet printer comprising: a second member that cleans a nozzle arrangement surface of the ink head and that has a different constituent material or cleaning method from the first member.

2. 2. The ink jet printer according to claim 1, An ink jet printer, wherein the first member is a blade and the second member is a fabric sheet.

3. A processing liquid head that ejects a processing liquid; An ink head that ejects ink; a first member configured as a non-liquid-absorbent wiper for cleaning a nozzle arrangement surface of the processing liquid head; and a second member configured as a liquid-absorbent wiper for cleaning the nozzle arrangement surface of the ink head.

4. A processing liquid head that ejects a processing liquid; An ink head that ejects ink; a first member formed of a solid wiper for cleaning a nozzle arrangement surface of the processing liquid head; and a second member made of a porous wiper that cleans the nozzle arrangement surface of the ink head.

5. In the ink jet printer according to any one of claims 1 to 4, a first device having the first member; a second device having the second member; and a controller that controls the first device and the second device, The controller executes control to cause the first device and the second device to clean the nozzle arrangement surface of the ink head, and to cause only the first device to clean the nozzle arrangement surface of the treatment liquid head.

6. 6. The ink jet printer according to claim 5, The controller executes control to cause the first device to clean the nozzle arrangement surface of the ink head, and then the second device to clean the nozzle arrangement surface of the ink head.

7. 7. The ink jet printer according to claim 6, The controller further controls the ink ejection operation of the ink head, and executes a purge to forcibly eject ink from the ink head, and then executes cleaning at the first device and cleaning at the second device in sequence.

8. In the ink jet printer according to any one of claims 1 to 4, a carriage carrying the treatment liquid head and the ink head; a printing area, which is a transport area of ​​a recording medium to be inkjet printed, in which the carriage reciprocates in a width direction perpendicular to a transport direction of the recording medium for inkjet printing; a first device having the first member; a second device having the second member; An inkjet printer, wherein the first device is disposed on one side of the printing area, and the second device is disposed on the other side of the printing area.

9. In the ink jet printer according to any one of claims 1 to 4, a carriage carrying the treatment liquid head and the ink head; a printing area, which is a transport area of ​​a recording medium to be inkjet printed, in which the carriage reciprocates in a width direction perpendicular to a transport direction of the recording medium for inkjet printing; a first device having the first member; a second device having the second member; An inkjet printer, wherein the first device and the second device are both located on one side of the printing area.

10. In the ink jet printer according to any one of claims 1 to 4, the treatment liquid head includes a pre-treatment head that ejects treatment liquid before ejecting the ink, and a post-treatment head that ejects treatment liquid after ejecting the ink, An ink jet printer, wherein the first member for the pre-treatment head and the first member for the post-treatment head have mutually different configurations, constituent materials, cleaning methods, or characteristics.

11. In the ink jet printer according to any one of claims 1 to 4, The ink heads include a black ink head that ejects black ink and a color ink head that ejects ink of a color other than black, The ink jet printer, wherein the second member for the black ink head and the second member for the color ink heads have mutually different configurations, constituent materials, cleaning methods, or characteristics.

12. In the ink jet printer according to claim 1, An inkjet printer, wherein a cleaning method for the second member differs from a cleaning method for the first member in at least one of a cleaning mode, a cleaning direction, a number of cleanings, a cleaning pressure, or a cleaning speed.

13. A method for cleaning a head unit having a treatment liquid head that ejects a treatment liquid and an ink head that ejects ink, comprising the steps of: cleaning a nozzle arrangement surface of the treatment liquid head with a first member; A head unit cleaning method, comprising cleaning a nozzle arrangement surface of the ink head with a second member having a different constituent material or cleaning method from the first member.

14. The method for cleaning a head unit according to claim 13, A method for cleaning a head unit, comprising the steps of: using a blade as the first member; and using a cloth sheet as the second member.

15. A method for cleaning a head unit according to claim 13 or 14, The nozzle arrangement surface of the processing liquid head is cleaned only by the first member, The head unit cleaning method includes a two-stage cleaning step of cleaning the nozzle arrangement surface of the ink head with the first member and then with the second member.

16. The method for cleaning a head unit according to claim 15, A method for cleaning a head unit, wherein cleaning of the ink head with the first member includes a first cleaning in which the first member is not brought into contact with the nozzle arrangement surface, and a second cleaning in which the first member is brought into contact with the nozzle arrangement surface.

17. The method for cleaning a head unit according to claim 15, The cleaning of the ink head by the first member includes: a first cleaning step in which the first member is not brought into contact with the nozzle arrangement surface; a second cleaning step of bringing the first member into contact with the nozzle arrangement surface, the second cleaning step being performed after the first cleaning step; After the second cleaning, cleaning is performed using a cloth sheet as the second member. How to clean the head unit.

18. The method for cleaning a head unit according to claim 17, A head unit cleaning method comprising: performing a purge to forcibly eject ink from the ink head before the first cleaning.