Liquid discharge device, liquid discharge system, liquid discharge method, and program

Abstract

To suppress deviation of a deterioration degree of a nozzle surface of a liquid discharge head.SOLUTION: A liquid discharge device 200 includes a plurality of liquid discharge heads 4 which have nozzle surfaces 41 and discharge a liquid, a wiping member 23 for wiping the nozzle surface 41, a driving part 15 for relatively moving the wiping member 23 with respect to the plurality of nozzle surfaces 41 of the plurality of liquid discharge heads 4, and a control part 500 for controlling a plurality of wiping operations by the wiping member 23, wherein the control part 500 controls first wiping operation of wiping the plurality of nozzle surfaces 41 in a first order, and second wiping operation of wiping the plurality of nozzle surfaces 41 in a second order different from the first order.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a liquid ejection apparatus, a liquid ejection system, a liquid ejection method, and a program. [Background technology]

[0002] A known liquid ejection device includes a plurality of liquid ejection heads that eject liquid from nozzles, a capping member that covers the nozzle faces of the liquid ejection heads, a suction pump that is connected to the capping member and sucks the nozzle faces, a wiping member that wipes the nozzle faces, and a drive mechanism that moves at least one of the liquid ejection heads and the wiping member relatively in a direction along the nozzle faces (see, for example, Patent Document 1). In the liquid ejection device described in Patent Document 1, maintenance is performed on the nozzle faces of the plurality of liquid ejection heads in sequence. Summary of the Invention [Problem to be solved by the invention]

[0003] In the liquid ejection device described in Patent Document 1, cleaning is performed on the same liquid ejection heads in sequence each time, which causes a problem that the deterioration of the nozzle surfaces of the liquid ejection heads is uneven.

[0004] An object of the present invention is to provide a liquid ejection device capable of suppressing uneven deterioration of the nozzle surface of a liquid ejection head. [Means for solving the problem]

[0005] A liquid ejection device according to one aspect of the present invention includes: A plurality of liquid ejection heads each having a nozzle surface and ejecting liquid; a wiping member that wipes the nozzle surfaces of the liquid ejection heads; a drive unit that moves the wiping member relatively to the nozzle faces; A control unit that controls a plurality of wiping operations by the wiping member, The control unit is configured to: a first wiping operation of wiping the plurality of nozzle surfaces in a first order; and a second wiping operation of wiping the plurality of nozzle faces in a second order different from the first order. Effect of the Invention

[0006] According to the present invention, it is possible to provide a liquid ejection apparatus capable of extending the life of the liquid ejection head. [Brief description of the drawings]

[0007] [Figure 1] 1 is a perspective view of a recording apparatus according to a first embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. 1 is a side view illustrating an example of a liquid ejection device according to a first embodiment of the present invention. [Figure 4] FIG. 2 is a plan view showing a main part of the liquid ejection device. [Diagram 5] FIG. 2 is a schematic diagram illustrating a discharge head of the liquid discharge device. [Figure 6] FIG. 2 is a bottom view showing a nozzle surface of the ejection head. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] 4 is a schematic diagram showing a supply tube connected to a head tank, a cap covering a nozzle surface, a suction tube connected to the cap, and a suction pump connected to the suction tube. FIG. [Figure 10] FIG. [Figure 11] FIG. 2 is a schematic diagram of a cap cam. [Figure 12] 2 is a side view showing a plurality of ejection heads and a cap mounted on a carriage. FIG. [Figure 13] 5 is a flowchart showing a procedure of a control process in a control unit. [Figure 14]13 is a flowchart showing the procedure of a wiping action order change process (Case 1). [Figure 15] 13 is a flowchart showing the procedure of a wiping action order change process (Case 2). [Figure 16] 1 is a block diagram showing an example of a hardware configuration of a liquid ejection device according to an embodiment of the present invention. [Figure 17] FIG. 2 is a functional block diagram of a control unit according to an embodiment of the present invention. [Figure 18] 4 is a flowchart showing a procedure of a liquid ejection method according to an embodiment of the present invention. [Figure 19] FIG. 11 is a plan view of a three-dimensional modeling apparatus according to a second embodiment of the present invention. [Figure 20] FIG. 5 is a cross-sectional view of a three-dimensional modeling apparatus according to a second embodiment of the present invention. [Figure 21] 10 is a cross-sectional view of a modeling unit of a three-dimensional modeling apparatus according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] First, a liquid ejection apparatus 200 according to a first embodiment of the present invention will be described. Fig. 3 is a side view showing an example of the liquid ejection apparatus 200 according to the first embodiment of the present invention. Fig. 4 is a plan view showing a main part of the liquid ejection device 200. Fig. 4 is a schematic view showing the ejection head 4 of the liquid ejection device 200.

[0009] [Outline of the liquid ejection device 200 according to the first embodiment] This liquid ejection device 200 is a serial type inkjet recording device, and a carriage 3 is held slidably in the main scanning direction by a main guide rod 1 and a sub guide rod, which are guide members that are horizontally mounted on the left and right side plates. A main scanning motor 15 moves and scans the carriage in the direction indicated by the arrow in FIG. 4 (the carriage main scanning direction X) via a timing belt 8.

[0010] [Discharge head 4] The carriage 3 is equipped with a plurality of liquid ejection heads 4a, 4b. Note that "liquid ejection head" may be abbreviated to "ejection head". In the following description, when there is no need to distinguish between the "ejection heads 4a, 4b", they will be referred to as "ejection head 4". The ejection head may also be referred to as a "recording head". The plurality of ejection heads 4 may be, for example, four ejection heads 4. In Figs. 4 and 6, ejection heads 4a and 4b out of the plurality of ejection heads 4 are shown.

[0011] FIG. 6 is a bottom view showing the nozzle surface 41 of the ejection head 4. As shown in FIG. 6, each of the ejection heads 4a and 4b has two nozzle rows Na and Nb in which a plurality of nozzles 4n are arranged. The nozzle rows Na and Nb are arranged in a staggered manner with the nozzles shifted in the nozzle arrangement direction. One nozzle row Na of the ejection head 4a ejects black (K) droplets, and the other nozzle row Nb ejects cyan (C) droplets. One nozzle row Na of the ejection head 4b ejects magenta (M) droplets, and the other nozzle row Nb ejects yellow (Y) droplets. Here, the two-head configuration ejects droplets of four colors, but the ejection head 4 may be provided for each color. The droplets are, for example, ink droplets or ultraviolet curable resin (ultraviolet curable ink) droplets, which are an example of liquid.

[0012] The ejection head 4 may be, for example, a piezoelectric actuator such as a piezoelectric element, or a thermal actuator that utilizes a phase change caused by film boiling of a liquid using an electrothermal conversion element such as a heating resistor.

[0013] [Head Tank 5] The carriage 3 is equipped with four head tanks 5a, 5b, 5c, and 5d that are provided corresponding to the two nozzle rows Na and Nb of each of the ejection heads 4a and 4b. In the following description, when there is no need to distinguish between the head tanks, they will be referred to as "head tanks 5." A cartridge holder 51 is disposed on the device body side, in which main tanks (liquid cartridges) 50 (50y, 50m, 50c, and 50k) that contain liquids of each color are replaceably mounted.

[0014] The cartridge holder 51 is provided with a liquid feed pump unit 52. A supply tube (also called a liquid supply path) 56 is connected to the liquid feed pump unit 52. The liquid feed pump unit 52 transfers the liquid in the ink cartridge 50 to each of the head tanks 5a, 5b, 5c, and 5d. The liquid of each color in the ink cartridge 50 flows through the supply tube 56 of each color and is supplied to the head tanks 5a, 5b, 5c, and 5d.

[0015] [Paper feed section] The liquid ejection device 200 includes a paper feed section for feeding the recording media P loaded on the recording medium loading section (pressure plate) 141 of the paper feed tray 102. The paper feed section has a crescent roller (paper feed roller) 143 that separates and feeds the recording media P one by one from the recording medium loading section 141. The paper feed section also has a separation pad 144 that faces the paper feed roller 143 and is made of a material with a large coefficient of friction. This separation pad 144 is biased towards the paper feed roller 143. The recording medium may be, for example, paper or something else. The recording medium is not limited to paper. Supplying the recording medium may be expressed as "paper feeding".

[0016] In the drawings of this embodiment, the recording medium is assumed to be paper or film, and is therefore described as a paper feed section, but the liquid ejection device 200 may be configured to include a movable recording medium stacking section, in which the recording medium is stacked on the recording medium stacking section and moved to the vicinity of the ejection head. Furthermore, the liquid ejection device may be a 3D printer that ejects liquid such as ink or ultraviolet curing resin onto a pedestal, base, or the surface of water. The liquid ejection device may eject liquid onto other objects instead of recording media.

[0017] [Recording medium transport path] The liquid ejection device 200 includes a recording medium transport path that transports the recording medium P. The recording medium transport path is a transport path that transports the recording medium P fed from a paper feed unit to below the ejection head 4. The recording medium transport path includes a guide member 145 that guides the recording medium P, a counter roller 146, a transport guide member 147, a tip pressure roller 149, and a pressing member 148. The liquid ejection device 200 may or may not include a recording medium transport path.

[0018] [Conveyor belt 12] The liquid ejection device 200 includes a conveyor belt (conveyor mechanism) 12 that electrostatically attracts the recording medium P and conveys it at a position facing the ejection head 4. The conveyor belt 12 is an endless belt that is stretched between a conveyor roller 13 and a tension roller 14 and rotates in a belt conveying direction (sub-scanning direction Y). As shown in FIG. 4, the conveyor belt 12 is driven by a sub-scanning motor 16. The driving force of the sub-scanning motor 16 is transmitted to the conveyor roller 13 via a timing belt 17. The conveyor roller 13 is driven to rotate, so that the conveyor belt 12 moves in a circular motion. The liquid ejection device 200 may or may not include the conveyor belt 12.

[0019] [Charging roller 156] The liquid ejection device 200 includes a charging roller (charging unit) 156 that charges the surface of the conveyor belt 12. The charging roller 156 is disposed so as to contact the surface layer of the conveyor belt 12 and rotate in accordance with the rotation of the conveyor belt 12. The liquid ejection device 200 may or may not include the charging roller 156.

[0020] [Paper output section] 3, the liquid ejection device 200 includes a paper ejection section for ejecting the recording medium P that has been recorded by the ejection head 4. The paper ejection section includes a separation claw 161 for separating the recording medium P from the conveyor belt 12, a paper ejection roller 162, and a paper ejection roller 163. A paper ejection tray 103 is disposed below the paper ejection roller 162. The liquid ejection device 200 may or may not include a paper ejection section.

[0021] [Double-sided unit 171] A double-sided unit 171 is detachably attached to the rear portion of the device body. This double-sided unit 171 takes in the recording medium P returned by the reverse rotation of the conveyor belt 12, inverts it, and feeds it again between the counter roller 146 and the conveyor belt 12. The upper surface of this double-sided unit 171 serves as a manual feed tray 172. The liquid ejection device 200 may or may not be equipped with the double-sided unit 171.

[0022] [Maintenance and Recovery Mechanism 20] As shown in Fig. 4, the liquid ejection device 200 includes a maintenance and recovery mechanism 20. As shown in Fig. 4, the maintenance and recovery mechanism 20 is disposed in a non-printing region on one side of the carriage 3 in the main scanning direction X. The maintenance and recovery mechanism 20 maintains and recovers the state of the nozzles Na, Nb of the ejection head 4. The maintenance and recovery mechanism 20 has a suction cap 21a, a moisture retention cap 21b, a wiper blade 23, and a first empty ejection receiver 24.

[0023] The suction cap 21a and the moisture cap 21b cap each nozzle surface 41 of the ejection head 4 to prevent evaporation of moisture from the ink inside the ejection head 4. When there is no need to distinguish between the suction cap 21a and the moisture cap 21b, they will be referred to as "cap 21".

[0024] The wiping member 23 is a wiping member for wiping the nozzle surface 41. The first discharge receiver 24 receives droplets when performing blank discharge in which droplets that do not contribute to recording are discharged in order to discharge thickened ink. Examples of the wiping member include a wiper blade made of an elastic material such as resin, a wiper blade made of a non-elastic material, and a web wipe made of a nonwoven fabric or absorbent material. The wiping member 23 is an example of a wiping member.

[0025] A suction pump 27, which is a suction unit, is connected to the suction cap 21a. The suction pump 27 sucks the nozzle surface 41 when the suction cap 21a is capping the nozzle surface 41 of the ejection head 4. The suction pump 27 removes thickened ink adhering to the wall surfaces of the nozzles and around the ejection openings of the nozzles. The suction cap 21a has both a moisturizing function to prevent evaporation of moisture from the ink inside the ejection head 4 and a suction function. The moisturizing cap 21b has only a moisturizing function.

[0026] [Discharge detection unit 100] As shown in FIG. 4, the liquid ejection device 200 includes an ejection detection unit 100. The ejection detection unit 100 is disposed outside the recording area between the conveyor belt 12 and the maintenance and recovery mechanism 20. The ejection detection unit 100 is disposed at a position that allows it to face the ejection head 4, and can detect the presence or absence of ejection of droplets (ejection state). The ejection detection unit 100 can detect whether droplets are being ejected from the nozzles. The ejection detection unit 100 has, for example, an electrode plate, and detects the presence or absence of ejection of droplets by detecting an electrical change that occurs when droplets land on the electrode plate. The ejection detection unit 100 has a light emitting section and a light receiving section, and may detect the presence or absence of ejection of droplets by laser light.

[0027] [Linear Encoder 124] The liquid ejection device 200 includes a linear encoder 124 (main scanning encoder). The linear encoder 124 has an encoder scale 124b and an encoder sensor 124a. The encoder scale 124b is disposed along the main scanning direction X of the carriage 3 between both side plates. The encoder sensor 124a is provided on the carriage 3. The encoder sensor 124a reads the pattern of the encoder scale 124b. The encoder sensor 124a may be, for example, a transmission type photosensor.

[0028] [Rotary Encoder 125] The liquid ejection device 200 includes a rotary encoder 125 (sub-scanning encoder). The rotary encoder 125 includes a code wheel 125b and an encoder sensor 125a. The code wheel 125b is provided on the shaft of the conveying roller 13. The encoder sensor 125a detects a pattern formed on the code wheel 125b. The encoder sensor 125a may be, for example, a transmissive photosensor.

[0029] [Second discharge receiver 81] The liquid ejection device 200 includes a second ejection receiver 81. The second ejection receiver 81 is disposed in a non-printing region on the other side of the carriage 3 in the main scanning direction X. The second ejection receiver 81 receives droplets ejected when performing blank ejection, which ejects droplets that do not contribute to recording in order to expel ink that has thickened during recording, etc. An opening is formed in the second blank ejection receiver 81 along the nozzle row direction of the ejection head 4. The nozzle row direction is along the sub-scanning direction Y.

[0030] [Feeding and transport of recording medium P] The liquid ejection device 200 separates the recording media P one by one from the paper feed tray 102 and feeds them to a guide member 245. The guide member 245 is provided, for example, approximately directly above the paper feed tray 102. The guide member 245 guides the recording media P. The recording media P is conveyed while being sandwiched between the conveyor belt 12 and a counter roller 146. The above configuration is sufficient when a thin material such as paper or film is used as the recording medium, but in the case of a thick recording medium such as cloth or plastic, the liquid ejection device 200 may include a movable recording medium stacking unit, and the recording media may be stacked on the recording medium stacking unit and the recording medium stacking unit may be moved near the ejection head.

[0031] The leading end of the recording medium P is guided by the conveying guide 137 and pressed against the conveying belt 12 by the leading end pressure roller 149, and the conveying direction of the recording medium P is changed by approximately 90 degrees. At this time, the liquid ejection device 200 applies an alternating voltage to the charging roller 156 so that positive and negative outputs are alternately repeated. In this case, the conveying belt 12 is charged with an alternating charging voltage pattern, that is, the conveying belt 12 is charged with alternating positive and negative voltages in a band shape of a predetermined width in the sub-scanning direction, which is the rotation direction.

[0032] When the recording medium P is fed onto this alternately positively and negatively charged conveyor belt 12, the recording medium P is attracted to the conveyor belt 12, and the recording medium P is conveyed in the sub-scanning direction by the circular movement of the conveyor belt 12. In the liquid ejection device 200, the recording medium P is electrostatically attracted to the conveyor belt 12, but the recording medium P may also be attracted to the conveyor belt 12 by attracting it to the conveyor belt 12 using a suction means.

[0033] [Home position when in standby] When the liquid ejection device 200 is on standby, the carriage 3 shown in Fig. 4 is located on the maintenance and recovery mechanism 20. This position is called the "home position." When the carriage 3 is in the home position, the suction cap 21a abuts against the nozzle surface 41 of the ejection head 4a, and the moisture cap 21b abuts against the nozzle surface 41 of the ejection head 4b. The nozzles of the nozzle surface 41 covered by the suction cap 21a or the moisture cap 21b are in a sealed state, and the inside of the ejection head 4 is kept moist.

[0034] [Maintenance operation at home position] The control unit 500 controls the maintenance operation at the home position. When an image signal is input, the control unit 500 drives and rotates the maintenance recovery motor 17 (see FIG. 17) of the maintenance recovery mechanism 20 to lower the caps 21a, 21b. The control unit 500 also drives the main scanning motor 15 to start moving the carriage 3 in the main scanning direction X. The control unit 500 stops the movement of the carriage 3 every time each of the ejection heads 4a, 4b is positioned at the first blank ejection receiver 24, and ejects several drops of ink toward the first blank ejection receiver 24.

[0035] [Liquid ejection operation by ejection head 4] When the idle ejection of each ejection head 4a, 4b is completed, the control unit 500 starts moving the carriage 3 in the main scanning direction X again. Then, as described above, the control unit 500 controls the movement of the carriage 3. The carriage 3 ejects a predetermined ink onto a predetermined location on the stationary recording medium P while moving over the recording medium P in the main scanning direction X in response to an image signal. The control unit 500 controls the liquid ejection operation by the ejection head 4. The ejection head 4 forms an image on the recording medium P within the range in the sub-scanning direction Y that the ejection head 4 can record on the recording medium P.

[0036] [Dry discharge] After forming an image for a predetermined range in the sub-scanning direction Y, the control unit 500 moves the carriage 3 to the position of the second blank discharge receiver 81 and blank discharges several droplets into the second blank discharge receiver 81 as necessary.

[0037] [Liquid ejection operation by ejection head 4] The control unit 500 drives the conveyor belt 12 for a predetermined time to convey the recording medium P. The control unit 500 moves the recording medium P in the discharge direction a predetermined range in the sub-scanning direction Y and stops the recording medium P. After stopping the movement of the conveyor belt 12, the control unit 500 forms one line of an image on the recording medium P while moving the carriage 3 in the main scanning direction X over the recording medium P in accordance with an image signal, as described above. The liquid ejection device 200 repeats this process a predetermined number of times to print the desired image on the recording medium P.

[0038] [Transport of recording medium P] In the liquid ejection device 200, when an image is formed on the recording medium P by repeatedly conveying and stopping the recording medium P, the recording medium P is electrostatically attracted to the conveyor belt 12, so that the recording medium P can be stably conveyed to a position facing the ejection head 4. After forming a desired image, when the control unit 500 receives an image data end signal or a signal indicating that the rear end of the recording medium P has reached the recording area, it ends the image formation and ejects the recording medium P to the paper ejection tray 103.

[0039] [Moisturizing operation after image formation] After the image formation is completed, the control unit 500 moves the carriage 3 back to the home position on the maintenance and recovery mechanism 20. The control unit 500 raises the caps 21a and 21b to moisten the nozzles of the ejection heads 4a and 4b.

[0040] [Cleaning mode] The liquid ejection device 200 can execute a cleaning mode. The operation unit of the liquid ejection device 200 is provided with a selection button (selection unit) that can select the cleaning mode. When a user sees an image formed on a recording medium P and recognizes that the image has deteriorated, the user can operate the selection button to select the cleaning mode. The liquid ejection device 200 may also count the number of recording media P on which images have been formed, and execute the cleaning mode based on the number of recording media P on which images have been formed.

[0041] [Suction operation] In the cleaning mode, the liquid ejection device 200 can perform a suction operation. When performing the cleaning mode, the control unit 500 can move the carriage 3 to position the ejection head 4 on the suction cap 21a. The control unit 500 raises the suction cap 21a to bring the suction cap 21a into contact with the nozzle surface. The control unit 500 can drive the suction pump 27 to suck and remove air bubbles in the nozzles and foreign matter (e.g., dust) attached to the nozzles. By suctioning with the suction pump 27, some of the ink in the nozzles is also sucked up.

[0042] [Wiping] In the cleaning mode, the liquid ejection device 200 can perform wiping. After the suction operation is completed, the control unit 500 lowers the suction cap 21a and simultaneously raises the wiper blade 23. The control unit 500 moves the carriage 3 when the tip of the wiper blade 23 comes into contact with the nozzle face 41. This movement of the carriage 3 causes the wiper blade 23 to rub against the nozzle face 41 and remove droplets adhering to the nozzle face 41. After removing the droplets from the ejection head 4a, the wiper blade 23 is lowered. The maintenance and recovery mechanism 20 includes a motor for raising and lowering the wiper blade 23.

[0043] [Dry discharge operation] The liquid ejection device 200 can execute an idle ejection operation in the cleaning mode. When the wiper blade 23 descends, the control unit 500 moves the carriage 3 to position the ejection head 4a above the first idle ejection receiver 24. After placing the ejection head 4a above the first idle ejection receiver 24, the control unit 500 performs idle ejection. The control unit 500 ejects liquid that does not contribute to image formation from the nozzles. The first idle ejection receiver 83 receives droplets ejected by the idle ejection.

[0044] The control unit 500 also executes a series of cleaning modes for the ejection head 4b in the same manner as for the ejection head 4a. By executing such cleaning modes, the liquid ejection device 200 can suppress ejection defects in the ejection head 4 and can remove droplets attached to the nozzle surface 41.

[0045] [Head Tank 5] Next, the head tank 5 will be described. The liquid ejection device 200 is equipped with the head tank 5. Fig. 7 is a plan view of the head tank 5, and Fig. 8 is a front view of the head tank 5. The head tank 5 has a tank case 201 including an ink containing section 202. An opening is formed in the ink containing section 202 of the tank case 201. The opening is sealed by a flexible film 203. A spring 204 is disposed within the tank case 201 as an elastic member. The film 203 is constantly urged outward by the restoring force of the spring 204.

[0046] Further, a displacement member 205 is provided on the outside of the ink containing section 202. The displacement member 205 has a filler supported rotatably around a support shaft 206. One end of the filler is supported by the support shaft 206. The displacement member 205 may be simply referred to as a "filler". The displacement member 205 is biased toward the ink containing section 202 by a spring 210, and is fixed to the film 203 by adhesion or the like. The displacement member 205 is displaced in conjunction with the movement of the film 203.

[0047] Furthermore, a supply port 209 for supplying ink from the ink cartridge 50 is formed at the top of the tank case 201. An ink supply tube 56 is connected to this supply port 209. Furthermore, an atmosphere opening mechanism 207 for opening the inside of the head tank 5 to the atmosphere is provided at a side of the tank case 201 perpendicular to the nozzle arrangement direction. This atmosphere opening mechanism 207 includes a valve body 207b for opening and closing an atmosphere opening path 207a communicating with the inside of the head tank 5, and a spring 207c for biasing this valve body 207b to a closed state.

[0048] [Detection of liquid level inside head tank 5] An atmosphere release solenoid 302 is disposed on the device body side of the liquid ejection device 200. The valve is opened by an operating member 303 of this atmosphere release solenoid pushing a valve body 207b against the biasing force of a spring 207c, and the inside of the head tank 5 becomes in an atmosphere open state (a state in which the inside of the head tank 5 is connected to the atmosphere).

[0049] A pair of electrode pins 208a, 208b are attached inside the head tank 5. The pair of electrode pins 208a, 208b can detect the liquid level of the liquid in the head tank 5. Ink, which is a liquid, is conductive. When ink is stored up to the height at which the electrode pins 208a, 208b are attached, a current flows between the pair of electrode pins 208a, 208b. The liquid ejection device 200 may detect a change in the resistance value between the pair of electrode pins 208a, 208b. The liquid ejection device 200 may detect that the amount of air in the head tank 5 has reached a predetermined amount or more when the liquid level in the head tank 5 falls below a predetermined height.

[0050] [Liquid transfer to head tank 5 and reverse transfer] 9 is a schematic diagram showing a supply tube 56 connected to the head tank 5, the cap 21 covering the nozzle surface 41, the suction tube 26 connected to the cap 21, and a suction pump 27 connected to the suction tube 26. The liquid ejection device 200 has a liquid supply path that supplies liquid from the ink cartridge 50 to the head tank 5. The liquid supply path includes a liquid feed pump 54 and a supply tube 56.

[0051] The liquid feed pump 54 (liquid feed unit) may be a reversible pump (reversible liquid feed unit) constituted by a tube pump or the like. The control unit 500 can drive the liquid feed pump 54 to supply liquid from the ink cartridge 50 to the head tank 5. The liquid flows through a supply tube 56 and is transferred from the ink cartridge 50 to the head tank 5. The liquid feed pump 54 can perform a liquid feed operation for supplying liquid from the ink cartridge 50 to the head tank 5, and a reverse feed operation for returning liquid from the head tank 5 to the ink cartridge 50.

[0052] [Suction pump 27 performs suction] A suction pump 27 is connected to the cap 21a that caps the nozzle surface 41 of the ejection head 4. The liquid ejection device 200 includes a suction tube 26 that connects the cap 21a and the suction pump 27. The control unit 500 can suck liquid from the nozzles of the ejection head 4 by driving the suction pump 27 with the nozzle surface 41 capped with the cap 21a. The liquid sucked from the nozzles of the ejection head 4 flows through the suction tube 26 and is discharged into the waste liquid tank 28. The control unit 500 may discharge the liquid in the head tank 5 into the waste liquid tank 28 by sucking the liquid from the ejection head 4. The liquid sucked from the ejection head 4 and discharged into the waste liquid tank 28 may be referred to as waste liquid.

[0053] [Fila Sensor 301] The liquid ejection device 200 includes a feeler sensor 301 that detects the displacement member 205. The feeler sensor 301 is disposed on the device body side, for example. The control unit 500 can control, for example, the liquid supply operation to the head tank 5 based on the detection result by the feeler sensor 301.

[0054] The control unit 500 can control the driving of the liquid feed pump 54, the atmosphere release solenoid 302, and the suction pump 27 described above.

[0055] [Liquid supply operation] Next, an example of the liquid supply operation will be described. The liquid supply operation is, for example, an operation of supplying ink to the head tank 5. Usually, the inside of the head tank 5 is under negative pressure. When performing the liquid supply operation, the control unit 500 drives the atmosphere release solenoid 302 to open the inside of the head tank to the atmosphere. This causes the film 203 to be displaced outward, and the ink liquid level drops. In addition, the outward displacement of the film 203 causes the displacement member to be displaced, and the feeler sensor 301 no longer detects the displacement member 205.

[0056] Next, the control unit 500 drives the liquid feed pump 54 to perform a liquid feed operation and feeds liquid from the ink cartridge 50 to the head tank 5. This causes the liquid level in the head tank 5 to rise. After detecting the liquid level using the electrode pins 208a and 208b, the control unit 500 stops the liquid feed by the liquid feed pump 54. After stopping the liquid feed pump 54, the control unit 500 closes the atmosphere release mechanism 207.

[0057] [Negative pressure created in head tank 5 by reverse feed] Next, the control unit 500 drives the liquid feed pump 54 to perform a reverse feed operation, returning the liquid from the head tank 5 to the ink cartridge 50. As a result, the film 203 moves inward, creating a negative pressure in the head tank 5. As the film 203 moves inward, the displacement member 205 moves to the feeler sensor 301, and the displacement member 205 is detected by the feeler sensor 301. After the displacement member 205 is detected by the feeler sensor 301, the control unit 500 stops the reverse feed operation by the liquid feed pump 54. This allows the control unit 500 to create a predetermined negative pressure in the head tank 5. Note that, in discharging the liquid to create a negative pressure in the head tank 5, the height of the liquid level hardly changes, so the state in which the liquid level is detected by the electrode pins 208a and 208b is maintained.

[0058] It is also possible to configure the structure so that when the displacement member 205 is displaced outward together with the film 203, the feeler sensor 301 detects the displacement member, and when the displacement member 205 is displaced inward together with the film 203, the feeler sensor 301 cannot detect the displacement member 205.

[0059] [Cap movement mechanism] Next, an example of the cap moving mechanism will be described. Fig. 10 is a side view showing the cap moving mechanism. The liquid ejection device 200 includes a cap moving mechanism. The cap moving mechanism can move the cap 21 to a sealed position where the cap 21 contacts the ejection head 4, and can also move the cap 21 to a retracted position where the cap 21 is retracted from the ejection head 4.

[0060] [Cap Holder 112A] The cap moving mechanism includes a cap holder 112A. The cap holder 112A has a holder 151 which is a holding member that holds the cap 21 so that it can be raised and lowered, and two springs 152 which are biasing means that are interposed between the bottom surface of the holder 151 and the bottom of the cap 21 and bias the vicinity of both ends of the cap 21 in the sub-scanning direction (the direction in which the nozzles of the ejection head 4 are arranged) upward.

[0061] The cap moving mechanism also has a slider 153 that holds the holder 151 and is supported by the frame 111 so as to be vertically movable. Guide pins 150a are provided on both ends of the cap 21. These guide pins 150a are inserted into guide grooves of the holder 151 so as to be vertically movable.

[0062] Furthermore, a guide shaft 150b is provided at the center of the bottom surface of the cap 21. The guide shaft 150b is inserted into the holder 151 so as to be vertically movable. As a result, the cap 21 is attached to the holder 151 so as to be vertically movable.

[0063] The slider 153 is provided with two guide pins 154, 155 at each end (left and right ends in the figure) in the sub-scanning direction Y. These guide pins 154, 155 are slidably fitted into guide grooves formed in the frame 111 and extending in the vertical direction.

[0064] [CAPCAM 122A] A cam pin 157 is provided at approximately the center of the lower surface of the slider 153. FIG. 11 is a schematic diagram of the cap cam. As shown in FIG. 11, this cam pin 157 fits into a cam groove 122a of a cap cam 122A. The cap cam 122A is fixed to a cam shaft 121. The cam shaft 121 is connected to a rotating shaft of a maintenance recovery motor 17. The control unit 500 can drive the maintenance recovery motor 17 to rotate the cam shaft 121.

[0065] [Move cap 21 up or down] The control unit 500 rotates the cam shaft 121 to rotate the cap cam 122A, and the rotation of the cap cam 122A can move the slider 153 up and down. As the slider 153 moves up and down, the holder 151 held by the slider 153 and the cap 21 held by the holder 151 move in the up and down direction. As the cap 21 moves in the up and down direction, the cap 21 approaches the nozzle surface 41 or moves away from the nozzle surface 41. An elastic member 84 made of rubber or the like is provided on the upper end of the cap 21.

[0066] [Damage to nozzle surface 41 due to head cleaning] When wiping is performed, the nozzle surface 41 of the ejection head 4 that is wiped first is wiped with a wiper that is not wet. By wiping, liquid adheres to the wiper. The nozzle surfaces 41 of the ejection heads 4 that are wiped second to fourth are wiped with the wiper that has liquid adhered thereto.

[0067] Due to differences in the degree of wetness of the wiper, the nozzle surface of the first ejection head 4 is more likely to be scraped off, while the nozzle surfaces of the second to fourth ejection heads 4 tend to have more liquid remaining. In this way, the amount of damage that accumulates on the nozzle surface differs depending on the order of head cleaning.

[0068] When the head cleaning order is fixed, the nozzle surface 41 of the first ejection head 4 is Damage is concentrated, shortening the lifespan of the carriage 3. This leads to a shorter cycle for carriage replacement, which in turn leads to increased costs associated with carriage 3 replacement and downtime for the liquid ejection device 200, resulting in cost losses.

[0069] [Head cleaning order] Next, the order in which head cleaning is performed will be described with reference to Fig. 12. The multiple ejection heads 4 include, for example, four ejection heads 4K, 4C, 4M, and 4Y. The ejection heads 4K, 4C, 4M, and 4Y each have a nozzle surface 41. As described above, multiple nozzles are formed on the nozzle surface 41. Head cleaning includes a suction operation and a wiping operation.

[0070] The number of the multiple ejection heads 4 is not limited to four. The number of the multiple ejection heads 4 may be two, three, or five or more. The number of nozzle surfaces 41 formed on the ejection head 4 may be one, or two or more.

[0071] The multiple ejection heads 4 are arranged in order in the first direction, for example. For example, the multiple ejection heads 4K, 4C, 4M, and 4Y are arranged in this order in the first direction. The multiple ejection heads 4 may be described as ejection heads 4A, 4B, 4C, and 4D. The multiple ejection heads 4A, 4B, 4C, and 4D are arbitrary ejection heads 4. The ejection head 4A may be the first ejection head, the ejection head 4B may be the second ejection head, the ejection head 4C may be the third ejection head, and the ejection head 4D may be the fourth ejection head. For example, the control unit 500 may perform head cleaning in the order in which the multiple ejection heads 4 are arranged in the head cleaning. The control unit 500 may perform head cleaning in an order different from the order in which the multiple ejection heads 4 are arranged in the head cleaning.

[0072] [Suction operation sequence] For example, in a first suction operation, the control unit 500 may execute the suction operation in the order of discharge head 4A → discharge head 4B → discharge head 4C → discharge head 4D. In a second suction operation, the control unit 500 may execute the suction operation in the order of discharge head 4B → discharge head 4C → discharge head 4D → discharge head 4A.

[0073] [Wipping Order] The control unit 500 can change the order in which wiping is performed on the ejection heads 4. The control unit 500 can execute a first wiping (first wiping operation) for wiping the nozzle surfaces 41 of the multiple ejection heads 4 in a first order, and a second wiping (second wiping operation) for wiping the nozzle surfaces 41 of the multiple ejection heads 4 in a second order different from the first order.

[0074] For example, in the first wiping, the control unit 500 may perform wiping in the order of ejection head 4A → ejection head 4B → ejection head 4C → ejection head 4D. In the second wiping, the control unit 500 may perform wiping in the order of ejection head 4B → ejection head 4C → ejection head 4D → ejection head 4A. The control unit 500 controls the main scanning motor 15 and the maintenance recovery motor 17 to move the carriage 3 and raise and lower the wiper blade 23, thereby wiping the nozzle surface 41 of the ejection head 4 in any order.

[0075] <Hardware Configuration of Liquid Ejection Apparatus 200> Next, a hardware configuration of the liquid ejection device 200 will be described with reference to Fig. 16. Fig. 16 is a block diagram showing an example of a hardware configuration of the liquid ejection device 200 according to an embodiment of the present invention. The liquid ejection device 200 includes a control device 510 having a control unit 500.

[0076] A printer driver 515 is connected to the control unit 500. The printer driver 515 generates print data. The printer driver 515 may generate the print data in a host device such as an information processing terminal such as a PC (Personal Computer), an image reading device such as an image scanner, or an imaging device such as a digital camera. The printer driver 515 generates dot pattern data for outputting an image in the liquid ejection device 200.

[0077] [Control unit 500] The control unit 500 has a CPU (Center Processing Unit) 501, a ROM (Read Only Memory) 502, a RAM (Random Access Memory) 503, and an NVRAM (Non Volatile Random Access Memory) 504.

[0078] The CPU 501 is a calculation unit and controls the overall operation of the liquid ejection device 200. The CPU 501 controls the transport operation of the recording medium P and the liquid ejection operation by the ejection head 4. The ROM 502 is a read-only non-volatile storage medium. The ROM 502 stores programs such as firmware. The RAM 503 is a volatile storage medium that can read and write information at high speed. The RAM 503 is used as a working area when the CPU 501 processes information.

[0079] The NVRAM 504 is a non-volatile storage medium that can read and write information, and stores an OS (Operating System), various control programs, application programs, and the like.

[0080] A software control unit is configured by reading out a program stored in the storage unit 570 into the RAM 503, and the CPU 501 performing calculations in accordance with the program loaded into the RAM 503. The storage unit 570 includes a ROM 502 and an NVRAM 504. The storage unit 570 may include a storage medium such as an optical disk.

[0081] A combination of hardware and software control units constitutes a functional block that realizes the functions of the liquid ejection device 200. The CPU 501 and RAM 503 function as various control units as shown in Fig. 17. The various control units will be described later.

[0082] [Operation Panel 516] The liquid ejection device 200 includes an operation panel 516. The operation panel 516 is connected to the control unit 500. The operation panel 516 is an input unit that allows a user to operate and input information. The operation panel 516 may be, for example, a liquid crystal panel. The user can operate the operation panel 516 to change the settings of printing conditions. The user can also operate the operation panel 516 to change the settings of various conditions. The user can operate the operation panel 516 to change the settings of a head cleaning operation. Information input via the operation panel 516 is transmitted to the control unit 500. The operation panel 516 may be a display unit and an input unit of a terminal (PC) connected to the control unit 500.

[0083] [Sensor 60] The liquid ejection device 200 includes a sensor 60. The sensor 60 may be a camera that captures an image of the nozzle surface 41 of the ejection head 4. The sensor 60 may be a sensor group including a plurality of types of sensors.

[0084] [Head control unit 521] The control unit 500 includes a head control unit 521 that controls the driving of the ejection head 4. The head control unit 521 can control the operation of a head driver 11 for driving the ejection head 4. The head driver 11 is mounted on the carriage 3 and is electrically connected to the ejection head 4. The head driver 11 is also called a driver IC. The head control unit 521 can control the drive elements of the ejection head 4 to eject liquid. The head control unit 521 can execute various controls related to the ejection head 4.

[0085] The head control unit 521 includes a drive signal generation unit that generates a drive signal for controlling the drive of the ejection head 4, and a data transfer unit that transfers the drive signal to the head driver 11.

[0086] The control unit 500 transfers the processed image data from the head control unit 521 to the head driver 11 .

[0087] The head control unit 521 can transfer the above-mentioned image data as serial data. The head control unit 521 may transfer a transfer clock signal required for transferring image data and confirming the transfer to the head driver 11. The head control unit 521 can output latch signals and control signals for controlling the ejection of liquid to the head driver 11.

[0088] The drive signal generation unit of the head control unit 521 includes a D / A converter, a voltage amplifier, and a current amplifier. The D / A converter can D / A convert pattern data of drive pulses stored in, for example, the ROM 502. The drive pulses are included in the drive signal. The voltage amplifier can amplify, for example, a voltage based on the drive pulse. The current amplifier may amplify a current based on the drive pulse. The drive signal generation unit outputs a drive signal consisting of one drive pulse or multiple drive pulses to the head driver 11.

[0089] The head driver 11 supplies a voltage based on the drive pulse to the piezoelectric element to eject liquid from the ejection head 4. The head control unit 521 can eject dots of different sizes, such as large droplets, medium droplets, and small droplets, by selecting the drive pulse.

[0090] [Motor drive unit 522] The liquid ejection device 200 includes a main scanning motor 15, a sub-scanning motor 16, and a maintenance and recovery motor 17. The control unit 500 includes a motor drive unit 522. The motor drive unit 522 controls the drive of the main scanning motor 15, the sub-scanning motor 16, and the maintenance and recovery motor 17. The motor drive unit 522 controls the drive of the main scanning motor 15, the sub-scanning motor 16, and the maintenance and recovery motor 17 in accordance with instructions from the CPU 501.

[0091] The main scanning motor 15 is a motor for driving the carriage 3. The sub-scanning motor 16 is a motor for circulating the conveyor belt 12. The maintenance recovery motor 17 is a motor for driving the maintenance recovery mechanism 20. The maintenance recovery motor 17 includes a motor for raising and lowering the cap 21. The maintenance recovery motor 17 includes a motor for raising and lowering the wiper blade 23.

[0092] The main scanning motor 15 and the maintenance and recovery motor 17 are an example of a drive unit that moves the wiping member relatively to the multiple nozzle faces. Relative movement includes, for example, a case where only the carriage 3 is moved, a case where only the wiper blade 23 is moved, and a case where both the carriage 3 and the wiper blade 23 are moved.

[0093] [Pump drive unit 523] The liquid ejection device 200 includes a suction pump 27 and a liquid feed pump 54. The control unit 500 includes a pump drive unit 523. The pump drive unit 523 controls the drive of the suction pump 27 and the liquid feed pump 54. The pump drive unit 523 controls the drive of the suction pump 27 and the liquid feed pump 54 in accordance with instructions from the CPU 501. [Function configuration]

[0094] Next, the functional configuration of the control unit 500 will be described with reference to Fig. 17. Fig. 17 is a functional block diagram of the control unit 500 according to an embodiment of the present invention. The CPU 501 shown in Fig. 17 executes a program stored in a storage unit such as a ROM 502 to realize the functions of a system control unit 531, a memory control unit 532, a communication control unit 533, a discharge control unit 534, a transport control unit 535, a maintenance control unit 540, a head order setting unit 541, a head order changing unit 542, and a storage unit 570 shown in Fig. 17. Note that external devices and sensors connected to the control unit 500 may execute some of these functions.

[0095] The system control unit 531 controls the overall operation of the liquid ejection device 200. The memory control unit 532 controls the operation of memories such as the ROM 502, the RAM 503, and the NVRAM 504. The communication control unit 533 controls communication with external devices connected to the control device 510.

[0096] The ejection control unit 534 controls the ejection of liquid by the ejection head 4. It controls the operation of the liquid supply unit and the ejection head 4. The transport control unit 535 controls the transport of the recording medium P by the transport unit. The transport unit includes rollers for transporting the recording medium P and a motor for driving the rollers.

[0097] The maintenance control unit 540 controls the maintenance operation of the ejection head 4. The maintenance operation includes a cleaning operation for the ejection head 4.

[0098] The head order setting unit 541 sets the order of the multiple ejection heads 4 in which the cleaning operation is performed. The head order setting unit 541 may set the order of the ejection heads 4 by referring to a table stored in the storage unit 570. The "order of the ejection heads 4" is the order in which the cleaning operation is performed.

[0099] The head order change unit 542 changes the order of the multiple ejection heads 4 in which the cleaning operation is performed. The head order change unit 542 can change the preset order of the ejection heads 4. The head order change unit 542 may change the order of the ejection heads 4 every time a cleaning operation is performed, or may change the order of the ejection heads 4 after multiple cleaning operations are performed.

[0100] The head order change unit 542 may change the order of the ejection heads 4 based on various information. The head order change unit 542 may change the order of the ejection heads 4 by detecting, for example, the dirt state of the nozzle surface 41. The head order change unit 542 may change the order of the ejection heads 4 by detecting, for example, the degree of damage to the nozzle surface 41. The head order change unit 542 may change the order of the ejection heads 4 according to, for example, the amount of liquid consumed. For example, the control unit 500 may detect the dirt state of the nozzle surface 41 based on information output from a camera (sensor 60) that captures an image of the nozzle surface 41. The control unit 500 may detect the degree of damage to the nozzle surface 41 based on information output from the sensor 60. The control unit 500 may detect the amount of liquid consumed based on information output from a liquid level sensor (sensor 60) that detects the liquid level inside the head tank 5.

[0101] [Storage section 570] The storage unit 570 stores various types of information. The storage unit 570 stores various types of information related to the cleaning operation. The storage unit 570 stores information related to the order of the ejection heads 4 for which the cleaning operation is executed.

[0102] [Control process procedure by control unit 500] Next, the procedure of the control process in the control unit 500 will be described with reference to Fig. 13. Fig. 13 is a flowchart showing the procedure of the control process in the control unit 500. As shown in Fig. 13, the control unit 500 determines whether or not a wiping activation condition is satisfied (step S11). The wiping activation condition may be a cleaning activation condition.

[0103] Examples of wiping activation conditions include the number of prints, the number of prints on the recording medium P, the amount of liquid consumed, the operating time of the liquid ejection device 200, and detection of a selection operation by the user. If the wiping activation condition is satisfied (step S11; YES), the control unit 500 proceeds to step SS12. If the wiping activation condition is not satisfied (step S11; NO), the control unit 500 waits for the wiping activation condition to be satisfied and then proceeds to step S12.

[0104] In step S12, the control unit 500 performs a wiping operation. The control unit 500 moves the carriage 3 to perform the wiping operation. For example, the wiping operation is performed on the ejection heads 4A, 4B, 4C, and 4D in this order. After the wiping operation is performed, the control unit 500 proceeds to step S13.

[0105] In step S13, the control unit 500 changes the wiping order. In step S13, the control unit 500 changes the order in which the wiping operations are performed.

[0106] [Wipe order change process (case 1)] Fig. 14 is a flowchart showing the procedure of the wiping operation order change process. The process shown in Fig. 14 may be executed in step S13 of Fig. 13. The control unit 500 executes the wiping operation order change process (step S21). Here, the ejection head 4 that performs the wiping operation first is changed. Note that the first (first surface) may be written as "order Nx=1".

[0107] The control unit 500 can change the order of the discharge heads 4 in which the wiping operation is performed, for example, in the following combinations. In the first wiping operation, the order is discharge head 4A → discharge head 4B → discharge head 4C → discharge head 4D. In the second wiping operation, the order is discharge head 4B → discharge head 4A → discharge head 4C → discharge head 4D. In the third cleaning operation, the order is discharge head 4C → discharge head 4B → discharge head 4A → discharge head 4D. In the fourth wiping operation, the order is discharge head 4D → discharge head 4B → discharge head 4C → discharge head 4A. In the fifth wiping operation, the order is discharge head 4B → discharge head 4C → discharge head 4D → discharge head 4A. The control unit 500 can perform the wiping operation of the discharge heads 4 in other orders.

[0108] In the first wiping operation, the first ejection head 4 is ejection head 4A, in the second cleaning operation, the first ejection head 4 is ejection head 4B, in the third wiping operation, the first ejection head 4 is ejection head 4C, in the fourth wiping operation, the first ejection head 4 is ejection head 4D, and in the fifth wiping operation, the first ejection head 4 is ejection head 4B.

[0109] In step S13 shown in FIG. 13, the control unit 500 can change the order of the wiping operations determined in step S21.

[0110] [Wipe order change process (case 2)] Fig. 15 is a flowchart showing the procedure of the process of changing the order of the wiping operations. The process shown in Fig. 15 may be executed in step S13 in Fig. 13. The control unit 500 executes the process of changing the order of the wiping operations (steps S31 and S32).

[0111] In step S31, the control unit 500 changes the order of the ejection heads 4 so that the order Nx=Nx+1. For example, the identification numbers of the ejection heads 4A, 4B, 4C, and 4D are head 1, head 2, head 3, and head 4. In the order of the first wiping operation, head 1 is the first (Nx=1), head 2 is the second (Nx=2), head 3 is the third (Nx=3), and head 4 is the fourth (Nx=4). In this case, the control unit 500 sets head 1 to the second (Nx=2), head 2 to the third (Nx=3), head 3 to the fourth (Nx=4), and head 4 to the fifth (Nx=5) in the order of the second cleaning operation.

[0112] In step S32, the control unit 500 sets the order of the ejection heads 4 so that the ejection head 4 with Nx>4 becomes Nx-4. For example, the control unit 500 sets the head 4 set to the fifth place (Nx=5, Nx>4) in step S31 to the first place (Nx=1, Nx=5-4). As a result, in the second wiping operation, head 1 is set to the second place, head 2 to the third place, head 3 to the fourth place, and head 4 to the first place.

[0113] In the third wiping operation, the control unit 500 can set head 1 to the third, head 2 to the fourth, head 3 to the first, and head 4 to the second. In the (N+1)th wiping operation (N is a natural number), the control unit 500 can set the ejection head 4 that was set to the xth position in the Nth wiping operation to the x+1th position in the next (N+1)th wiping operation.

[0114] [CL order change process (case 3)] For example, in the first wiping operation, the control unit 500 sets head 1 to be the first (Nx=1), head 2 to be the second (Nx=2), head 3 to be the third (Nx=3), and head 4 to be the fourth (Nx=4).

[0115] In this case, in step S31, the control unit 500 sets head 1 to third (Nx=1+2), head 2 to fourth (Nx=2+2), head 3 to fifth (Nx=3+2), and head 4 to sixth (Nx=4+2) in the order of the second wiping operation.

[0116] In step S32, the control unit 500 sets head 3, which was set to fifth (Nx=5, Nx>4) in step S31, to first (Nx=1, Nx=5-4). Also, the control unit 500 sets head 4, which was set to sixth (Nx=5, Nx>4) in step S31, to first (Nx=2, Nx=6-4). As a result, in the second cleaning operation, head 1 is set to third, head 2 to fourth, head 3 to first, and head 4 to second.

[0117] In the third wiping operation, the control unit 500 can set head 1 to the fourth position, head 2 to the first position, head 3 to the second position, and head 4 to the third position. In the (N+1)th wiping operation (N is a natural number), the control unit 500 can set the ejection head 4 that was set to the xth position in the Nth wiping operation to the x+2th position in the next (N+1)th wiping operation.

[0118] [CL order change process (Case 4)] For example, in the first wiping operation, the control unit 500 sets head 1 to be the first (Nx=1), head 2 to be the second (Nx=2), head 3 to be the third (Nx=3), and head 4 to be the fourth (Nx=4).

[0119] In the second wiping operation, the control unit 500 can set head 1 to be fourth, head 2 to be first, head 3 to be second, and head 4 to be third.

[0120] In the third wiping operation, the control unit 500 can set head 1 to third, head 2 to fourth, head 3 to second, and head 4 to second. In the (N+1)th wiping operation (N is a natural number), the control unit 500 can set the ejection head 4 that was set to xth in the Nth wiping operation to x+3rd in the next (N+1)th wiping operation.

[0121] [Effects of the liquid ejection device 200] In a liquid ejection device, when the nozzle surface is wiped to maintain the ejection state of the ejection head, the nozzle surface may be gradually worn down and deteriorated due to contact with a wiping member accompanying the wiping operation. When at least one of the multiple nozzle surfaces deteriorates to the point where it cannot be used, the ejection head reaches the end of its life. When multiple nozzle surfaces of multiple liquid ejection heads are always wiped in the same order, deterioration of a specific nozzle surface progresses more rapidly than deterioration of other nozzle surfaces, which may shorten the life of the ejection head.

[0122] A liquid ejection device 200 according to one embodiment includes a plurality of ejection heads 4, each having a nozzle surface 41 and ejecting liquid, a wiper blade (wiping member) 23 that wipes the plurality of nozzle surfaces 41 of the plurality of liquid ejection heads 4, a main scanning motor (drive unit) 15 that moves the wiper blade 23 relative to the plurality of nozzle surfaces 41, and a control unit 500 that controls multiple wiping operations by the wiper blade 23.

[0123] The control unit 500 controls a first wiping (first wiping operation) for wiping the multiple nozzle faces 41 in a first order, and a second wiping (second wiping operation) for wiping the multiple nozzle faces 41 in a second order different from the first order. The control unit 500 controls the wiper blade 23 to perform the first wiping and the second wiping.

[0124] According to such a liquid ejection device 200, the order in which the nozzle faces 41 are wiped is not fixed. By not fixing the nozzle face 41 that is wiped first, deterioration of a specific nozzle face 41 among the multiple nozzle faces 41 is suppressed from progressing more rapidly than deterioration of the other nozzle faces. In the liquid ejection device 200, unevenness in the degree of deterioration among the multiple nozzle faces 41 is suppressed. As a result, the life of the ejection head 4 can be extended. Damage to only the nozzle face 41 of a specific ejection head 4 can be prevented, so the replacement time for the ejection head 4 is not shortened.

[0125] In the liquid ejection device 200, after a cleaning operation is performed, the order of the ejection heads 4 to be cleaned is changed before the next cleaning operation. By cleaning the ejection heads 4 in a different order during the next cleaning, it is possible to reduce the concentration of damage on the nozzle surfaces 41 and postpone the need to replace the carriage 3.

[0126] As described above, when the order in which the ejection heads 4 are cleaned is fixed, the degree of damage to the nozzle surface 41 differs between the first ejection head 4 and the second to fourth ejection heads 4. In the liquid ejection device 200, the ejection head 4 for which the cleaning operation is performed first can be changed, so that the cleaning operation can be performed without concentrating damage on the nozzle surface 41. The liquid ejection device 200 can equalize the degree of damage to the nozzle surface 41 for the multiple ejection heads 4.

[0127] The control unit 500 controls multiple wiping operations so that the second wiping operation is performed after the first wiping operation. In the liquid ejection device 200 configured in this manner, wiping can be performed in a different order (second order) from the previous order (first order). For example, the control unit 500 can change the order every time wiping is performed. This can further reduce uneven damage to the multiple nozzle faces 41.

[0128] In the liquid ejection device 200, the multiple liquid ejection heads 4 include an ejection head (first liquid ejection head) 4A and an ejection head (second liquid ejection head) 4B, and the control unit 500 controls multiple wiping operations so that in the first wiping, wiping is performed first on the ejection head 4A, and in the second wiping, wiping is performed first on the ejection head 4B.

[0129] According to the liquid ejection device 200 having this configuration, it is possible to change the ejection head 4 that is first wiped. In the first wiping, wiping can be performed from the ejection head 4A, and in the second wiping, wiping can be performed from the ejection head 4B. This allows the control unit 500 to change the first ejection head 4 that is first wiped when the wiper blade 23 is not wet.

[0130] In the liquid ejection device 200, the control unit 500 performs control so that the second wiping is performed after the first wiping, and in the second wiping, the ejection head 4D that was wiped last in the first wiping is wiped first.

[0131] In the first wiping, the control unit 500 can wipe in the order of ejection head 4A → ejection head 4B → ejection head 4C → ejection head 4D, and in the second wiping, can wipe in the order of ejection head 4D → ejection head 4A → ejection head 4B → ejection head 4C.

[0132] The liquid ejection device 200 includes a cap 21 that covers the nozzle surface 41, and a suction pump 27 that sucks the nozzle surface 41 covered by the cap 21. A control unit 500 controls a cleaning operation that cleans the multiple nozzle surfaces 41, and the cleaning operation includes wiping and a suction operation that sucks the nozzle surface 41 with the suction pump 27. The control unit 500 controls a first cleaning operation that cleans the multiple nozzle surfaces 41 in a first order, and a second cleaning operation that cleans the multiple nozzle surfaces 41 in a second order different from the first order.

[0133] The thus configured liquid ejection device 200 can perform wiping and suction operations as cleaning operations. In a cleaning operation including wiping and suction operations, the control unit 500 can change the order of the nozzle surfaces 41 on which the cleaning operation is performed.

[0134] [Water-based ink] In the liquid ejection device 200, the liquid ejected from the ejection head 4 may be, for example, a water-based ink. For example, the liquid may be a water-based ink having a solid content concentration of 20% by weight or more, which is the total concentration of the resin and the pigment.

[0135] When using an aqueous ink with a high solid content, damage to the nozzle surface 41 becomes more noticeable compared to when using an aqueous ink with a low solid content. With the liquid ejection device 200, it is possible to extend the life of the ejection head 4 even when using an aqueous ink with a solid content concentration of 20% wt or more. With the liquid ejection device 200, it is possible to extend the replacement cycle of the carriage 3.

[0136] [Water-based inks containing ammonium salts] In the liquid ejection device 200, the liquid may be, for example, a water-based ink containing an ammonium salt in a pigment dispersion or a resin.

[0137] When ink containing an ammonium salt is used as the liquid, damage to the nozzle surface 41 is more noticeable than when ink not containing an ammonium salt is used. When ink containing an ammonium salt is used as the liquid, after a cleaning operation, ammonia derived from the ammonium salt volatilizes from the ink adhering to the nozzle surface 41, and solids tend to adhere to the nozzle surface 41. Therefore, concentration of damage on the nozzle surface 41 becomes more noticeable. According to the liquid ejection device 200, it is possible to extend the life of the ejection head 4 even when water-based ink containing an ammonium salt is used. With the liquid ejection device 200, it is possible to extend the replacement cycle of the carriage 3.

[0138] <Liquid ejection system> The liquid ejection system according to the embodiment includes a plurality of liquid ejection heads 4 each having a nozzle surface 41 and ejecting liquid, a wiper blade 23 which is a wiping member for wiping the nozzle surfaces 41 of the plurality of liquid ejection heads 4, a main scanning motor 15 and a maintenance and recovery motor 17 which are driving units for moving the wiper blade 23 relatively to the nozzle surfaces 41, and a control unit 500 which controls multiple wiping operations (wiping operations) by the wiper blade 23. The control unit 500 controls a first wiping (wiping operation) for wiping the nozzle surfaces 41 in a first order, and a second wiping (wiping operation) for wiping the nozzle surfaces 41 in a second order different from the first order. The liquid ejection system may include the above-mentioned liquid ejection device 200 and a control unit provided outside the liquid ejection device 200. All or a part of the control processing executed in the above-mentioned liquid ejection device 200 may be executed by a control unit provided outside the liquid ejection device 200.

[0139] <Liquid discharge method> 18 is a flowchart showing the steps of a liquid ejection method according to one embodiment of the present invention. The liquid ejection method according to the embodiment includes a liquid ejection step (S41) in which liquid is ejected from liquid ejection heads 4 each having a nozzle surface 41, and a wiping step in which the wiper blade 23 is moved relative to the nozzle surfaces 41 of the liquid ejection heads 4 to wipe the nozzle surfaces 41 multiple times, the multiple wiping steps including a first wiping step (first wiping step; S42) in which the nozzle surfaces 41 are wiped in a first order, and a second wiping step (second wiping step; S43) in which the nozzle surfaces 41 are wiped in a second order different from the first order.

[0140] The liquid ejection device 200 can execute a liquid ejection method. First, in the liquid ejection method, a liquid ejection step S41 is executed. Next, in the liquid ejection method, a first wiping step S42 is executed. Next, in the liquid ejection method, a second wiping step S43 is executed. In the liquid ejection method, the liquid ejection step S41, the first wiping step S42, and the second wiping step S43 may be executed multiple times. In the liquid ejection method, the order of the steps S41 to S43 may be appropriately changed. For example, in the liquid ejection method, the first wiping step S42 may be executed before the liquid ejection step S41. For example, in the liquid ejection method, the liquid ejection step S41 may be executed between the first wiping step S42 and the second wiping step S43.

[0141] <Program> The program according to the embodiment is a program that causes a computer (CPU 501) to execute a control process for executing a liquid ejection process in which liquid is ejected from liquid ejection heads 4 each having a nozzle surface 41, and a control process for executing a wiping process multiple times in which a wiping member is moved relatively to the multiple nozzle surfaces 41 of the multiple liquid ejection heads 4 to wipe the nozzle surfaces 41. The multiple wiping processes include a first wiping process in which the multiple nozzle surfaces 41 are wiped in a first order, and a second wiping process in which the multiple nozzle surfaces 41 are wiped in a second order different from the first order.

[0142] [Three-dimensional modeling apparatus 600 according to the second embodiment] Next, a three-dimensional modeling apparatus 600 according to a second embodiment of the present invention will be described. The three-dimensional modeling apparatus 600 is an example of a liquid ejection apparatus. FIG. 19 is a plan view of the three-dimensional modeling apparatus 600 according to the second embodiment of the present invention. FIG. 20 is a cross-sectional view of the three-dimensional modeling apparatus 600 according to the second embodiment of the present invention. FIG. 21 is a cross-sectional view of a modeling unit 601 of the three-dimensional modeling apparatus 600 according to the second embodiment of the present invention. Note that FIG. 21 shows the modeling unit 601 in a state during modeling.

[0143] The three-dimensional modeling apparatus 600 can execute the first wiping operation and the second wiping operation, similarly to the liquid ejection apparatus 200 according to the first embodiment described above. In the description of the second embodiment, the same description as in the first embodiment will be omitted.

[0144] The three-dimensional modeling apparatus 600 is a powder modeling apparatus, and includes a modeling section 601 in which a layered structure 630 formed by bonding powders (powder) is formed, and a modeling unit 605 that ejects modeling liquid 610 onto a layer (powder layer) 631 of powder spread in layers in the modeling section 601. The three-dimensional modeling apparatus 600 is also called a powder modeling apparatus.

[0145] The modeling unit 601 may include a powder tank 611 and a flattening roller 612, which is a rotating member serving as a flattening member constituting the flattening means. The flattening member may have, for example, a plate-like member instead of a rotating member. The flattening means is also called a recoater. The plate-like member may be a blade.

[0146] The powder tank 611 has a supply tank 621 that stores powder 620 to be supplied to the modeling tank 622, a modeling tank 622 in which layered structures 630 are stacked to form a three-dimensional object, and an excess powder receiving tank 629 that collects excess powder supplied to the modeling tank 622.

[0147] A supply stage 623 constituting the bottom of the supply tank 621 is capable of freely rising and lowering in the vertical direction Z. Similarly, a modeling stage 624 constituting the bottom of the modeling tank 622 is also capable of freely rising and lowering. A three-dimensional model is formed by stacking layered structures 630 on the modeling stage 624. The supply stage 623 is raised and lowered by a motor, and the modeling stage 624 is also raised and lowered by a motor.

[0148] The side surface of the supply stage 623 is disposed so as to contact the inner surface of the supply tank 621. The side surface of the modeling stage 624 is also disposed so as to contact the inner surface of the modeling tank 622. The upper surfaces of the supply stage 623 and the modeling stage 624 are kept horizontal.

[0149] A powder supplying device is disposed in the supply tank 621. At the initial stage of modeling or when the amount of powder in the supply tank 621 decreases, powder in a tank constituting the powder supplying device is supplied to the supply tank 621. Examples of a powder transport method for supplying powder include a screw conveyor method using a screw and a pneumatic transport method using air.

[0150] The flattening roller 612 transfers and supplies the powder 620 stored on the supply stage 623 of the supply tank 621 to the modeling tank 622, and also smooths and flattens the surface of the powder 620 supplied to the modeling tank 622 to form a powder layer of a predetermined thickness. The flattening roller 612 has an axial length longer than the inner widths of the modeling tank 622 and the supply tank 621, is disposed along the stage surface of the modeling stage 624 in the sub-scanning direction Y so as to be movable back and forth relative to the stage surface, and is moved by a reciprocating mechanism 625. The stage surface of the modeling stage 624 is the surface on which the powder 620 is loaded.

[0151] In addition, the flattening roller 612 is rotated by a motor 626. The flattening roller 612 reciprocates horizontally while being rotated by the motor 626, passing above the supply tank 621 and the modeling tank 622. As a result, the powder 620 in the supply tank 621 is transferred and supplied to the modeling tank 622, and the flattening roller 612 passes over the modeling tank 622, thereby transferring and flattening the powder 620, and a powder layer 631 of a desired thickness is formed.

[0152] The three-dimensional modeling apparatus 600 may include a lubricant application device 80. The lubricant application device 80 can scrape off the solid lubricant 81 by a rotationally driven brush roller 82, and apply the lubricant adhering to the brush roller 82 to the circumferential surface of the flattening roller 612. This can reduce the friction coefficient of the circumferential surface of the flattening roller 612.

[0153] The three-dimensional modeling apparatus 600 may include a cleaning blade 613 of a cleaning device that cleans the peripheral surface of the flattening roller 612. The cleaning blade 613 comes into contact with the peripheral surface of the flattening roller 612. By rotating the flattening roller 612, the lubricant and powder 620 attached to the peripheral surface of the flattening roller 612 are scraped off and removed by the cleaning blade 613. In the three-dimensional modeling apparatus 600, during the flattening process on the outward path to form the next powder layer 631, the flattening roller 612 having no lubricant attached to its peripheral surface is used again, and the frictional force generated between the peripheral surface of the flattening roller 612 and the powder 620 is large, so that the transport ability to distribute a uniform amount of the powder 620 throughout the entire modeling tank 622 can be ensured.

[0154] The cleaning device for cleaning the circumferential surface of the flattening roller 612 is not limited to one equipped with the cleaning blade 613, and may be of another type, such as a type that scrapes off with a brush or a type that cleans electrostatically.

[0155] The modeling unit 605 is equipped with a liquid ejection unit 450 that ejects (applies) modeling liquid 610 that bonds powder 620 to a powder layer 631 on the modeling stage 624, thereby forming a layered structure 430 as a layered structure in which the powder 620 is bonded.

[0156] The liquid ejection unit 650 includes a carriage 651 and two ejection heads 652a, 652b mounted on the carriage 651. When there is no need to distinguish between the ejection heads 652a, 652b, they may be referred to as ejection heads 652. The number of ejection heads 652 mounted on the carriage 651 is not limited to two, and may be one, or three or more.

[0157] The carriage 651 is movably held by guide members 654, 655. The guide members 654, 655 are held by side plates 670, 670 on both sides so that they can be raised and lowered. The carriage 651 is reciprocated in the main scanning direction X via a pulley and a belt by a main scanning motor constituting a main scanning direction scanning mechanism 550.

[0158] Each of the two ejection heads 652a, 652b has two nozzle rows in which a plurality of nozzles that eject the modeling liquid 610 are arranged. The two nozzle rows of one of the ejection heads 652a eject the cyan modeling liquid and the magenta modeling liquid. The two nozzle rows of the other ejection head 652b eject the yellow modeling liquid and the black modeling liquid, respectively. Note that the head configuration is not limited to this.

[0159] The three-dimensional modeling device 600 includes a plurality of tanks 660. The plurality of tanks 660 respectively contain a cyan modeling liquid, a magenta modeling liquid, a yellow modeling liquid, and a black modeling liquid. The plurality of tanks 660 are mounted on a tank mounting portion 656. The cyan modeling liquid, the magenta modeling liquid, the yellow modeling liquid, and the black modeling liquid contained in the plurality of tanks 660 are supplied to the discharge heads 652a and 652b via supply tubes.

[0160] The three-dimensional modeling device 600 includes a maintenance mechanism 661. The maintenance mechanism 661 maintains and recovers the discharge head 652. The maintenance mechanism 661 may be disposed on one side of the main scanning direction X. The maintenance mechanism 661 mainly includes a cap 662 and a wiping member 663. The wiping member 663 may be a wiper. The maintenance mechanism 661 brings the cap 662 into close contact with the nozzle surface of the discharge head 652 and sucks the modeling liquid from the nozzle. This is to discharge powder clogging the nozzle and to discharge the highly viscous modeling liquid. After that, the wiping member 663 of the maintenance mechanism 661 performs a first wiping operation and a second wiping operation (wiping) on ​​the nozzle surface. This removes foreign matter adhering to the nozzle surface. The maintenance mechanism 661 covers the nozzle surface of the discharge head 652 with the cap 662 during a period when the modeling liquid is not discharged. This prevents the powder 620 from entering the nozzle and the modeling liquid 610 from drying out.

[0161] The modeling unit 605 has a slider portion 672 movably held by a guide member 671 disposed on a base member 607. The modeling unit 605 is capable of reciprocating in the main scanning direction X and the sub-scanning direction Y. The modeling unit 605 is capable of reciprocating in the sub-scanning direction Y by a sub-scanning mechanism 552.

[0162] The liquid discharge unit 650 can be raised and lowered in the vertical direction Z together with the guide members 654, 655. The three-dimensional modeling apparatus 600 may include a lifting mechanism 551 that raises and lowers the liquid discharge unit 650 in the vertical direction Z.

[0163] The three-dimensional modeling apparatus 600 according to the second embodiment can also execute the first wiping operation and the second wiping operation, similarly to the liquid ejection apparatus 200 according to the first embodiment.

[0164] The control unit of the three-dimensional modeling apparatus 600 controls a first wiping (first wiping operation) for wiping the multiple nozzle faces in a first order, and a second wiping (second wiping operation) for wiping the multiple nozzle faces in a second order different from the first order. The control unit controls the wiping member to perform the first wiping and the second wiping.

[0165] The three-dimensional modeling apparatus 600 uses ink or powder with a high solid content, so it is prone to wear during the wiping operation of the nozzle surface, and ejection defects due to residual ink sticking to the nozzle surface or inside the nozzles. Therefore, in the three-dimensional modeling apparatus 600, it is particularly effective to control the first wiping operation and the second wiping operation so as to change the order in which the nozzle surface is wiped.

[0166] <Ink> The organic solvent, water, coloring material, resin, additives, etc. used in the ink will be described below.

[0167] <Organic solvent> The organic solvent used in the present invention is not particularly limited, and any water-soluble organic solvent can be used. Examples of the organic solvent include polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, and sulfur-containing compounds. Specific examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, and the like. polyhydric alcohols such as pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, and petriol, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether. polyhydric alcohol alkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; nitrogen-containing heterocyclic compounds such as 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, and γ-butyrolactone; amides such as formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide; amines such as monoethanolamine, diethanolamine, and triethylamine; sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, and thiodiethanol; propylene carbonate, and ethylene carbonate. It is preferable to use an organic solvent having a boiling point of 250° C. or less, since this not only functions as a wetting agent but also provides good drying properties.

[0168] Polyol compounds having 8 or more carbon atoms and glycol ether compounds are also suitably used. Specific examples of polyol compounds having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol. Specific examples of the glycol ether compound include polyhydric alcohol alkyl ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; and polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

[0169] Polyol compounds having 8 or more carbon atoms and glycol ether compounds can improve the permeability of ink when paper is used as the recording medium.

[0170] The content of the organic solvent in the ink is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoints of the drying property and ejection reliability of the ink, however, the content is preferably from 10% by mass to 60% by mass, and more preferably from 20% by mass to 60% by mass.

[0171] <Water> The water content in the ink is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoint of the drying property and ejection reliability of the ink, however, it is preferably from 10% to 90% by mass, and more preferably from 20% to 60% by mass.

[0172] <Coloring material> The coloring material is not particularly limited, and pigments and dyes can be used. The pigment may be an inorganic pigment or an organic pigment. These may be used alone or in combination of two or more. Mixed crystals may also be used. Examples of pigments that can be used include black pigments, yellow pigments, magenta pigments, cyan pigments, white pigments, green pigments, orange pigments, glossy pigments such as gold and silver pigments, and metallic pigments. As inorganic pigments, titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, as well as carbon black produced by known methods such as the contact method, furnace method, and thermal method can be used. As organic pigments, azo pigments, polycyclic pigments (e.g., phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc.), dye chelates (e.g., basic dye chelates, acid dye chelates, etc.), nitro pigments, nitroso pigments, aniline black, etc. can be used. Among these pigments, those having good affinity with the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used. Specific examples of pigments for black colors include carbon blacks (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black; metals such as copper, iron (CI Pigment Black 11), and titanium oxide; and organic pigments such as aniline black (CI Pigment Black 1). In addition, for color, CI Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, CI Pigment Yellow Range 5, 13, 16, 17, 36, 43, 51, CI Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48:2, 48:2 (Permanent Red 2B (Ca)), 48:3, 48:4, 49:1, 52:2, 53:1, 57:1 (Brilliant Carmine 6B), 60:1, 63:1, 63:2, 64:1, 81, 83, 88 , 101 (red oxide), 104, 105, 106, 108 (cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, CI Pigment Violet 1 (Rhodamine Lake), 3, 5:1, 16, 19, 23, 38; CI Pigment Blue 1, 2, 15 (Phthalocyanine Blue), 15:1, 15:2, 15:3, 15:4 (Phthalocyanine Blue), 16, 17:1, 56, 60, 63; CI Pigment Green 1, 4, 7, 8, 10, 17, 18, 36, etc. The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used. One type of dye may be used alone, or two or more types may be used in combination. Examples of the dyes include CI Acid Yellow 17, 23, 42, 44, 79, 142, CI Acid Red 52, 80, 82, 249, 254, 289, CI Acid Blue 9, 45, 249, CI Acid Black 1, 2, 24, 94, CI Food Black 1, 2, CI Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173, CI Direct Red 1, 4, 9, 80, 81, 225, 227, CI Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202, CI Directed Black 19, 38, 51, 71, 154, 168, 171, 195, and CI Reactive Red. 14, 32, 55, 79, 249, and CI Reactive Black 3, 4, and 35.

[0173] The content of the coloring material in the ink is preferably from 0.1% to 15% by mass, and more preferably from 1% to 10% by mass, from the viewpoints of improving image density, good fixing property and ejection stability.

[0174] Methods for dispersing a pigment to obtain an ink include a method of introducing a hydrophilic functional group into the pigment to make it a self-dispersing pigment, a method of dispersing the pigment by coating the surface of the pigment with a resin, and a method of dispersing the pigment using a dispersant. As a method for introducing a hydrophilic functional group into a pigment to make it a self-dispersing pigment, for example, a method in which a functional group such as a sulfone group or a carboxyl group is added to a pigment (e.g., carbon) to make it dispersible in water can be mentioned. As a method for dispersing a pigment by coating its surface with a resin, there is a method in which the pigment is encapsulated in a microcapsule to make it dispersible in water. This can be called a resin-coated pigment. In this case, it is not necessary for all of the pigments blended in the ink to be coated with a resin, and uncoated or partially coated pigments may be dispersed in the ink as long as the effect of the present invention is not impaired. Examples of the method for dispersing using a dispersant include a method for dispersing using a known low molecular weight dispersant or a polymeric dispersant, typified by a surfactant. As the dispersant, for example, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc. can be used depending on the pigment. RT-100 (nonionic surfactant) manufactured by Takemoto Oil Co., Ltd. and sodium naphthalenesulfonate formalin condensate can also be suitably used as dispersants. The dispersants may be used alone or in combination of two or more.

[0175] <Pigment dispersion> It is possible to obtain ink by mixing a pigment with materials such as water or an organic solvent, or it is also possible to manufacture ink by mixing a pigment with other materials such as water and a dispersant to prepare a pigment dispersion, and then mixing the resulting mixture with materials such as water or an organic solvent. The pigment dispersion is obtained by mixing and dispersing water, a pigment, a pigment dispersant, and other components as required, and adjusting the particle size. Dispersion is preferably performed using a dispersing machine. The particle size of the pigment in the pigment dispersion is not particularly limited, but the maximum frequency in terms of the maximum number is preferably 20 nm or more and 500 nm or less, more preferably 20 nm or more and 150 nm or less, in order to improve the dispersion stability of the pigment and the image quality such as ejection stability and image density. The particle size of the pigment can be measured using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.). The content of the pigment in the pigment dispersion is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoints of obtaining good ejection stability and increasing image density, the content is preferably 0.1% by mass or more and 50% by mass or less, and more preferably 0.1% by mass or more and 30% by mass or less. It is preferable that the pigment dispersion is degassed, if necessary, by filtering coarse particles using a filter, a centrifugal separator, or the like.

[0176] <Resin> The type of resin contained in the ink is not particularly limited and can be appropriately selected depending on the purpose. Examples of the resin include urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, styrene-butadiene resin, vinyl chloride resin, acrylic styrene resin, and acrylic silicone resin. Resin particles made of these resins may be used. The resin particles may be dispersed in water as a dispersion medium to form a resin emulsion, and then mixed with materials such as coloring materials and organic solvents to obtain an ink. The resin particles may be appropriately synthesized or may be commercially available. These may be used alone or in combination of two or more types of resin particles.

[0177] The volume average particle size of the resin particles is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoint of obtaining good fixing property and high image hardness, however, it is preferably from 10 nm to 1,000 nm, more preferably from 10 nm to 200 nm, and particularly preferably from 10 nm to 100 nm. The volume average particle size can be measured, for example, using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac-Bell Co., Ltd.). The resin content is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoints of fixation property and storage stability of the ink, however, the resin content is preferably from 1% by mass to 30% by mass, and more preferably from 5% by mass to 20% by mass, of the total amount of the ink. The particle size of the solid content in the ink is not particularly limited and can be appropriately selected depending on the purpose, but in terms of improving image quality such as ejection stability and image density, the maximum frequency in terms of maximum number is preferably 20 nm or more and 1000 nm or less, more preferably 20 nm or more and 150 nm or less. The solid content includes resin particles, pigment particles, etc. The particle size can be measured using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

[0178] <Additives> If necessary, surfactants, antifoaming agents, antiseptics, antifungals, rust inhibitors, pH adjusters, etc. may be added to the ink. The silicone surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples of the silicone surfactant include side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and both-end side-chain modified polydimethylsiloxane. Polyether-modified silicone surfactants having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group are particularly preferred because they exhibit good properties as an aqueous surfactant. Such surfactants may be appropriately synthesized or commercially available products, such as those available from BYK-Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Dow Corning Toray Silicone Co., Ltd., Nippon Emulsion Co., Ltd., and Kyoeisha Chemical Co., Ltd. The polyether-modified silicone surfactant is not particularly limited and can be appropriately selected depending on the purpose. For example, it can be a surfactant represented by the general formula (S-1) in which a polyalkylene oxide structure is introduced into the Si part side chain of dimethylpolysiloxane. [ka] General formula (S-1) (In the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R' represents an alkyl group.) As the polyether-modified silicone surfactant, commercially available products can be used, such as KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS-1906EX (Nihon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Dow Corning Toray Silicone Co., Ltd.), BYK-33, BYK-387 (BYK-Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.), and the like. The fluorine-based surfactant is preferably a compound having 2 to 16 fluorine-substituted carbon atoms, and more preferably a compound having 4 to 16 fluorine-substituted carbon atoms. Examples of fluorine-based surfactants include perfluoroalkyl phosphate compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in side chains, etc. Among these, polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in side chains are preferred because they have low foaming properties, and fluorine-based surfactants represented by general formula (F-1) and general formula (F-2) are particularly preferred. [ka] General formula (F-1) In the compound represented by the above general formula (F-1), m is preferably an integer of 0 to 10, and n is preferably an integer of 0 to 40 in order to impart water solubility. General formula (F-2) C n F 2n+1- CH2CH(OH)CH2-O-(CH2CH2O) a -Y In the compound represented by the above general formula (F-2), Y is H or CmF 2m+1 where m is an integer from 1 to 6, or CH2CH(OH)CH2-CmF 2m+1 where m is an integer between 4 and 6, or CpH 2p+1 where p is an integer from 1 to 19. n is an integer from 1 to 6. a is an integer from 4 to 14. As the fluorine-based surfactant, commercially available products may be used. Examples of such commercially available products include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullard FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, and FC-431 (all manufactured by Sumitomo 3M Limited); Megafa F-470, F-1405, F-474 (all manufactured by Dainippon Ink & Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, FS-31, FS-3100, FS-34, FS-35 (all manufactured by Chemours); FT-110, FT- 250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by NEOS Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by OMNOVA Co., Ltd.), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.), and the like. Among these, FS-3100, FS-34, FS-300 manufactured by Chemours Co., Ltd., FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW manufactured by NEOS Co., Ltd., Polyfox PF-151N manufactured by OMNOVA Co., Ltd., and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. are particularly preferred from the viewpoint of excellent print quality, particularly color development, penetration into paper, wettability, and uniform dyeing. The content of the surfactant in the ink is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoints of excellent wettability and ejection stability and improved image quality, the content is preferably from 0.001% by mass to 5% by mass, and more preferably from 0.05% by mass to 5% by mass.

[0179] <Antifoaming agent> The defoaming agent is not particularly limited, and examples thereof include silicone defoaming agents, polyether defoaming agents, fatty acid ester defoaming agents, and the like. These may be used alone or in combination of two or more. Among these, silicone defoaming agents are preferred because of their excellent defoaming effect.

[0180] <Antiseptic and mildew-proof agent> The antiseptic and mildew-proof agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

[0181] <Rust inhibitor> The rust inhibitor is not particularly limited, and examples thereof include acid sulfite and sodium thiosulfate.

[0182] <pH adjuster> The pH adjuster is not particularly limited as long as it can adjust the pH to 7 or higher, and examples thereof include amines such as diethanolamine and triethanolamine. The physical properties of the ink are not particularly limited and can be appropriately selected according to the purpose. For example, it is preferable that the viscosity, surface tension, pH, etc. are in the following ranges. The viscosity of the ink at 25°C is preferably 5 mPa·s or more and 30 mPa·s or less, more preferably 5 mPa·s or more and 25 mPa·s or less, from the viewpoints of improving the printing density and the quality of the characters and obtaining good ejection properties. Here, for example, a rotational viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used to measure the viscosity. The measurement conditions are as follows: at 25°C, using a standard cone rotor (1°34'×R24), a sample liquid volume of 1.2 mL, a rotation speed of 50 rpm, and it can be measured in 3 minutes. The surface tension of the ink is preferably 35 mN / m or less, more preferably 32 mN / m or less at 25°C, from the viewpoints of the ink being preferably leveled on the recording medium and shortening the drying time of the ink. The pH of the ink is preferably 7 to 12, more preferably 8 to 11, from the viewpoint of preventing corrosion of the metal members in contact with the liquid.

[0183] <Pretreatment liquid> The pretreatment liquid contains a flocculant, an organic solvent, and water, and may contain, as necessary, a surfactant, an antifoaming agent, a pH adjuster, an antiseptic / fungal agent, an antirust agent, and the like. The organic solvent, surfactant, defoamer, pH adjuster, antiseptic / fungal agent, and rust inhibitor may be the same as those used in ink, and other materials used in known treatment liquids may be used. The type of the flocculant is not particularly limited, and examples thereof include water-soluble cationic polymers, acids, and polyvalent metal salts.

[0184] <Post-processing solution> The post-treatment liquid is not particularly limited as long as it can form a transparent layer. The post-treatment liquid is obtained by selecting and mixing organic solvents, water, resins, surfactants, defoamers, pH adjusters, antiseptics, antifungals, rust inhibitors, etc. as necessary. The post-treatment liquid may be applied to the entire recording area formed on the recording medium, or may be applied only to the area where the ink image is formed.

[0185] <Recording Media> The recording medium used for recording is not particularly limited, but examples thereof include plain paper, glossy paper, special paper, cloth, film, OHP sheets, general-purpose printing paper, and the like.

[0186] <Recording Media> There are no particular limitations on the recording medium, and although plain paper, glossy paper, special paper, cloth, etc. can be used, good image formation is also possible using a non-permeable substrate. The non-permeable substrate is a substrate having a surface with low water permeability and absorbency, and includes materials that have many cavities inside but are not open to the outside. More quantitatively, in the Bristow method, 1 / 2 Water absorption up to 10mL / m 2 The term "substrate" refers to a substrate that is: As the non-permeable substrate, for example, a plastic film such as a polyvinyl chloride resin film, a polyethylene terephthalate (PET) film, a polypropylene film, a polyethylene film, or a polycarbonate film can be suitably used. The recording medium is not limited to those generally used as recording media, and may be wallpaper, flooring, building materials such as tiles, cloth for clothing such as T-shirts, textiles, leather, etc. By adjusting the configuration of the path for conveying the recording medium, ceramics, glass, metal, etc. may also be used.

[0187] <Recordings> The ink recorded matter of the present invention comprises an image formed on a recording medium using the ink of the present invention. A recorded matter can be obtained by recording using an inkjet recording apparatus and an inkjet recording method.

[0188] <Recording device and recording method> The ink of the present invention can be suitably used in various recording devices using the ink jet recording method, such as printers, facsimile machines, copying machines, printer / fax / copier combination machines, and three-dimensional modeling devices. In the present invention, the recording apparatus and recording method refer to an apparatus capable of ejecting ink, various treatment liquids, etc. onto a recording medium, and a method of recording using the apparatus. The recording medium refers to an object onto which ink or various treatment liquids can be attached even temporarily. This recording device can include not only a head portion that ejects ink, but also means related to feeding, transporting, and discharging the recording medium, as well as other devices called pre-processing devices and post-processing devices. The recording apparatus and the recording method may have a heating means used in the heating step and a drying means used in the drying step. The heating means and the drying means include, for example, a means for heating and drying the printed surface and the back surface of the recording medium. The heating means and the drying means are not particularly limited, but for example, a hot air heater and an infrared heater can be used. Heating and drying can be performed before, during, or after printing. In addition, the recording device and recording method are not limited to those that visualize meaningful images such as characters and figures with ink. For example, those that form patterns such as geometric designs and those that create three-dimensional images are also included. Furthermore, unless otherwise specified, the recording apparatus includes both a serial type apparatus in which the ejection head moves and a line type apparatus in which the ejection head does not move. Furthermore, this recording device includes not only desktop types, but also wide-width recording devices capable of printing on A0-sized recording media, and continuous-feed printers that can use continuous paper wound into a roll as a recording medium. An example of a recording device will be described with reference to Figs. 1 and 2. Fig. 1 is a perspective view of the device. Fig. 2 is a perspective view of a main tank. An image forming device 400 as an example of a recording device is a serial type image forming device. A mechanism unit 420 is provided inside an exterior 401 of the image forming device 400. Each ink storage unit 411 of the main tanks 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), and yellow (Y) is formed of a packaging material such as an aluminum laminate film. The ink storage unit 411 is stored in a storage container case 414 made of plastic, for example. As a result, the main tanks 410 are used as ink cartridges of each color. On the other hand, a cartridge holder 404 is provided at the back side of the opening when the cover 401c of the apparatus body is opened. A main tank 410 is detachably attached to the cartridge holder 404. As a result, each ink outlet 413 of the main tank 410 communicates with an ejection head 434 for each color via a supply tube 436 for each color, and ink can be ejected from the ejection head 434 to a recording medium.

[0189] This recording apparatus can include not only a portion that ejects ink, but also devices called pre-processing devices and post-processing devices. As an embodiment of the pre-treatment device and post-treatment device, a liquid storage section having a pre-treatment liquid and a liquid ejection head, similar to the case of inks such as black (K), cyan (C), magenta (M), and yellow (Y), and the like, are added, and the pre-treatment liquid and the post-treatment liquid are ejected by an inkjet recording method. As another embodiment of the pre-treatment device and the post-treatment device, there is an embodiment in which a pre-treatment device and a post-treatment device using a method other than the inkjet recording method, for example, a blade coating method, a roll coating method, or a spray coating method, are provided.

[0190] The ink can be used in a wide variety of ways, including, but not limited to, inkjet recording, blade coating, gravure coating, bar coating, roll coating, dip coating, curtain coating, slide coating, die coating, and spray coating.

[0191] In the present invention, the terms image formation, recording, printing, printing, etc. are all synonymous.

[0192] Recording medium, media, and printed material are all synonymous.

[0193] The above-described embodiment is presented as an example, and is not intended to limit the scope of the present invention. This embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. In addition, the embodiment and modifications of the embodiment are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

[0194] [Processing circuit] Each function of the above-described embodiments can be realized by one or more processing circuits. Here, the term "processing circuit" in this specification includes a processor programmed to execute each function by software, such as a processor implemented by an electronic circuit, and a device such as an ASIC (Application Specific Integrated Circuit), a DSP (digital signal processor), an FPGA (field programmable gate array), or a conventional circuit module designed to execute each function described above.

[0195] One aspect of the present invention may be as follows.

[0196] <1> A plurality of liquid ejection heads each having a nozzle surface and ejecting liquid; a wiping member that wipes the nozzle surfaces of the liquid ejection heads; a drive unit that moves the wiping member relatively to the nozzle faces; A control unit that controls a plurality of wiping operations by the wiping member, The control unit is configured to: a first wiping operation of wiping the plurality of nozzle surfaces in a first order; a second wiping operation of wiping the plurality of nozzle faces in a second order different from the first order. <2> The control unit is configured to: The above-mentioned wiping device controls the second wiping operation to be performed after the first wiping operation. <1> The liquid ejection device according to claim 1 . <3> the plurality of liquid ejection heads include a first liquid ejection head and a second liquid ejection head, The control unit is configured to: In the first wiping operation, a wiping operation is first performed on the first liquid ejection head; In the second wiping operation, the wiping operation is first performed on the second liquid ejection head. <1> or <2> The liquid ejection device according to claim 1 . <4> The control unit is configured to: The second wiping action is performed after the first wiping action, In the second wiping operation, the wiping operation is controlled so as to firstly perform a wiping operation on the liquid ejection head on which the wiping operation was last performed in the first wiping operation. <1> ~ <3> 13. The liquid ejection device according to claim 12, <5> The liquid is an aqueous ink having a solid content of 20% by weight or more including resin and pigment. <1> ~ <4> 13. The liquid ejection device according to claim 12, <6> The liquid is a water-based ink containing an ammonium salt in a pigment dispersion or a resin. <1> ~ <5> 13. The liquid ejection device according to claim 12, <7> a cap for covering the nozzle surface; a suction pump that sucks the nozzle surface covered by the cap, The control unit is Controlling a cleaning operation for cleaning the plurality of nozzle surfaces; The cleaning operation includes: The wiping action; a suction operation of sucking the nozzle surface by the suction pump, The control unit is a first cleaning operation of cleaning the plurality of nozzle faces in the first order; and a second cleaning operation for cleaning the plurality of nozzle faces in a second order different from the first order. <1> ~ <6> 13. The liquid ejection device according to claim 12, <8> A plurality of liquid ejection heads each having a nozzle surface and ejecting liquid; a wiping member that wipes the nozzle surfaces of the liquid ejection heads; a drive unit that moves the wiping member relatively to the nozzle faces; A control unit that controls a plurality of wiping operations by the wiping member, The control unit is configured to: a first wiping operation of wiping the plurality of nozzle surfaces in a first order; a second wiping action of wiping the plurality of nozzle faces in a second order different from the first order. <9> a liquid ejection step of ejecting liquid from a plurality of liquid ejection heads each having a nozzle surface; a wiping step of wiping the nozzle surfaces a plurality of times by moving a wiping member relative to the nozzle surfaces of the plurality of liquid ejection heads, The multiple wiping steps include a first wiping step of wiping the plurality of nozzle surfaces in a first order; a second wiping step of wiping the plurality of nozzle faces in a second order different from the first order. <10> a control process for executing a liquid ejection process for ejecting liquid from a plurality of liquid ejection heads each having a nozzle surface; a control process for executing a wiping process multiple times to wipe the nozzle surfaces by moving a wiping member relatively to the nozzle surfaces of the liquid ejection heads, The multiple wiping steps include a first wiping step of wiping the plurality of nozzle surfaces in a first order; a second wiping step of wiping the plurality of nozzle surfaces in a second order different from the first order. [Explanation of symbols]

[0197] 3: Carriage 4n: Nozzle 4: Liquid ejection head (recording head) 5 Head Tank 12 Conveyor belt 15 Main scanning motor (drive unit) 20 Maintenance and Recovery Mechanism 21 Cap 23 Wiper blade (wiping member) 27 Suction Pump 41 Nozzle surface 84 Elastic Members 112A Cap Holder 124 Linear Encoder 124a Encoder Sensor 124b Encoder Scale 151 Holder 152 Spring 200 Liquid dispensing device 400 Image forming device 401 Exterior of image forming device 401c Device body cover 404 Cartridge Holder 410 Main Tank 410k, 410c, 410m, 410y Main tanks for black (K), cyan (C), magenta (M), and yellow (Y) 411 Ink storage unit 413 Ink outlet 414 Storage container case 420 Mechanism Department 434 Discharge Head 436 Supply Tube 500 Control section 510 Control device 600 Three-dimensional printing device (liquid discharge device) 652, 652a, 652b Liquid ejection head 663 Wiping materials [Prior art documents] [Patent documents]

[0198] [Patent Document 1] Patent No. 2014-100892

Claims

1. A plurality of liquid ejection heads each having a nozzle surface and ejecting liquid; a wiping member that wipes the nozzle surfaces of the liquid ejection heads; a drive unit that moves the wiping member relatively to the nozzle faces; A control unit that controls a plurality of wiping operations by the wiping member, The control unit is configured to: a first wiping operation of wiping the plurality of nozzle surfaces in a first order; a second wiping operation of wiping the nozzle surfaces in a second order different from the first order.

2. The control unit is configured to: The liquid ejection apparatus according to claim 1 , wherein the second wiping operation is controlled to be performed after the first wiping operation.

3. the plurality of liquid ejection heads include a first liquid ejection head and a second liquid ejection head, The control unit is configured to: In the first wiping operation, a wiping operation is first performed on the first liquid ejection head; The liquid ejection apparatus according to claim 2 , wherein in the second wiping operation, the wiping operation is controlled so as to be performed on the second liquid ejection head first.

4. The control unit is configured to: The second wiping action is performed after the first wiping action, The liquid ejection apparatus according to claim 1 , wherein the second wiping operation is controlled so that the wiping operation is first performed on the liquid ejection head that was last wiped in the first wiping operation.

5. 2. The liquid ejection device according to claim 1, wherein the liquid is a water-based ink having a solid content concentration of resin and pigment combined of 20% by weight or more.

6. 2. The liquid ejection device according to claim 1, wherein the liquid is a water-based ink containing an ammonium salt in a pigment dispersion or a resin.

7. a cap for covering the nozzle surface; a suction pump that sucks the nozzle surface covered by the cap, The control unit is Controlling a cleaning operation for cleaning the plurality of nozzle surfaces; The cleaning operation includes: The wiping action; a suction operation of sucking the nozzle surface by the suction pump, The control unit is a first cleaning operation of cleaning the plurality of nozzle surfaces in the first order; The liquid ejection apparatus according to claim 1 , further comprising: a second cleaning operation for cleaning the plurality of nozzle faces in a second order different from the first order.

8. A plurality of liquid ejection heads each having a nozzle surface and ejecting liquid; a wiping member that wipes the nozzle surfaces of the liquid ejection heads; a drive unit that moves the wiping member relatively to the nozzle faces; A control unit that controls a plurality of wiping operations by the wiping member, The control unit is configured to: a first wiping operation of wiping the plurality of nozzle surfaces in a first order; a second wiping operation for wiping the plurality of nozzle faces in a second order different from the first order.

9. a liquid ejection step of ejecting liquid from a plurality of liquid ejection heads each having a nozzle surface; a wiping step of wiping the nozzle surfaces a plurality of times by moving a wiping member relative to the nozzle surfaces of the plurality of liquid ejection heads, The multiple wiping steps include a first wiping step of wiping the plurality of nozzle surfaces in a first order; a second wiping step of wiping the nozzle surfaces in a second order different from the first order.

10. a control process for executing a liquid ejection process for ejecting liquid from a plurality of liquid ejection heads each having a nozzle surface; a control process for executing a wiping process multiple times to wipe the nozzle surfaces by moving a wiping member relatively to the nozzle surfaces of the liquid ejection heads, The multiple wiping steps include a first wiping step of wiping the plurality of nozzle surfaces in a first order; a second wiping step of wiping the plurality of nozzle surfaces in a second order different from the first order.

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