Liquid discharge device and control method for liquid discharge device

Abstract

To provide a liquid discharge device capable of reducing a drive load of a drive section when wiping a wiped surface including a nozzle formation surface of a liquid discharge section, and a control method for the liquid discharge device.SOLUTION: A control section drives a drive section to execute various types of control. The control section executes first movement control for relatively moving a wiping section to a liquid discharge section in a wiping direction along a nozzle formation surface to cause the wiping section to wipe a wiped surface. Following the first movement control, the control section executes deflection reduction control for reducing a deflection amount of the wiping section by relatively moving the wiping section to the liquid discharge section in an intersection direction intersecting with the nozzle formation surface while maintaining contact between the wiping section and the liquid discharge section. Following the deflection reduction control, the control section executes second movement control for relatively moving the wiping section to the liquid discharge section in a retract direction that is a direction along the nozzle formation surface and that is different from the wiping direction to separate the wiping section from the liquid discharge section.SELECTED DRAWING: Figure 15

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device including a wiping unit that wipes a nozzle surface of a liquid ejection unit, and a method for controlling the liquid ejection device. [Background technology]

[0002] For example, Patent Document 1 discloses a liquid ejection device that includes a transport unit that transports a medium and a recording head (an example of a liquid ejection unit) that ejects liquid such as ink onto the medium. This liquid ejection device includes a wiping member (an example of a wiping unit) that moves relative to the recording head in the main scanning direction to wipe the nozzle forming surface, and a control device (an example of a control unit) that moves at least one of the recording head and the wiping member. The control device selects and performs one of the following processes: a first wiping process for wiping the nozzle forming surface until the wiping member moves away from the nozzle forming surface in the main scanning direction, and a second wiping process for wiping the nozzle forming surface until the wiping member contacts a specified position on the nozzle forming surface, and then moving the wiping member away from the nozzle forming surface in a retraction direction different from the main scanning direction. The wiping member moves in a retraction direction different from the wiping direction by the driving force of a drive unit such as a motor.

[0003] In the second wiping process, the liquid ejection section is moved in the wiping direction, and then the wiping member is moved in a retraction direction different from the wiping direction, thereby gradually eliminating the deflection of the wiping member and reducing the amount of ink scattering. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-187859 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the liquid ejection device described in Patent Document 1, when the wiping member is changed in direction and moved in a retraction direction different from the wiping direction during the second wiping process, the drive load on the drive unit becomes excessive, making it difficult to retract the wiping member. Various factors can cause the drive load on the drive unit to become excessive, including a shape factor that makes it difficult for the wiping member to bend in the retraction direction due to its shape, and deterioration factors such as increased sliding friction resistance due to aging. Even if the relative movement of the wiping member in the retraction direction different from the wiping direction while in contact with the surface to be wiped of the liquid ejection unit is due to movement of the liquid ejection unit rather than the wiping member, the same problem of excessive drive load being imposed on the drive unit of the liquid ejection unit still exists. [Means for solving the problem]

[0006] A liquid ejection device that solves the above problem comprises a liquid ejection unit having a plurality of nozzles capable of ejecting liquid and a nozzle forming surface on which the plurality of nozzles are formed, a wiping unit that wipes a surface to be wiped including the nozzle forming surface, a drive unit that moves at least one of the liquid ejection unit and the wiping unit, and a control unit, wherein the control unit drives the drive unit to perform first movement control to move the wiping unit relative to the liquid ejection unit in a wiping direction along the nozzle forming surface, thereby causing the wiping unit to wipe the surface to be wiped, and after the first movement control, performs deflection reduction control to reduce the amount of deflection of the wiping unit by moving the wiping unit relative to the liquid ejection unit in a cross direction that intersects the nozzle forming surface while maintaining contact between the wiping unit and the liquid ejection unit, and after the deflection reduction control, performs second movement control to move the wiping unit relative to the liquid ejection unit in a retraction direction that is a direction along the nozzle forming surface but different from the wiping direction, thereby separating the wiping unit from the liquid ejection unit.

[0007] A liquid ejection device that solves the above problem comprises a liquid ejection unit having a plurality of nozzles capable of ejecting liquid and a nozzle forming surface on which the plurality of nozzles are formed, a wiping unit that wipes a surface to be wiped including the nozzle forming surface, a drive unit that moves at least one of the liquid ejection unit and the wiping unit, and a control unit, wherein the control unit drives the drive unit to perform first movement control to move the wiping unit relative to the liquid ejection unit in a wiping direction along the nozzle forming surface, thereby causing the wiping unit to wipe the nozzle forming surface, and after the first movement control, performs second movement control to move the wiping unit relative to the liquid ejection unit in a retraction direction that is a direction along the nozzle forming surface but different from the wiping direction, thereby moving the wiping unit away from the liquid ejection unit, and if the drive load of the drive unit becomes greater than a threshold value while the second movement control is being performed, stops the second movement control and performs deflection reduction control to reduce the amount of deflection of the wiping unit.

[0008] A control method for a liquid ejection device that solves the above-described problems is a control method for a liquid ejection device that includes a liquid ejection unit having a plurality of nozzles capable of ejecting liquid and a nozzle forming surface on which the plurality of nozzles are formed, a wiping unit that wipes a surface to be wiped that includes the nozzle forming surface, and a drive unit that moves at least one of the liquid ejection unit and the wiping unit, and that drives the drive unit to move the wiping unit relative to the liquid ejection unit in a wiping direction along the nozzle forming surface, thereby performing first movement control that causes the wiping unit to wipe the surface to be wiped. and after the first movement control, performing a deflection reduction control to reduce the amount of deflection of the wiping portion by moving the wiping portion relative to the liquid discharge portion in a direction intersecting the nozzle forming surface while maintaining contact between the wiping portion and the liquid discharge portion, and performing a second movement control to move the wiping portion relative to the liquid discharge portion in a retraction direction that is a direction along the nozzle forming surface and different from the wiping direction, thereby separating the wiping portion from the liquid discharge portion.

[0009] A control method for a liquid ejection device that solves the above-described problems is a control method for a liquid ejection device that includes a liquid ejection unit having a plurality of nozzles capable of ejecting liquid and a nozzle forming surface on which the plurality of nozzles are formed, a wiping unit that wipes a surface to be wiped including the nozzle forming surface, and a drive unit that moves at least one of the liquid ejection unit and the wiping unit, and includes: executing a first movement control by driving the drive unit to move the wiping unit relative to the liquid ejection unit in a wiping direction along the nozzle forming surface, thereby causing the wiping unit to wipe the nozzle forming surface; executing a second movement control after the first movement control to move the wiping unit relative to the liquid ejection unit in a retraction direction that is a direction along the nozzle forming surface but different from the wiping direction, thereby separating the wiping unit from the liquid ejection unit; and if a drive load of the drive unit becomes greater than a threshold value during execution of the second movement control, stopping the second movement control and executing a deflection reduction control that reduces the amount of deflection of the wiping unit. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a liquid ejection device according to the first embodiment. [Figure 2] FIG. 2 is a schematic plan view showing the periphery of the home position of the liquid ejection device. [Figure 3] FIG. 3 is a perspective view showing the maintenance device. [Figure 4] FIG. 4 is a perspective view showing the maintenance device. [Figure 5] FIG. 5 is a schematic front view showing the liquid discharge unit and the wiping unit at the wiping start position. [Figure 6] FIG. 6 is a schematic front view showing a state in which the wiping part wipes the wiped surface of the liquid ejection part. [Figure 7] FIG. 7 is a schematic front view showing a state where wiping has been completed with the wiping part in contact with the wiped surface of the liquid discharge part. [Figure 8] FIG. 8 is a front view of the main part showing the liquid discharge unit. [Figure 9]FIG. 9 is a schematic bottom view showing the bottom surface of the liquid ejection unit. [Figure 10] FIG. 10 is a partial front view showing the liquid discharge section. [Figure 11] FIG. 11 is a partial front view showing the wiping unit and the liquid discharge unit at the wiping end position. [Figure 12A] FIG. 12A is a partial front view showing the liquid ejection section. [Figure 12B] FIG. 12B is a partial front view showing the liquid ejection section. [Figure 12C] FIG. 12C is a partial front view showing the liquid ejection section. [Figure 13] FIG. 13 is a schematic bottom view showing the positional relationship between the liquid discharge unit, the wiping unit, and the removal unit. [Figure 14] FIG. 14 is a block diagram showing the electrical configuration of the liquid ejection device. [Figure 15] FIG. 15 is a flowchart showing the wiping process routine. [Figure 16] FIG. 16 is a flowchart showing the cleaning control routine. [Figure 17] FIG. 17 is a flowchart showing the wiping control routine. [Figure 18] FIG. 18 is a partial front view showing the wiping unit and the liquid discharge unit when stopped at the wiping end position. [Figure 19] FIG. 19 is a partial front view showing the wiping unit and the liquid discharge unit after the bending reduction control has been completed. [Figure 20] FIG. 20 is a schematic bottom view showing the process in which the wiping unit retreats in the retreat direction from the wiping end position. [Figure 21] FIG. 21 is a flowchart showing a wiping process routine in the second embodiment. [Figure 22] FIG. 22 is a partial front view showing the wiping unit and the liquid discharge unit when stopped at the wiping end position. [Figure 23] FIG. 23 is a schematic bottom view showing the wiping unit and the liquid discharge unit starting a retraction operation in the retraction direction from the wiping end position. [Figure 24]FIG. 24 is a partial front view showing the wiping unit and the liquid discharge unit after the bending reduction control has been completed. [Figure 25] FIG. 25 is a schematic bottom view showing the process in which the wiping part, having completed the deflection reduction control, retreats in the retreat direction. [Figure 26] FIG. 26 is a flowchart showing a wiping process routine in the third embodiment. [Figure 27] FIG. 27 is a partial front view showing the wiping unit and the liquid discharge unit when stopped at the wiping end position. [Figure 28] FIG. 28 is a schematic bottom view showing the wiping unit and the liquid discharge unit starting a retraction operation in the retraction direction from the wiping end position. [Figure 29] FIG. 29 is a partial front view showing the wiping unit and the liquid discharge unit after the bending reduction control has been completed. [Figure 30] FIG. 30 is a schematic bottom view showing the wiping section and the liquid discharge section when the standby time after the bending reduction control has ended. [Figure 31] FIG. 31 is a schematic bottom view illustrating the operation of the wiping unit, which has finished standby, moving in the wiping direction and then retreating in the retreat direction. [Figure 32] FIG. 32 is a flowchart showing a wiping process routine in the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] (First embodiment) A first embodiment of a liquid ejection device will be described below with reference to FIGS. As shown in FIG. 1, the liquid ejection device 10 of this embodiment is, for example, an inkjet printer. The liquid ejection device 10 includes a housing 11. Although only a portion of the liquid ejection device 10 is shown in FIG. 1, the housing 11 has a substantially rectangular parallelepiped shape. The housing 11 may include a bottomed box-shaped main body that opens upward, and an openable / closable lid that can cover the opening of the main body (both not shown). The liquid ejection device 10 may also be a multifunction device that includes an image reading unit (scanner) on top of the housing 11 that can read documents.

[0012] As shown in FIG. 1, the liquid ejection device 10 includes a liquid ejection unit 12 within a housing 11. The liquid ejection unit 12 includes a carriage 121 that moves in a main scanning direction X, and a liquid ejection head 13 that is mounted on the carriage 121. That is, the liquid ejection device 10 of this embodiment is, for example, a serial printer in which the liquid ejection unit 12 is movable in the main scanning direction X. The liquid ejection device 10 includes a medium support unit 14 that can face the liquid ejection unit 12 and supports a medium M, and a detection unit 15 that detects the movement of the liquid ejection unit 12.

[0013] The liquid ejection head 13 is provided at a position on the carriage 121 where it can face a medium M such as paper supported by the medium support unit 14. In the example shown in FIG.

[0014] The liquid ejection head 13 has a nozzle forming surface 131 that faces the printing surface Ma of the medium M when printing on the medium M supported by the medium support unit 14, and a plurality of nozzles 132 that eject ink, which is an example of a liquid. In the example shown in FIG. 1, the nozzle forming surface 131 is formed on the bottom surface of the liquid ejection head 13. The plurality of nozzles 132 each open to the nozzle forming surface 131. As a result, the liquid ejection unit 12 has a plurality of nozzles 132 and the nozzle forming surface 131 in which the plurality of nozzles 132 are formed.

[0015] The medium support unit 14 is configured, for example, by a platen having a rectangular plate shape that is long in the main scanning direction X. The platen may have a plurality of ribs that support the medium M. The platen may also have an absorbing member made of a porous material that can absorb liquid such as ink that is ejected from the liquid ejection head 13 to locations other than the medium M.

[0016] When not printing, the carriage 121 waits at a home position HP indicated by a two-dot chain line in FIG. 1 . When printing, the carriage 121 moves from the home position HP to a printing area located on the medium support unit 14 side. The carriage 121 is capable of reciprocating in the main scanning direction X. That is, the carriage 121 is capable of moving forward in the +X direction and moving backward in the -X direction. When the carriage 121 reciprocates, the liquid ejection head 13 ejects liquid such as ink from the nozzles 132 to print characters or images on the medium M at least during one of the forward and backward movements. In the liquid ejection device 10, which is a serial printer of this type, characters or images are printed on the medium M by alternating a printing operation in which the liquid ejection head 13 prints one line (one pass) on the medium M and a transport operation in which the transport unit 40 transports the medium M to the next printing position.

[0017] The detection unit 15 is, for example, a linear encoder 15E that detects movement of the liquid ejection head 13 in the main scanning direction X. The linear encoder 15E includes a long, tape-like linear scale 151 that is installed behind the carriage 121 in a direction perpendicular to the plane of the paper in FIG. 1, and a sensor 152 (see FIG. 2) that is provided on the carriage 121. The linear scale 151 is installed in the main scanning direction X along the movement path of the carriage 121. The linear scale 151 has a number of light-transmitting portions 151A (e.g., slits) arranged at a constant pitch in the main scanning direction X. The sensor 152 includes a light-emitting portion and a light-receiving portion (both not shown) on either side of the linear scale 151. The sensor 152 outputs a detection signal that includes a pulse that is generated each time the light-receiving portion receives light that has passed through the light-transmitting portions 151A of the linear scale 151 from the light-emitting portion. That is, the linear encoder 15E outputs a detection signal including pulses whose number is proportional to the movement distance of the carriage 121 in the main scanning direction X.

[0018] Furthermore, the liquid ejection device 10 is equipped with a maintenance device 20 that performs various maintenance operations on the liquid ejection unit 12. The maintenance device 20 is provided at a position outside the medium support unit 14 in the main scanning direction X (on the right side in FIG. 1). Of the two areas located outside the medium support unit 14 in the main scanning direction X, the area where the maintenance device 20 is located is referred to as the "home position HP." The home position HP is a standby position where the liquid ejection unit 12 waits when not printing. Examples of maintenance operations referred to here include cleaning, which forcibly discharges ink from each nozzle 132, and wiping the nozzle forming surface 131.

[0019] As shown in FIG. 1, the maintenance device 20 includes a cleaning device 21 and a wiping device 30. The cleaning device 21 includes a cap 23 that houses a liquid absorbent material 22 therein, and a suction pump 24 that operates to generate negative pressure within the cap 23. The cap 23 is movable between a retracted position shown by a solid line in FIG. 1 and a capping position shown by a two-dot chain line in FIG. 1. The suction pump 24 is provided midway through a suction tube 25 that communicates with the cap 23. The cleaning device 21 is used when cleaning is performed by the cap 23, the suction pump 24, and the suction tube 25.

[0020] When cleaning is performed, the cap 23, which has risen to the capping position, abuts against the nozzle forming surface 131 of the liquid ejection head 13, which is located at the home position HP, thereby capping the liquid ejection head 13. In this capped state, a substantially closed space is formed between the nozzle forming surface 131 and the cap 23. In this capped state, the suction pump 24 is operated. This creates a negative pressure in the substantially closed space within the cap 23, forcing ink to be discharged from each nozzle 132 of the liquid ejection head 13 into the cap 23. This cleaning discharges thickened ink, air bubbles, and the like from the nozzles 132 together with the ink. This eliminates or prevents clogging of the nozzles 132. The ink discharged into the cap 23 is then discharged into a waste liquid tank (not shown) via a suction tube 25.

[0021] 1 is used to wipe the nozzle forming surface 131. In the example shown in FIG. 1, the wiping device 30 has a wiping unit 31 that wipes the nozzle forming surface 131 of the liquid ejection unit 12. The wiping unit 31 of this embodiment is disposed closer to the medium support unit 14 than the cap 23 in the main scanning direction X. The wiping unit 31 is, for example, a wiper blade. A wiper blade is made of a flexible material such as synthetic resin or rubber, and has, for example, a rectangular plate shape. The wiping unit 31 wipes the nozzle forming surface 131 by moving relative to the liquid ejection unit 12 in a wiping direction WD that is a direction along the nozzle forming surface 131. The wiping direction WD is, for example, a direction along the main scanning direction X. Note that the wiping direction WD includes both the +X direction and the −X direction.

[0022] In the example shown in FIG. 1 , the liquid ejection unit 12 moves in one of the wiping directions WD (for example, the +X direction), causing the wiping unit 31 to wipe the nozzle forming surface 131. The wiping direction WD in which the liquid ejection unit 12 moves during wiping is the direction from the wiping unit 31 toward the medium support unit 14. The wiping unit 31 in this embodiment does not move in the main scanning direction X. The wiping unit 31 wipes the nozzle forming surface 131 as the liquid ejection unit 12 moves in the +X direction from the home position HP. Note that hereinafter, the wiping direction WD may be used to distinguish between different directions. In this embodiment, the liquid ejection unit 12 moves in the +X direction, causing the wiping unit 31 to wipe the nozzle forming surface 131 in the -X direction. In this case, the wiping direction WD in which the liquid ejection unit 12 moves is the +X direction. The wiping direction WD in which the wiping unit 31 wipes the nozzle forming surface 131 is the -X direction.

[0023] As shown in FIG. 1, the liquid ejection device 10 includes a transport unit 40 that transports the medium M. The transport unit 40 transports the medium M along a transport path that passes through a recording position, which is a position where the medium M is supported by the support surface 14A of the medium support unit 14. The transport unit 40 has multiple transport roller pairs 41 (only one of which is shown in FIG. 1) that transport the medium M along the transport path. The transport unit 40 includes a feed unit (both not shown) that includes a feed roller and the like that feeds the medium M stored in a cassette (not shown) or the medium M placed on a feed tray (not shown) one sheet at a time. The transport unit 40 includes one or more motors (not shown) as drive sources that drive the feed rollers and the transport roller pairs 41.

[0024] In this embodiment, the direction in which the medium M is transported at the recording position on the medium support unit 14 is also referred to as the transport direction PF. In the example of the liquid ejection device 10 shown in FIG. 1, the transport direction PF is equal to the +Y direction. The transport direction PF is a direction perpendicular to both the main scanning direction X and the vertical direction Z. The transport direction of the medium M at each position on the transport path changes depending on the position on the transport path. The width direction, which is a direction intersecting the transport direction of the medium M, is a direction parallel to the main scanning direction X. For this reason, the width direction of the medium M is also referred to as the width direction X.

[0025] As shown in FIG. 2, the wiping unit 31 of this embodiment is movable in a movement direction Y between a retracted position RP indicated by a two-dot chain line in the figure and a wiping position WP indicated by a solid line in the figure. The wiping unit 31 is located at the retracted position RP when not wiping. The wiping unit 31 moves from the retracted position RP to the wiping position WP when wiping. As shown in FIG. 2, with the wiping unit 31 located at the wiping position WP, the wiping unit 31 wipes the nozzle surface 131 as the liquid ejection unit 12 moves from the home position HP in the wiping direction WD (+X direction). In this way, the wiping unit 31 wipes the nozzle surface 131 by moving relative to the liquid ejection unit 12 in the wiping direction WD, which is the direction along the nozzle surface 131. Wiping by the wiping unit 31 wipes away liquid such as ink adhering to the nozzle surface 131.

[0026] 2, the wiping unit 31 is closer to the linear scale 151 when it is at the wiping position WP than when it is at the retracted position RP. If ink wiped from the nozzle surface 131 by the wiping unit 31 scatters at the wiping position WP after wiping is completed, the scattered ink may adhere to the linear scale 151, which may result in erroneous detection by the linear encoder 15E (detection unit 15). In this embodiment, the wiping process is performed in a manner that can prevent erroneous detection by the linear encoder 15E due to this type of scattered ink. Details of the wiping process will be described later.

[0027] <Configuration of Maintenance Device 20> Next, a detailed configuration of the maintenance device 20 will be described with reference to FIGS. 3 and 4. As shown in FIGS. 3 and 4, the wiping device 30 has an actuation mechanism 32 that moves the wiping unit 31 in a movement direction Y, which is also the extension direction of the wiping unit 31, and a drive unit 26 that is a drive source for the actuation mechanism 32. The drive unit 26 is, for example, a motor 26A. The wiping device 30 moves at least one of the liquid ejection unit 12 and the wiping unit 31 to wipe the nozzle forming surface 131 with the wiping unit 31. In this embodiment, the wiping device 30 uses the movement of the liquid ejection unit 12, of the liquid ejection unit 12 and the wiping unit 31, in the +X direction to wipe the nozzle forming surface 131 of the liquid ejection unit 12 with the wiping unit 31. The wiping device 30 drives the drive unit 26 to move the wiping unit 31 between a retracted position RP shown in FIG. 3 and a wiping position WP shown in FIG. 4. The wiping device 30 includes a holder 34 that holds the wiping unit 31 and is movable in the movement direction Y.

[0028] The wiping unit 31 extends in a movement direction Y of the wiping unit 31, which is a direction along the nozzle forming surface 131 and a direction different from the main scanning direction X. In other words, the movement direction Y is a direction different from the wiping direction WD (i.e., the main scanning direction X), which is a direction in which the wiping unit 31 moves relative to the liquid ejection unit 12 when wiping the nozzle forming surface 131. In other words, the movement direction Y is a direction along the nozzle forming surface 131 and a direction intersecting the wiping direction WD (i.e., the main scanning direction X). In this embodiment, the movement direction Y is perpendicular to the main scanning direction X. Note that the movement direction Y does not necessarily have to be perpendicular to the main scanning direction X, as long as it is a direction along the nozzle forming surface 131 and a direction different from the main scanning direction X.

[0029] Here, the wiping position WP is a position of the wiping unit 31 where the upper end 311 of the wiping unit 31 can come into contact with the nozzle forming surface 131 of the liquid ejection unit 12 moving in the main scanning direction X. On the other hand, the retracted position RP is a position of the wiping unit 31 where the upper end 311 of the wiping unit 31 cannot come into contact with the nozzle forming surface 131. In FIG. 1, the retracted position RP is set, for example, on the front side of the page relative to the liquid ejection unit 12.

[0030] 3 and 4, the drive unit 26 included in the maintenance device 20 of this embodiment may be a common drive source for the cleaning device 21 and the wiping device 30. In this example, the drive force of the drive unit 26 is transmitted to the wiping unit 31, the cap 23, and the suction pump 24 via an operating mechanism 32. The operating mechanism 32 includes a cam mechanism 33 that selects the destination of the drive force of the drive unit 26, thereby operating the wiping unit 31, the cap 23, and the suction pump 24 in a predetermined operating sequence.

[0031] For example, when the motor 26A, which is an example of the drive unit 26, is driven in the forward direction, the wiping unit 31 moves in the advance direction -Y from the retracted position RP shown in Fig. 3 to the wiping position WP shown in Fig. 4, and the cap 23 descends from the capping position to the retracted position. In this state, when the carriage 121 moves in the +X direction (forward movement direction) in the main scanning direction X from the home position HP shown in Figs. 1 and 2, the nozzle forming surface 131 of the liquid ejection unit 12 is wiped by the wiping unit 31.

[0032] <Wiping operation using the first movement control> Next, with reference to FIGS. 5 to 7, a first movement control will be described in which the control unit 100 moves the wiping unit 31 relative to the liquid ejection unit 12 in the wiping direction WD, thereby causing the wiping unit 31 to wipe the nozzle forming surface 131. The first movement control in this embodiment causes the wiping unit 31 to wipe the nozzle forming surface 131 by moving the carriage 121 in the +X direction (forward direction), which is the direction opposite to the wiping direction WD. Here, the wiping direction WD is a direction along the nozzle forming surface 131. A predetermined amount of interference between the upper end 311 of the wiping unit 31 and the nozzle forming surface 131 in the vertical direction Z is ensured. In addition, the liquid ejection unit 12 has a wiped surface 130 that includes the nozzle forming surface 131.

[0033] 5, the position where the carriage 121 is at the home position HP is the wiping start position. For this reason, in this embodiment, the home position HP is also referred to as the wiping start position HP.

[0034] 6, the wiping unit 31 moves in a wiping direction WD along the nozzle-forming surface 131, causing the upper end 311 of the wiping unit 31 to slide against the nozzle-forming surface 131 while being curved in the direction opposite to the wiping direction WD. The curved upper end 311 of the wiping unit 31 slides against the nozzle-forming surface 131 while being pressed against the nozzle-forming surface 131, thereby wiping away liquid such as ink adhering to the nozzle-forming surface 131. Furthermore, wiping the nozzle-forming surface 131 by the wiping unit 31 straightens the meniscus of liquid such as ink in the nozzles 132 after cleaning, for example. The wiping unit 31 wipes the surface to be wiped 130 so as to wipe the entire nozzle-forming surface 131.

[0035] 7, the wiping unit 31 stops at a wiping end position WE where it comes into contact with the wiped surface 130 relative to the liquid discharge unit 12. In this embodiment, the liquid discharge unit 12 starts moving in the +X direction from the wiping start position HP, and stops at a position at the wiping end position WE where the wiping unit 31 has finished wiping the entire nozzle forming surface 131 from the wiped surface 130. The wiped surface 130 is a surface that needs to be wiped by the wiping unit 31 from the liquid discharge unit 12.

[0036] The wiped surface 130 includes a nozzle surface 131 and a horizontal surface portion that is outward of the nozzle surface 131 in the wiping direction WD. The wiping unit 31, which is at the wiping end position WE, is in contact with the wiped surface 130 with its upper end 311 bent as shown by the solid line in FIG. 7 . If the wiping unit 31 moves away from the liquid ejection unit 12 in the wiping direction WD, the upper end 311 of the wiping unit 31 returns to its upright position from its curved state as shown by the two-dot chain line in FIG. 7 . During this restoration, liquid such as ink adhering to the upper end 311 of the wiping unit 31 scatters. Such liquid such as ink scattered from the wiping unit 31 can contaminate structures within the housing 11. In this embodiment, the wiping unit 31 is stopped at the wiping end position WE to prevent such liquid from scattering. In this embodiment, the first movement control is the control that occurs when the wiping unit 31 wipes the wiped surface 130 including the nozzle forming surface 131 by relative movement between the liquid ejection unit 12 and the wiping unit 31 in the wiping direction WD, and then stops at the wiping end position WE while in contact with the wiped surface 130.

[0037] After the first movement control is completed, when the motor 26A, which is an example of the drive unit 26 shown in Figures 3 and 4, is driven in the reverse direction, the wiping unit 31 moves in the retraction direction +Y from the wiping position WP shown in Figure 4 to the retraction position RP shown in Figure 3. Here, the retraction direction +Y is a direction along the nozzle forming surface 131 and is different from the wiping direction WD.

[0038] When the motor 26A, which is an example of the drive unit 26, is driven in the forward direction, the wiping unit 31 advances in the movement direction Y from the retracted position RP to the wiping position WP, and the cap 23 descends from the capping position to the retracted position. On the other hand, when the motor 26A is driven in the reverse direction, the wiping unit 31 retreats in the movement direction Y (particularly the retraction direction +Y) from the wiping position WP to the retracted position RP, and the cap 23 rises from the retracted position to the capping position. In other words, the retraction operation of the wiping unit 31 from the wiping position WP and the capping operation of the cap 23 on the nozzle forming surface 131 are performed in conjunction with each other. At this time, as a result of the wiping unit 31 retreating in the retraction direction +Y from the movement path of the liquid discharger 12, the liquid discharger 12, which no longer interferes with the wiping unit 31, moves from the wiping end position WE to the home position HP. Then, slightly after the liquid discharge section 12 reaches the home position HP, the cap 23 rises to the capping position indicated by the two-dot chain line in FIG.

[0039] During this time, the reverse driving force of the drive unit 26 is transmitted to the suction pump 24 after a predetermined amount of idle rotation due to a delay mechanism of the operating mechanism 32, which is located midway along the power transmission path between the drive unit 26 and the suction pump 24. Therefore, the suction pump 24 starts to operate after the cap 23 rises to the capping position and caps the nozzle forming surface 131 of the liquid ejection head 13. The suction pump 24 creates a negative pressure in the substantially closed space formed between the cap 23 and the nozzle forming surface 131. This negative pressure forcibly expels thickened ink, air bubbles, and other foreign matter from the nozzles 132 along with the ink. In this manner, the nozzles 132 are cleaned. In this embodiment, the wiping unit 31, cap 23, and suction pump 24 are driven at predetermined timing by the driving force of the drive unit 26, which is a common drive source, via the cam mechanism 33.

[0040] As shown in FIGS. 3 and 4, the wiping device 30 also includes a cleaning unit 35 that cleans the wiping unit 31. The cleaning unit 35 is disposed midway as the wiping unit 31 moves from the wiping position WP to the retracted position RP, in a position where it can come into contact with the wiping unit 31. The wiping unit 31 comes into contact with the cleaning unit 35 while moving in the movement direction Y. The cleaning unit 35 may be an absorbent material capable of absorbing liquid. The absorbent material is, for example, a porous material with an open pore structure made of synthetic resin or a fibrous absorbent material, and is made of a material capable of absorbing liquid such as ink. The absorbent material may be, for example, a sponge or nonwoven fabric.

[0041] 13, as the liquid discharger 12 moves in the main scanning direction X, the wiping unit 31 wipes the wiped surface 130 and then ends the wiping at a wiping end position WE. After wiping ends, the wiping unit 31 moves in a movement direction Y that is different from the main scanning direction X (wiping direction WD). That is, the wiping unit 31 moves (retreats) from a wiping position WP (see FIGS. 2 and 4) to a retracted position RP (see FIGS. 2 and 3). While the wiping unit 31 is retracting, the wiping unit 31 comes into contact with the cleaning unit 35. By contacting the wiping unit 31 with the cleaning unit 35, it is possible to remove ink and other adhering matter from the wiping unit 31. At this time, the wiping unit 31 comes into contact with the cleaning unit 35 before moving away from the wiped surface 130. Specifically, the linear distance L1 in the movement direction Y between the liquid discharge unit 12 and the cleaning unit 35 when they are at the wiping end position WE is shorter than the length L2 in the movement direction Y of the wiping unit 31. Therefore, when the wiping unit 31 is retracted in the movement direction Y and the wiping unit 31 is restored from the bent state when it is separated from the liquid discharge head 13, any adhering matter such as ink has been removed, thereby suppressing the scattering of liquid such as ink.

[0042] <Configuration of the liquid ejection unit 12 and the wiped surface 130> Next, the configurations of the liquid ejection section 12 and the wiped surface 130 will be described with reference to FIGS. 8 to 11. As shown in FIG. 8, the liquid ejection section 12 has, on its underside, the wiped surface 130, which includes a nozzle forming surface 131. The wiped surface 130 includes the nozzle forming surface 131, a surface portion 133, and an inclined surface 134. The liquid ejection head 13 has, on its underside, the nozzle forming surface 131. The carriage 121 has, on its underside, the surface portion 133 and an inclined surface 134. The surface portion 133 is located outside the nozzle forming surface 131 in the main scanning direction X. The surface portion 133 is a horizontal surface located at the same height as the nozzle forming surface 131. The inclined surface 134 is an inclined surface that is inclined upward in the -Z direction as it moves toward the wiping direction WD (-X direction).

[0043] As shown in FIG. 9 , the bottom surface of the liquid ejection unit 12 includes a nozzle forming surface 131, a surface portion 133, and an inclined surface 134, which are arranged in this order along the wiping path WT of the wiping unit 31. A plurality of nozzles 132 are formed in the nozzle forming surface 131. The surface portion 133 is located outside (for example, adjacent to) the nozzle forming surface 131 in the wiping direction WD. The nozzle forming surface 131 has a nozzle row 13R in which a plurality of nozzles 132 are arranged at a constant nozzle pitch in the transport direction PF. A plurality of nozzle rows 13R (eight rows in the example of FIG. 9 ) are provided in the main scanning direction X. In the transport direction PF, the length of the wiping unit 31 is slightly longer than the width of the nozzle forming surface 131. Furthermore, in the transport direction PF, the width of the surface portion 133 is the same as or slightly shorter than the width of the nozzle forming surface 131. Therefore, the wiping unit 31 can wipe the entire width of the surface to be wiped 130 in the transport direction PF.

[0044] The wiped surface 130 is defined as the surface that needs to be wiped. As shown in Figures 9 and 10, the wiped surface 130 may include a nozzle forming surface 131, a surface portion 133 that is a horizontal surface portion outside the wiping direction WD, and an inclined surface 134 portion of the surface portion 133 that is also outside the wiping direction WD.

[0045] The inclined surface 134 is located on the downstream side of the wiping direction WD (-X direction) of the surface portion 133. The inclined surface 134 has an oblique shape formed by cutting a corner at the bottom of the end face on the downstream side of the wiping direction WD of the carriage 121. In the bottom view shown in FIG. 9 , the inclined surface 134 extends in a direction intersecting the movement direction Y of the wiping part 31 at an acute angle.

[0046] 9, target position WC is a target position at which the upper end 311 of the wiping unit 31 is to stop. The target position WC is set relative to the liquid discharger 12 so that when the wiping unit 31 stops at the wiping end position WE (see FIG. 7), the upper end 311 will be located at the target position WC. In other words, the position of the wiping unit 31 set so that the upper end 311 stops at the target position WC is the wiping end position WE. The liquid discharger 12 is controlled to stop so that the wiping unit 31 stops at the wiping end position WE on the wiping path WT.

[0047] A target range SA for stopping the upper end 311 is set on the wiped surface 130. A target position WC is set at the center of the target range SA. The target range SA is the allowable stopping range for the upper end 311 when the upper end 311 is stopped at the target position WC. The setting of the wiping end position WE for stopping the upper end 311 in the target range SA will be described later.

[0048] In the bottom view of the liquid discharger 12 shown in FIG. 9 , the target range SA is set to a range in which at least a portion of the upper end 311 in the extension direction of the wiping part 31 can be located within the area of the slope 134. When the upper end 311 of the wiping part 31 stops within the target range SA, the wiping part 31 always passes through the slope 134 while moving in the retraction direction +Y. The slope 134 extends along an inclined direction that is oblique to the movement direction Y so that the slope 134 is located more upstream in the wiping direction WD (leftward in FIG. 9 ) toward the retraction direction +Y (upward in FIG. 9 ). Therefore, in the movement path along which the upper end 311 located within the target range SA moves in the retraction direction +Y, the portion of the slope 134 that the upper end 311 comes into contact with is located more downstream in the retraction direction +Y than toward the upper direction −Z. Therefore, as the wiping part 31 moves in the retraction direction +Y, the amount of deflection of the wiping part 31 gradually decreases from upstream to downstream in the retraction direction +Y.

[0049] For example, in a configuration in which the carriage 121 does not have the inclined surface 134, or in a configuration in which the upper end 311 of the wiping unit 31 contacts only the horizontal surface 133 even if the carriage 121 has the inclined surface 134, the contact pressure between the upper end 311 and the surface to be wiped 130 is relatively high over the entire movement path of the upper end 311 in the retraction direction +Y. In contrast, in this embodiment in which at least a portion of the upper end 311 is located in the area of the inclined surface 134, the contact pressure between the upper end 311 and the surface to be wiped 130 when the wiping unit 31 moves in the retraction direction +Y is relatively low in the area of the inclined surface 134. In other words, the drive load of the drive unit 26 when the wiping unit 31 moves in the retraction direction +Y can be reduced.

[0050] <About deflection reduction control> Furthermore, in this embodiment, in addition to reducing the deflection of the wiping unit 31 using the slope 134, the control unit 100 executes deflection reduction control to reduce the deflection of the wiping unit 31. The deflection reduction control is control that reduces the deflection of the wiping unit 31 that has stopped at the wiping end position WE relative to the wiped surface 130 by relative movement of the liquid discharger 12 and the wiping unit 31 in the intersecting direction Z. As shown in FIG. 11 , the deflection reduction control of this embodiment moves the liquid discharger 12 upward in the -Z direction, thereby moving the liquid discharger 12 and the wiping unit 31 away from each other in the intersecting direction Z while maintaining their contact. As a result, the relatively large deflection of the wiping unit 31A shown by the solid line in FIG. 11 is reduced to a small amount as shown by wiping unit 31B or wiping unit 31C shown by the two-dot chain line in FIG. 11 due to the upward displacement of the liquid discharger 12 in the -Z direction. Moreover, the deflection reduction control is performed while maintaining the upper end 311 of the wiping part 31 in contact with the wiped surface 130. Therefore, when the wiping part 31 moves away from the wiped surface 130, the wiping part 31 quickly restores its deflection, which prevents liquid such as ink from scattering.

[0051] <Setting the wiping end position WE> Next, setting of the wiping end position WE will be described with reference to FIGS. 12A to 12C. As shown in FIGS. 12A to 12C, the amount of deflection of the wiping unit 31 at the wiping end position WE varies due to factors such as variations in the height position H of the liquid discharger 12. For ease of explanation, in FIGS. 12A to 12C, the height position H of the liquid discharger 12 in the intersecting direction Z is shown relative to the upper surface of the holder 34 that supports the wiping unit 31. Variations in the height position H of the liquid discharger 12 cause changes in the distance ΔH in the intersecting direction Z between the upper surface of the holder 34 and the wiped surface 130. Furthermore, the extension length of the wiping unit 31 from the upper surface of the holder 34 varies due to factors such as variations in the assembly of the wiping unit 31 to the holder 34 and the degree of wear of the wiping unit 31 due to aging and other factors. Due to variations in the distance ΔH in the cross direction Z, variations in the extension length of the wiping part 31, etc., the position in the wiping direction WD where the upper end 311 of the wiping part 31 comes into contact with the wiped surface 130 varies.

[0052] As shown in FIG. 12A, when the distance ΔH is small due to variations or the like, the wiping part 31 at the wiping end position WE bends by a relatively large amount. Also, as shown in FIG. 12B, when the distance ΔH is an intermediate value due to variations or the like, the wiping part 31 at the wiping end position WE bends by a smaller amount than in the case shown in FIG. 12A. Furthermore, as shown in FIG. 12C, when the distance ΔH is large due to variations or the like, the wiping part 31 at the wiping end position WE bends by a relatively small amount. For a given extension length of the wiping part 31, the smaller the distance ΔH, the more the contact position of the upper end 311 shifts upstream in the wiping direction WD (in the +X direction). Variations in the extension length of the wiping part 31 also change the contact position of the upper end 311 in the wiping direction WD. For example, even if the distance ΔH is the same, the shorter the extension length of the wiping part 31, the more the contact position of the upper end part 311 is shifted downstream in the wiping direction WD (in the −X direction).

[0053] In this embodiment, the wiping end position WE and the target range SA are set within a tolerance range, taking into account the distance ΔH and variations in the extension length of the wiping part 31, so that at least a portion of the upper end 311 of the wiping part 31 in the bottom view shown in Fig. 9 is located in the area of the slope 134. The width of the slope 134 and the inclination of the extension direction of the slope 134 with respect to the movement direction Y are set so that at least a portion of the upper end 311 is located in the area of the slope 134 within the target range SA. Note that the slope 134 is not limited to a configuration extending in an extension direction intersecting the movement direction Y in the bottom view of the liquid discharger 12, and may extend along the movement direction Y.

[0054] <Electrical configuration of the liquid ejection device 10> Next, the electrical configuration of the liquid ejection device 10 will be described with reference to FIG. As shown in FIG. 14, the control unit 100 of the liquid ejection device 10 has, as functional units, a printing control unit 101, a cleaning control unit 102, and a wiping control unit 103. The control unit 100 further has a counter 104 and a memory unit 105. The control unit 100 may be configured to include a computer (not shown) that includes the counter 104 and the memory unit 105. The memory unit 105 may store programs shown in the flowcharts of FIGS. 15 to 17. The printing control unit 101, cleaning control unit 102, and wiping control unit 103 may be software that is constructed by a computer executing a program stored in the memory unit 105.

[0055] The control unit 100 is not limited to a system that performs all of its processing using software. For example, the control unit 100 may include a dedicated hardware circuit (e.g., an application-specific integrated circuit (ASIC)) that performs hardware processing for at least some of the processing it performs. That is, the control unit 100 may be configured as a circuit including one or more processors that operate according to a computer program (software), one or more dedicated hardware circuits that perform at least some of the various processes, or a combination thereof. The processor includes a CPU and memory such as RAM and ROM, and the memory stores program code or instructions configured to cause the CPU to perform processing. The memory, i.e., computer-readable medium, includes any available medium that can be accessed by a general-purpose or dedicated computer.

[0056] In this way, the print control unit 101, cleaning control unit 102, and wiping control unit 103 are not limited to software, but may be hardware, or may be configured by a combination of software and hardware.

[0057] The control unit 100 is electrically connected to the transport unit 40, the liquid discharge unit 12, the carriage moving device 50, and the maintenance device 20. The transport unit 40 includes one or more motors (not shown) that are drive sources for the feed roller and the transport roller pair 41 (see FIG. 1). The control unit 100 controls the motors that configure the transport unit 40, thereby controlling the transport of the medium M.

[0058] The liquid ejection unit 12 has an ejection drive element (not shown) that ejects liquid for each nozzle 132 (see FIG. 1). The ejection drive element is, for example, built into the liquid ejection head 13. The ejection drive element is, for example, a piezoelectric element. The piezoelectric element ejects droplets from the nozzle 132 by deforming the wall of a liquid chamber that communicates with the nozzle 132 through electrostriction. The ejection drive element may also be a heater element that boils liquid such as ink. The heater element causes the nozzle 132 to eject droplets by the pressure of bubbles generated by boiling the liquid. Note that the ejection drive element may be any other drive element, such as an electrostatic element, as long as it is capable of ejecting droplets from the nozzle 132.

[0059] The carriage moving device 50 has a function of moving the carriage 121. The carriage moving device 50 of this embodiment includes a scanning mechanism 51 and an elevating mechanism 52. The scanning mechanism 51 is a mechanism that moves the carriage 121 in the main scanning direction X. The elevating mechanism 52 is a mechanism that raises and lowers the liquid ejection unit 12. The elevating mechanism 52 is used to adjust the gap between the nozzle forming surface 131 and the medium support unit 14 (see Figure 1 for both) in accordance with the thickness of the medium M. The scanning mechanism 51 includes a driving unit 53 as a driving source that reciprocates the carriage 121 in the main scanning direction X. The elevating mechanism 52 includes a driving unit 54 as a driving source that raises and lowers the liquid ejection unit 12.

[0060] The scanning mechanism 51 uses, for example, a belt drive system to reciprocate the carriage 121 in the main scanning direction X using the driving force of the drive unit 53. The belt drive scanning mechanism 51 includes a guide unit that guides the carriage 121 in the main scanning direction X, a carriage motor serving as the drive unit 53, and an endless timing belt (all not shown) wound around a pair of pulleys. The output shaft of the carriage motor is connected to one of the pair of pulleys, a drive pulley. The carriage 121 is fixed to a portion of the timing belt. The carriage 121 reciprocates in the main scanning direction X as the timing belt rotates forward and backward due to the forward and reverse drive of the carriage motor. In this way, the scanning mechanism 51 reciprocates the carriage 121 in the main scanning direction X using the driving force of the drive unit 53. Note that the scanning mechanism 51 is not limited to a belt drive system and may use any drive system that can scan the carriage 121 in the main scanning direction X, such as a ball screw drive system or a linear motor drive system.

[0061] The lifting mechanism 52 is a mechanism for adjusting the gap between the nozzle forming surface 131 of the liquid ejection head 13 and the medium support unit 14 (see FIG. 1 for both). The carriage 121 may have, for example, a support unit fixed to a timing belt constituting the scanning mechanism 51 and a main body unit that is movable (up and down) relative to the support unit in the vertical direction Z. In this case, the liquid ejection head 13 may be fixed to the lower part of the main body unit. The lifting mechanism 52 may raise and lower the main body unit relative to the support unit constituting the carriage 121, thereby raising and lowering the liquid ejection head 13 fixed to the main body unit. The lifting mechanism 52 displaces the liquid ejection head 13 in the intersecting direction Z (vertical direction Z) that intersects with the nozzle forming surface 131. Note that the lifting mechanism 52 may also be a mechanism for raising and lowering the liquid ejection head 13 by raising and lowering a guide unit that supports the carriage 121 so as to be able to guide it in the main scanning direction X, using the driving force of a drive unit 54.

[0062] The maintenance device 20 includes a wiping device 30 and a cleaning device 21. The wiping device 30 includes a wiping unit 31 that is movable in a movement direction Y. The cleaning device 21 includes a cap 23 that is movable up and down in a vertical direction Z. The maintenance device 20 also includes a drive unit 26. The drive unit 26 is a drive source that drives the wiping device 30. The drive unit 26 is, for example, a motor. The drive unit 26 may be a drive source common to the wiping device 30 and the cleaning device 21. The drive force of the drive unit 26 may be transmitted to the wiping device 30 and the cleaning device 21 via an actuation mechanism 32 (see FIGS. 3 and 4). In this case, the drive force of the drive unit 26 may cause the wiping device 30 and the cleaning device 21 to operate at predetermined timings via a cam mechanism 33 (see FIGS. 3 and 4) that constitutes the actuation mechanism 32. For example, the cam mechanism 33 may cause the wiping unit 31 and the cap 23 to operate at predetermined timings. Specifically, the cap 23 may be lowered from the capping position to the retracted position while the wiping unit 31 moves in the advance direction -Y from the retracted position RP to the wiping position WP. Alternatively, the cap 23 may be raised from the retracted position to the capping position while the wiping unit 31 moves in the retracted direction +Y from the wiping position WP to the retracted position RP. Furthermore, the suction pump 24 may be driven at a timing after the liquid ejection head 13 is capped by the cap 23 being raised to the capping position by the cam mechanism 33.

[0063] The print control unit 101 controls the liquid ejection unit 12, the transport unit 40, and the carriage moving device 50 when printing on the medium M. The print control unit 101 controls the transport unit 40 to transport the medium M during printing. The print control unit 101 controls the carriage moving device 50 to move the carriage 121 in the main scanning direction X, and ejects liquid such as ink from the nozzles 132 of the liquid ejection head 13 during the movement. In this way, the print control unit 101 prints characters or images on the medium M by controlling the transport of the medium M and the ejection of liquid by the liquid ejection head 13.

[0064] When cleaning is performed, the cleaning control unit 102 controls the carriage moving device 50 and the cleaning device 21 of the maintenance device 20. When it is time to perform cleaning, the cleaning control unit 102 places the carriage 121 at the home position HP and sets the liquid ejection head 13 in a capping state in which the cap 23 abuts against the nozzle forming surface 131. The cleaning control unit 102 cleans the liquid ejection head 13 by driving the suction pump 24 in the capping state.

[0065] The wiping control unit 103 controls the carriage moving device 50 and the wiping device 30 of the maintenance device 20 when wiping the nozzle forming surface 131. The wiping control unit 103 controls the wiping device 30 to move the wiping unit 31 from the retracted position RP to the wiping position WP. Next, the wiping control unit 103 controls the carriage moving device 50 (more specifically, the scanning mechanism 51) to move the carriage 121, for example, from the wiping start position HP in the wiping direction WD (+X). This causes the wiping unit 31 to move relative to the liquid ejection unit 12 in the wiping direction WD, thereby causing the wiping unit 31 to wipe the surface to be wiped 130. Note that the wiping control unit 103 in this embodiment controls the carriage moving device 50 (more specifically, the lifting mechanism 52) to perform control to move the wiping unit 31 and the liquid ejection unit 12 relative to each other in the intersecting direction Z.

[0066] The linear encoder 15E outputs a detection signal containing pulses whose number is proportional to the distance traveled by the carriage 121. The control unit 100 resets the counter 104 when the carriage 121 is located at the home position HP. The control unit 100 causes the counter 104 to count the number of pulse edges in the detection signal input from the linear encoder 15E. Therefore, the count value of the counter 104 indicates the position of the carriage 121 in the main scanning direction X, with the home position HP as the origin. The control unit 100 recognizes the position of the carriage 121 in the main scanning direction X from the count value of the counter 104. The control unit 100 also obtains the movement speed of the carriage 121 based on the number of pulses or pulse edges per unit time contained in the detection signal input from the linear encoder 15E. The control unit 100 controls the carriage movement device 50 (more specifically, the scanning mechanism 51) so that the movement speed of the carriage 121 becomes a target speed.

[0067] When controlling the carriage moving device 50, each of the control units 101 to 103 controls the position and speed of the carriage 121 in the main scanning direction X based on the detection signal from the linear encoder 15E.

[0068] <Operation of the First Embodiment> Next, with reference to FIGS. 1 to 20, the operation of the liquid ejection device 10 when wiping the wiped surface 130 will be described.

[0069] While the liquid ejection device 10 is powered on, the control unit 100 executes a cleaning control routine shown in FIG. 16 and a wiping control routine shown in FIG. 17. The cleaning control routine is a processing routine including a determination process for determining whether a cleaning execution condition is met and a process for performing cleaning when the cleaning execution condition is met. On the other hand, the wiping control routine is a processing routine including a determination process for determining whether a wiping execution condition is met and a wiping process that is executed when the wiping execution condition is met. If the cleaning execution condition is met in the cleaning control routine, the control unit 100 executes a wiping process before and after cleaning in the wiping control routine. If the wiping execution condition is met in the wiping control routine, the control unit 100 executes a wiping process independently of cleaning. In this way, the wiping process may be executed before or after cleaning, or may be executed when a predetermined wiping condition is met regardless of cleaning. The control unit 100 executes the wiping process routine shown in FIG. 15 to perform the wiping process.

[0070] Hereinafter, the cleaning control will be described first with reference to FIG. 16, and then the wiping process that is performed when cleaning is performed in association with this cleaning control and when the wiping execution condition is met will be described with reference to FIGS.

[0071] The cleaning control routine shown in Fig. 16 is executed by the cleaning control unit 102 of the control unit 100. As shown in Fig. 16, in the cleaning control routine, the cleaning control unit 102 sets the cleaning permission flag FLG1 to ON (step S111). The cleaning permission flag FLG1 is a flag that is set to ON to notify the wiping control unit 103 that cleaning will be performed. Next, the cleaning control unit 102 determines whether the wiping flag FLG2, which will be described later, is set to ON (step S112).

[0072] If the wiping flag FLG2 is set to OFF (step S112: NO), the cleaning control unit 102 repeats the determination in step S112 until the wiping flag FLG2 is set to ON. On the other hand, if the wiping flag FLG2 is set to ON (step S112: YES), the cleaning control unit 102 performs cleaning (step S113). That is, the cleaning control unit 102 operates the carriage moving device 50 so that the liquid ejection unit 12 is positioned so that cleaning can be performed. Then, when the movement of the liquid ejection unit 12 in the main scanning direction X is completed, the cleaning control unit 102 operates the cleaning device 21 to bring the cap 23 into contact with the liquid ejection head 13, and in this state, ink is forcibly discharged from each nozzle 132 into the cap 23.

[0073] When the cleaning is completed, the cleaning control unit 102 sets the cleaning permission flag FLG1 to OFF (step S114), and then ends this control routine.

[0074] Next, the wiping control routine executed by the wiping control unit 103 will be described with reference to Fig. 17. The wiping control routine is executed every time a predetermined time has elapsed since the end of the previous execution of the wiping control routine.

[0075] 17, in the wiping control routine, the wiping control unit 103 determines whether the cleaning permission flag FLG1 described above is set to ON (step S121). If the cleaning permission flag FLG1 is set to ON, it can be determined that the conditions for wiping the nozzle forming surface 131 in association with the execution of cleaning are met. On the other hand, if the cleaning permission flag FLG1 is set to OFF, it cannot be determined that the conditions for wiping the nozzle forming surface 131 in association with the execution of cleaning are met.

[0076] If the cleaning permission flag FLG1 is set to OFF (step S121: NO), the wiping control unit 103 determines whether the conditions for wiping the nozzle surface 131 are met when cleaning is not being performed (step S122). When printing on paper, an example of medium M, foreign matter such as paper dust scattered from the paper may adhere to the nozzle surface 131. Therefore, for example, when printing is performed on multiple media M consecutively, it may be determined that the conditions for wiping the nozzle surface 131 are met when printing on a predetermined number of media M is completed. The predetermined number may be an integer of 2 or greater. For example, the predetermined number may be a value in the range of 10 to 100.

[0077] If the wiping execution condition is not met (step S122: NO), the wiping control unit 103 temporarily ends the wiping control routine. On the other hand, if the wiping execution condition is met (step S122: YES), the wiping control unit 103 executes the wiping process described below (step S123). Then, after the wiping process is completed, the wiping control unit 103 proceeds to step S128 described below.

[0078] On the other hand, if the cleaning permission flag FLG1 is set to ON (step S121: YES), the wiping control unit 103 performs the wiping process (step S124). After the wiping process is completed, the wiping control unit 103 proceeds to step S125, which will be described later.

[0079] In step S125, the wiping control unit 103 sets the wiping flag FLG2 to ON. That is, in this embodiment, when cleaning is performed, wiping of the nozzle forming surface 131 is performed before the cleaning. The wiping flag FLG2 is set to OFF when wiping before cleaning has not been completed, and is set to ON when wiping before cleaning has been completed. Next, the wiping control unit 103 determines whether the cleaning performed by the cleaning control unit 102 has been completed (step S128). For example, if the cleaning permission flag FLG1 is set to OFF, it can be determined that the cleaning has been completed. If the cleaning has not yet been completed (step S126: NO), the wiping control unit 103 repeats the determination of step S126. On the other hand, if the cleaning has been completed (step S126: YES), the wiping control unit 103 performs a wiping process (step S127). After the wiping process is completed, the wiping control unit 103 proceeds to the next step S128.

[0080] In step S128, the wiping control section 103 sets the wiping flag FLG2 to OFF, and then the wiping control section 103 temporarily ends the wiping control routine. Next, the wiping process will be described. The wiping control unit 103 starts the wiping process when the wiping unit 31 is positioned at the wiping position WP and the liquid ejection unit 12 is positioned closer to the home position HP in the main scanning direction X (wiping direction) than the wiping unit 31 (i.e., on the opposite side from the medium support unit 14) (see FIG. 5). Then, the wiping control unit 103 operates the carriage movement device 50 to move the liquid ejection unit 12 toward the medium support unit 14 in the main scanning direction X (+X direction). During this movement, as shown in FIG. 6, the upper end 311 of the wiping unit 31 wipes the nozzle forming surface 131. This wiping by the wiping unit 31 wipes away liquid such as ink that has adhered to the nozzle forming surface 131. At this time, foreign matter such as paper dust that has scattered from the medium M such as paper and adhered to the nozzle forming surface 131 is also removed from the nozzle forming surface 131. The wiping unit 31 wipes the surface to be wiped 130, which includes the nozzle forming surface 131. That is, after wiping the nozzle forming surface 131, the wiping unit 31 also wipes the surface portion 133 located further outward than the nozzle forming surface 131 in the wiping direction WD as part of the surface to be wiped 130.

[0081] 7, the wiping unit 31, which is in contact with the surface to be wiped 130, stops wiping when it reaches a wiping end position WE of the liquid discharger 12 on the surface to be wiped 130. That is, when the wiping unit 31 reaches the wiping end position WE on the surface to be wiped 130, the wiping control unit 103 controls the operation of the carriage moving device 50 to stop the liquid discharger 12. In this embodiment, the wiping end position WE is set between the nozzle row 13R, among the multiple nozzle rows 13R aligned in the main scanning direction X, which is located closest to the home position HP in the main scanning direction X (to the right in FIG. 7), and the edge of the surface to be wiped 130 on the home position HP side in the main scanning direction X (the left edge in FIG. 7). In particular, in this embodiment, the wiping end position WE of the wiping section 31 is set so that wiping stops when the upper end 311 is positioned at a target position WC (see Figure 9) within a target range SA set on a surface portion 133 that is located outside the wiping direction WD of the nozzle forming surface 131 on the wiped surface 130.

[0082] Next, the wiping control unit 103 operates the wiping device 30 to move the wiping unit 31 in the retraction direction +Y, as shown in Fig. 20. Then, when the wiping unit 31 moves away from the liquid discharger 12 and reaches the retraction position RP (see Fig. 3), the wiping control unit 103 controls the operation of the wiping device 30 to stop the wiping unit 31.

[0083] In this way, the wiping process includes a first movement control that stops the wiping unit 31 with the upper end 311 in contact with the target position WC on the surface 133 after the wiping unit 31 has wiped the nozzle forming surface 131. The wiping process also includes a second movement control that, after the first movement control, moves the wiping unit 31 in the retraction direction +Y different from the wiping direction WD to move it away from the wiped surface 130. The wiping control unit 103 executes the wiping process that includes the first movement control and the second movement control by controlling the operation of the carriage movement device 50 and the wiping device 30.

[0084] In this embodiment, when the wiping unit 31 is moved from the wiping end position WE in the retraction direction +Y, which is different from the wiping direction WD, the drive load of the drive unit 26, which is the drive source of the wiping unit 31, is likely to increase. One of the reasons for this is a geometric factor of the wiping unit 31, namely, that the retraction direction +Y is a direction in which the wiping unit 31 is less likely to bend, unlike the wiping direction WD, in which the wiping unit 31 is more likely to bend. Another reason is that the upper end 311 of the wiping unit 31 strongly contacts the wiped surface 130 in a bent state, resulting in high contact pressure, which increases the sliding friction resistance between the wiping unit 31 and the wiped surface 130. Another reason is that the sliding friction resistance between the wiping unit 31 and the wiped surface 130 increases due to aging deterioration of at least one of the wiping unit 31 and the wiped surface 130.

[0085] An excessive drive load caused by this type of factor hinders movement of the wiping unit 31 in the retraction direction +Y. When an excessive drive load is applied to the drive unit 26, the movement speed of the wiping unit 31 may become excessively slow, the wiping unit 31 may stop mid-movement, or even starting of the wiping unit 31 may become difficult. In these cases, this leads to an increase in the frequency of error occurrence. Therefore, in this embodiment, the control unit 100 performs deflection reduction control to reduce deflection of the wiping unit 31, which is one of the causes of the drive load on the drive unit 26.

[0086] The wiping process routine executed by the control unit 100 will be described below with reference to Fig. 15. Although the wiping control unit 103 of the control unit 100 executes the wiping process in detail, the wiping process will be described here as being controlled by the control unit 100.

[0087] In step S11, the control unit 100 executes a first movement control. Specifically, the control unit 100 executes a first movement control to move the wiping unit 31 relative to the liquid discharge unit 12 in a wiping direction WD along the nozzle forming surface 131, causing the wiping unit 31 to wipe the wiped surface 130. In this first movement control, the liquid discharge unit 12 moves in the wiping direction WD (more specifically, the +X direction). By moving the wiping unit 31 and the liquid discharge unit 12 relative to each other in the wiping direction WD, the wiping unit 31 wipes the wiped surface 130 and stops at a wiping end position WE. In other words, after the liquid discharge unit 12 has wiped the nozzle forming surface 131, the wiping unit 31 stops at the wiping end position WE with the wiping unit 31 in contact with a surface portion 133 of the wiped surface 130 that is positioned outside the nozzle forming surface 131 in the wiping direction WD. More specifically, the control unit 100 controls the carriage moving device 50 to stop the liquid discharge unit 12 when the wiping unit 31 reaches the wiping end position WE. As a result, as shown in Fig. 18, the wiping unit 31 finishes wiping the wiped surface 130 in a state where it is bent in the opposite direction to the wiping direction WD with its upper end 311 in contact with the wiped surface 130. Liquid IL, such as ink, that has been wiped from the wiped surface 130 adheres to the vicinity of the upper end 311 of the wiping unit 31.

[0088] In step S12, the control unit 100 executes deflection reduction control. Specifically, the control unit 100 executes deflection reduction control to reduce the amount of deflection of the wiping unit 31 by moving the wiping unit 31 relative to the liquid ejection unit 12 in the intersecting direction Z that intersects the nozzle forming surface 131. In this deflection reduction control, the liquid ejection unit 12 moves in the intersecting direction Z. The control unit 100 controls the carriage moving device 50 to raise the liquid ejection unit 12 upward in the -Z direction, thereby separating the wiping unit 31 and the liquid ejection unit 12 in the intersecting direction Z while maintaining contact between the wiping unit 31 and the wiped surface 130. As a result, as shown in FIG. 19 , the lifting of the liquid ejection unit 12 reduces the amount of deflection of the wiping unit 31 while maintaining contact with the wiped surface 130. The reduction in the amount of deflection of the wiping unit 31 reduces the contact pressure of the wiping unit 31 with the wiped surface 130.

[0089] In step S13, the control unit 100 executes second movement control. Specifically, the control unit 100 executes second movement control to move the wiping unit 31 relative to the liquid discharger 12 in a retraction direction +Y different from the wiping direction WD to separate it from the liquid discharger 12. In this second movement control, the wiping unit 31 moves in the retraction direction +Y. The control unit 100 controls the drive unit 26 to move the wiping unit 31, which is in contact with the wiped surface 130 at the wiping end position WE, in the retraction direction +Y from the wiping position WP to the retraction position RP. Specifically, the control unit 100 reversely drives the motor 26A, which is an example of the drive unit 26. The wiping unit 31, which is in the wiping end position WE relative to the wiped surface 130 of the liquid discharger 12, moves in the retraction direction +Y from the wiping position WP to the retraction position RP. At this time, since the amount of bending of the wiping part 31 has been reduced by the bending reduction control, the wiping part 31 slides against the wiped surface 130 with a relatively small contact pressure. This allows a relatively small driving load on the drive part 26. Therefore, as shown in Fig. 20, the wiping part 31 can move smoothly in the retraction direction +Y by the driving force of the drive part 26. The wiping part 31 moves away from the liquid discharge part 12 in the process of moving in the retraction direction +Y.

[0090] The amount of bending of the wiping unit 31 during separation in this second movement control is small. Therefore, even when the wiping unit 31 returns to a straight state from a bent state during separation, scattering of liquid such as ink from the wiping unit 31 is suppressed. Furthermore, the side on which the wiping unit 31 moves away from the liquid ejection unit 12 is opposite (the retraction direction +Y side) to the linear scale 151 (see FIG. 2) of the detection unit 15. Therefore, even if liquid such as ink splashes when the wiping unit 31 returns to its bent state, the splashed liquid is unlikely to adhere to the linear scale 151. Therefore, erroneous detection of the position of the carriage 121 due to liquid such as ink adhering to the linear scale 151 is suppressed.

[0091] 20, the wiping unit 31 comes into contact with the cleaning unit 35 while moving in the retraction direction +Y, and liquid such as ink adhering to the wiping unit 31 is removed by the cleaning unit 35. After moving away from the liquid ejection unit 12, the wiping unit 31 moves to the retraction position RP (see FIG. 3) and stops there.

[0092] In this embodiment, the drive unit 26 is a common drive source for the wiping unit 31, the cap 23, and the suction pump 24, and therefore the cap 23 rises during the retraction of the wiping unit 31. Therefore, the drive unit 26 is subjected to a load when retracting the wiping unit 31 and a load when lifting the cap 23. This means that the drive load on the drive unit 26 is likely to be large during the retraction of the wiping unit 31. This is due to factors such as the shape of the wiping unit 31, in which the retraction direction +Y in which the wiping unit 31 moves is a direction in which the wiping unit 31 is less likely to bend, and deterioration over time, which increases the frictional resistance between the wiping unit 31 and the wiped surface 130, and the fact that the drive unit 26 is a common drive source. This, in addition to factors such as the shape of the wiping unit 31, in which the retraction direction +Y in which the wiping unit 31 moves is a direction in which the wiping unit 31 is less likely to bend, and deterioration over time, which increases the frictional resistance between the wiping unit 31 and the wiped surface 130, makes it more likely that the drive load on the drive unit 26 will become excessive. However, in this embodiment, even in situations where such driving loads are likely to become excessive, deflection reduction control is performed that can alleviate the driving load during the wiping process, so that the wiping section 31 can be moved smoothly to the retracted position RP.

[0093] <Effects of the first embodiment> Therefore, according to the first embodiment, the following effects can be obtained. (1-1) The liquid ejection device 10 includes a liquid ejection unit 12, a wiping unit 31, a drive unit 26, and a control unit 100. The liquid ejection unit 12 has a plurality of nozzles 132 capable of ejecting liquid and a nozzle forming surface 131 on which the plurality of nozzles 132 are formed. The wiping unit 31 wipes a surface to be wiped 130 including the nozzle forming surface 131. The drive unit 26 moves at least one of the liquid ejection unit 12 and the wiping unit 31. The control unit 100 drives the drive unit 26 to perform the following controls. That is, the control unit 100 performs first movement control to move the wiping unit 31 relative to the liquid ejection unit 12 in a wiping direction WD along the nozzle forming surface 131, causing the wiping unit 31 to wipe the surface to be wiped 130. After the first movement control, the control unit 100 executes deflection reduction control to reduce the amount of deflection of the wiping unit 31 by moving the wiping unit 31 relative to the liquid discharge unit 12 in the intersecting direction Z that intersects the nozzle forming surface 131 while maintaining contact between the wiping unit 31 and the liquid discharge unit 12. After the deflection reduction control, the control unit 100 executes second movement control to move the wiping unit 31 relative to the liquid discharge unit 12 in the retraction direction +Y that is a direction along the nozzle forming surface 131 and different from the wiping direction WD, thereby separating the wiping unit 31 from the liquid discharge unit 12. According to this configuration, by executing the deflection reduction control before executing the second movement control, the drive load of the drive unit 26 can be reduced.

[0094] (1-2) In the first movement control, the liquid discharger 12 moves in the wiping direction WD. In the deflection reduction control, the liquid discharger 12 moves in the intersecting direction Z. In the second movement control, the wiping unit 31 moves in the retraction direction +Y. According to this configuration, by performing the deflection reduction control before performing the second movement control, the driving load of the drive unit 26 can be reduced.

[0095] (1-3) The liquid ejection device 10 includes a medium support unit 14 and a detection unit 15. The medium support unit 14 is capable of facing the liquid ejection unit 12 and supports the medium M. The detection unit 15 detects the movement of the liquid ejection unit 12. The wiping direction WD is the direction from the wiping unit 31 toward the medium support unit 14. With this configuration, the second movement control is performed when it is desired to reduce the risk of the detection unit 15 being contaminated by liquid such as ink being scattered by the first movement control, and in this case, the risk of an increase in the drive load can be reduced.

[0096] (1-4) The liquid ejection device 10 includes a cleaning unit 35 that cleans the wiping unit 31. The wiping unit 31 comes into contact with the cleaning unit 35 during the relative movement in the second movement control. With this configuration, the wiping unit 31 comes into contact with both the liquid discharge unit 12 and the cleaning unit 35 during the second movement control, which tends to increase the drive load. Even with this configuration, the drive load can be effectively reduced.

[0097] (1-5) The cleaning part 35 is an absorbent body capable of absorbing liquid. With this configuration, the wiping part 31 can be cleaned with a simple configuration. (1-6) A control method for the liquid ejection device 10 including the liquid ejection unit 12, the wiping unit 31, and the drive unit 26 includes controlling the drive unit 26 and includes the following (a1), (b1), and (c1). (a1) Driving the drive unit 26 to move the wiping unit 31 relative to the liquid ejection unit 12 in the wiping direction WD along the nozzle forming surface 131, thereby executing a first movement control to cause the wiping unit 31 to wipe the wiped surface 130 (step S11). (b1) After the first movement control, a deflection reduction control is performed to reduce the amount of deflection of the wiping portion 31 by moving the wiping portion 31 relative to the liquid ejection portion 12 in the intersecting direction Z that intersects the nozzle forming surface 131 while maintaining contact between the wiping portion 31 and the liquid ejection portion 12 (step S12). (c1) After the deflection reduction control, a second movement control is executed to move the wiping portion 31 relative to the liquid ejection portion 12 in a retraction direction +Y, which is a direction along the nozzle forming surface 131 and different from the wiping direction WD, thereby moving the wiping portion 31 away from the liquid ejection portion 12 (step S13). According to this method, the drive load on the drive unit 26 can be reduced by executing the deflection reduction control before executing the second movement control.

[0098] (Second embodiment) Next, a second embodiment of the liquid ejection device will be described with reference to FIGS. 21 to 25. The second embodiment differs from the first embodiment in the content of the wiping process routine. In the first embodiment, flexure reduction control was executed for each wiping process, but this embodiment differs from the first embodiment in that flexure reduction control is executed only when the drive load is excessive. Other configurations apart from the wiping process are the same as those of the first embodiment. Only the wiping process will be described below.

[0099] In the second embodiment, the control unit 100 executes a wiping process routine shown in the flowchart of FIG. First, in step S21, the control unit 100 executes a first movement control. Specifically, the control unit 100 executes the first movement control to move the wiping unit 31 relative to the liquid discharge unit 12 in the wiping direction WD along the nozzle forming surface 131, causing the wiping unit 31 to wipe the nozzle forming surface 131. In this first movement control, the liquid discharge unit 12 moves in the wiping direction WD (specifically, the +X direction). The process of step S21 is basically the same as step S11 in the first embodiment. When the first movement control is completed, the wiping unit 31 is at a wiping end position WE where its upper end portion 311 contacts the wiped surface 130 at the target position WC relative to the liquid discharge unit 12. As shown in FIG. 22 , the wiping unit 31 is in contact with the wiped surface 130 while being bent by a large amount.

[0100] In step S22, the control unit 100 executes second movement control. Specifically, the control unit 100 executes second movement control to move the wiping unit 31 relative to the liquid discharge unit 12 in the retraction direction +Y to separate it from the liquid discharge unit 12. In this second movement control, the wiping unit 31 moves in the retraction direction +Y. Specifically, the control unit 100 controls the drive unit 26 to move the wiping unit 31 from the wiping position WP in the retraction direction +Y. Specifically, the control unit 100 reversely drives the motor 26A, which is an example of the drive unit 26. The reverse driving force of the motor 26A is transmitted as a propulsion force in the retraction direction +Y of the wiping unit 31 via the actuation mechanism 32, which includes the cam mechanism 33. At this time, as shown in FIG. 22 , the wiping unit 31 is in a relatively large deflected state. Therefore, the drive load of the drive unit 26 may become excessively large. Therefore, as shown in Figure 23, even if the wiping unit 31 receives the driving force of the drive unit 26, it may not be able to move in the retraction direction +Y, or even if it can move, the movement speed may be extremely slow.

[0101] In step S23, the control unit 100 determines whether the drive load of the drive unit 26 exceeds a threshold value during execution of the second movement control. The control unit 100 obtains the drive load of the drive unit 26 from a command value that controls the rotational speed of the drive unit 26. The control unit 100 obtains the actual speed of the drive unit 26 and controls the speed of the drive unit 26 through feedback control that brings the actual speed closer to the target speed. If the actual speed is lower than the target speed, the control unit 100 increases the command value to reduce the difference. If the drive load is excessive, the actual speed cannot catch up with the target speed and the command value increases. The control unit 100 can estimate the drive load based on the command value. The control unit 100 may also use the command value as the drive load. For example, if the wiping unit 31 cannot start due to an excessive drive load, or if the wiping unit 31 moves at a speed significantly slower than the target speed, the drive load of the drive unit 26 exceeds the threshold value. If the drive load of the drive unit 26 exceeds the threshold, the control unit 100 proceeds to step S24. On the other hand, if the drive load of the drive unit 26 is equal to or less than the threshold, the wiping process routine ends. That is, if the drive load of the drive unit 26 is equal to or less than the threshold, the wiping unit 31 can move smoothly to the retracted position RP at approximately the target speed. When the wiping unit 31 reaches the retracted position RP, the control unit 100 stops the reverse driving of the drive unit 26. This causes the control unit 100 to end the wiping process routine.

[0102] In step S24, the control unit 100 stops the second movement control, that is, the control unit 100 stops the reverse driving of the drive unit 26. In step S25, the control unit 100 executes deflection reduction control. More specifically, the control unit 100 executes deflection reduction control to reduce the amount of deflection of the wiping unit 31. In this embodiment, the control unit 100 executes deflection reduction control by moving the liquid discharger 12 in the transverse direction Z as the deflection reduction control. That is, the control unit 100 executes deflection reduction control similar to step S12 in the first embodiment. The control unit 100 controls the carriage moving device 50 to raise the liquid discharger 12 upward in the -Z direction, thereby separating the wiping unit 31 and the liquid discharger 12 in the transverse direction Z while maintaining contact between the wiping unit 31 and the wiped surface 130. As a result, as shown in FIG. 24 , the lifting of the liquid discharger 12 reduces the amount of deflection of the wiping unit 31 while maintaining contact with the wiped surface 130.

[0103] In step S26, the control unit 100 executes the second movement control. More specifically, the control unit 100 executes the second movement control to move the wiping unit 31 relative to the liquid discharge unit 12 in the retraction direction +Y, which is different from the wiping direction WD, to move the wiping unit 31 away from the liquid discharge unit 12. That is, the control unit 100 resumes the second movement control after the deflection reduction control. In this way, in the second embodiment, the wiping unit 31 is moved relative to the liquid discharge unit 12 in the intersecting direction Z intersecting the nozzle forming surface 131 while maintaining contact between the wiping unit 31 and the liquid discharge unit 12, and then the second movement control is resumed.

[0104] In this case, the speed of the relative movement in the second movement control after the deflection reduction control may be slower than the speed of the relative movement in the second movement control before the deflection reduction control. If the speed of the relative movement in the second movement control before the deflection reduction control is defined as a first speed V1 and the speed of the relative movement in the second movement control after the deflection reduction control is defined as a second speed V2, then V1 > V2. Here, if the drive unit 26 is a motor 26A, a large torque can be obtained when the rotation speed is low. By moving the wiping unit 31 at a target speed of the second speed V2 that satisfies V1 > V2, the wiping unit 31 can be moved with a large torque of the motor 26A. Therefore, when the second movement control is resumed, the wiping unit 31 can move to the retracted position RP at approximately the target speed due to the reduced deflection and the large torque, even with a somewhat large drive load.

[0105] 25, the wiping unit 31 can be moved smoothly in the retraction direction +Y by the driving force of the drive unit 26. The wiping unit 31 moves away from the liquid discharge unit 12 while moving in the retraction direction +Y. The wiping unit 31 is only bent by a small amount during this separation in the second movement control. Therefore, even if the wiping unit 31 returns from its bent state to a straight state during separation, scattering of liquid such as ink from the wiping unit 31 is suppressed.

[0106] <Effects of the second embodiment> Therefore, according to the second embodiment, in addition to the effects (1-1) to (1-6) in the first embodiment, the following effects can be obtained.

[0107] (2-1) The liquid ejection device 10 includes a liquid ejection unit 12, a wiping unit 31, a drive unit 26, and a control unit 100. The liquid ejection unit 12 has a plurality of nozzles 132 capable of ejecting liquid and a nozzle forming surface 131 on which the plurality of nozzles 132 are formed. The wiping unit 31 wipes a wiped surface 130 including the nozzle forming surface 131. The drive unit 26 moves at least one of the liquid ejection unit 12 and the wiping unit 31. The control unit 100 drives the drive unit 26 to perform the following controls. The control unit 100 performs first movement control to move the wiping unit 31 relative to the liquid ejection unit 12 in a wiping direction WD along the nozzle forming surface 131, causing the wiping unit 31 to wipe the nozzle forming surface 131. After the first movement control, the control unit 100 executes second movement control to move the wiping unit 31 relative to the liquid discharge unit 12 in a retraction direction +Y that is a direction along the nozzle forming surface 131 and different from the wiping direction WD, thereby separating the wiping unit 31 from the liquid discharge unit 12. If the drive load of the drive unit 26 becomes greater than a threshold value while the control unit 100 is executing the second movement control, the control unit 100 stops the second movement control and executes deflection reduction control to reduce the amount of deflection of the wiping unit 31. With this configuration, by executing deflection reduction control when the drive load becomes large, the drive load of the drive unit 26 can be reduced. Compared to the configuration of claim 1, there is no need to execute deflection reduction control each time, which saves time.

[0108] (2-2) As the deflection reduction control, the control unit 100 moves the wiping unit 31 relatively to the liquid discharge unit 12 in the intersecting direction Z that intersects with the nozzle surface 131 while maintaining contact between the wiping unit 31 and the liquid discharge unit 12, and then resumes the second movement control. According to this configuration, the amount of deflection of the wiping unit 31 can be reduced by moving the wiping unit 31 relatively in the intersecting direction Z. Therefore, the second movement control can be resumed.

[0109] (2-3) The speed of the relative movement in the second movement control is slower after the deflection reduction control than before the deflection reduction control. With this configuration, an increase in the drive load can be reduced. (2-4) A control method for the liquid ejection device 10 including the liquid ejection unit 12, the wiping unit 31, and the drive unit 26 includes controlling the drive unit 26 and includes the following (a2), (b2), and (c2). (a2) Executing a first movement control to move the wiping unit 31 relative to the liquid ejection unit 12 in a wiping direction WD along the nozzle forming surface 131, and causing the wiping unit 31 to wipe the nozzle forming surface 131 (step S21). (b2) After the first movement control, a second movement control is executed to move the wiping portion 31 relative to the liquid ejection portion 12 in a retraction direction +Y, which is a direction along the nozzle forming surface 131 and a direction different from the wiping direction WD, thereby moving the wiping portion 31 away from the liquid ejection portion 12 (step S22). (c2) If the drive load of the drive unit 26 becomes greater than a threshold value while the second movement control is being executed, the second movement control is stopped, and a deflection reduction control is executed to reduce the amount of deflection of the wiping unit 31 (steps S23, S24). According to this method, when the driving load becomes large, deflection reduction control is performed, thereby reducing the driving load of the driving unit 26. Compared to the method described in (2-6) in the first embodiment, it is not necessary to perform deflection reduction control each time, which reduces the time required.

[0110] (2-5) The control method of the liquid ejection device 10 includes, as deflection reduction control, moving the wiping unit 31 relative to the liquid ejection unit 12 in the intersecting direction Z that intersects with the nozzle surface 131 while maintaining contact between the wiping unit 31 and the liquid ejection unit 12, and then resuming the second movement control. According to this method, the amount of deflection of the wiping unit 31 can be reduced by moving it relative to the liquid ejection unit 12 in the intersecting direction Z. Therefore, the second movement control can be resumed.

[0111] (2-6) In the control method for the liquid ejection device 10, the speed of the relative movement in the second movement control is slower after the deflection reduction control than before the deflection reduction control. This method can reduce the increase in the drive load.

[0112] It should be noted that (a1), (b1), and (c1) in the control method for the liquid ejection device 10 shown in effect (1-6) of the first embodiment correspond to steps S21, S25, and S26, respectively, in the second embodiment.

[0113] (Third embodiment) Next, a third embodiment of the liquid ejection device will be described with reference to Figures 26 to 31. The third embodiment differs from the first and second embodiments in the content of the wiping process routine. In the second embodiment, the second movement control is resumed after the deflection reduction control, which is performed when the drive load exceeds a threshold value. However, this embodiment differs from the second embodiment in that the movement direction of the wiping unit 31 is switched to the wiping direction WD after the deflection reduction control. The configuration other than the wiping process is the same as that of the first embodiment. Only the wiping process will be described below.

[0114] In the third embodiment, the control unit 100 executes a wiping process routine shown in the flowchart of FIG. First, in step S31, the control unit 100 executes a first movement control. Specifically, the control unit 100 executes the first movement control to relatively move the wiping unit 31 and the liquid discharge unit 12 in the wiping direction WD, causing the wiping unit 31 to wipe the nozzle forming surface 131 and then stop at a wiping end position WE. In the first movement control, the liquid discharge unit 12 moves in the wiping direction WD (specifically, the +X direction). The process of step S31 is basically the same as step S11 in the first embodiment. When the first movement control is completed, the wiping unit 31 is at the wiping end position WE where its upper end 311 contacts the wiped surface 130 at the target position WC relative to the liquid discharge unit 12. As shown in FIG. 27 , the wiping unit 31 is in contact with the wiped surface 130 while being bent by a large amount.

[0115] In step S32, the control unit 100 executes second movement control. More specifically, the control unit 100 executes second movement control to move the wiping unit 31 relative to the liquid discharge unit 12 in the retraction direction +Y to separate it from the liquid discharge unit 12. In this second movement control, the wiping unit 31 moves in the retraction direction +Y. The processing of this step S31 is basically the same as the processing of step S22 in the second embodiment. Therefore, as shown in FIG. 28 , even if the wiping unit 31 receives the driving force of the drive unit 26, there are cases where it cannot move in the retraction direction +Y, or even if it can move, the moving speed is extremely slow.

[0116] In step S33, the control unit 100 determines whether the drive load of the drive unit 26 exceeds a threshold value while the second movement control is being executed. The determination process in step S23 is basically the same as step S23 in the second embodiment. If the drive load of the drive unit 26 exceeds the threshold value, the control unit 100 proceeds to step S34. On the other hand, if the drive load of the drive unit 26 is equal to or less than the threshold value, the control unit 100 confirms that the wiping unit 31 has stopped at the retracted position RP, and then ends the wiping process routine.

[0117] In step S34, the control unit 100 stops the second movement control and starts timing the waiting time. The control unit 100 counts the time until the waiting time has elapsed by the counting process of a built-in timing counter. As an example, the waiting time is set to a predetermined time within a range of 10 seconds to 3 minutes (for example, 1 minute). This waiting time is set based on the time required for the liquid IL, such as ink, adhering to the wiping unit 31 after wiping has finished to flow down the wiping unit 31. Once the control unit 100 starts timing the waiting time, it proceeds to the next step, S35. The waiting time may be less than 10 seconds or more than 3 minutes.

[0118] In step S35, the control unit 100 executes deflection reduction control to reduce the amount of deflection of the wiping unit 31 during standby. The processing in step S35 is basically the same as that in step S25 of the second embodiment. That is, as the deflection reduction control, the control unit 100 moves the wiping unit 31 relative to the liquid discharge unit 12 in the intersecting direction Z intersecting the nozzle forming surface 131 while maintaining contact between the wiping unit 31 and the liquid discharge unit 12. In this deflection reduction control, the liquid discharge unit 12 moves in the intersecting direction Z. As a result, as shown in FIG. 29 , the liquid discharge unit 12 rises, reducing the amount of deflection of the wiping unit 31 while maintaining contact with the wiped surface 130. In this embodiment, the deflection reduction control is performed in parallel while utilizing the waiting time until the standby time has elapsed.

[0119] In step S36, the control unit 100 determines whether the standby time has elapsed. If the standby time has elapsed, the process proceeds to step S37. On the other hand, if the standby time has not elapsed, the process continues to wait until the standby time has elapsed. When the standby time has elapsed, as shown in FIG. 30, most of the liquid IL, such as ink, adhering to the wiping unit 31 has flowed down along the wiping unit 31.

[0120] In step S37, the control unit 100 executes third movement control. Specifically, the control unit 100 executes third movement control to move the wiping unit 31 relative to the liquid discharge unit 12 in the wiping direction WD to separate it from the liquid discharge unit 12. The control unit 100 controls the carriage movement device 50 to move the liquid discharge unit 12 in the wiping direction WD (+X direction) from a state in which the wiping unit 31 is at the wiping end position WE. As a result, as shown in FIG. 31 , the wiping unit 31 moves relative to the liquid discharge unit 12 in the wiping direction WD (-X direction) from the wiping end position WE indicated by the two-dot chain line in the figure, and moves away from the liquid discharge unit 12 to the outside of the wiping direction WD. During this separation, the wiping unit 31 returns to its original state. However, because only a small amount of liquid, such as ink, adheres to the wiping unit 31 at this time, little or no liquid splashes, or even if it does splash, it splashes only very little. Therefore, problems such as erroneous detection of the position or speed of the liquid discharger 12 due to scattered liquid adhering to the linear scale 151 are unlikely to occur. Note that in FIG. 31, the wiping unit 31 is shown in a relative position with respect to the liquid discharger 12.

[0121] In this third movement control, since it is performed after the deflection reduction control, the contact pressure between the wiping unit 31 and the wiped surface 130 is small. Furthermore, the movement direction of the wiping unit 31 is the wiping direction WD, which is prone to deflection. Therefore, compared to the second movement control, which moves the wiping unit 31 in the retraction direction +Y, the drive load is smaller. Furthermore, when moving the wiping unit 31 in the wiping direction WD, the drive unit 53, which is made up of a carriage motor that can obtain a larger torque than the motor 26A, which is an example of the drive unit 26 of the maintenance device 20, is driven. Therefore, it is possible to move the wiping unit 31 to a position separated from the liquid discharger 12 in the main scanning direction X.

[0122] In step S38, the control unit 100 moves the wiping unit 31 in the retraction direction +Y to return it to the retraction position RP. The process of step S38 is basically the same as the second movement control process of step S13 in the first embodiment. That is, the control unit 100 drives the drive unit 26 in the reverse direction to move the wiping unit 31 from the wiping position WP to the retraction position RP. However, in the second movement control, the wiping unit 31 moves in the retraction direction +Y while in contact with the surface to be wiped 130. In contrast, in step S38, as shown in FIG. 31, the wiping unit 31 moves in the retraction direction +Y from the wiping position WP indicated by the solid line in the figure without contacting the surface to be wiped 130. In this way, the wiping unit 31 reaches the retraction position RP (see FIG. 3) and stops after the cleaning unit 35 removes liquid such as ink adhering to the wiping unit 31 during its movement in the retraction direction +Y.

[0123] <Effects of the third embodiment> Therefore, according to the third embodiment, in addition to the effects (1-2) to (1-6) in the first embodiment and the effects (2-1) and (2-4) in the second embodiment being similarly obtained, the following effects are also obtained.

[0124] (3-1) As the deflection reduction control, the control unit 100 moves the wiping unit 31 relative to the liquid ejection unit 12 in the intersecting direction Z that intersects the nozzle surface 131 while maintaining contact between the wiping unit 31 and the liquid ejection unit 12, and then moves the wiping unit 31 relative to the liquid ejection unit 12 in the wiping direction WD to separate the wiping unit 31 from the liquid ejection unit 12. With this configuration, by switching the movement direction from the second movement control, the risk of a drive load being applied again is reduced. The relative movement in the intersecting direction Z reduces the amount of deflection of the wiping unit 31, thereby reducing the amount of splashing of liquid such as ink.

[0125] (3-2) The control method for the liquid ejection device 10 includes, as deflection reduction control, moving the wiping unit 31 relative to the liquid ejection unit 12 in the intersecting direction Z intersecting the nozzle surface 131 while maintaining contact between the wiping unit 31 and the liquid ejection unit 12, and then moving the wiping unit 31 relative to the liquid ejection unit 12 in the wiping direction WD to separate the wiping unit 31 from the liquid ejection unit 12. This method reduces the risk of a drive load being applied again by switching the movement direction from the second movement control. The relative movement in the intersecting direction Z reduces the amount of deflection of the wiping unit 31, thereby reducing the amount of splashing of liquid such as ink.

[0126] (3-3) In the second movement control, if the drive load of the drive unit 26 exceeds the threshold, the control waits until a waiting time has elapsed, which is the time it takes for the liquid IL, such as ink, adhering to the wiping unit 31 to flow down the wiping unit 31. Therefore, even if the wiping unit 31 is subsequently separated from the liquid ejection unit 12, scattering of ink from the wiping unit 31 can be suppressed, and the wiping unit 31 can be moved in the wiping direction WD. The wiping direction WD is a direction in which the wiping unit 31 is likely to bend, so the wiping unit 31 can be separated from the liquid ejection unit 12 with a relatively small drive load.

[0127] (Fourth embodiment) Next, a fourth embodiment of the liquid ejection device will be described with reference to FIG. 32. The fourth embodiment is a modification of the third embodiment. In the third embodiment, the standby time and the deflection reduction control are performed in parallel. However, in this embodiment, the deflection reduction control is not performed and only the standby time is performed. The processes of steps S41 to S43 are essentially the same as the processes of steps S31 to S33 in the third embodiment. In step S41, the control unit 100 executes the first movement control to cause the wiping unit 31 to wipe the surface to be wiped 130. Next, in step S42, the control unit 100 executes the second movement control to move the wiping unit 31 in the retraction direction +Y. In the next step S43, the control unit 100 determines whether the drive load of the drive unit 26 exceeds a threshold value while the second movement control is being performed. If the drive load of the drive unit 26 exceeds the threshold value, in step S44, the control unit 100 stops the second movement control and waits for the standby time. The standby time is, as in the third embodiment, a predetermined time (e.g., 1 minute) within a range of 10 seconds to 3 minutes. As a result of waiting for the standby time, most of the liquid IL, such as ink, adhering to the wiping unit 31 flows down along the wiping unit 31, as shown in Fig. 30. In step S45, the control unit 100 executes third movement control to move the wiping unit 31 relative to the liquid discharge unit 12 in the wiping direction WD.

[0128] As a result, as shown in FIG. 31 , the wiping unit 31 moves relative to the liquid discharger 12 in the wiping direction WD (-X direction) from the wiping end position WE indicated by the two-dot chain line in the figure, and moves away from the liquid discharger 12 to the outside of the wiping direction WD. When the wiping unit 31 moves away, it returns to its original state. However, because only a small amount of liquid, such as ink, adheres to the wiping unit 31 at this time, almost no liquid, or even if it does, only a very small amount, splashes. Then, in step S46, the control unit 100 moves the wiping unit 31 in the retraction direction +Y to return it to the retraction position RP. As shown in FIG. 31 , the wiping unit 31 moves from a position separated from the liquid discharger 12 in the main scanning direction X to the retraction direction +Y from the wiping position WP indicated by the solid line in the figure. During this movement, the cleaning unit 35 removes the liquid, such as ink, adhering to the wiping unit 31, and the wiping unit 31 then reaches the retraction position RP (see FIG. 3 ) and stops.

[0129] Therefore, according to the fourth embodiment, the effects (1-2) to (1-6) in the first embodiment and the effect (3-3) in the third embodiment can be obtained in the same way. The above embodiment can be modified as shown in the following modified examples. Furthermore, the above embodiment and the modified examples shown below can be appropriately combined to form further modified examples, or the modified examples shown below can be appropriately combined to form further modified examples.

[0130] In the third and fourth embodiments, after waiting for a predetermined time (for example, one minute), flushing (blank ejection) may be performed in which droplets unrelated to printing are ejected from the nozzles 132 of the liquid ejection unit 12. The ejection amount during flushing may be greater than the ejection amount during normal flushing. In this case, the ejection amount per ejection during flushing may be increased, or the number of ejections during flushing may be increased.

[0131] In the above embodiments, when wiping the nozzle forming surface 131, the wiping unit 31 is fixed at the wiping position, and the liquid ejection unit 12 is moved in the main scanning direction X. However, the nozzle forming surface 131 may be wiped by moving the wiping unit 31 in the main scanning direction X without moving the liquid ejection unit 12.

[0132] The wiped surface 130, which is the surface within the range that needs to be wiped, is not limited to a surface that includes the nozzle forming surface 131, the horizontal surface portion 133 located outside the wiping direction WD, and the inclined surface 134 located further outside the wiping direction WD. The wiped surface 130 may be the nozzle forming surface 131 alone. The wiped surface 130 may be the nozzle forming surface 131 alone and the horizontal surface portion 133 located outside the wiping direction WD. The wiped surface 130 may be the nozzle forming surface 131 alone and the inclined surface 134 located outside the wiping direction WD.

[0133] In each of the above embodiments, in the example of a serial printer, the liquid ejection unit 12 moves in the wiping direction WD(+X), causing the wiping unit 31 to wipe the surface to be wiped 130 in the wiping direction WD(-X), but the wiping unit 31 may also move in the wiping direction WD.

[0134] In the above-described embodiments, after the wiping unit 31 wipes the wiped surface 130, the retraction direction Y, which is the movement direction when the wiping unit 31 retracts from the wiping path relative to the liquid discharge unit 12, is the +Y direction, but the retraction direction may also be the -Y direction. Furthermore, the retraction direction may also be a direction along the nozzle forming surface 131 and a direction intersecting the wiping direction WD.

[0135] In the deflection reduction control, the liquid discharge part 12 is raised, but the wiping part 31 may be lowered. Although the driving units are provided as driving units 26, 53, and 54 for each direction in which the liquid discharger 12 and the wiping unit 31 are moved relative to each other during the wiping process, a single driving unit may be used in common for the different directions of relative movement. In other words, the number of driving units may be one, two, or three.

[0136] The drive unit 26 is a common drive source that drives the cap 23 and the suction pump 24 in addition to the wiping unit 31, but it may also be a drive unit dedicated to the wiping unit 31. In the above-described embodiments, in the example of a serial printer, the liquid discharger 12 moves in the wiping direction WD, but the wiping unit 31 may move instead. Also, in the above-described embodiments, the wiping unit 31 moves in the movement direction Y, but the liquid discharger 12 may move in the movement direction Y. Furthermore, the liquid discharger 12 moves upward, but the wiping unit 31 may move downward.

[0137] In the above-described embodiments, the liquid discharger 12 moves in the wiping direction WD, the wiping unit 31 moves in the retraction direction +Y, and the liquid discharger 12 moves in the intersecting direction Z, but this is not limited to this. The liquid discharger 12 may move in the wiping direction WD, the wiping unit 31 may move in the retraction direction, and the wiping unit 31 may move in the intersecting direction Z. Alternatively, the liquid discharger 12 may move in the wiping direction WD, the liquid discharger 12 may move in the retraction direction, and the wiping unit 31 may move in the intersecting direction Z. Alternatively, the liquid discharger 12 may move in the wiping direction WD, the liquid discharger 12 may move in the retraction direction, and the wiping unit 31 may move in the intersecting direction Z. Alternatively, the liquid discharger 12 may move in the wiping direction WD, the liquid discharger 12 may move in the retraction direction, and the liquid discharger 12 may move in the intersecting direction Z. Alternatively, the wiping unit 31 may move in the wiping direction WD, the liquid discharger 12 may move in the retraction direction, and the wiping unit 31 may move in the intersecting direction Z. The wiping unit 31 may move in the wiping direction WD, the liquid discharge unit 12 may move in the retraction direction, and the liquid discharge unit 12 may move in the intersecting direction Z. Alternatively, the wiping unit 31 may move in the wiping direction WD, the wiping unit 31 may move in the retraction direction, and the wiping unit 31 may move in the intersecting direction Z. Furthermore, the wiping unit 31 may move in the wiping direction WD, the wiping unit 31 may move in the retraction direction, and the liquid discharge unit 12 may move in the intersecting direction Z.

[0138] In the above-described embodiments, the wiping direction WD in which the liquid discharger 12 moves is the direction from the wiping unit 31 toward the medium support unit 14, but it may also be the direction from the medium support unit 14 toward the wiping unit 31.

[0139] In the above-described embodiments, the wiping direction WD is a direction along the main scanning direction X, but it may also be a direction along the transport direction PF. The wiping direction WD may also be a diagonal direction having a component in the main scanning direction X and a component in the transport direction PF. When the wiping direction WD is a direction along the main scanning direction X, the retraction direction may also be a direction along the transport direction PF. When the wiping direction WD is a diagonal direction, the retraction direction may also be a direction along the nozzle forming surface 131 and a direction intersecting the diagonal direction.

[0140] The cleaning unit 35 is not limited to cleaning absorbents. Cleaning by the cleaning unit 35 may also be washing. The liquid ejection head 13 may have nozzles 132 that eject pigment ink and nozzles 132 that eject dye ink. In this case, the area of the nozzle forming surface 131 where the nozzles 132 that eject pigment ink are open and the area where the nozzles 132 that eject dye ink are open may be wiped separately.

[0141] Cleaning may be performed when an abnormality such as clogging of the nozzle 132 is detected as a result of a nozzle inspection in a liquid ejection device 10 equipped with a nozzle inspection function. An example of such a nozzle inspection function is one in which a drive element (e.g., a piezoelectric element) that operates to eject ink from the nozzle 132 is driven to a degree that prevents ink from being ejected from the nozzle 132, and the presence or absence of foreign matter, air bubbles, or thickened ink in the nozzle 132 is determined based on residual vibrations of a cavity that communicates with the nozzle 132. A wiping process may be performed at least either before or after cleaning that is performed based on the results of the nozzle inspection.

[0142] The liquid discharge process, which is performed at least either before or after the wiping process, may be a process other than cleaning. For example, the liquid discharge process may be flushing (blank ejection) in which ink is ejected from the nozzles 132 toward the cap 23 or the liquid receiving portion. For example, the control unit 100 may perform the wiping process at least either before or after the flushing.

[0143] The cleaning unit 35 may be disposed at a position where it comes into contact with the wiping unit 31 after the wiping unit 31 moves away from the liquid discharge unit 12 in the retraction direction +Y. The cleaning unit 35 does not need to be provided.

[0144] The movement direction of the wiping unit 31 does not have to coincide with the extension direction of the wiping unit 31. For example, the movement direction of the wiping unit 31 may be a direction along the nozzle surface 131 and a direction intersecting both the extension direction of the wiping unit 31 and the wiping direction WD. The movement direction of the wiping unit 31 may also be a rotational direction about an axis extending in a direction perpendicular to the nozzle surface 131. In this case, even when the wiping unit 31 is moved in the retracted direction from the wiping end position WE, it is possible to wipe a portion of the horizontal surface portion 133 or the inclined surface 134 of the wiped surface 130 that was not wiped by the first movement control. In other words, it is possible to reduce the amount of liquid, such as ink, remaining on the wiped surface 130 after the first movement control is performed.

[0145] The wiping portion 31 is not limited to a wiper blade made of a material such as synthetic resin or rubber, but may be a cloth wiper. The medium M is not limited to paper, but may be an envelope, cardboard, fabric, synthetic resin film, laminated medium, or the like.

[0146] The liquid ejection device 10 may not be the serial type described in the above embodiment, but may be a lateral type in which the carriage 121 is movable in two directions, the main scanning direction X and the transport direction PF of the medium M, or may be a line type in which the liquid ejection head 13 extends in the width direction X of the medium M. In the case of the lateral type, a wiping process including relative movement between the wiping unit 31 and the liquid ejection unit 12 in two directions, the wiping direction WD and the retraction direction, may be performed by two drive units that separately perform drive in the two directions, the main scanning direction X and the transport direction PF.

[0147] The liquid ejection device 10 is not limited to an inkjet printer equipped with a liquid ejection head 13 that ejects liquid such as ink. The liquid ejection device 10 may also be a textile printing device that ejects liquid such as ink to print on a medium M such as fabric.

[0148] In the above-described embodiment, the liquid ejection device 10 may be a liquid ejection device equipped with a liquid ejection unit 12 that ejects a liquid other than ink. Note that the state of the liquid ejected as minute droplets from the liquid ejection device includes granular, teardrop-like, and string-like tails. The term "liquid" as used herein refers to any material that can be ejected from the liquid ejection device. For example, the term "liquid" refers to any material in a liquid phase, including fluids such as high or low viscosity liquids, sols, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, and liquid metals (metal melts). The term "liquid" also refers to not only liquids as a single state of matter, but also to solid functional material particles, such as pigments and metal particles, dissolved, dispersed, or mixed in a solvent. Typical examples of liquids include inks and liquid crystals, as described in the above-described embodiments. Here, "ink" encompasses various liquid compositions, such as general water-based inks and oil-based inks, as well as gel inks and hot-melt inks. Specific examples of the liquid ejection device include a liquid ejection device that ejects a liquid containing dispersed or dissolved materials such as electrode materials and color materials used in the manufacture of liquid crystal displays, electroluminescent (EL) displays, surface-emitting displays, and color filters. Other examples include a liquid ejection device that ejects bioorganic materials used in biochip manufacture, a liquid ejection device used as a precision pipette to eject sample liquids, a textile printing device, a microdispenser, and the like. Furthermore, the liquid ejection device may be a liquid ejection device that ejects lubricating oil with pinpoint accuracy onto precision machinery such as watches and cameras, or a liquid ejection device that ejects transparent resin liquid such as ultraviolet-curable resin onto a substrate to form micro-hemispherical lenses (optical lenses) used in optical communication devices. Furthermore, the liquid ejection device may be a liquid ejection device that ejects an etching solution such as an acid or alkali to etch a substrate. This type of liquid ejection device 10 may also include a wiping unit 31 that wipes a wiped surface 130 including a nozzle-forming surface 131 of the liquid ejection unit 12. When the wiping unit 31 wipes the wiped surface 130, the control unit 100 may perform the control of each of the above-described embodiments. For example, the control unit 100 may perform the first movement control and the deflection reduction control, or may additionally perform the second movement control, or may additionally perform the third movement control.

[0149] The technical concepts and effects that can be understood from the above-described embodiment and modified examples will be described below. (A) A liquid ejection device includes a liquid ejection unit having a plurality of nozzles capable of ejecting liquid and a nozzle forming surface on which the plurality of nozzles are formed, a wiping unit that wipes a surface to be wiped including the nozzle forming surface, a drive unit that moves at least one of the liquid ejection unit and the wiping unit, and a control unit, wherein the control unit drives the drive unit to perform first movement control to move the wiping unit relative to the liquid ejection unit in a wiping direction along the nozzle forming surface to cause the wiping unit to wipe the surface to be wiped, and after the first movement control, performs deflection reduction control to reduce the amount of deflection of the wiping unit by moving the wiping unit relative to the liquid ejection unit in a cross direction that intersects the nozzle forming surface while maintaining contact between the wiping unit and the liquid ejection unit, and after the deflection reduction control, performs second movement control to move the wiping unit relative to the liquid ejection unit in a retraction direction that is a direction along the nozzle forming surface and different from the wiping direction to separate the wiping unit from the liquid ejection unit. According to this configuration, by executing the deflection reduction control before executing the second movement control, it is possible to reduce the drive load on the drive unit.

[0150] (B) A liquid ejection device includes a liquid ejection unit having a plurality of nozzles capable of ejecting liquid and a nozzle forming surface on which the plurality of nozzles are formed, a wiping unit that wipes a wiped surface including the nozzle forming surface, a drive unit that moves at least one of the liquid ejection unit and the wiping unit, and a control unit, wherein the control unit drives the drive unit to perform a first movement control to move the wiping unit relative to the liquid ejection unit in a wiping direction along the nozzle forming surface to cause the wiping unit to wipe the nozzle forming surface, and after the first movement control, performs a second movement control to move the wiping unit relative to the liquid ejection unit in a retraction direction that is a direction along the nozzle forming surface but different from the wiping direction to move the wiping unit away from the liquid ejection unit, and if a drive load on the drive unit exceeds a threshold during the second movement control, the control unit stops the second movement control and performs a deflection reduction control to reduce the amount of deflection of the wiping unit. With this configuration, the control unit can reduce the drive load on the drive unit by performing the deflection reduction control when the drive load increases. Compared to the configuration of claim 1, there is no need to perform deflection reduction control each time, so time can be saved.

[0151] (C) In the liquid ejection device described in (B) above, the control unit may perform the deflection reduction control by moving the wiping unit relative to the liquid ejection unit in a direction intersecting the nozzle surface while maintaining contact between the wiping unit and the liquid ejection unit, and then resume the second movement control. With this configuration, the amount of deflection of the wiping unit can be reduced by moving the wiping unit relative to the liquid ejection unit in the intersecting direction. Therefore, the second movement control can be resumed.

[0152] (D) In the liquid ejection device described in (C) above, the speed of the relative movement in the second movement control may be slower after the deflection reduction control than before the deflection reduction control. With this configuration, an increase in the drive load can be reduced.

[0153] (E) In the liquid ejection device described in (B) above, the control unit may perform the deflection reduction control by moving the wiping unit relative to the liquid ejection unit in an intersecting direction intersecting the nozzle forming surface while maintaining contact between the wiping unit and the liquid ejection unit, and then moving the wiping unit relative to the liquid ejection unit in the wiping direction to separate the wiping unit from the liquid ejection unit. This configuration reduces the risk of a drive load being applied again by switching the movement direction from the second movement control. The relative movement in the intersecting direction reduces the amount of deflection of the wiping unit, thereby reducing the amount of splashing of liquid such as ink.

[0154] (F) In the liquid ejection device described in any one of (A) to (E) above, the first movement control may cause the liquid ejection unit to move in the wiping direction, the deflection reduction control may cause the liquid ejection unit to move in the intersecting direction, and the second movement control may cause the wiping unit to move in the retraction direction. With this configuration, by performing the deflection reduction control before performing the second movement control, the drive load on the drive unit can be reduced.

[0155] (G) The liquid ejection device described in (F) above may include a medium support unit that can face the liquid ejection unit and supports a medium, and a detection unit that detects movement of the liquid ejection unit, and the wiping direction may be a direction from the wiping unit toward the medium support unit. With this configuration, the second movement control is performed when it is desired to reduce the risk of liquid such as ink being scattered by the first movement control and contaminating the detection unit, and in this case, the risk of an increase in the drive load can be reduced.

[0156] (H) The liquid ejection device described in any one of (B) to (G) above may include a cleaning unit that cleans the wiping unit, and the wiping unit may come into contact with the cleaning unit during the relative movement in the second movement control. With this configuration, the wiping unit comes into contact with both the liquid ejection unit and the cleaning unit during the second movement control, which tends to increase the drive load. Even with this configuration, the drive load can be effectively reduced.

[0157] (I) In the liquid ejection device described in (H) above, the cleaning part may be an absorbent body capable of absorbing liquid. With this configuration, the wiping part can be cleaned with a simple configuration. (J) A control method for a liquid ejection device including a liquid ejection section having a plurality of nozzles capable of ejecting liquid and a nozzle forming surface on which the plurality of nozzles are formed, a wiping section that wipes a surface to be wiped including the nozzle forming surface, and a drive section that moves at least one of the liquid ejection section and the wiping section, the control method comprising: driving the drive section to move the wiping section relative to the liquid ejection section in a wiping direction along the nozzle forming surface, and executing first movement control to cause the wiping section to wipe the surface to be wiped; and performing, after the first movement control, a deflection reduction control to reduce the amount of deflection of the wiping unit by moving the wiping unit relative to the liquid discharge unit in a direction intersecting the nozzle forming surface while maintaining contact between the wiping unit and the liquid discharge unit, and performing, after the deflection reduction control, a second movement control to move the wiping unit relative to the liquid discharge unit in a retraction direction that is a direction along the nozzle forming surface but different from the wiping direction, to separate the wiping unit from the liquid discharge unit. According to this method, by performing the deflection reduction control before performing the second movement control, it is possible to reduce the drive load of the drive unit.

[0158] (K) A control method for a liquid ejection device is a control method for a liquid ejection device including a liquid ejection unit having a plurality of nozzles capable of ejecting liquid and a nozzle forming surface on which the plurality of nozzles are formed, a wiping unit that wipes a surface to be wiped including the nozzle forming surface, and a drive unit that moves at least one of the liquid ejection unit and the wiping unit, the control method including: executing a first movement control by driving the drive unit to move the wiping unit relative to the liquid ejection unit in a wiping direction along the nozzle forming surface to cause the wiping unit to wipe the nozzle forming surface; executing a second movement control after the first movement control to move the wiping unit relative to the liquid ejection unit in a retraction direction that is a direction along the nozzle forming surface but different from the wiping direction to move the wiping unit away from the liquid ejection unit; and if the drive load of the drive unit becomes greater than a threshold value during execution of the second movement control, stopping the second movement control and executing a deflection reduction control to reduce the amount of deflection of the wiping unit. According to this method, when the drive load becomes large, the drive load of the drive unit can be reduced by executing the deflection reduction control. Compared to the method of claim 10, it is not necessary to execute the deflection reduction control each time, so it is possible to shorten the time.

[0159] (L) In the control method for a liquid ejection device described in (K) above, the deflection reduction control may include moving the wiping unit relative to the liquid ejection unit in a direction intersecting the nozzle surface while maintaining contact between the wiping unit and the liquid ejection unit, and then resuming the second movement control. According to this method, the amount of deflection of the wiping unit can be reduced by moving the wiping unit relative to the liquid ejection unit in the intersecting direction. Therefore, the second movement control can be resumed.

[0160] (M) In the method for controlling a liquid ejection device described in (K) or (L) above, the speed of the relative movement in the second movement control may be slower after the deflection reduction control than before the deflection reduction control. This method can reduce an increase in the drive load.

[0161] (N) The control method for a liquid ejection device described in (K) above may include, as the deflection reduction control, moving the wiping unit relative to the liquid ejection unit in a cross direction that crosses the nozzle surface while maintaining contact between the wiping unit and the liquid ejection unit, and then moving the wiping unit relative to the liquid ejection unit in the wiping direction to separate the wiping unit from the liquid ejection unit. This method reduces the risk of a drive load being applied again by switching the movement direction from the second movement control. The relative movement in the cross direction reduces the amount of deflection of the wiping unit, thereby reducing the amount of splashing of liquid such as ink. [Explanation of symbols]

[0162] 10...liquid ejection device, 11...housing, 12...liquid ejection section, 13...liquid ejection head, 13R...nozzle row, 14...medium support section, 14A...support surface, 15...detection section, 15E...linear encoder, 20...maintenance device, 21...cleaning device, 22...liquid absorbent material, 23...cap, 24...suction pump, 25...suction tube, 26...drive section, 26A...motor, 30...wiping device, 31...wiping section, 311...upper end, 32...operating mechanism, 33...cam mechanism, 34...holder, 35...cleaning section, 40...conveyance section, 41...conveyance roller pair, 50...carriage movement device, 51...scanning mechanism, 52...lifting mechanism, 53...drive section, 54...drive section, 100...control section, 101...printing control section, 102...cleaning control section, 103...wiping control portion, 104...counter, 105...memory portion, 121...carriage, 130...wiped surface, 131...nozzle formation surface, 132...nozzle, 133...surface portion, 134...inclined surface, 151...linear scale, 151A...light-transmitting portion, 152...sensor, X...main scanning direction (width direction), Y...movement direction, Z...cross direction (vertical direction), +Y...retreat direction, -Y...advance direction, -Z...upward direction, PF...conveyance direction, WD...wiping direction, M...medium, Ma...printing surface, HP...home position (wiping start position), RP...retreat position, WP...wiping position, H...height position, ΔH...distance, L1...linear distance, L2...length, WE...wiping end position, SA...target range, WC...target position, FLG1...cleaning permission flag, FLG2...wiping flag, IL...liquid (ink).

Claims

1. a liquid ejection section having a plurality of nozzles capable of ejecting liquid and a nozzle forming surface on which the plurality of nozzles are formed; a wiping unit that wipes a surface to be wiped, the surface including the nozzle forming surface; a drive unit that moves at least one of the liquid discharge unit and the wiping unit; a control unit, The control unit drives the drive unit, a first movement control is executed to move the wiping unit relative to the liquid ejection unit in a wiping direction along the nozzle forming surface, so as to cause the wiping unit to wipe the wiped surface; after the first movement control, a deflection reduction control is executed to reduce the amount of deflection of the wiping portion by moving the wiping portion relative to the liquid ejection portion in a direction intersecting the nozzle forming surface while maintaining contact between the wiping portion and the liquid ejection portion, A liquid ejection device characterized in that, after the deflection reduction control, a second movement control is performed in which the wiping portion is moved relative to the liquid ejection portion in a retraction direction that is a direction along the nozzle forming surface and different from the wiping direction, thereby moving the wiping portion away from the liquid ejection portion.

2. a liquid ejection section having a plurality of nozzles capable of ejecting liquid and a nozzle forming surface on which the plurality of nozzles are formed; a wiping unit that wipes a surface to be wiped, the surface including the nozzle forming surface; a drive unit that moves at least one of the liquid discharge unit and the wiping unit; a control unit, The control unit drives the drive unit, a first movement control is executed to move the wiping unit relative to the liquid ejection unit in a wiping direction along the nozzle forming surface, so as to cause the wiping unit to wipe the nozzle forming surface; after the first movement control, a second movement control is executed to move the wiping unit relatively to the liquid ejection unit in a retraction direction that is a direction along the nozzle forming surface and different from the wiping direction, thereby separating the wiping unit from the liquid ejection unit; A liquid ejection device characterized in that, when the drive load of the drive unit becomes greater than a threshold value while the second movement control is being executed, the second movement control is stopped and a deflection reduction control is executed to reduce the amount of deflection of the wiping unit.

3. The liquid ejection device according to claim 2, The control unit performs the deflection reduction control by: A liquid ejection device characterized in that, while maintaining contact between the wiping portion and the liquid ejection portion, the wiping portion is moved relative to the liquid ejection portion in a direction intersecting the nozzle forming surface, and then the second movement control is resumed.

4. The liquid ejection device according to claim 3, The liquid ejection device, wherein the speed of the relative movement in the second movement control is slower after the deflection reduction control than before the deflection reduction control.

5. The liquid ejection device according to claim 2, The control unit performs the deflection reduction control by: A liquid ejection device characterized in that, while maintaining contact between the wiping portion and the liquid ejection portion, the wiping portion is moved relative to the liquid ejection portion in a direction intersecting the nozzle forming surface, and then the wiping portion is moved relative to the liquid ejection portion in the wiping direction to separate the wiping portion from the liquid ejection portion.

6. 4. The liquid ejection device according to claim 1, In the first movement control, the liquid discharger moves in the wiping direction, In the deflection reduction control, the liquid discharger moves in the intersecting direction, The liquid ejection device, wherein the wiping unit moves in the retraction direction in the second movement control.

7. The liquid ejection device according to claim 6, a medium support section that is capable of facing the liquid ejection section and supports a medium; a detection unit that detects movement of the liquid discharge unit, The liquid ejection device, wherein the wiping direction is a direction from the wiping unit toward the medium support unit.

8. 3. The liquid ejection device according to claim 1, a cleaning unit that cleans the wiping unit, The liquid ejection device, wherein the wiping unit comes into contact with the cleaning unit during the relative movement in the second movement control.

9. The liquid ejection device according to claim 8, The liquid ejection device is characterized in that the cleaning unit is an absorbent body capable of absorbing liquid.

10. A control method for a liquid ejection device including a liquid ejection unit having a plurality of nozzles capable of ejecting liquid and a nozzle forming surface on which the plurality of nozzles are formed, a wiping unit that wipes a surface to be wiped including the nozzle forming surface, and a drive unit that moves at least one of the liquid ejection unit and the wiping unit, Driving the drive unit, executing a first movement control to move the wiping unit relative to the liquid ejection unit in a wiping direction along the nozzle forming surface, thereby causing the wiping unit to wipe the wiped surface; after the first movement control, performing a deflection reduction control to reduce an amount of deflection of the wiping unit by moving the wiping unit relatively to the liquid ejection unit in a direction intersecting the nozzle forming surface while maintaining contact between the wiping unit and the liquid ejection unit; a second movement control that moves the wiping portion relative to the liquid ejection portion in a retraction direction that is a direction along the nozzle forming surface and different from the wiping direction, after the deflection reduction control, thereby moving the wiping portion away from the liquid ejection portion.

11. a liquid ejection unit having a plurality of nozzles capable of ejecting liquid and a nozzle forming surface on which the plurality of nozzles are formed; and a wiping unit that wipes a surface to be wiped including the nozzle forming surface; a drive unit that moves at least one of the liquid ejection unit and the wiping unit, Driving the drive unit, executing a first movement control to move the wiping unit relative to the liquid ejection unit in a wiping direction along the nozzle forming surface, thereby causing the wiping unit to wipe the nozzle forming surface; executing, after the first movement control, a second movement control for moving the wiping unit relative to the liquid ejection unit in a retraction direction that is a direction along the nozzle forming surface and different from the wiping direction, to separate the wiping unit from the liquid ejection unit; A control method for a liquid ejection device, characterized by including: if the drive load of the drive unit becomes greater than a threshold value while the second movement control is being executed, stopping the second movement control and executing a deflection reduction control that reduces the amount of deflection of the wiping unit.

12. A method for controlling a liquid ejection device according to claim 11, A control method for a liquid ejection device, characterized in that the deflection reduction control includes moving the wiping portion relative to the liquid ejection portion in a direction intersecting the nozzle forming surface while maintaining contact between the wiping portion and the liquid ejection portion, and then resuming the second movement control.

13. A method for controlling a liquid ejection device according to claim 12, The method for controlling a liquid ejection device, wherein the speed of the relative movement in the second movement control after the deflection reduction control is slower than the speed before the deflection reduction control.

14. A method for controlling a liquid ejection device according to claim 11, a control method for a liquid ejection device, characterized in that the deflection reduction control includes moving the wiping portion relative to the liquid ejection portion in a direction intersecting the nozzle forming surface while maintaining contact between the wiping portion and the liquid ejection portion, and then moving the wiping portion relative to the liquid ejection portion in the wiping direction to separate the wiping portion from the liquid ejection portion.

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