Inkjet recording apparatus

Abstract

To provide an inkjet recording device capable of simplifying and miniaturizing a cleaning part while maintaining cleaning performance of an inkjet head.SOLUTION: The inkjet recording apparatus includes an inkjet head having a plurality of ink ejection heads configured to eject ink and a treatment liquid ejection head configured to eject a treatment liquid having an aggregating action, the inkjet head being configured to form an image on a recording material while scanning in a main scanning direction, and a cleaning member configured to clean an ink ejection surface of the ink ejection head and a treatment liquid ejection surface of the treatment liquid ejection head.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an inkjet recording apparatus. [Background technology]

[0002] Conventionally, there is known a scanning inkjet recording device that forms an image while scanning an inkjet head in a main scanning direction (see, for example, Patent Document 1). As shown in Fig. 1, a typical inkjet recording device 1A includes an inkjet head 11 that is movable in the main scanning direction (X-axis direction) and a cleaning unit 40. The cleaning unit 40 cleans the ejection surface of the inkjet head 11 while moving, for example, in a wiping direction (Y-axis direction) perpendicular to the main scanning direction relative to the inkjet head 11.

[0003] The inkjet head 11 may include, for example, an ink ejection head 12 that ejects color inks and a treatment liquid ejection head 13 that ejects treatment liquid. The ink ejection head 12 and the treatment liquid ejection head 13 are arranged side by side in the main scanning direction, for example.

[0004] When pigment ink is used as the color ink, the treatment liquid contains an aggregating agent that aggregates the pigment ink. In this case, if the ejection surfaces of the ink ejection head 12 and the treatment liquid ejection head 13 are cleaned with the same cleaning member, the treatment liquid and the pigment ink may mix and aggregate, and the aggregate may adhere to the ejection surface, causing clogging of the nozzles. Conventionally, to prevent the adhesion of aggregates, the ejection surfaces of the ink ejection head 12 and the treatment liquid ejection head 13 are cleaned with dedicated cleaning members 41 and 42, respectively (see FIG. 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-033944 Summary of the Invention [Problem to be solved by the invention]

[0006] However, if the cleaning members 41 and 42 are provided separately for the ink ejection head 12 and the treatment liquid ejection head 13, respectively, the configuration of the cleaning unit 40 becomes complicated, the cost of the device increases, and it becomes difficult to downsize the device. In addition, the labor required for parts management increases.

[0007] SUMMARY OF THE INVENTION An object of the present invention is to provide an inkjet recording apparatus that can simplify and downsize the cleaning unit while maintaining the cleaning performance of the inkjet head. [Means for solving the problem]

[0008] The inkjet recording apparatus according to the present invention comprises: an inkjet head having a plurality of ink ejection heads that eject ink and a treatment liquid ejection head that ejects a treatment liquid having an aggregating effect, and that forms an image on a recording material while scanning in a main scanning direction; a cleaning member that cleans the ink ejection surface of the ink ejection head and the treatment liquid ejection surface of the treatment liquid ejection head, An ink wiping area of ​​the cleaning member that cleans the ink ejection surface is different from a treatment liquid wiping area that cleans the treatment liquid ejection surface. [Effects of the Invention]

[0009] According to the present invention, it is possible to simplify and miniaturize the cleaning unit while maintaining the inkjet head cleaning performance. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a conventional inkjet recording apparatus. [Figure 2]FIG. 2 is a diagram showing a cleaning mode in a conventional inkjet recording apparatus. [Figure 3] FIG. 3 is a diagram showing a schematic configuration of an inkjet recording apparatus according to an embodiment. [Figure 4] FIG. 4 is a diagram showing the main parts of the control system of the inkjet recording apparatus. [Figure 5] FIG. 5 is a diagram showing an example of an arrangement of inkjet heads. [Figure 6] FIG. 6 is a diagram showing an example of a nozzle configuration in an inkjet head. [Figure 7] FIG. 7 is a diagram schematically illustrating the configuration of the cleaning unit. [Figure 8] FIG. 8 is a diagram showing an example of a cleaning mode in the cleaning unit. [Figure 9] FIG. 9 is a diagram showing another example of the cleaning mode in the cleaning unit. [Figure 10] FIG. 10 is a diagram showing another example of the cleaning mode in the cleaning unit. [Figure 11] FIG. 11 is a diagram showing another example of the cleaning mode in the cleaning unit. [Figure 12] FIG. 12 is a diagram showing another example of the cleaning mode in the cleaning unit. [Figure 13] FIG. 13 is a diagram showing another example of the cleaning mode in the cleaning unit. [Figure 14] FIG. 14 is a diagram showing another example of the cleaning mode in the cleaning unit. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiments described below, common elements are designated by the same reference numerals, and redundant description thereof will be omitted.

[0012] 3 is a diagram showing a schematic configuration of an inkjet recording apparatus 1 according to an embodiment of the present invention, and FIG.

[0013] Here, the explanation will be given using a Cartesian coordinate system (X, Y, Z). The XYZ three-dimensional coordinate system shown in FIG. 3 is a coordinate system in which the XY plane is the horizontal plane and the Z axis direction is the vertical direction. The X axis direction is the movement direction of the inkjet head 11 and is called the main scanning direction. The Y axis direction is the transport direction of the recording material M and is called the sub-scanning direction. The Y axis direction is also called the wiping direction when describing the operation of the cleaning unit 40. This is also true for other figures.

[0014] The inkjet recording apparatus 1 is a printing device that forms an image by ejecting ink onto a recording material M that is transported along a predetermined transport direction (Y-axis direction). The inkjet recording apparatus 1 includes an image forming section 10, a transport section 20, a purging section 30, a cleaning section 40, and a control section 60. The recording material M is, for example, a web-like recording material in the form of a roll of fabric, paper, film, or the like.

[0015] The control unit 60 includes a CPU (Central Processing Unit) 61 as a calculation / control device, a ROM (Read Only Memory) 62 as a main storage device, and a RAM (Random Access Memory) 63. The ROM 62 stores a basic program and basic setting data. The CPU 61, for example, reads out a program corresponding to the processing content from the ROM 62 and loads it into the RAM 63. The CPU 61 executes the loaded program to centrally control the operations of each block (image forming unit 10, conveying unit 20, purging unit 30, and cleaning unit 40) of the inkjet recording apparatus 1.

[0016] In addition, some or all of the processing performed by the control unit 60 may be performed by electronic circuits such as a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), or a PLD (Programmable Logic Device) provided depending on the processing.

[0017] The image forming unit 10 includes an inkjet head 11, a carriage 14, a carriage driving unit 15, a head driving unit 16, and the like.

[0018] The inkjet head 11 has an ink ejection head 12 capable of ejecting colored inks, and a treatment liquid ejection head 13 capable of ejecting treatment liquid. The ink ejection head 12 and the treatment liquid ejection head 13 are, for example, ink cartridges that are detachable from a carriage 14, and have the same configuration. The ink ejection head 12 includes, for example, ink ejection heads 12C, 12M, 12Y, and 12K of four colors: cyan (C), magenta (M), yellow (Y), and black (K) (see FIG. 5). At least one treatment liquid ejection head 13 is provided in the inkjet head 11.

[0019] The ink ejection head 12 and the treatment liquid ejection head 13 have a large number of nozzles 121, 131 on their ink ejection surfaces 12a and treatment liquid ejection surfaces 13a, respectively, that face the recording material M (see FIG. 6). The nozzles 121 of the ink ejection head 12 are arranged along the sub-scanning direction (Y-axis direction) and define the printing width when forming an image on the recording material M. The configuration of the nozzles 131 in the treatment liquid ejection head 13 may be the same as or different from the nozzle configuration of the ink ejection head 12.

[0020] The ink ejected from the ink ejection head 12 is, for example, a pigment ink. The treatment liquid ejected from the treatment liquid ejection head 13 contains an aggregating agent that aggregates the pigment ink. The treatment liquid is ejected before or after ejecting the ink. The treatment liquid controls the behavior of ink droplets that land on the recording material M, thereby improving color development and suppressing color unevenness.

[0021] The ink ejection head 12 and the treatment liquid ejection head 13 each incorporate a head drive unit 16. The head drive unit 16 is a drive source such as a piezoelectric element that ejects a predetermined amount of ink or treatment liquid at a predetermined timing from the ink ejection head 12 or the treatment liquid ejection head 13. The operation of each head drive unit 16 is controlled by a control unit 60.

[0022] The ink ejection heads 12C, 12M, 12Y, and 12K and the treatment liquid ejection head 13 are arranged, for example, at predetermined intervals (for example, equal intervals) along the main scanning direction. The treatment liquid ejection head 13 is arranged, for example, on one side in the main scanning direction (the positive side in the X-axis direction in FIG. 5) of a head group consisting of the four ink ejection heads 12C, 12M, 12Y, and 12K.

[0023] The ink ejection heads 12 and the treatment liquid ejection heads 13 may be configured in one row or multiple rows. In the example shown in Fig. 5, the ink ejection heads 12 and the treatment liquid ejection heads 13 are arranged in four rows in the sub-scanning direction (Y-axis direction).

[0024] The carriage 14 is a head holder capable of mounting the ink ejection head 12 and the treatment liquid ejection head 13. The ink ejection head 12 and the treatment liquid ejection head 13 may be mounted at the same interval or at different intervals. The carriage 14 is capable of reciprocating movement above the recording material M in the main scanning direction (X-axis direction).

[0025] Here, the carriage 14 is attached to a rail 17 that extends in the main scanning direction. At least one side of the rail 17 (the negative side in the X-axis direction in FIG. 3) extends outward from the conveying path along which the recording material M is conveyed, allowing the carriage 14 to move further outward from the conveying path of the recording material M. A purge unit 30 and a cleaning unit 40 are disposed on the extended portion of the rail 17.

[0026] A carriage drive unit 15 is connected to the carriage 14. The carriage drive unit 15 is a drive source (for example, a motor) that moves the carriage 14 back and forth in the main scanning direction. The operation of the carriage drive unit 15 is controlled by a control unit 60.

[0027] The image forming unit 10 forms an image on the recording material M under the control of the control unit 60. Specifically, the image forming unit 10 causes the inkjet head 11 mounted on a carriage 14 to scan in the main scanning direction while the recording material M is stationary. At the same time, the image forming unit 10 causes the ink ejection head 12 and the treatment liquid ejection head 13 to eject ink and treatment liquid onto the recording material M, thereby forming an image.

[0028] The conveying unit 20 conveys the recording material M along the conveying direction (Y-axis direction). Specifically, the conveying unit 20 intermittently conveys the recording material M along the conveying direction under the control of the control unit 60. The intermittent conveying is a conveying mode in which the conveying operation and the stopping operation of the recording material M are repeated. The conveying unit 20 includes, for example, a pair of conveying rollers 21, 21 and a platen 22.

[0029] The transport roller 21 rotates around a rotation axis parallel to the X-axis direction by driving a transport motor (not shown). The platen 22 is a plate-shaped member and is disposed between the pair of transport rollers 21, 21 so that its upper surface is approximately horizontal. The recording material M is stretched across the pair of transport rollers 21, 21 and supported in a horizontal state by the platen 22.

[0030] The conveying section 20 is not limited to the above configuration, and may be configured, for example, such that an endless conveying belt is stretched between a pair of conveying rollers 21, 21, and the recording material M is conveyed in the conveying direction by the conveying belt that circulates in accordance with the rotation of the conveying rollers 21, 21. The conveying section 20 may also have a configuration in which the recording material M is attracted to the upper surface of the platen 22. In this case, the recording material M is conveyed in a predetermined conveying direction while being attracted to the upper surface of the platen 22.

[0031] The purge unit 30 recovers the ink and treatment liquid discharged from the inkjet head 11. The purge unit 30 has an ink purge unit 31 that recovers the ink, and a treatment liquid purge unit 32 that recovers the treatment liquid.

[0032] The ink purge unit 31 has an ink purge tub, an ink discharge tube, and an ink recovery tank (reference numerals omitted). Ink discharged from the ink ejection head 12 is received by the ink purge tub and collected in the ink recovery tank through the ink discharge tube.

[0033] The processing liquid purge unit 32 has a processing liquid purge tub, a processing liquid discharge tube, and a processing liquid recovery tank. The processing liquid discharged from the processing liquid discharge head 13 is received by the processing liquid purge tub and then passed through the processing liquid discharge tube to be recovered in the processing liquid recovery tank.

[0034] The ink purge section 31 and the treatment liquid purge section 32 are physically separated, and are configured so that the ink and treatment liquid collected in each section do not mix. This prevents the ink discharge tube or the treatment liquid discharge tube from becoming clogged with aggregates, and allows the ink and treatment liquid to be collected appropriately.

[0035] The cleaning unit 40 cleans the ejection surface 11a of the inkjet head 11 (see FIG. 7). The ejection surface 11a includes the ink ejection surface 12a of the ink ejection head 12 and the treatment liquid ejection surface 13a of the treatment liquid ejection head 13. The treatment liquid contains less resin than the ink. Therefore, the treatment liquid ejection surface 13a is easier to clean than the ink ejection surface 12a.

[0036] The cleaning unit 40 has one cleaning member 41. The cleaning member 41 is, for example, a cleaning roller that wipes off droplets L remaining on the ejection surface 11a while rotating at a predetermined rotation speed. The cleaning member 41 is, for example, immersed in a cleaning liquid 43. The cleaning member 41 comes into contact with the ejection surface 11a with an appropriate contact pressure, and cleans off droplets L of ink or treatment liquid remaining on the ejection surface 11a.

[0037] The cleaning unit 40 is capable of reciprocating movement along the sub-scanning direction (Y-axis direction) below the inkjet head 11. Here, the cleaning unit 40 is attached to a rail 44 extending in the sub-scanning direction. The cleaning unit 40 reciprocates along the rail 44, for example, when a wiper drive unit (not shown) is driven under the control of the control unit 60.

[0038] Since the cleaning portion 40 can move back and forth in the sub-scanning direction relative to the inkjet head 11, the ejection surface 11a can be properly cleaned even if the contact area between the cleaning member 41 and the ejection surface 11a is small.

[0039] For example, when forming an image on the recording material M, the control section 60 controls the operation of the conveying section 20 to convey the recording material M intermittently in the conveying direction (Y-axis direction).

[0040] The control unit 60 controls the operation of the carriage drive unit 15 while the conveyance of the recording material M is stopped, to move the carriage 14 forward or backward along the main scanning direction (X-axis direction). Furthermore, while the control unit 60 is moving the carriage 14 forward or backward, it controls the operation of the head drive unit 16 to eject ink and treatment liquid from the inkjet head 11 onto the recording material M, thereby forming an image of one line in the main scanning direction. The width of the image of one line formed on the recording material M corresponds to the printing width of the inkjet head 11.

[0041] Specifically, the control unit 60 causes the ink ejection head 12 to eject ink onto the recording material M based on image data to be printed. When moving in the main scanning direction, the ink ejection head 12 ejects ink onto image areas that contain valid image components in the image data to be printed. On the other hand, the ink ejection head 12 does not eject ink onto marginal areas that do not contain valid image components. In addition, the treatment liquid ejection head 13 ejects a predetermined treatment liquid onto the recording material M before or after the ink ejection head 12 ejects ink onto the recording material M.

[0042] Once one line of image has been formed, the control unit 60 again intermittently transports the recording material M. The transport amount of the recording material M at this time corresponds to the width of one line of image formed by the inkjet head 11. When the recording material M has been transported by the width of one line of image, the control unit 60 stops transport of the recording material M and moves the carriage 14 again along the main scanning direction. If the previous time the carriage 14 was moved forward, the current movement direction will be a return movement, which is the opposite direction to the previous time. By repeatedly performing such intermittent operations, the control unit 60 forms an image on the recording material M.

[0043] In the inkjet recording apparatus 1, cleaning of the inkjet head 11 is performed at a predetermined timing. The predetermined timing includes, for example, before the start of a print job or after the end of a print job. Alternatively, cleaning of the inkjet head 11 may be performed in accordance with an input from a user via an operation unit (not shown).

[0044] The control unit 60 executes a purge process before cleaning the inkjet head 11. In the purge process, the control unit 60 controls the operation of the carriage drive unit 15 to move the carriage 14 to a position above the purge unit 30. In this state, the control unit 60 controls the operation of the head drive unit 16 to discharge the ink and treatment liquid from the inkjet head 11 toward a purge tub (reference number omitted) of the purge unit 30. The discharged ink and treatment liquid are collected in a collection tank (reference number omitted). By performing the purge process before the cleaning process, clogging of the nozzles can be prevented.

[0045] After the purging process, the control unit 60 executes a cleaning process for the inkjet head 11. In the cleaning process, the control unit 60 controls the operation of the carriage drive unit 15 to move the carriage 14 to a position above the cleaning unit 40. In this state, the control unit 60 controls the operation of the cleaning unit 40 to clean the ejection surface 11a of the inkjet head 11 while moving the cleaning unit 40 along the sub-scanning direction (Y-axis direction) (wiping process). This makes it possible to prevent clogging of the nozzles of the inkjet head 11. The wiping process is performed, for example, by moving the cleaning unit 40 forward and backward.

[0046] In this embodiment, the ink ejection surface 12a of the ink ejection head 12 and the treatment liquid ejection surface 13a of the treatment liquid ejection head 13 are all cleaned by a single cleaning member 41. Hereinafter, the cleaning area of ​​the ink ejection surface 12a of the cleaning member 41 will be referred to as the "ink wiping area," and the cleaning area of ​​the treatment liquid ejection surface 13a will be referred to as the "treatment liquid wiping area."

[0047] Cleaning the ejection surface 11a of the inkjet head 11 with a single cleaning member 41 simplifies the configuration of the cleaning unit 40, thereby reducing device costs and the effort required for parts management. However, a single cleaning member 41 includes both an ink wiping area and a treatment liquid wiping area, which makes it easy for the ink and treatment liquid to become physically mixed. This can lead to the risk of aggregates adhering to the ink ejection surface 12a or the treatment liquid ejection surface 13a, preventing the inkjet head 11 from being properly cleaned.

[0048] In this embodiment, the movement control of the cleaning member 41 and the arrangement of the ink ejection head 12 and the treatment liquid ejection head 13 are devised so that the ink wiping area and the treatment liquid wiping area of ​​the cleaning member 41 do not overlap.

[0049] 8 is a diagram showing an example of a cleaning mode in the cleaning unit 40. In the example shown in FIG. 8, the treatment liquid ejection head 13 and four ink ejection heads 12C, 12M, 12Y, and 12K are arranged at equal intervals along the main scanning direction. The length of the cleaning member 41 in the main scanning direction is such that it is unable to clean all of the inkjet heads 11 at once. The length of the cleaning member 41 is set to, for example, such that it is able to clean three inkjet heads 11 simultaneously.

[0050] In this case, the relative position of the cleaning member 41 with respect to the inkjet head 11 in the main scanning direction is changed, and the inkjet head 11 is cleaned by performing two wiping processes. In this embodiment, the inkjet head 11 is moved to change the relative position of the cleaning member 41 with respect to the inkjet head 11 in the main scanning direction (cleaning position change process). Note that the relative positions of the two in the main scanning direction may also be changed by moving the cleaning member 41.

[0051] Of the inkjet heads 11, the head group that is cleaned in the first wiping process is referred to as the "first head group 11-1," and the head group that is cleaned in the second wiping process is referred to as the "second head group 11-2." The inkjet heads 11 are selectively classified into the first head group 11-1 and the second head group 11-2. The first head group 11-1 includes a treatment liquid ejection head 13 and an ink ejection head 12. The second head group 11-2 includes an ink ejection head 12. The second head group 11-2 may or may not include a treatment liquid ejection head 13.

[0052] Specifically, the control unit 60 controls the position of the inkjet heads 11 so that the first head group 11-1 is positioned above the cleaning member 41. In this state, the first wiping process is performed. The position of the inkjet heads 11 at this time is referred to as the "first position." Here, the treatment liquid ejection head 13 and the two ink ejection heads 12C, 12M form the first head group 11-1.

[0053] After the first wiping process, the control unit 60 moves the inkjet head 11 in the main scanning direction (positive side of the X-axis direction) so that the second head group 11-2 is positioned above the cleaning member 41 (cleaning position change process). In this state, the second wiping process is executed. The position of the inkjet head 11 at this time is referred to as the "second position." Here, the two ink ejection heads 12Y and 12K are the second head group 11-2.

[0054] 8, in the first wiping process, the ejection surface 13a of the treatment liquid ejection head 13 is cleaned in the treatment liquid wiping area 52-1 of the cleaning member 41. Also, the ink ejection surfaces 12a of the ink ejection heads 12C and 12M are cleaned in the ink wiping areas 51-1 and 51-1.

[0055] In the second wiping process, the ink ejection surfaces 12a of the ink ejection heads 12Y and 12K are cleaned by the ink wiping areas 51-2 and 51-2 of the cleaning member 41. The control unit 60 controls the movement of the inkjet head 11 after the first wiping process so that the treatment liquid wiping area 52-1 in the first wiping process and the ink wiping area 51-2 in the second wiping process do not overlap.

[0056] In the cleaning member 41, the ink wiping areas 51-1, 51-2 and the treatment liquid wiping area 52-1 are separated by a predetermined distance, which makes it possible to prevent the wiped treatment liquid and ink from mixing and forming aggregates. This makes it possible to properly clean the ejection surfaces 12a, 13a of the ink ejection head 12 and the treatment liquid ejection head 13. Furthermore, by performing the wiping process multiple times, the length of the cleaning member 41 can be shortened, thereby making it possible to reduce the size and weight of the cleaning unit 40.

[0057] 8, the treatment liquid ejection head 13 of the first head group 11-1 and the ink ejection head 12Y of the second head group 11-2 are located at the same position in the main scanning direction in their respective head groups (both on the most positive side in the X-axis direction). That is, in the second head group 11-2, the ink ejection head 12Y is disposed at a position corresponding to the treatment liquid ejection head 13 of the first head group 11-1. In this case, since no unnecessary empty space is provided in the inkjet head 11, the size in the main scanning direction can be reduced. Meanwhile, the treatment liquid wiping area 52-1 in the first wiping process and the ink wiping area 51-2 in the second wiping process are adjacent to each other.

[0058] On the other hand, the ink ejection heads 12 of the second head group 11-2 may not be disposed at positions corresponding to the treatment liquid ejection heads 13 of the first head group 11-1 (see FIGS. 9 and 10). In this case, the size of the inkjet heads 11 in the main scanning direction increases, but the separation distance between the treatment liquid wiping area 52-1 in the first wiping process and the ink wiping area 51-2 in the second wiping process can be increased.

[0059] Fig. 9 is a diagram showing another example of the cleaning mode in the cleaning unit 40. In the example shown in Fig. 9, an empty space for one cartridge is provided between the magenta ink ejection head 12M and the yellow ink ejection head 12Y. That is, in the second head group 11-2, the position corresponding to the treatment liquid ejection head 13 of the first head group 11-1 is an empty space.

[0060] In this case, the ink wiping area 51-2 in the second wiping process is closer to the ink wiping area 51-1 than the treatment liquid wiping area 52-1 in the first wiping process. The distance between the ink wiping area 51-2 in the second wiping process and the treatment liquid wiping area 52-1 in the first wiping process can be made larger than in the example shown in Figure 8, making it possible to more effectively prevent the formation of aggregates.

[0061] Fig. 10 is a diagram showing another example of the cleaning mode in the cleaning unit 40. In the example shown in Fig. 10, the treatment liquid ejection head 13 is disposed between the magenta ink ejection head 12M and the yellow ink ejection head 12Y, that is, at a position corresponding to the treatment liquid ejection head 13 of the first head group 11-1.

[0062] In this case as well, the ink wiping area 51-2 in the second wiping process is closer to the ink wiping area 51-1 than the treatment liquid wiping area 52-1 in the first wiping process. The distance between the ink wiping area 51-2 in the second wiping process and the treatment liquid wiping area 52-1 in the first wiping process can be made larger than in the example shown in Fig. 8, making it possible to more effectively prevent the formation of aggregates.

[0063] 9 and 10, the ink wiping area 51-1 in the first wiping process and the ink wiping area 51-2 in the second wiping process may overlap (see FIGS. 11 and 12). This allows the treatment liquid wiping area 52-1 and the ink wiping area 51-2 to be spatially separated by an even greater amount, making it possible to reliably prevent the formation of aggregates.

[0064] 8 to 12 are merely examples. The movement control of the inkjet head 11 after the first wiping process may be performed so that the treatment liquid wiping area 52-1 in the first wiping process does not overlap with the ink wiping areas in the second and subsequent wiping processes.

[0065] For example, as shown in Fig. 13, a treatment liquid ejection head 13 may be arranged as a third head group 11-3 at a position corresponding to the treatment liquid ejection head 13 of the first head group 11-1, and cleaning may be performed by three wiping processes. Note that Fig. 13 shows an example in which the third head group 11-3 is added to the head configuration shown in Fig. 11, but the treatment liquid ejection head 13 may also be arranged as the third head group 11-3 in the head configuration shown in Fig. 9, Fig. 10 or Fig. 12.

[0066] In this case, only the treatment liquid ejection surface 13a is cleaned in the third wiping process. The treatment liquid ejection surface 13a can be cleaned more easily than the ink ejection surface 12a. Therefore, the wiping process may be performed during either the forward movement or the backward movement in the sub-scanning direction, or the movement speed of the cleaning member 41 in the sub-scanning direction may be controlled to be high. Furthermore, the contact pressure of the cleaning member 41 against the inkjet head 11 may be controlled to be low, or the rotation speed of the cleaning member 41 (cleaning roller) may be controlled to be low.

[0067] As described above, the inkjet recording apparatus 1 according to the embodiment has the following features either alone or in appropriate combination.

[0068] That is, the inkjet recording device 1 has an inkjet head 11 which has a plurality of ink ejection heads 12 that eject ink and a treatment liquid ejection head 13 that ejects a treatment liquid having an aggregating effect, and which forms an image on a recording material M while scanning in the main scanning direction, and is equipped with a cleaning member 41 which cleans the ink ejection surface 12a of the ink ejection head 12 and the treatment liquid ejection surface 13a of the treatment liquid ejection head 13, and the ink wiping areas 51-1 and 51-2 which clean the ink ejection surface 12a of the cleaning member 41 and the treatment liquid wiping areas 52-1 and 52-2 which clean the treatment liquid ejection surface 13a are different (do not overlap).

[0069] The ink wiping areas 51-1, 51-2 and the treatment liquid wiping area 52-1 are separated by a predetermined distance, which prevents the treatment liquid wiped by the cleaning member 41 from mixing with the ink and forming aggregates. This allows the ink ejection surface 12a and the treatment liquid ejection surface 13a to be properly cleaned, ensuring cleaning performance equivalent to that of conventional devices. Furthermore, because cleaning is performed using a single cleaning member 41, the cleaning unit 40 can be simplified and made smaller, reducing device costs and the effort required for parts management.

[0070] In the inkjet recording device 1, the treatment liquid ejection head 13 is arranged next to the ink ejection head 12 in the main scanning direction, and the cleaning member 41 cleans the ink ejection surface 12a and the treatment liquid ejection surface 13a while moving in the sub-scanning direction perpendicular to the main scanning direction relative to the inkjet head 11. Even if the contact area between the cleaning member 41 and the ejection surface 11a is small, cleaning performance can be maintained, and the cleaning unit 40 can be simplified and made smaller.

[0071] The inkjet recording device 1 is equipped with a control unit 60 that controls the operation of the cleaning member 41, and the control unit 60 alternately performs a wiping process in which the cleaning member 41 moves in the sub-scanning direction relative to the inkjet head 11 to clean the ink ejection surface 12a and the treatment liquid ejection surface 13a, and a cleaning position change process in which the cleaning member 41 moves relatively to the inkjet head 11 in the main scanning direction.

[0072] Specifically, in the inkjet recording apparatus 1, the inkjet head 11 has a first head group 11-1 that is cleaned by a cleaning member 41 at a first position in the main scanning direction, and a second head group 11-2 that is cleaned by the cleaning member 41 at a second position different from the first position, the first head group 11-1 includes a treatment liquid ejection head 13 and an ink ejection head 12, and the second head group 11-2 includes an ink ejection head 12, and the control unit 60 moves the inkjet head 11 in a cleaning position change process so that an ink wiping area 51-2 when cleaning the second head group 11-2 does not overlap with a treatment liquid wiping area 52-1 when cleaning the first head group 11-1. Since cleaning is performed by multiple wiping processes, a small cleaning member 41 can be used, and the cleaning unit 40 can be simplified and made smaller.

[0073] In the inkjet recording apparatus 1, the inkjet head 11 can be arranged with the ink ejection heads 12 and the treatment liquid ejection heads 13 at equal intervals, and in the second head group 11-2, the ink ejection heads 12 are arranged at positions corresponding to the treatment liquid ejection heads 13 of the first head group 11-1 (see FIG. 8). Since no empty space is required and the ink ejection heads 12 can be arranged closely together, the size of the inkjet head 11 in the main scanning direction can be reduced.

[0074] In the inkjet recording apparatus 1, the inkjet head 11 can have the ink ejection heads 12 and the treatment liquid ejection heads 13 arranged at equal intervals, and in the second head group 11-2, the positions corresponding to the treatment liquid ejection heads 13 of the first head group 11-1 are either empty spaces or have treatment liquid ejection heads 13 arranged therein (see FIGS. 9 and 10). The separation distance between the treatment liquid wiping area 52-1 in the first wiping process and the ink wiping area 51-2 in the second wiping process can be increased, making it possible to effectively suppress the generation of aggregates.

[0075] In the inkjet recording apparatus 1, the treatment liquid wiping areas 52-1 and 52-2 include a first treatment liquid wiping area 52-1 when cleaning the first head group 11-1, and the ink wiping areas 51-1 and 51-2 include a first ink wiping area 51-1 when cleaning the first head group 11-1 and a second ink wiping area 51-2 when cleaning the second head group 11-2, and the distance between the first treatment liquid wiping area 52-1 and the second ink wiping area 51-2 is larger than the distance between the first ink wiping area 51-1 and the second ink wiping area 51-2. Since the distance between the treatment liquid wiping area 52-1 and the ink wiping area 51-2 is wider, the effect of suppressing aggregation is improved.

[0076] In the inkjet recording apparatus 1, the cleaning member 41 is configured as a cleaning roller, which makes it possible to obtain high cleaning performance.

[0077] In the inkjet recording apparatus 1, the control unit 60 executes the wiping process during both the forward movement and the backward movement in the sub-scanning direction, thereby making it possible to more appropriately clean the treatment liquid ejection surface 13a and the ink ejection surface 12a.

[0078] In the inkjet recording apparatus 1, when cleaning only the treatment liquid ejection surface 13a (see FIG. 13), the control unit 60 may execute the wiping process during either the forward movement or the backward movement in the sub-scanning direction. Also, the movement speed of the cleaning member 41 during the wiping process may be controlled to be high. In this case, the efficiency of the cleaning process can be improved.

[0079] In the inkjet recording apparatus 1, when only the treatment liquid ejection surface 13a is cleaned (see FIG. 13), the control unit 60 may control the contact pressure of the cleaning member 41 against the inkjet head 11 during the wiping process to be lower than when the ink ejection surface 12a is cleaned. Also, the rotation speed of the cleaning roller during the wiping process may be controlled to be lower. In this case, deterioration of the cleaning member 41 can be suppressed.

[0080] In the inkjet recording apparatus 1, a purge process for discharging the treatment liquid or ink may be performed before the wiping process, thereby making it possible to more effectively prevent clogging of the nozzles.

[0081] The invention made by the inventor has been specifically described above based on an embodiment, but the present invention is not limited to the above embodiment and can be modified within the scope of the gist thereof.

[0082] In the embodiment, the length of the cleaning member 41 in the main scanning direction is set to a length that makes it impossible to clean all of the inkjet heads 11 at once, but it may also be set to a length that makes it possible to clean all of the inkjet heads 11 at once, as shown in Figure 14. In this case as well, the ink ejection surface 12a and the treatment liquid ejection surface 13a can be cleaned by different wiping areas.

[0083] In the above embodiment, a cleaning roller is used as the cleaning member 41, but other configurations may be used for the cleaning member 41. For example, the cleaning member 41 may be a cleaning web made of nonwoven fabric or the like that slides against the ejection surface 11a to wipe off the liquid droplets L. In this case, it is preferable to replace the cleaning web (update the wiping area) before and after the wiping process. Also, for example, the cleaning member 41 may be a cleaning blade that is a plate-like member made of a rubber material that slides against the ejection surface 11a to scrape off the liquid droplets L.

[0084] Furthermore, in the cleaning member 41, areas (for example, grooves) that suppress spreading of wetting may be provided between the treatment liquid wiping areas 52-1, 52-2 and the ink wiping areas 51-1, 51-2.

[0085] In the above embodiment, the inkjet recording apparatus 1 is illustrated as being equipped with four ink ejection heads 12C, 12M, 12Y, and 12K, but the number of ink ejection heads 12 is not limited to four. The number of ink ejection heads 12 may be, for example, five or six. Furthermore, the inkjet recording apparatus 1 is not limited to an apparatus capable of forming color images, and may be, for example, a monochrome-only machine.

[0086] Furthermore, a non-aggregating treatment liquid that does not aggregate with pigment ink can be used in the inkjet head 11. The non-aggregating treatment liquid has functionality such as improved flexibility, improved friction resistance, and improved color density. In this case, the configuration for the cleaning process of the head for the non-aggregating treatment liquid (e.g., head arrangement in the inkjet head 1) can be treated in the same way as the ink ejection head 12, not the treatment liquid ejection head 13 in the above embodiment.

[0087] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0088] 1. Inkjet recording device 10 Image forming unit 11 Inkjet head 12 Ink ejection head 12a Ink ejection surface 13 Processing liquid ejection head 13a Processing liquid discharge surface 14 Carriage 20 Conveying section 30 Purge section 40 Cleaning Section 41 Cleaning material

Claims

1. an inkjet head having a plurality of ink ejection heads that eject ink and a treatment liquid ejection head that ejects a treatment liquid having an aggregating effect, and that forms an image on a recording material while scanning in a main scanning direction; a cleaning member that cleans the ink ejection surface of the ink ejection head and the treatment liquid ejection surface of the treatment liquid ejection head, an ink wiping area of ​​the cleaning member that cleans the ink ejection surface and a treatment liquid wiping area that cleans the treatment liquid ejection surface are different from each other; Inkjet recording device.

2. the treatment liquid ejection head is disposed next to the ink ejection head in the main scanning direction, the cleaning member cleans the ink ejection surface and the treatment liquid ejection surface while moving relative to the inkjet head in a sub-scanning direction perpendicular to the main scanning direction. The inkjet recording apparatus according to claim 1 .

3. a control unit for controlling the operation of the cleaning member; the control unit alternately executes a wiping process in which the cleaning member cleans the ink ejection surface and the treatment liquid ejection surface while moving the cleaning member in the sub-scanning direction relative to the inkjet head, and a cleaning position change process in which the cleaning member moves relatively to the inkjet head in the main scanning direction. The inkjet recording apparatus according to claim 2 .

4. the inkjet heads are a first head group that are cleaned by the cleaning member at a first position in the main scanning direction; a second head group that is cleaned by the cleaning member at a second position different from the first position; the first head group includes the treatment liquid ejection head and the ink ejection head, the second head group includes the ink ejection head, the control unit moves the inkjet heads in the cleaning position change process so that the ink wiping area when cleaning the second head group does not overlap with the treatment liquid wiping area when cleaning the first head group. The inkjet recording apparatus according to claim 3 .

5. the inkjet head can arrange the ink ejection head and the treatment liquid ejection head at equal intervals; In the second head group, the ink ejection heads are disposed at positions corresponding to the treatment liquid ejection heads of the first head group. The inkjet recording apparatus according to claim 4 .

6. the inkjet head can arrange the ink ejection head and the treatment liquid ejection head at equal intervals; In the second head group, positions corresponding to the treatment liquid ejection heads of the first head group are empty spaces or the treatment liquid ejection heads are disposed therein. The inkjet recording apparatus according to claim 4 .

7. the treatment liquid wiping area includes a first treatment liquid wiping area for cleaning the first head group, the ink wiping area includes a first ink wiping area for cleaning the first head group and a second ink wiping area for cleaning the second head group, a distance between the first treatment liquid wiping area and the second ink wiping area is greater than a distance between the first ink wiping area and the second ink wiping area; The inkjet recording apparatus according to claim 4 .

8. The cleaning member is composed of a roller. The inkjet recording apparatus according to claim 3 .

9. The cleaning member is composed of a blade. The inkjet recording apparatus according to claim 3 .

10. The cleaning member is made of a web. The inkjet recording apparatus according to claim 3 .

11. the control unit executes the wiping process during both forward movement and backward movement in the sub-scanning direction. The inkjet recording apparatus according to claim 3 .

12. when cleaning only the treatment liquid ejection surface, the control unit executes the wiping process during either one of the forward movement and the backward movement in the sub-scanning direction. The inkjet recording apparatus according to claim 3 .

13. the control unit controls the moving speed of the cleaning member in the wiping process to be higher when cleaning only the treatment liquid ejection surface than when cleaning the ink ejection surface. The inkjet recording apparatus according to claim 3 .

14. the control unit controls the contact pressure of the cleaning member against the inkjet head during the wiping process to be lower when cleaning only the treatment liquid ejection surface than when cleaning the ink ejection surface. The inkjet recording apparatus according to claim 3 .

15. the control unit controls the number of rotations of the roller in the wiping process to be lower when cleaning only the treatment liquid ejection surface than when cleaning the ink ejection surface. The inkjet recording apparatus according to claim 8.

16. The web is replaced before and after the wiping process. The inkjet recording apparatus according to claim 10.

17. the cleaning member has a region for suppressing wetting and spreading between the treatment liquid wiping region and the ink wiping region; The inkjet recording apparatus according to claim 1 .

18. performing a purging process to discharge the treatment liquid and the ink before cleaning; The inkjet recording apparatus according to claim 1 .

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