Capping Device

Abstract

To provide a cap device capable that can prevent an increase in the size of a liquid discharge device by performing receiving and discharge of liquid discharged from a nozzle and humidification of the nozzle with a single cap.SOLUTION: A cap device 50 capable of forming a space SP for enclosing an opening 22a of a nozzle 22 for discharging liquid upon coming into contact with a liquid discharge head 21 having the nozzle 22, includes a unit cap 51a as an example of a cap having: a recessed part 57 forming the space SP; a humidification chamber 55 having an inflow port 55a into which a humidification fluid L1a for humidifying the space SP flows; and an outflow port 55b out of which the humidification fluid L1a flows; and a first permeable membrane 54 as an example of a partition wall with gas permeability partitioning the recessed part 57 and the humidification chamber 55. The recessed part 57 has a discharge hole 56b as an example of a hole capable of discharging liquid discharged into the unit cap 51a as an example of the cap from the liquid discharge head 21.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a capping device used in a liquid ejection device that ejects liquid onto a medium. [Background technology]

[0002] Patent Document 1 discloses a liquid ejection device, which is an example of a liquid ejection device, that includes a capping mechanism that contacts the liquid ejection head to form a space surrounding the nozzles and that uses suction to remove thickened liquid and air bubbles from within the liquid ejection head. The liquid ejection device also includes a capping device that contacts the liquid ejection head to form a space surrounding the nozzles and that supplies a moisturizing fluid, an example of a humidifying fluid, from a moisturizing fluid reservoir, an example of a humidifying fluid storage unit, through a connecting flow path to humidify the nozzles. In other words, the patent document discloses a liquid ejection device that includes the capping mechanism and capping device for maintenance purposes, thereby preventing nozzle clogging and suppressing nozzle drying. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-38159 Summary of the Invention [Problem to be solved by the invention]

[0004] In the liquid ejection device described in Patent Document 1, the liquid ejection head moves from the ejection area where printing is performed on the medium to a maintenance area outside the ejection area for maintenance. That is, the cap of the capping mechanism and the cap of the capping device are arranged side by side in the movement direction of the liquid ejection head in the maintenance area. This requires space for both caps, which makes the liquid ejection device larger. [Means for solving the problem]

[0005] A cap device that solves the above problem is a cap device that can form a space surrounding the opening of a nozzle when it comes into contact with a liquid ejection head having a nozzle that ejects liquid, and is equipped with a cap having a recess that forms the space, a humidification chamber having an inlet through which humidifying fluid flows in to humidify the space, and an outlet through which the humidifying fluid flows out, and a gas-permeable partition that separates the recess from the humidification chamber, and the recess has a hole that can discharge liquid ejected from the liquid ejection head into the cap. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view showing a liquid ejection device according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the arrangement of components around the liquid ejection head. [Figure 3] 3 is a schematic front view of the components as viewed from the direction along the discharge direction in FIG. 2. FIG. [Figure 4] 3 is a schematic front view of the components as viewed from a direction along the first transport direction in FIG. 2. FIG. [Figure 5] FIG. 4 is an exploded perspective view of the unit cap in FIG. 3 as seen obliquely from above. [Figure 6] FIG. 4 is an exploded perspective view of the unit cap in FIG. 3, as viewed obliquely from below. [Figure 7] FIG. 6 is a plan view of the humidifying chamber as viewed from the direction along the discharge direction in FIG. 5. [Figure 8] Schematic front cross-sectional view of a unit cap. [Figure 9] 9 is a schematic diagram showing the flow of liquid in FIG. 8 with arrows. [Figure 10] 9 is a schematic diagram showing the gas flow in FIG. 8 with arrows. [Figure 11] FIG. 2 is a schematic diagram showing the configuration of a capping device. [Figure 12] FIG. 2 is a block diagram showing the electrical configuration of the liquid ejection device. [Figure 13] 5A and 5B are schematic diagrams showing the state of the humidifying fluid when the circulation operation is performed. [Figure 14] 10 is a flowchart showing a circulation operation. [Figure 15] 5A and 5B are schematic diagrams showing the state of humidification fluid when a concentration adjustment operation is performed. [Figure 16] 10 is a flowchart showing a density adjustment operation. [Figure 17] 10A and 10B are schematic diagrams showing the state of the humidification fluid when the cap replacement preparation operation is performed. [Figure 18] 10 is a flowchart showing a cap replacement preparation operation. [Figure 19] 10A and 10B are schematic diagrams showing the state of the humidification fluid when the pre-water storage unit replacement operation is performed; [Figure 20] 10 is a flowchart showing the operation before replacing the water storage unit. [Figure 21] 5A and 5B are schematic diagrams showing the state of the humidifying fluid when the humidifying fluid filling operation is performed. [Figure 22] 10 is a flowchart showing a humidifying fluid filling operation. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present invention relates to a liquid ejection device, a capping device for use in the liquid ejection device, and a maintenance method for the capping device for use in the liquid ejection device, and is not limited to this. The liquid ejection device is, for example, an inkjet printer that prints by ejecting ink, which is an example of a liquid, onto a medium such as paper.

[0008] In the drawings, the liquid ejection device 11 is placed on a flat surface, with the width and depth directions being substantially horizontal. The vertical direction is indicated as the Z axis, and the directions along the plane intersecting the Z axis are indicated as the X and Y axes. The X, Y, and Z axes are preferably perpendicular to one another. In the following description, the X axis direction is also referred to as the width direction X, the Y axis direction as the depth direction Y, and the Z axis direction as the vertical direction Z.

[0009] <Configuration of the liquid ejection device> 1, the liquid ejection device 11 includes a rectangular parallelepiped main body 12, an image reading unit 13 attached to the top thereof, and an automatic feed unit 14. The liquid ejection device 11 has a configuration in which the main body 12, the image reading unit 13, and the automatic feed unit 14 are stacked in this order from the bottom in the vertical direction Z.

[0010] The image reading unit 13 is configured to be able to read images such as characters and photographs recorded on a document. The automatic feeding unit 14 is configured to be able to feed a document toward the image reading unit 13. The image reading unit 13 also has an operation unit 15 that is operated when giving instructions to the liquid ejection device 11. The operation unit 15 has, for example, a touch panel type liquid crystal display, operation buttons, etc.

[0011] The main body 12 has a plurality of medium storage sections 16 that can store media such as paper. In this embodiment, the main body 12 has a total of four medium storage sections 16. The medium storage sections 16 are configured to be removable from the main body 12. The main body 12 also has a recording section 20 that records on the medium M within the main body 12. The recording section 20 is equipped with a head unit 24 that has a liquid ejection head 21 that can eject liquid. Furthermore, the main body 12 has a mounting section 17 on its upper part on which the medium M that has been recorded on is placed. The mounting section 17 has a mounting surface 17a on which the medium M is placed. It should be noted that the number of medium storage sections 16 may be only one.

[0012] The medium M contained in the medium storage unit 16 is transported along a transport path 19 from the medium storage unit 16 through the recording unit 20 to the mounting unit 17. A feed roller (not shown) rotates in contact with the uppermost medium M among the multiple media M contained in the medium storage unit 16, thereby sending the uppermost medium M from the medium storage unit 16 to the recording unit 20 located above the medium storage unit 16. As the medium M passes through the recording unit 20, a liquid ejection head 21 ejects liquid toward the medium M, and the ejected liquid adheres to the medium M to perform recording. After recording, the medium M is ejected toward the mounting unit 17 by a pair of ejection rollers (not shown).

[0013] 2, a cap unit 51 and a wiper carriage 41 provided in a capping device described below are arranged around the liquid ejection head 21 provided in the recording unit 20 on the opposite side of the conveyance path 19 from the side on which the head unit 24 is located. The head unit 24 includes the liquid ejection head 21 and a support unit 25 that holds the liquid ejection head 21.

[0014] The liquid ejection head 21 is configured to eject liquid onto the medium M from a plurality of nozzles 22 constituting a plurality of nozzle groups while extending in the width direction X. When the liquid ejection head 21 ejects the liquid onto the medium M, the direction in which the liquid is ejected is referred to as the ejection direction Y1. Furthermore, when the liquid ejection head 21 ejects the liquid onto the medium M, the direction in which the medium M is transported is referred to as the first transport direction Z1.

[0015] In this embodiment, the nozzle surface 23 on which the nozzles 22 are arranged is not horizontal, but has a first predetermined angle θ1 with respect to the horizontal. That is, in this embodiment, the liquid ejection head 21 is arranged in a state in which the nozzle surface 23 has the first predetermined angle θ1 with respect to the horizontal, and in this state the liquid ejection head 21 ejects liquid onto the medium M. Note that the nozzle surface 23 on which the nozzles 22 are arranged may also be arranged horizontally. That is, the liquid ejection head 21 may be arranged in a state in which the nozzle surface 23 is horizontal.

[0016] The liquid ejection head 21 of this embodiment is a line head having a number of nozzles 22 that can simultaneously eject liquid across the entire width of the medium M in the width direction X that intersects with the first transport direction Z1 and the ejection direction Y1. The liquid ejection device 11 performs line printing by ejecting liquid from the multiple nozzles 22 that are positioned opposite the entire width of the medium M, which is transported at a constant speed.

[0017] In the liquid ejection device 11, maintenance operations such as capping, cleaning, flushing, wiping, etc. are performed to prevent or resolve ejection problems caused by clogging of the nozzles 22 of the liquid ejection head 21 or adhesion of foreign matter.

[0018] Capping refers to the operation of the cap unit 51 coming into contact with the nozzle surface 23 of the liquid ejection head 21 so as to surround the nozzles 22 when the liquid ejection head 21 is not ejecting liquid. Capping suppresses the increase in viscosity of the liquid inside the nozzles 22, thereby preventing ejection defects.

[0019] Cleaning refers to an operation of applying pressure to the upstream side of the liquid ejection head 21 to forcibly expel the liquid from the nozzles 22, or applying suction force to the nozzles 22 of the liquid ejection head 21 to forcibly expel the liquid from the nozzles 22.

[0020] Flushing refers to a discharge operation in which droplets unrelated to printing are discharged from the nozzles 22. Flushing is also called idling. Flushing discharges thickened ink, air bubbles, or foreign matter that can cause discharge defects from the nozzles 22, thereby preventing clogging of the nozzles 22. Liquid discharged from the liquid discharge head 21 that is not used for printing is called waste liquid. Liquid discharged by flushing is waste liquid because it is not used for printing. The waste liquid discharged by flushing is received by the cap unit 51. In other words, flushing is performed when the liquid discharge head 21 discharges droplets from the nozzles 22 into the cap unit 51.

[0021] Wiping refers to the operation of wiping the nozzle surface 23 with a rubber wiper, cloth wiper, or the like. Wiping removes liquid and dirt such as dust adhering to the nozzle surface 23 of the liquid ejection head 21. Note that the liquid wiped off by wiping is also waste liquid, as it is not used for printing.

[0022] The position of the head unit 24 when the liquid ejection head 21 ejects liquid onto the medium M, i.e., when the liquid ejection head 21 records on the medium M, is referred to as the recording position. The position of the cap unit 51 when the liquid ejection head 21 ejects liquid onto the medium M is referred to as the retracted position. The position of the head unit 24 when the liquid ejection device 11 performs a maintenance operation is referred to as the maintenance position. The position of the cap unit 51 when the liquid ejection device 11 performs a maintenance operation is also referred to as the maintenance position.

[0023] As shown in Fig. 2, the head unit 24 is moved by a head movement mechanism (not shown) between a recording position indicated by a solid line in Fig. 2 and a maintenance position indicated by a two-dot chain line in Fig. 2. The direction in which the head unit 24 moves from the recording position to the maintenance position is called a first direction D1. The direction in which the head unit 24 moves from the maintenance position to the recording position is called a second direction D2.

[0024] The cap unit 51 is moved by a cap moving mechanism (not shown) between a retracted position indicated by a solid line in Fig. 2 and a maintenance position indicated by a two-dot chain line in Fig. 2. The direction in which the cap unit 51 moves from the recording position to the maintenance position is referred to as a third direction D3. The direction in which the cap unit 51 moves from the maintenance position to the recording position is referred to as a fourth direction D4.

[0025] As shown in FIG. 2, the cap unit 51 moves in the third direction D3 from the retracted position shown by the solid line in FIG. 2 to the maintenance position shown by the two-dot chain line in FIG. 2, and then the head unit 24 moves in the first direction D1 from the recording position shown by the solid line in FIG. 2 to the maintenance position shown by the two-dot chain line in FIG. 2. As a result, the head unit 24 is capped by the cap unit 51. In this embodiment, flushing is performed by having the liquid ejection head 21 eject liquid droplets from the nozzles 22 into the cap unit 51 in this capped state. That is, in the liquid ejection device 11 of this embodiment, both capping and flushing are performed at the maintenance position. Flushing may be performed when the liquid ejection head 21 is separated from the cap unit 51.

[0026] When maintenance is completed, the head unit 24 moves in the second direction D2 from the maintenance position shown by the two-dot chain line in Fig. 2 to the recording position shown by the solid line in Fig. 2. After that, the cap unit 51 moves in the fourth direction D4 from the maintenance position shown by the two-dot chain line in Fig. 2 to the retracted position shown by the solid line in Fig. 2. At this time, the wiper carriage 41 is positioned so as not to overlap the head unit 24 and the cap unit 51 in the width direction X. The movement of the wiper carriage 41 will be described later.

[0027] <Configuration of the liquid ejection head and cap unit> As shown in FIG. 3, the liquid ejection head 21 includes a plurality of unit ejection heads 21a. The plurality of unit ejection heads 21a are arranged at a first predetermined pitch P1 in the width direction X on the surface of the support part 25 facing the transport path 19 shown in FIG. 2. Each unit ejection head 21a is composed of a plurality of nozzle rows 21b. The plurality of unit ejection heads 21a are arranged in a state inclined at a second predetermined angle θ2 with respect to a first transport direction Z1 in which the medium M is transported. In other words, the nozzle rows 21b are also arranged in a state inclined at the second predetermined angle θ2 with respect to the first transport direction Z1. In this embodiment, the liquid ejection head 21 includes five unit ejection heads 21a, and each unit ejection head 21a is composed of six nozzle rows 21b.

[0028] In this embodiment, the cap unit 51 has a plurality of unit caps 51a and a holder 59 that holds the plurality of unit caps 51a. The unit caps 51a are an example of a cap. The plurality of unit caps 51a are arranged at a first predetermined pitch P1 in the width direction X on the side opposite to the side where the head unit 24 is located with respect to the transport path 19 shown in FIG. 2. The plurality of unit caps 51a are arranged in a state inclined by a second predetermined angle θ2 with respect to the first transport direction Z1 in which the medium M is transported. In other words, the unit caps 51a have a substantially parallelogram shape when viewed from a direction along the ejection direction Y1. In this embodiment, the cap unit 51 has five unit caps 51a.

[0029] One unit cap 51a is disposed in a position facing each unit ejection head 21a. Therefore, when the head unit 24 is capped by the cap unit 51, each of the plurality of unit ejection heads 21a is covered by a separate unit cap 51a. That is, the plurality of nozzles 22 of the liquid ejection head 21 are covered for each unit ejection head 21a by the same number of unit caps 51a as the number of unit ejection heads 21a. In this embodiment, the plurality of nozzles 22 of the liquid ejection head 21 made up of five unit ejection heads 21a are covered for each unit ejection head 21a by the five unit caps 51a of the cap unit 51. As a result, all of the nozzles 22 of the liquid ejection head 21 are covered by the cap unit 51 during capping.

[0030] As shown in FIG. 4, the head unit 24 is moved by a head moving mechanism (not shown) between a recording position indicated by a solid line in FIG. 4 and a maintenance position indicated by a two-dot chain line in FIG. The wiper carriage 41 is moved back and forth between a retracted position indicated by a solid line in Fig. 4 and a turned-back position indicated by a two-dot chain line in Fig. 4 by a wiper movement mechanism (not shown). The direction in which the wiper carriage 41 moves from the retracted position to the turned-back position is referred to as a fifth direction D5. The direction in which the wiper carriage 41 moves from the turned-back position to the retracted position is referred to as a sixth direction D6.

[0031] As shown in Fig. 4, the head unit 24 moves in the first direction D1 from the recording position shown by the solid line in Fig. 4, and after being positioned at the maintenance position shown by the two-dot chain line in Fig. 4, the wiper carriage 41 moves in the fifth direction D5 from the retracted position shown by the solid line in Fig. 4, and moves to the turning back position shown by the two-dot chain line in Fig. 4. As a result, the nozzle surface 23 of the head unit 24 is wiped by the wiper member 42 of the wiper carriage 41.

[0032] When wiping is completed, the head unit 24 moves in the second direction D2 from the maintenance position shown by the two-dot chain line in Fig. 4, and is positioned at the recording position shown by the solid line in Fig. 4. After that, the wiper carriage 41 moves in the sixth direction D6 from the turning back position shown by the two-dot chain line in Fig. 4, and is positioned at the retracted position shown by the solid line in Fig. 4.

[0033] <About the cap structure> As shown in FIG. 5, a unit cap 51a, which is an example of a cap, includes a restricting member 52, an absorber 53, a first moisture-permeable membrane 54, which is an example of a partition wall, a humidification chamber 55, and a case 56. The unit cap 51a has a low rectangular prism shape with a substantially parallelogram-shaped bottom. In this embodiment, the unit cap 51a is used with the substantially parallelogram-shaped bottom aligned on the XZ1 plane shown in FIG. 2. That is, the unit cap 51a shown in FIG. 5 is used with the substantially parallelogram-shaped bottom inclined relative to the horizontal. The XZ1 plane is a plane parallel to the nozzle surface 23 of the liquid ejection head 21 shown in FIG. 4.

[0034] The regulating member 52 has a substantially parallelogram-shaped regulating surface 52a for regulating the position of the -Y1 direction side of the surface 53a of the absorber 53, and a positioning engaged portion 52c. The regulating member 52 is made of a thin metal plate such as stainless steel. The regulating member 52 has four sides around the regulating surface 52a bent toward the +Y1 direction side, thereby ensuring the flatness and strength of the regulating surface 52a and regulating the position of the absorber 53.

[0035] The restricting member 52 has a restricting surface 52a formed in a mesh pattern. That is, the restricting surface 52a has a plurality of communication holes 52b. The -Y1 side and +Y1 side of the restricting surface 52a are in communication with each other via the plurality of communication holes 52b. This allows the unit cap 51a to allow liquid to pass through the unit cap 51a from the -Y1 side to the +Y1 side of the restricting surface 52a and from the +Y1 side to the -Y1 side.

[0036] 5, the absorber 53 is formed in the shape of a thin plate having a substantially parallelogram shape extending in the XZ1 plane. The absorber 53 is configured to be able to absorb liquid. Therefore, when the absorber 53 absorbs liquid, it may displace so that its volume increases, that is, it may swell.

[0037] The restricting member 52 restricts the absorber 53 at a predetermined position so that the surface 53a of the absorber 53 is widely exposed while the distance between the surface 53a and the nozzle surface 23 shown in FIG. 4 is constant. That is, when the absorber 53 swells, the restricting member 52 restricts the absorber 53 from being displaced in the −Y1 direction.

[0038] As shown in FIG. 5, the first moisture-permeable membrane 54 is formed in the shape of a substantially parallelogram sheet extending in the XZ1 plane. The first moisture-permeable membrane 54 is gas-permeable. That is, the first moisture-permeable membrane 54 allows gas to pass through but restricts the passage of liquid. In this embodiment, the material used for the first moisture-permeable membrane 54 is a material in which a fabric is coated with a fluororesin. The material used for the first moisture-permeable membrane 54 may be any material that is impermeable to liquids but permeable to gases, and may be a film membrane or an elastomer membrane.

[0039] The first moisture permeable membrane 54 has communication portions 54a on three of the four sides of the approximate parallelogram. The first moisture permeable membrane 54 is configured such that the central portions of the three sides are slightly cut out toward the inside of the approximate parallelogram, thereby allowing liquid to pass from the -Y1 direction side to the +Y1 direction side and from the +Y1 direction side to the -Y1 direction side of the first moisture permeable membrane 54 only near the three sides of the first moisture permeable membrane 54. Note that the first moisture permeable membrane 54 may also have a communication portion 54a on one side of the approximate parallelogram that is closest to the +Z direction.

[0040] 5 is provided on the XZ1 plane, which is inclined relative to the horizontal, with the bottom surface of the approximate parallelogram. Because gravity acts as a force that causes the liquid to flow vertically in the -Z direction, the liquid is less likely to flow to the side of the approximate parallelogram closest to the +Z direction. Therefore, in this embodiment, the first moisture permeable membrane 54 does not have a communicating portion 54a on the side of the approximate parallelogram closest to the +Z direction.

[0041] As shown in FIG. 5, the humidifying chamber 55 has a substantially parallelogram-shaped bottom surface extending in the XZ1 plane. The humidifying chamber 55 has a groove 55c in the center of its bottom surface through which a humidifying fluid (described later) flows. The humidifying chamber 55 is formed by resin molding or the like. That is, the material used for the humidifying chamber 55 is a material that does not allow liquid to pass through. The groove 55c has a groove wall 55i. The end of the groove wall 55i on the -Y1 direction side and the first moisture-permeable membrane 54 are sealed by, for example, welding or bonding. In this way, the groove 55c and the first moisture-permeable membrane 54 of the humidifying chamber 55 form a chamber.

[0042] The humidification chamber 55 has communication portions 55e on three of the four sides of its approximate parallelogram and positioning engagement portions 55d on two of the four sides. The three sides of the humidification chamber 55 are slightly cut out inward of the approximate parallelogram at multiple locations, allowing liquid to pass from the -Y1 side of the humidification chamber 55 to the +Y1 side and from the +Y1 side to the -Y1 side only near the three sides of the humidification chamber 55. The humidification chamber 55 may also have a communication portion 55e on the side of the approximate parallelogram closest to the +Z direction. Because the periphery of the humidification chamber 55 is sealed, the humidification chamber 55 does not communicate with the communication portion 55e.

[0043] As described above, in this embodiment, unit cap 51a shown in Figure 5 is used with the bottom surface of its approximate parallelogram inclined relative to the horizontal. Gravity acts as a force that causes liquid to flow vertically in the -Z direction, making it difficult for liquid to flow to the side of the approximate parallelogram closest to the +Z direction. Therefore, in this embodiment, humidifying chamber 55 does not have communication part 55e on the side of the approximate parallelogram closest to the +Z direction.

[0044] Humidifying chamber 55 has communication hole 55f, which communicates with the space inside case 56, at communication part 55e on the side furthest in the -Z direction of the approximate parallelogram, slightly toward the +X direction from the center of communication part 55e. This allows humidifying chamber 55 to be configured so that liquid flowing due to gravity flows more evenly and efficiently through communication hole 55f.

[0045] Case 56 has atmosphere communication hole 56a on one side of its approximate parallelogram closest to the +Z direction, slightly toward the -X direction from the center of that side. Humidification chamber 55 also has communication hole 55j (shown in FIG. 6 ) that connects the space within case 56 to atmosphere communication hole 56a. This allows communication between the space within case 56 and the atmosphere, which will be described later. To allow the atmosphere to circulate within case 56 more efficiently, it is desirable to position atmosphere communication hole 56a in the center of case 56. In this embodiment, the humidifying chamber 55 has a substantially parallelogram-shaped bottom surface, so that the air communication hole 56a is located slightly to the −X direction side in the width direction X.

[0046] As shown in FIG. 6, the humidifying chamber 55 has an inlet 55a, an outlet 55b, an engaging portion 55g, and a positioning engaging portion 55h on the +Y1 side of the bottom of the approximately parallelogram. The engaging portion 55g is tubular, with the inlet 55a formed inside the engaging portion 55g on the +X side and the outlet 55b formed inside the engaging portion 55g on the −X side. The inlet 55a and the outlet 55b communicate with the +Y1 side and the −Y1 side of the bottom of the approximately parallelogram. The inlet 55a and the outlet 55b communicate with each other through a flow path formed by a groove 55c and the first moisture-permeable membrane 54 inside the humidifying chamber 55. The flow path formed by the groove 55c and the first moisture-permeable membrane 54 will be described later.

[0047] The case 56 has an atmosphere communication hole 56a, a discharge hole 56b which is an example of a hole, an engaged portion 56c, a positioning engaged portion 56d shown in Fig. 5, and a seal portion 56e. The atmosphere communication hole 56a and the discharge hole 56b communicate with the +Y1 side and the -Y1 side of the bottom surface of the approximate parallelogram.

[0048] The seal portion 56e is formed in a frame shape along the surface of the peripheral wall forming the case 56 closest to the -Y1 direction. The seal portion 56e is made of a flexible material, such as rubber or elastomer. To prevent the liquid inside the unit cap 51a from dripping from the seal portion 56e to the outside of the unit cap 51a, the seal portion 56e may be made of a water-repellent elastomer that repels the liquid ejected from the liquid ejection head 21. In this embodiment, the surface of the peripheral wall forming the case 56 closest to the -Y1 direction is located on the XZ1 plane, which is inclined relative to the horizontal. The liquid moves vertically due to gravity. Therefore, the seal portion 56e below the center of the unit cap 51a in the vertical direction Z may be more water-repellent than the upper seal portion 56e, or only the lower seal portion 56e may be water-repellent.

[0049] The case 56 has a low, rectangular prism-like outer shape with a substantially parallelogram-shaped base similar to that of the unit cap 51a, and houses the restricting member 52, absorber 53, first moisture-permeable membrane 54, and humidification chamber 55. A positioning engaging portion 55d of the humidification chamber 55 engages with a positioning engaged portion 52c of the restricting member 52. An engaging portion 55g of the humidification chamber 55 engages with an engaged portion 56c of the case 56. A positioning engaging portion 55h of the humidification chamber 55 engages with a positioning engaged portion 56d of the case 56 (shown in FIG. 5). This holds the restricting member 52, absorber 53, first moisture-permeable membrane 54, and humidification chamber 55 in the case 56. Furthermore, a communication hole 55f of the humidification chamber 55 communicates with a discharge hole 56b of the case 56. The communication hole 55j of the humidification chamber 55 and the atmosphere communication hole 56a of the case 56 are in communication with each other.

[0050] As shown in FIG. 7, groove 55c of humidifying chamber 55 is formed on the −Y1 side of the bottom surface of the approximately parallelogram. Groove 55c is meandering and covers the entire surface, forming a maze-like, linear path from inlet 55a to outlet 55b. The −Y1 side end of groove wall 55i forming groove 55c and first moisture-permeable membrane 54 shown in FIG. 5 are sealed across the entire area from inlet 55a to outlet 55b. Therefore, groove 55c and first moisture-permeable membrane 54 form a linear, winding flow path with a complex, serpentine route, connecting inlet 55a and outlet 55b. That is, humidifying chamber 55 is formed into a flow path connecting inlet 55a and outlet 55b by groove 55c, through which a humidifying fluid flows (described later), and first moisture-permeable membrane 54 shown in FIG. 5, which is an example of a partition wall covering groove 55c.

[0051] As will be described later, the space within the unit cap 51a is humidified by the humidifying fluid flowing through the groove 55c, so it is desirable that the area occupied by the groove 55c within the unit cap 51a in the XZ1 plane be large. That is, in order to increase the area occupied by the groove 55c relative to the bottom surface of the unit cap 51a, it is desirable to route the flow path over the entire bottom surface of the unit cap 51a.

[0052] <Regarding the recess that forms the space> As shown in Fig. 8, the liquid ejection device 11 includes a capping device 50. The capping device 50 has a movable capping unit 51 shown in Fig. 3. The capping unit 51 has unit caps 51a.

[0053] When the cap unit 51 moves in the first direction D1 to the maintenance position shown in FIG. 8 and then the head unit 24 moves in the third direction D3 to the maintenance position shown in FIG. 8, the unit cap 51a of the cap device 50 comes into contact with the nozzle surface 23 of the liquid ejection head 21. The surface of the seal portion 56e located around the periphery of the case 56 on the -Y1 direction side is referred to as the contact surface 56f. When the cap device 50 comes into contact with the liquid ejection head 21, the nozzle surface 23 and the contact surface 56f come into contact with each other, and the nozzle surface 23 is sealed by the seal portion 56e. That is, the cap device 50 is configured to form a space SP surrounding the opening 22a of the nozzle 22 when the unit cap 51a, which is an example of a cap, comes into contact with the liquid ejection head 21 having the nozzle 22 that ejects liquid. In other words, when the unit cap 51a, which is an example of a cap, comes into contact with the liquid ejection head 21 having the nozzle 22 that ejects liquid, the space SP surrounding the opening 22a of the nozzle 22 can be formed.

[0054] The unit cap 51a has a recess 57 that forms a space SP. In this embodiment, as shown in FIG. 8, the recess 57 is formed by the inner surface of the case 56, the outer surface of the humidification chamber 55, and the surface of the first moisture-permeable membrane 54 facing the absorber 53. The recess 57 has the absorber 53, which is capable of absorbing liquid, in contact with the first moisture-permeable membrane 54, which is an example of a partition wall. The gas-permeable first moisture-permeable membrane 54 separates the recess 57 from the humidification chamber 55. As a result, when the cap device 50 and the liquid ejection head 21 come into contact with each other, the recess 57 forms a space SP surrounding the opening 22a of the nozzle 22. The recess 57 has a volume that prevents liquid ejected into the recess by flushing from overflowing from the seal portion 56e.

[0055] In this embodiment, the nozzle surface 23 on which the nozzles 22 are arranged is not horizontal, but is angled at a first predetermined angle θ1 with respect to the horizontal. Therefore, the surface of the seal portion 56e located around the periphery of the case 56 on the -Y1 direction side is also not horizontal, but is angled at the first predetermined angle θ1 with respect to the horizontal. As a result, with the unit cap 51a tilted at the first predetermined angle θ1 with respect to the horizontal, the nozzle surface 23 and the contact surface 56f of the seal portion 56e come into close contact with each other, and the nozzle surface 23 is sealed by the seal portion 56e. Even in this embodiment in which the unit cap 51a is tilted with respect to the horizontal, the recess 57 has a volume that prevents liquid ejected into the recess by flushing from overflowing from below the tilted seal portion 56e when flushing is performed.

[0056] The nozzle surface 23 on which the nozzles 22 are arranged and the surface of the seal portion 56e on the -Y1 direction side may be arranged horizontally. That is, the nozzle surface 23 may be sealed by the seal portion 56e in a state in which the liquid ejection head 21 and the unit cap 51a are arranged horizontally.

[0057] As shown in FIG. 9 , the regulating member 52 and the absorbent body 53 are liquid permeable, while the first moisture permeable membrane 54 is not. Therefore, during flushing, the liquid discharged from the nozzle 22 passes through the regulating member 52 and the absorbent body 53 from the −Y1 direction to the +Y1 direction, but does not pass through the first moisture permeable membrane 54 from the −Y1 direction to the +Y1 direction. The liquid is also absorbed by the absorbent body 53. The liquid absorbed by the absorbent body 53 then spreads throughout the absorbent body 53. More specifically, when there are areas within the absorbent body 53 where less liquid has been absorbed around an area where a large amount of liquid has been absorbed, the liquid flows from the area where a large amount of liquid has been absorbed to the areas where less liquid has been absorbed.

[0058] As the absorber 53 absorbs more liquid and approaches a state where it can no longer absorb any more liquid, gravity causes the liquid to flow in the vertical −Z direction within the absorber 53. As a result, when the liquid reaches the −Y1 side of the first moisture-permeable membrane 54, gravity causes the liquid to flow in the −Z1 direction. Because the first moisture-permeable membrane 54 is not permeable to liquid, the first moisture-permeable membrane 54 restricts the passage of liquid. In other words, the liquid does not flow into the humidification chamber 55. Then, the liquid passes through the communicating portion 54a and the communicating portion 55e by gravity and is discharged to the outside of the unit cap 51a through the discharge hole 56b of the case 56. That is, the recess 57 has the discharge hole 56b, which is an example of a hole that can discharge the liquid discharged from the liquid ejection head 21 into the unit cap 51a.

[0059] In the present embodiment, the discharge hole 56b, which is an example of a hole, is provided in the recess 57 at a position lower than the first moisture permeable membrane 54, which is an example of a partition wall. That is, the discharge hole 56b is provided on the -Z direction side of the first moisture permeable membrane 54. Furthermore, the discharge hole 56b, which is an example of a hole, may be provided at the bottom of the recess 57. That is, the discharge hole 56b may be provided at the side furthest from the recess 57 in the -Z direction.

[0060] The humidifying chamber 55 has an inlet 55a through which a humidifying fluid (described later) flows in to humidify the space SP, and an outlet 55b through which the humidifying fluid flows out. Because the first moisture-permeable membrane 54 is not liquid-permeable, the first moisture-permeable membrane 54 restricts the passage of liquid within the humidifying chamber 55 from the +Y1 direction to the -Y1 direction. As a result, in the humidifying chamber 55, liquid that flows in through the inlet 55a flows out through the outlet 55b. The humidifying chamber 55 is disposed at an angle relative to the horizontal. Inflow inlet 55a and outflow outlet 55b are provided above the center of humidifying chamber 55 in the vertical direction Z. In this embodiment, inflow inlet 55a and outflow outlet 55b are located on the +Z side of the center of humidifying chamber 55 in the vertical direction Z. By providing inflow inlet 55a and outflow outlet 55b on the +Z side of humidifying chamber 55, it is possible to prevent liquid within humidifying chamber 55 from flowing out of humidifying chamber 55 from inflow inlet 55a or outflow outlet 55b due to head pressure.

[0061] 10, the restricting member 52, the absorber 53, and the first moisture-permeable membrane 54 are gas-permeable. Therefore, gas such as air and water vapor passes through the restricting member 52, the absorber 53, and the first moisture-permeable membrane 54 from the -Y1 direction to the +Y1 direction, and from the +Y1 direction to the -Y1 direction. As a result, the cap device 50 is configured so that water vapor evaporated from the humidifying fluid (described later) can flow from the humidifying chamber 55 into the recess 57 within the unit cap 51a.

[0062] The recess 57 has an atmosphere-communicating hole 56a for communicating the space SP with the atmosphere. The atmosphere-communicating hole 56a is provided above the center of the unit cap 51a in the vertical direction. In this embodiment, the atmosphere-communicating hole 56a is provided on the +Z direction side of the center of the recess 57 in the vertical direction Z. By providing the atmosphere-communicating hole 56a above the center of the unit cap 51a in the vertical direction, it is possible to prevent the atmosphere-communicating hole 56a from being blocked by liquid. Furthermore, the atmosphere-communicating hole 56a may be provided at a position higher than the first moisture permeable membrane 54, i.e., on the +Z direction side of the first moisture permeable membrane 54.

[0063] <Configuration of the humidified fluid circulation mechanism provided in the capping device> As shown in FIG. 11, the capping device 50 includes a capping unit 51 having unit caps 51a, a cap moving mechanism (not shown), a humidified fluid circulating mechanism 60, and a waste liquid collecting mechanism 80.

[0064] The cap device 50 includes a humidifying fluid circulation mechanism 60 having a humidifying fluid storage unit 61 that stores humidifying fluid L1a, a supply flow path 62a, and a recovery flow path 62b. The supply flow path 62a connects the humidifying fluid storage unit 61 to the inlet 55a. That is, the supply flow path 62a connects the humidifying fluid storage unit 61 to a unit cap 51a, which is an example of a cap. The recovery flow path 62b connects the outlet 55b to the humidifying fluid storage unit 61. That is, the recovery flow path 62b connects the unit cap 51a, which is an example of a cap, to the humidifying fluid storage unit 61. The humidifying fluid circulation mechanism 60 includes a circulation path 62 that includes the humidifying fluid storage unit 61, the supply flow path 62a, and the recovery flow path 62b.

[0065] The humidifying fluid storage section 61 has an inlet 61f and an outlet 61g. The humidifying fluid storage section 61 communicates with the recovery passage 62b at the inlet 61f. The humidifying fluid storage section 61 communicates with the supply passage 62a at the outlet 61g.

[0066] In the humidified fluid circulation mechanism 60, the humidified fluid L1a flowing within the circulation path 62 is a fluid containing moisture for humidifying the space SP shown in FIG. 8. The moisturizing power of the humidified fluid L1a is preferably equivalent to that of the liquid ejected from the liquid ejection head 21. The moisturizing power refers to the concentration of the humidifier contained in the humidified fluid L1a or the liquid ejected from the liquid ejection head 21. For example, when the liquid ejection head 21 ejects ink, which is an example of a liquid, onto a medium such as paper to print, it is preferable that the moisturizing power of the humidified fluid L1a be equivalent to that of fresh ink. It is also preferable that the moisturizing power of the ink is balanced for each color. Details of the humidified fluid L1a will be described later.

[0067] As shown in FIG. 3, the capping unit 51 included in the capping device 50 of this embodiment has five unit caps 51a shown in FIG. 6. That is, the capping device 50 is configured with a plurality of unit caps 51a, which are an example of caps, lined up. Each of the five unit caps 51a in the capping device 50 has an inlet 55a shown in FIG. 6 and an outlet 55b shown in FIG. 6. Therefore, in this embodiment, the outlet 55b of one of the unit caps 51a among the plurality of unit caps 51a is connected to the inlet 55a of another unit cap 51a adjacent to that unit cap 51a. For example, the outlet 55b of one unit cap 51a and the inlet 55a of another unit cap 51a adjacent to that unit cap 51a are connected by a tube (not shown), so that the outlet 55b and the inlet 55a communicate with each other. As a result, the inlet 55a located most upstream communicates with the outlet 55b located most downstream. The inlet 55a located most upstream is connected to the supply flow path 62a shown in Fig. 11. The outlet 55b located most downstream is connected to the recovery flow path 62b shown in Fig. 11. That is, the capping device 50 of this embodiment is configured so that the humidifying fluid L1a flowing in the circulation path 62 shown in Fig. 11 can flow through the grooves 55c of the humidifying chambers 55 shown in Fig. 7 of all the unit caps 51a. When the capping device 50 has only one unit cap 51a, the inlet 55a of that unit cap 51a may be connected to the supply flow path 62a, and the outlet 55b of that unit cap 51a may be connected to the recovery flow path 62b.

[0068] As shown in Fig. 11, the humidifying fluid container 61 contains a humidifying fluid L1a containing moisture for humidifying the space SP shown in Fig. 8. The humidifying fluid container 61 has a detection unit 61a that detects the liquid level in the humidifying fluid container 61. The detection unit 61a has a first electrode 61b and a second electrode 61c.

[0069] The humidifying fluid L1a contains a conductive additive. The detection unit 61a detects the liquid level in the humidifying fluid storage unit 61 by measuring the electrical resistance between the first electrode 61b and the second electrode 61c. When the liquid level of the humidifying fluid L1a stored in the humidifying fluid storage unit 61 is higher than a first predetermined height H1, which is an example of a "predetermined height," electrical continuity is established between the first electrode 61b and the second electrode 61c. When the liquid level of the humidifying fluid L1a stored in the humidifying fluid storage unit 61 is lower than the first predetermined height H1 and higher than a second predetermined height H2, electrical continuity is not established between the first electrode 61b and the second electrode 61c. In this way, the detection unit 61a is configured to be able to determine whether the liquid level of the humidifying fluid L1a is higher than the first predetermined height H1 by detecting a change in output level depending on whether the first electrode 61b is in contact with the liquid level or not.

[0070] When the detection unit 61a detects that the liquid level of the humidifying fluid L1a is above the first predetermined level H1, this means that the humidifying fluid L1a is sufficiently contained in the humidifying fluid storage unit 61, that is, the humidifying fluid storage unit 61 is full with humidifying fluid L1a. In this embodiment, the full state of the humidifying fluid storage unit 61 is detected. Instead of detecting only the full state of the humidifying fluid storage unit 61, it is also possible to detect an empty or nearly empty state of the humidifying fluid storage unit 61. Furthermore, the method for detecting the liquid level is not limited to an electrode method, and optical or capacitance methods may also be used.

[0071] The humidifying fluid storage portion 61 has a second atmosphere-communicating passage 61d and a second moisture-permeable membrane 61e. The second atmosphere-communicating passage 61d connects the humidifying fluid storage portion 61 to the atmosphere. The second atmosphere-communicating passage 61d may have a labyrinthine thin tube structure. A labyrinthine thin tube structure refers to a tube structure having a complex, narrow, and winding path that allows air to pass through but significantly restricts the passage of liquid. The labyrinthine thin tube structure suppresses evaporation of the liquid in the humidifying fluid storage portion 61.

[0072] The second moisture permeable membrane 61e is provided at the connection between the humidifying fluid storage portion 61 and the second atmosphere-communicating passage 61d. The second moisture permeable membrane 61e allows gas to pass from the humidifying fluid storage portion 61 to the second atmosphere-communicating passage 61d, while restricting the passage of liquid from the humidifying fluid storage portion 61 to the second atmosphere-communicating passage 61d. To increase the efficiency with which gas passes from the humidifying fluid storage portion 61 to the second atmosphere-communicating passage 61d, it is desirable for the area of ​​the second moisture permeable membrane 61e to be large.

[0073] 11, the humidified fluid circulation mechanism 60 provided in the cap device 50 includes a first pump 63, which is an example of a pump that can cause the humidified fluid L1a to flow within the circulation path 62, a first check valve 64, and a pressure adjustment valve 65. The first pump 63 causes the fluid to flow within the circulation path 62. When the first pump 63 is driven, the liquid flowing through the supply flow path 62a is sent to the humidifying chamber 55 in the unit cap 51a.

[0074] The first check valve 64 allows the flow of liquid from the humidifying fluid storage portion 61 side to the unit cap 51a side, and prevents the liquid from flowing back from the unit cap 51a side to the humidifying fluid storage portion 61 side due to a head difference. An on-off valve may be provided instead of the first check valve 64. When the on-off valve is opened, the first pump 63 is driven, and the liquid may flow from the humidifying fluid storage portion 61 side to the unit cap 51a side. Opening an on-off valve is referred to as "opening the valve" or "opening the valve." Closing an on-off valve is referred to as "closing the valve" or "closing the valve."

[0075] The pressure adjustment valve 65 allows liquid to flow from the unit cap 51a side to the humidifying fluid storage portion 61 side when a predetermined negative pressure is reached on the humidifying fluid storage portion 61 side, and always prevents liquid from flowing back from the humidifying fluid storage portion 61 side to the unit cap 51a side. The pressure adjustment valve 65 adjusts the pressure difference due to the head differential so that liquid does not flow from the unit cap 51a side to the humidifying fluid storage portion 61 side due to head pressure.

[0076] 11, the humidified fluid circulation mechanism 60 included in the capping device 50 includes a moisture supply unit 66 that can supply moisture L1b into the circulation path 62. The moisture supply unit 66 includes a moisture storage unit 66a, a moisture supply flow path 66b, a first on-off valve 66c that is an example of an on-off valve, and a second check valve 66d. The moisture storage unit 66a stores moisture L1b that can be supplied into the circulation path 62. The moisture supply flow path 66b communicates with the circulation path 62. The first on-off valve 66c is configured to be able to open and close the moisture supply flow path 66b.

[0077] The moisture storage section 66a has an outflow section 66f. The moisture storage section 66a communicates with a moisture supply flow path 66b at the outflow section 61g. The moisture supply flow path 66b communicates with the circulation path 62 at a first junction 62c of the circulation path 62. That is, the moisture storage section 66a communicates with the circulation path 62. It is desirable that the moisture storage section 66a be configured to be replaceable.

[0078] The moisture L1b supplied from the moisture storage section 66a into the circulation path 62 is moisture to replenish the moisture evaporated from the humidifying fluid L1a. The moisture L1b is made up of pure water and a small amount of antiseptic.

[0079] When the first on-off valve 66c is opened, the water storage section 66a and the circulation path 62 are connected by the water supply flow path 66b. The second check valve 66d allows the liquid to flow from the water storage section 66a side to the circulation path 62 side, but prevents the liquid from flowing back from the circulation path 62 side to the water storage section 66a side due to a head difference. Note that the second check valve 66d is not necessary. When the second check valve 66d is not provided, the first pump 63 may flow water L1b from the water storage section 66a side to the unit cap 51a side by driving the first pump 63 when the first on-off valve 66c is opened.

[0080] As shown in FIG. 11 , the humidified fluid circulation mechanism 60 included in the capping device 50 further includes a pressurized air supply unit 67. The pressurized air supply unit 67 is configured to be able to supply pressurized air into the circulation path 62. The pressurized air supply unit 67 includes a pressurized air supply path 67a that communicates with the circulation path 62, a second on-off valve 67b, and a second pump 67c. When the second on-off valve 67b is opened, the second pump 67c communicates with the circulation path 62 via the pressurized air supply path 67a. The second pump 67c is, for example, a pressure pump. The second pump 67c applies pressure to the atmosphere to generate pressurized air and supplies the pressurized air to the pressurized air supply path 67a.

[0081] In the circulation path 62, instead of providing the pressurized air supply unit 67 downstream of the first pump 63, an air supply unit may be provided upstream of the first pump 63 and downstream of the first junction 62c. The atmosphere supply unit may have an atmosphere communication passage that communicates with the atmosphere, and an on-off valve. Then, by opening the on-off valve, the circulation path 62 and the atmosphere are communicated through the atmosphere communication passage, and the first pump 63 may send the atmosphere to the circulation path 62. That is, the capping device 50 may have an atmosphere supply unit that supplies atmosphere to the circulation path 62, in the circulation path 62 through which the humidifying fluid L1a flows, between the first junction 62c where the moisture supply unit 66 and the circulation path 62 join, and the inlet 55a of the unit cap 51a. The capping device 50 may further have a pump that sends the atmosphere to the circulation path 62.

[0082] <Configuration of waste liquid recovery mechanism equipped in capping device> As shown in FIG. 11, the waste liquid recovery mechanism 80 provided in the capping device 50 has a waste liquid recovery path 81, a third pump 82, a buffer chamber 83, a fourth pump 84, a third atmosphere communication passage 85, and a waste liquid storage section 86.

[0083] The waste liquid recovery path 81 includes a first waste liquid recovery path 81a and a second waste liquid recovery path 81b. The first waste liquid recovery path 81a communicates with a space SP formed by a recess 57 (shown in FIG. 8) inside the unit cap 51a at a discharge hole 56b of the unit cap 51a. The first waste liquid recovery path 81a communicates with the space SP and the waste liquid storage section 86 through a buffer chamber 83. The second waste liquid recovery path 81b communicates with the wiper carriage 41 at a waste liquid outlet 43 of the wiper carriage 41. The second waste liquid recovery path 81b communicates with the wiper carriage 41 and the waste liquid storage section 86.

[0084] During flushing, cleaning, and the like, liquid is discharged from the nozzles 22 of the liquid ejection head 21 as waste liquid L2. The waste liquid L2, which is an example of a liquid, is collected from within the unit cap 51a and flows into the first waste liquid recovery path 81a. During wiping, liquid adhering to the nozzle surface 23 of the liquid ejection head 21 is wiped away and collected into the wiper carriage 41 as waste liquid L2. The waste liquid L2 is collected from within the wiper carriage 41 and flows into the second waste liquid recovery path 81b. The waste liquid L2 collected during flushing or cleaning and the waste liquid L2 collected during wiping are sent to the waste liquid storage section 86 by the third pump 82. The waste liquid L2 is then stored in the waste liquid storage section 86.

[0085] 3, the cap unit 51 included in the capping device 50 of this embodiment has five unit caps 51a shown in FIG. 6. That is, the capping device 50 is configured with a plurality of unit caps 51a lined up, and each of the five unit caps 51a has a drain hole 56b. Therefore, in this embodiment, the five drain holes 56b are connected to the first waste liquid recovery channel 81a, and the first waste liquid recovery channel 81a connects the five drain holes 56b to the waste liquid storage section 86. When the capping device 50 has only one unit cap 51a, only the drain hole 56b of that unit cap 51a may be connected to the first waste liquid recovery channel 81a.

[0086] 11, in this embodiment, the fourth pump 84 is a pressure reducing pump. The fourth pump 84 lowers the air pressure inside the buffer chamber 83 by discharging the air inside the buffer chamber 83 to the outside through the third atmosphere communicating passage 85. This makes it easier for the waste liquid L2 discharged into the unit cap 51a from the nozzles 22 of the liquid ejection head 21 during flushing or cleaning to flow into the buffer chamber 83 through the first waste liquid recovery passage 81a. Note that the buffer chamber 83, the fourth pump 84, and the third atmosphere communicating passage 85 may be omitted.

[0087] 11, the cap unit 51 having the unit cap 51a has an atmosphere opening mechanism 58. The atmosphere opening mechanism 58 has a first atmosphere communication passage 58a and a third opening / closing valve 58b.

[0088] The first atmosphere communication passage 58a connects the atmosphere communication holes 56a of each unit cap 51a in the cap unit 51 to the atmosphere. The third on-off valve 58b is an on-off valve that can open and close the first atmosphere communication passage 58a. In this embodiment, the atmosphere side of the first atmosphere communication passage 58a is open. The cap device 50 is configured so that when the cap unit 51 moves in the fourth direction D4 from the maintenance position indicated by the two-dot chain line in FIG. 11 to the retracted position indicated by the solid line in FIG. 11, the open portion hits a wall (not shown), which closes the first atmosphere communication passage 58a. That is, the third on-off valve 58b is opened and closed by the movement of the cap unit 51. During flushing or cleaning, the first atmosphere communication passage 58a is open, and the liquid ejection head 21 discharges liquid into the unit cap 51a.

[0089] <Electrical configuration of the liquid ejection device> 12, the liquid ejection device 11 includes a control unit 90 that controls the head unit 24, the wiper device 40, and the capping device 50. The capping device 50 includes a detector group 91 controlled by the control unit 90. The detector group 91 includes a detector 61a that detects the liquid level in the humidifying fluid storage unit 61. The detector 61a outputs the detection result to the control unit 90.

[0090] The control unit 90 has an interface unit 94, a CPU 95, a memory 96, a control circuit 97, and a drive circuit 98. The interface unit 94 transmits and receives data between a computer 99, which is an external device, and the liquid ejection device 11. The drive circuit 98 generates a drive signal that drives the actuator of the liquid ejection head 21.

[0091] The CPU 95 is an arithmetic processing unit. The memory 96 is a storage device that secures an area for storing programs for the CPU 95, a working area, etc., and has storage elements such as RAM and EEPROM. The CPU 95 controls the head unit 24, the wiper device 40, the cap device 50, etc. via a control circuit 97 in accordance with the programs stored in the memory 96.

[0092] <About the circulation of humidifying fluid> The circulation operation in the maintenance method for the cap device will now be described. As shown in Fig. 13, the capping device 50 performs a circulation operation. During the circulation operation, the first on-off valve 66c is closed, and the control unit 90 causes the humidified fluid circulation mechanism 60 to flow the humidified fluid L1a through the circulation path 62 in the direction of the solid arrow shown in Fig. 13. The control unit 90 then checks the amount of water evaporated from the humidified fluid L1a.

[0093] The circulation path is made up of a humidifying fluid storage portion 61 that stores humidifying fluid L1a containing moisture for humidifying the space SP shown in Fig. 8, a supply flow path 62a that connects the humidifying fluid storage portion 61 to the unit cap 51a, a recovery flow path 62b that connects the unit cap 51a to the humidifying fluid storage portion 61, and the humidifying chamber 55 shown in Fig. 8 inside the unit cap 51a. Note that during circulation, the internal pressure inside the unit cap 51a is preferably kept below the meniscus withstand pressure of the liquid ejection head 21 by adjusting the circulation flow rate using the first pump 63.

[0094] As shown in FIG. 13 , during the circulation of the humidifying fluid L1a, the humidifying fluid L1a flows through the circulation path 62 in the direction of the solid arrow in FIG. 13 and circulates through the circulation path. The control unit 90 causes the humidifying fluid L1a to flow through the circulation path 62, causing the humidifying fluid L1a to flow through the humidifying chamber 55 in a single, winding path with a complex, serpentine path as shown in FIG. 7 . Moisture from the humidifying fluid L1a evaporates primarily in the humidifying chamber 55 within the unit cap 51a. Then, for example, when the humidifying fluid L1a in the humidifying chamber 55 flows into the humidifying fluid storage portion 61 and the humidifying fluid L1a in the humidifying fluid storage portion 61 flows into the humidifying chamber 55, the control unit 90 stops the flow of the humidifying fluid L1a and checks the amount of moisture evaporated from the humidifying fluid L1a. In other words, the purpose of the circulation in the maintenance method for a cap device includes checking the amount of moisture evaporated from the humidifying fluid L1a.

[0095] As shown in FIG. 13 , the control unit 90 periodically executes the circulation operation by managing time using a timer or the like. For example, when the liquid ejection device 11 is powered on, the control unit 90 executes the circulation operation once a day. At the end of the circulation operation flow described below, the control unit 90 acquires information on the liquid level in the humidifying fluid storage unit 61 from the detection unit 61a to check the amount of water evaporation from the humidifying fluid L1a. If the amount of water evaporation in the unit cap 51a is large, the liquid level in the humidifying fluid storage unit 61 decreases. The amount of water evaporation increases when the unit cap 51a is in the retracted position shown in FIG. 13 , i.e., when the unit cap 51a does not form the space SP surrounding the opening 22a of the nozzle 22 shown in FIG. 8 . Therefore, the control unit 90 may execute the circulation operation by managing the time when the unit cap 51a is in the retracted position for each temperature and humidity environment. In addition, the control unit 90 may also perform the circulation operation before the first recording is performed on the medium M after the liquid ejection device 11 is installed, before the first recording is performed on the medium M after the cap unit 51 is replaced with a new cap unit 51, or before the first recording is performed on the medium M after the moisture storage section 66a is replaced with a full moisture storage section 66a.

[0096] To reduce the frequency of the circulation operation, it is desirable that the humidifying fluid storage portion 61 have a large liquid surface area relative to the depth within the humidifying fluid storage portion 61. This makes it possible to reduce changes in the height of the liquid surface when the amount of liquid within the humidifying fluid storage portion 61 changes due to evaporation of moisture contained in the humidifying fluid L1a. Also, to make changes in the concentration of the humidifying fluid L1a due to evaporation of moisture contained in the humidifying fluid L1a as gradual as possible, it is desirable to make the volume of the humidifying fluid storage portion 61 as large as possible within the size of the liquid ejection device 11.

[0097] Next, with reference to the flowchart shown in FIG. 14, the control executed by the control unit 90 in each step of the flow of the circulation operation in the maintenance method for the capping device will be described in order.

[0098] In step S101, the control unit 90 determines whether the first on-off valve 66c is closed. If the first on-off valve 66c is closed, the process proceeds to step S103. If the first on-off valve 66c is open, the process proceeds to step S102. Then, in step S102, the control unit 90 closes the first on-off valve 66c.

[0099] In step S103, the control unit 90 drives the first pump 63 for a first predetermined time T1 with the first on-off valve 66c in a closed state, thereby causing the humidifying fluid L1a to flow in the circulation path 62 in the direction of the solid arrow shown in FIG.

[0100] In step S104, the control unit 90 stops the first pump 63 for a second predetermined time T2 with the first on-off valve 66c closed. This stabilizes the liquid level state in the humidifying fluid storage unit 61. In order to shorten the time it takes for the liquid level state to stabilize, it is desirable to increase the area of ​​the liquid surface relative to the depth within the humidifying fluid storage unit 61, thereby reducing the amount by which the height of the liquid level changes when the amount of liquid in the humidifying fluid storage unit 61 changes.

[0101] In step S105, the control unit 90 acquires information on the liquid level in the humidifying fluid container 61 from the detection unit 61a. Then, in step S106, the control unit 90 determines whether the liquid level is higher than a first predetermined height H1. If the liquid level is higher than the first predetermined height H1, the flow ends.

[0102] If the liquid level is lower than the first predetermined height H1, the process proceeds to step S200. In step S200, the control unit 90 executes a concentration adjustment operation subroutine, which will be described later. When the concentration adjustment operation subroutine ends, the control unit 90 ends the flow.

[0103] <About the humidification fluid concentration adjustment operation> The density adjustment operation in the maintenance method for the capping device will be described. As shown in Fig. 15, the capping device 50 performs a concentration adjustment operation. During the concentration adjustment operation, the first on-off valve 66c is open, and the control unit 90 causes the humidified fluid circulation mechanism 60 to flow the humidified fluid L1a in the circulation path 62 in the direction of the solid arrow shown in Fig. 15. At this time, because the first on-off valve 66c is open, moisture L1b in the moisture supply unit 66 flows in the direction of the dashed arrow shown in Fig. 15 and is supplied into the circulation path 62. In other words, the concentration adjustment operation in the maintenance method for the capping device includes supplying moisture L1b into the circulation path 62 by the moisture supply unit 66 and flowing the humidified fluid L1a in the circulation path 62.

[0104] The concentration adjustment operation is performed by the control unit 90 at the end of the circulation operation flow described above, when the detection unit 61a detects that the liquid level in the humidifying fluid storage unit 61, when the control unit 90 acquires information about the liquid level in the humidifying fluid storage unit 61, is below a first predetermined height H1, which is an example of a "predetermined height." That is, when performing the concentration adjustment operation when the detection unit 61a detects that the liquid level in the humidifying fluid storage unit 61 is below the predetermined height, the capping device 50 supplies moisture L1b in the moisture storage unit 66a into the circulation path 62 until it detects that the liquid level has reached or exceeded the predetermined height. Then, the humidifying fluid L1a is caused to flow in the circulation path 62.

[0105] Moisture evaporates from the humidifying fluid L1a within the unit cap 51a, and the humidifying fluid L1a circulates within the circulation path 62 through the circulation operation described above. As a result, the moisture within the humidifying fluid storage portion 61 also decreases, causing the liquid level within the humidifying fluid storage portion 61 to decrease. As evaporation continues, the liquid level within the humidifying fluid storage portion 61 becomes lower than the first predetermined height H1. The first predetermined height H1 is set so that the concentration of the humidifying fluid L1a at this time is greater than the predetermined concentration. The control portion 90 performs a concentration adjustment operation, and moisture L1b within the moisture storage portion 66a is supplied into the circulation path 62 so that the liquid level is higher than the first predetermined height H1. As a result, approximately the same amount of moisture as that evaporated within the unit cap 51a is supplied into the circulation path 62, causing the concentration of the humidifying fluid L1a to become lower than the predetermined concentration. That is, the concentration of the humidifying fluid L1a returns to the concentration of the humidifying fluid L1a before the water evaporated in the unit cap 51a.

[0106] In the concentration adjustment operation, the control unit 90 opens the first on-off valve 66c and supplies moisture L1b from the moisture storage unit 66a into the circulation path 62. Then, when the control unit 90 determines that the liquid level in the humidifying fluid storage unit 61 has become higher than the first predetermined height H1, it closes the first on-off valve 66c and performs the circulation operation described above, causing the humidifying fluid L1a from the humidifying fluid storage unit 61 to flow through the circulation path 62. In other words, the concentration adjustment operation in the maintenance method for a capping device includes opening the first on-off valve 66c, which is an example of an on-off valve, when supplying moisture L1b from the moisture storage unit 66a into the circulation path 62, and closing the first on-off valve 66c when causing the humidifying fluid L1a to flow through the circulation path 62.

[0107] At first junction 62c of circulation path 62, humidifying fluid L1a flowing from humidifying fluid storage section 61 and moisture L1b flowing from moisture supply section 66 merge. When the volume of moisture L1b flowing from moisture supply section 66 is greater than the volume of humidifying fluid L1a flowing from humidifying fluid storage section 61, the rate of change of the liquid level in humidifying fluid storage section 61 increases, resulting in greater variability in liquid level detection, making it difficult to detect the liquid level in a timely manner. For this reason, it is desirable to set first junction 62c so that the pressure loss in the flow path on the moisture supply section 66 side is the same as or greater than the pressure loss in the flow path on the humidifying fluid storage section 61 side.

[0108] Next, with reference to the flowchart shown in FIG. 16, the control executed by the control unit 90 in each step of the flow of the concentration adjustment operation in the maintenance method for the capping device will be described in order.

[0109] In step S201, the control unit 90 determines whether the first on-off valve 66c is open. If the first on-off valve 66c is open, the process proceeds to step S203. If the first on-off valve 66c is closed, the process proceeds to step S202, where the control unit 90 opens the first on-off valve 66c.

[0110] In step S203, the control unit 90 drives the first pump 63 for a third predetermined time T3 with the first on-off valve 66c open. As a result, as shown in FIG. 15, the humidifying fluid L1a flows in the circulation path 62 in the direction of the solid arrow shown in FIG. 15. Then, moisture L1b flows in the moisture supply flow path 66b in the direction of the dashed arrow shown in FIG. 15 and merges with the humidifying fluid L1a at the first junction 62c. The merged humidifying fluid L1a and moisture L1b become humidifying fluid L1a with an increased moisture content, which flows from the first junction 62c toward the unit cap 51a, within the circulation path 62 in the direction of the solid arrow shown in FIG. 15, and into the humidifying fluid storage unit 61. Then, the liquid level in the humidifying fluid storage unit 61 becomes higher than the first predetermined height H1.

[0111] In step S204, the control unit 90 acquires information about the liquid level in the humidifying fluid container 61 from the detection unit 61a. Then, in step S205, the control unit 90 determines whether the liquid level is higher than a first predetermined height H1. If the liquid level is higher than the first predetermined height H1, the process proceeds to step S206. If the liquid level is lower than the first predetermined height H1, the process proceeds to step S207.

[0112] In step S206, the control unit 90 closes the first on-off valve 66c, and proceeds to the subroutine for the circulation operation described above in step S100. When the control unit 90 ends the subroutine for the circulation operation, it ends the flow.

[0113] In step S207, the control unit 90 determines that the water L1b in the water storage unit 66a has run out, and in step S400, the control unit 90 executes a subroutine for the water storage unit pre-replacement operation, which will be described later. That is, when the amount of water L1b in the water storage unit 66a reaches an amount at which it is determined that replacement of the water storage unit 66a is necessary, the capping device 50 executes the water storage unit pre-replacement operation. When the control unit 90 completes the subroutine for the water storage unit pre-replacement operation, it ends the flow.

[0114] In steps S203 to S205, the control unit 90 may drive the first pump 63 while the first on-off valve 66c is open and while acquiring information about the liquid level in the humidifying fluid storage unit 61 from the detection unit 61a, and may stop the first pump 63 when the liquid level becomes higher than the first predetermined height H1. Then, when the third predetermined time T3 has elapsed since the first pump 63 was driven and the detection unit 61a has detected that the liquid level is below the first predetermined height H1, the control unit 90 may determine in step S207 that the moisture L1b in the moisture storage unit 66a has run out.

[0115] <Cap replacement preparation operation> The cap replacement preparation operation in the maintenance method for the cap device will now be described. The cap replacement preparation operation is an operation that is performed when the cap is replaced by the cap device 50. Before the cap is replaced, the humidifying fluid L1a inside the cap is collected. In the capping device 50 of this embodiment, when replacing the caps, the cap unit 51 shown in Fig. 3 is replaced. Note that the capping device 50 may be configured so that when replacing the caps, the unit cap 51a is replaced.

[0116] As shown in Fig. 17, the capping device 50 performs a cap replacement preparation operation. During the cap replacement preparation operation, the first on-off valve 66c is closed and the second on-off valve 67b is open, and the control unit 90 causes the pressurized air supply unit 67 of the humidified fluid circulation mechanism 60 to flow pressurized air through the pressurized air supply path 67a in the direction of the dashed arrows shown in Fig. 17. At this time, because the second on-off valve 67b is open, the humidified fluid L1a in the circulation path 62 flows in the direction of the solid arrows shown in Fig. 17, and pressurized air is supplied into the circulation path 62.

[0117] As the pressurized air supply unit 67 continues to supply pressurized air into the circulation path 62, the humidifying fluid L1a in the flow path from the second junction 66e to the inflow portion 61f of the circulation passage that constitutes the circulation path 62 is pushed out into the humidifying fluid storage unit 61. Then, air is filled in the flow path from the second junction 66e to the inflow portion 61f. As a result, the humidifying fluid L1a in the unit cap 51a is collected in the humidifying fluid storage unit 61. In other words, the cap replacement preparation operation in the maintenance method for a cap device is an operation in which pressurized air is supplied from the pressurized air supply unit 67 into the unit cap 51a, which is an example of a cap, to discharge the humidifying fluid L1a in the unit cap 51a to the humidifying fluid storage unit 61 and supply the pressurized air into the unit cap 51a.

[0118] Because moisture evaporates from the humidifying fluid L1a within the unit cap 51a, the concentration of the humidifying fluid L1a within the unit cap 51a is high. As a result, when the humidifying fluid L1a within the unit cap 51a is collected into the humidifying fluid storage section 61, the concentration of the humidifying fluid L1a within the humidifying fluid storage section 61 becomes high. Furthermore, when the humidifying fluid L1a within the unit cap 51a is collected into the humidifying fluid storage section 61, a small amount of the humidifying fluid L1a with a high concentration remains within the unit cap 51a. As a result, the next time the humidifying fluid L1a is replenished with moisture L1b, the concentration of the humidifying fluid L1a within the humidifying fluid storage section 61 becomes low. In order to minimize this change in the concentration of the humidifying fluid L1a, it is desirable to make the volume of the humidifying fluid storage section 61 as large as possible within the size of the liquid ejection device 11.

[0119] Next, with reference to the flowchart shown in FIG. 18, the control executed by the control unit 90 in each step of the flow of the cap replacement preparation operation in the maintenance method for the cap device will be described in order.

[0120] In step S301, the control unit 90 determines whether the first on-off valve 66c is closed. If the first on-off valve 66c is closed, the process proceeds to step S303. If the first on-off valve 66c is open, the process proceeds to step S302. Then, in step S302, the control unit 90 closes the first on-off valve 66c.

[0121] In step S303, the control unit 90 opens the second on-off valve 67b. Then, in step S304, the control unit 90 drives the second pump 67c for a fourth predetermined time T4 with the first on-off valve 66c closed and the second on-off valve 67b open. This causes the humidifying fluid L1a in the unit cap 51a to be collected into the humidifying fluid storage section 61. Then, in step S305, the control unit 90 closes the second on-off valve 67b, ending the flow.

[0122] <Operation before replacing the water storage unit> The operation before replacing the water storage unit in the maintenance method for the capping device will be described. As shown in FIG. 19 , the cap device 50 performs a pre-replacement operation for the water storage unit. The pre-replacement operation for the water storage unit is an operation executed by the control unit 90 when the amount of water L1b in the water storage unit 66a reaches a level at which it is determined that replacement of the water storage unit 66a is necessary. In this embodiment, during the concentration adjustment operation described above, if the detection unit 61a detects that the liquid level in the humidifying fluid storage unit 61 is below the first predetermined height H1 when the first pump 63 is driven for the third predetermined time T3, the control unit 90 determines that the water storage unit 66a has run out. In other words, if the concentration of the humidifying fluid L1a in the circulation path 62 cannot be restored to the concentration before the water evaporated in the unit cap 51a, the control unit 90 determines that replacement of the water storage unit 66a is necessary.

[0123] When it is determined that the moisture containing portion 66a needs to be replaced, the same operation as the cap replacement preparation operation described above is executed by the control portion 90. Then, after the humidifying fluid L1a in the unit cap 51a is collected, the first parameter table for flushing is switched to the second parameter table used when the moisture L1b in the moisture containing portion 66a is depleted until the moisture containing portion 66a is replaced.

[0124] The parameter table is a table that describes the conditions and number of times for flushing, and flushing is performed based on this table. When the humidifying fluid L1a in the unit cap 51a is collected, the space SP in the unit cap 51a is not humidified by the humidifying fluid L1a, so the control unit 90 performs a blank ejection, which is the ejection of a liquid unrelated to printing, into the space SP in the unit cap 51a to humidify the nozzles 22. Therefore, the conditions and number of times for flushing are changed to parameters suitable for humidifying the nozzles 22.

[0125] In summary, the pre-water storage unit replacement operation includes the aforementioned cap replacement preparation operation and the cap device 50 humidifying the nozzles 22 by performing idle ejection, which is the ejection of liquid not related to printing, from the liquid ejection head 21 into the space SP within the unit cap 51a, which is an example of a cap, until the water storage unit 66a is replaced.

[0126] Note that the previously described circulation operation, which had been performed periodically until the moisture storage section 66a is replaced, is not executed. When the moisture storage section 66a is replaced, the control section 90 returns the second parameter table to the first parameter table that existed before the parameter table was switched, and then starts the previously described concentration adjustment operation. Thereafter, the previously described circulation operation is also executed periodically.

[0127] Next, with reference to the flowchart shown in FIG. 20, the control executed by the control unit 90 in each step of the flow of the operation before replacing the water storage unit in the maintenance method for the cap device will be described in order.

[0128] In step S300, the control unit 90 executes the subroutine for the cap replacement preparation operation described above. When the subroutine for the cap replacement preparation operation ends, in step S401, the control unit 90 switches the parameter table and ends the flow.

[0129] <About the humidifying fluid filling operation> The humidifying fluid filling operation in the maintenance method for the capping device will now be described. The humidifying fluid filling operation is a flow performed to accommodate the humidifying fluid L1a in the humidifying fluid storage portion 61 after the liquid ejector 11 shown in FIG. 1 is assembled and before it is shipped from the factory. After the humidifying fluid L1a is stored in the humidifying fluid storage portion 61, the liquid ejector 11 is shipped from the factory with the humidifying fluid L1a in the unit cap 51a collected in the humidifying fluid storage portion 61. The humidifying fluid filling operation is performed before the moisture storage portion 66a is attached to the moisture supply flow path 66b. If the moisture storage portion 66a is already attached to the moisture supply flow path 66b, the moisture storage portion 66a is removed from the moisture supply flow path 66b before the humidifying fluid filling operation flow is executed. Some steps in the humidifying fluid filling operation flow are performed manually by an operator.

[0130] 21, a humidifying fluid pack 68 containing humidifying fluid L1a to be contained in the humidifying fluid containing portion 61 is attached to the moisture supply flow path 66b. The humidifying fluid pack 68 and the moisture supply flow path 66b communicate with each other at an outlet portion 68a of the humidifying fluid pack 68. As a result, when the first on-off valve 66c is in an open state, the humidification fluid pack 68 and the first junction 62c are in a communication state via the moisture supply flow path 66b.

[0131] The circulation path 62 has a clamp portion 62d upstream of the first junction 62c. It is desirable that the distance between the clamp portion 62d and the first junction 62c be as short as possible. When the clamp portion 62d is closed with a clamp 69, the flow path is closed at the clamp portion 62d. In other words, the humidifying fluid storage portion 61 and the first junction 62c are not in communication with each other due to the clamp 69. A clamp is a device that is provided midway along a flow path and adjusts the flow rate of the flow path by clamping the flow path.

[0132] In this state, with the first on-off valve 66c open, the control unit 90 drives the first pump 63 to cause the humidifying fluid L1a to flow in the circulation path 62 of the humidifying fluid circulation mechanism 60 in the direction of the solid arrow shown in FIG. 21. At this time, the humidifying fluid L1a in the humidifying fluid pack 68 flows in the direction of the solid arrow shown in FIG. 21. Then, because the first on-off valve 66c is open, the humidifying fluid L1a is supplied into the circulation path 62. At this time, the clamp 62d is closed by the clamp 69. Therefore, the humidifying fluid L1a in the humidifying fluid storage unit 61 is not supplied into the circulation path 62. As a result, a predetermined amount of the humidifying fluid L1a in the humidifying fluid pack 68 flows into the humidifying fluid storage unit 61. Then, the liquid level in the humidifying fluid storage unit 61 becomes higher than the first predetermined height H1.

[0133] The control unit 90 closes the first on-off valve 66c, and the operator removes the clamp 69. The humidifying fluid L1a then circulates through the circulation path 62, stabilizing the liquid level in the humidifying fluid storage unit 61. The control unit 90 then executes a cap replacement preparation operation, causing the humidifying fluid L1a in the unit cap 51a to be collected into the humidifying fluid storage unit 61. The liquid ejector 11 is shipped from the factory in this state.

[0134] Next, with reference to the flowchart shown in FIG. 22, the process in each step of the flow of the humidifying fluid filling operation will be described in order. In step S501, the humidification fluid pack 68 is attached by an operator. Then, in step S502, the operator attaches the clamp 69 to the clamping portion 62d and closes the clamp 69.

[0135] In step S503, the control unit 90 determines whether the first on-off valve 66c is open. If the first on-off valve 66c is open, the process proceeds to step S505. If the first on-off valve 66c is closed, the process proceeds to step S504. Then, in step S504, the control unit 90 opens the first on-off valve 66c.

[0136] In step S505, the control unit 90 starts driving the first pump 63. As a result, as shown in Fig. 21, the humidifying fluid L1a flows in the water supply channel 66b in the direction of the solid arrow shown in Fig. 21. The humidifying fluid L1a then flows from the first junction 62c toward the unit cap 51a, and flows in the circulation path 62 in the direction of the solid arrow shown in Fig. 21.

[0137] In step S506, the control unit 90 acquires information about the liquid level in the humidifying fluid storage unit 61 from the detection unit 61a. Then, in step S507, it is determined whether the liquid level in the humidifying fluid storage unit 61 is higher than a first predetermined height H1. If the liquid level is higher than the first predetermined height H1, the process proceeds to step S508. Then, in step S508, the control unit 90 stops driving the first pump 63. If the liquid level is lower than the first predetermined height H1, the control unit 90 continues driving the first pump 63 and proceeds to step S506.

[0138] In step S509, the control unit 90 closes the first on-off valve 66c. Then, in step S510, the clamp 69 is removed by the operator. In step S511, the control unit 90 drives the first pump 63 for a first predetermined time T1 with the first on-off valve 66c in a closed state, thereby causing the humidifying fluid L1a to flow in the circulation path 62 in the direction of the solid arrow shown in FIG.

[0139] In step S512, the control unit 90 stops the first pump 63 for the second predetermined time T2 with the first on-off valve 66c in a closed state, thereby stabilizing the liquid level state in the humidifying fluid container 61.

[0140] In step S513, the control unit 90 acquires information about the liquid level in the humidifying fluid storage unit 61 from the detection unit 61a. Then, in step S514, it is determined whether the liquid level in the humidifying fluid storage unit 61 is higher than the first predetermined height H1. If the liquid level is higher than the first predetermined height H1, the process proceeds to step S300. Then, in step S300, the control unit 90 executes a subroutine for the cap replacement preparation operation. As a result, the humidifying fluid L1a in the unit cap 51a is collected into the humidifying fluid storage unit 61. Note that when the cap replacement preparation operation is executed, the liquid level may further increase due to the humidifying fluid L1a in the unit cap 51a. Therefore, in the cap replacement preparation operation, the first predetermined height H1 is set to a height that prevents the humidifying fluid storage unit 61 from being completely filled with the humidifying fluid L1a before the humidifying fluid L1a in the unit cap 51a is completely collected into the humidifying fluid storage unit 61.

[0141] If the liquid level is lower than the first predetermined height H1 in step S514, the control unit 90 proceeds to step S502. As a result, the humidifying fluid L1a in the humidifying fluid pack 68 is again supplied into the circulation path 62. In other words, fine adjustment of the liquid level in the humidifying fluid storage unit 61 is performed.

[0142] When the cap replacement preparation subroutine is completed, in step S515, the worker removes the humidification fluid pack 68 and attaches the water storage portion 66a, and the flow then ends.

[0143] <Liquid ejected by the liquid ejection head> Ink, which is an example of the liquid ejected by the liquid ejection device 11, will be described in detail below. The ink used in the liquid ejection device 11 contains a resin by composition and is substantially free of glycerin, which has a boiling point of 290°C at 1 atmosphere. If the ink substantially contains glycerin, the ink's drying properties will be significantly reduced. As a result, on various media, particularly non-ink-absorbent or low-ink-absorbent media, not only will image shading become more noticeable, but the ink will also not adhere well. Furthermore, it is preferable that the ink be substantially free of alkyl polyols (excluding the above-mentioned glycerin) with a boiling point of 280°C or higher at a pressure equivalent to 1 atmosphere.

[0144] Here, "substantially free" in this specification means that the content is not more than the amount that fully demonstrates the significance of adding glycerin. Quantitatively speaking, the ink preferably contains no more than 1.0% by mass of glycerin relative to the total mass (100% by mass), more preferably no more than 0.5% by mass, even more preferably no more than 0.1% by mass, even more preferably no more than 0.05% by mass, and particularly preferably no more than 0.01% by mass. It is most preferable that the ink contains no more than 0.001% by mass of glycerin.

[0145] Next, additives (components) that are or can be contained in the ink will be described. [1. Coloring material] The ink may include a colorant selected from pigments and dyes.

[0146] [1-1. Pigments] The use of a pigment as a coloring material can improve the lightfastness of the ink. The pigment may be either an inorganic pigment or an organic pigment. Examples of inorganic pigments include, but are not limited to, carbon black, iron oxide, titanium oxide, and silica oxide.

[0147] The organic pigment is not particularly limited, but examples thereof include quinacridone pigments, quinacridonequinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments, and azo pigments. Specific examples of organic pigments include the following:

[0148] Pigments used in cyan inks include CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 15:34, 16, 18, 22, 60, 65, and 66, and CI Vat Blue 4 and 60. Of these, CI Pigment Blue 15:3 and 15:4 are preferred.

[0149] Pigments used in magenta inks include CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48(Ca), 48(Mn), 57(Ca), 57:1, 88, 112, and 114. , 122, 123, 144, 146, 149, 150, 166, 168, 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, 245, 254, 264, CI Pigment Violet 19, 23, 32, 33, 36, 38, 43, and 50. Among these, one or more selected from the group consisting of CI Pigment Red 122, CI Pigment Red 202, and CI Pigment Violet 19 are preferred.

[0150] Examples of pigments used in yellow inks include CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 155, 167, 172, 180, 185, and 213. Of these, one or more pigments selected from the group consisting of CI Pigment Yellow 74, 155, and 213 are preferred.

[0151] Pigments used in inks of colors other than those mentioned above, such as green ink and orange ink, include conventionally known pigments. The average particle diameter of the pigment is preferably 250 nm or less, as this can prevent clogging of the nozzle 22 and improve ejection stability. Note that the average particle diameter in this specification is based on volume. Measurement methods include, for example, measurement using a particle size distribution measuring device that uses laser diffraction scattering as its measurement principle. Examples of particle size distribution measuring devices include a particle size distribution meter (e.g., Microtrac UPA manufactured by Nikkiso Co., Ltd.) that uses dynamic light scattering as its measurement principle.

[0152] [1-2.Dye] A dye can be used as the coloring material. The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used. The content of the coloring material is preferably 0.4 to 12% by mass, and more preferably 2% to 5% by mass, relative to the total mass of the ink (100% by mass).

[0153] [2. Resin] The ink contains a resin. By including a resin in the ink, a resin film is formed on the medium, which results in the ink being sufficiently fixed to the medium and primarily improves the abrasion resistance of the image. For this reason, the resin emulsion is preferably a thermoplastic resin. The heat distortion temperature of the resin is preferably 40°C or higher, and more preferably 60°C or higher, because this advantageously reduces clogging of the nozzle 22 and improves the abrasion resistance of the medium.

[0154] Here, the term "heat distortion temperature" in this specification refers to a temperature value expressed as glass transition temperature (Tg) or minimum film forming temperature (MFT). In other words, "heat distortion temperature of 40°C or higher" means that either Tg or MFT is 40°C or higher. Note that, since MFT makes it easier to determine the redispersibility of a resin than Tg, it is preferable that the heat distortion temperature be a temperature value expressed as MFT. Ink with excellent resin redispersibility does not solidify, and therefore nozzle 22 is less likely to clog.

[0155] Specific examples of the thermoplastic resin include, but are not limited to, (meth)acrylic polymers such as poly(meth)acrylic acid esters or copolymers thereof, polyacrylonitrile or copolymers thereof, polycyanoacrylate, polyacrylamide, and poly(meth)acrylic acid; polyethylene, polypropylene, polybutene, polyisobutylene, and polystyrene, and copolymers thereof; polyolefin polymers such as petroleum resins, coumarone-indene resins, and terpene resins; vinyl acetate or vinyl alcohol polymers such as polyvinyl acetate or copolymers thereof, polyvinyl alcohol, polyvinyl acetal, and polyvinyl ether; halogen-containing polymers such as polyvinyl chloride or copolymers thereof, polyvinylidene chloride, fluororesins, and fluororubber; nitrogen-containing vinyl polymers such as polyvinylcarbazole, polyvinylpyrrolidone or copolymers thereof, polyvinylpyridine, and polyvinylimidazole; diene polymers such as polybutadiene or copolymers thereof, polychloroprene, and polyisoprene (butyl rubber); and other ring-opening polymerization resins, condensation polymerization resins, and natural polymer resins.

[0156] The resin content is preferably 1 to 30% by mass, more preferably 1 to 5% by mass, relative to the total mass (100% by mass) of the ink. When the content is within the above range, the gloss and abrasion resistance of the overcoat image formed can be further improved. Examples of resins that may be contained in the ink include resin dispersants, resin emulsions, and waxes.

[0157] [2-1. Resin emulsion] The ink may contain a resin emulsion. When the medium is heated, the resin emulsion preferably forms a resin coating together with the wax (emulsion), thereby sufficiently fixing the ink to the medium and improving the abrasion resistance of the image. Due to the above effect, when a medium is printed with an ink containing the resin emulsion, the ink has excellent abrasion resistance, particularly on a medium that does not absorb ink or has low ink absorption.

[0158] The resin emulsion that functions as a binder is contained in the ink in an emulsion state. By containing the resin that functions as a binder in the ink in an emulsion state, it is easy to adjust the viscosity of the ink to an appropriate range for inkjet recording methods, and the storage stability and ejection stability of the ink can be improved.

[0159] Examples of resin emulsions include, but are not limited to, homopolymers or copolymers of (meth)acrylic acid, (meth)acrylic acid esters, acrylonitrile, cyanoacrylate, acrylamide, olefin, styrene, vinyl acetate, vinyl chloride, vinyl alcohol, vinyl ether, vinylpyrrolidone, vinylpyridine, vinylcarbazole, vinylimidazole, and vinylidene chloride, fluororesins, and natural resins. Among these, either methacrylic resins or styrene-methacrylic acid copolymer resins are preferred, either acrylic resins or styrene-acrylic acid copolymer resins are more preferred, and styrene-acrylic acid copolymer resins are even more preferred. The copolymers may be in the form of any of random copolymers, block copolymers, alternating copolymers, and graft copolymers.

[0160] To further improve the storage stability and ejection stability of the ink, the average particle size of the resin emulsion is preferably in the range of 5 nm to 400 nm, and more preferably in the range of 20 nm to 300 nm. The content of the resin emulsion is preferably in the range of 0.5 to 7 mass % relative to the total mass of the ink (100 mass %). If the content is within the above range, the solid content can be reduced, thereby further improving the ejection stability.

[0161] [2-2. Wax] The ink may contain wax. When the ink contains wax, the ink has better fixability on non-ink-absorbent and low-ink-absorbent media. Among these, emulsion-type waxes are more preferred. Examples of the wax include, but are not limited to, polyethylene wax, paraffin wax, and polyolefin wax, and among these, polyethylene wax, which will be described later, is preferred. In this specification, "wax" mainly refers to solid wax particles dispersed in water using a surfactant, which will be described later.

[0162] The ink contains polyethylene wax, which can provide excellent abrasion resistance. The average particle size of the polyethylene wax is preferably in the range of 5 nm to 400 nm, and more preferably in the range of 50 nm to 200 nm, in order to further improve the storage stability and ejection stability of the ink.

[0163] The content of the polyethylene wax (solid content equivalent) is preferably, independently of one another, in the range of 0.1 to 3 mass%, more preferably 0.3 to 3 mass%, and even more preferably 0.3 to 1.5 mass%, relative to the total mass of the ink (100 mass%). When the content is within the above range, the ink can be solidified and fixed satisfactorily even on a non-ink-absorbent or low-ink-absorbent medium, and the storage stability and ejection stability of the ink can be further improved.

[0164] [3. Surfactants] The ink may contain a surfactant. Examples of surfactants include, but are not limited to, nonionic surfactants. Nonionic surfactants have the effect of spreading the ink evenly on a medium. Therefore, when printing is performed using ink containing a nonionic surfactant, high-resolution images with almost no bleeding can be obtained. Examples of such nonionic surfactants include, but are not limited to, silicone-based, polyoxyethylene alkyl ether-based, polyoxypropylene alkyl ether-based, polycyclic phenyl ether-based, sorbitan derivative, and fluorine-based surfactants, with silicone-based surfactants being preferred.

[0165] The surfactant content is preferably in the range of 0.1% by mass to 3% by mass relative to the total mass of the ink (100% by mass), as this further improves the storage stability and ejection stability of the ink.

[0166] [4. Organic Solvents] The ink may contain a known volatile water-soluble organic solvent. However, as described above, it is preferable that the ink does not substantially contain glycerin (a type of organic solvent with a boiling point of 290°C under 1 atmosphere) and does not substantially contain alkyl polyols (other than the above-mentioned glycerin) with a boiling point of 280°C or higher under a pressure equivalent to 1 atmosphere.

[0167] 5. Aprotic Polar Solvents The ink may contain an aprotic polar solvent. By including an aprotic polar solvent in the ink, the resin particles contained in the ink dissolve, effectively preventing clogging of the nozzles 22 during printing. In addition, the ink has the property of dissolving media such as vinyl chloride, improving the adhesion of the image.

[0168] The aprotic polar solvent is not particularly limited, but preferably includes one or more selected from pyrrolidones, lactones, sulfoxides, imidazolidinones, sulfolanes, urea derivatives, dialkylamides, cyclic ethers, and amide ethers. Representative examples of pyrrolidones include 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone. Representative examples of lactones include γ-butyrolactone, γ-valerolactone, and ε-caprolactone. Representative examples of sulfoxides include dimethyl sulfoxide and tetramethylene sulfoxide.

[0169] Representative examples of imidazolidinones include 1,3-dimethyl-2-imidazolidinone, representative examples of sulfolanes include sulfolane and dimethylsulfolane, representative examples of urea derivatives include dimethylurea and 1,1,3,3-tetramethylurea, representative examples of dialkylamides include dimethylformamide and dimethylacetamide, and representative examples of cyclic ethers include 1,4-dioxane and tetrahydrofuran.

[0170] Among these, pyrrolidones, lactones, sulfoxides, and amide ethers are particularly preferred from the viewpoint of the effects described above, and 2-pyrrolidone is the most preferred. The content of the aprotic polar solvent is preferably in the range of 3 to 30% by mass, and more preferably in the range of 8 to 20% by mass, relative to the total mass of the ink (100% by mass).

[0171] [6. Other Ingredients] In addition to the above components, the ink may further contain a mildew inhibitor, a rust inhibitor, a chelating agent, and the like.

[0172] <About humidifying fluid> The components of the surfactant mixed into the humidifying fluid L1a will be described. Examples of surfactants that can be used include cationic surfactants such as alkylamine salts and quaternary ammonium salts; anionic surfactants such as dialkyl sulfosuccinates, alkylnaphthalene sulfonates, and fatty acid salts; zwitterionic surfactants such as alkyldimethylamine oxide and alkylcarboxybetaine; and nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, and polyoxyethylene-polyoxypropylene block copolymers. Of these, anionic surfactants or nonionic surfactants are particularly preferred.

[0173] The content of the surfactant is preferably 0.1 to 5.0 mass% relative to the total mass of the humidifying fluid L1a. Furthermore, from the viewpoint of foaming properties and defoaming properties after foaming, the content of the surfactant is preferably 0.5 to 1.5 mass% relative to the total mass of the humidifying fluid L1a. The surfactant may be one type or two or more types. The surfactant contained in the humidifying fluid L1a is preferably the same as the surfactant contained in the ink (liquid). For example, when the surfactant contained in the ink (liquid) is a nonionic surfactant, examples of the nonionic surfactant include, but are not limited to, silicone-based, polyoxyethylene alkyl ether-based, polyoxypropylene alkyl ether-based, polycyclic phenyl ether-based, sorbitan derivative, and fluorine-based surfactants, with silicone-based surfactants being preferred.

[0174] In particular, to achieve the above-mentioned range of foam heights immediately after foaming and 5 minutes after foaming using the Ross-Miles method (foam height of 50 mm or more immediately after foaming and 5 mm or less 5 minutes after foaming), it is preferable to use an adduct of ethylene oxide (EO) added to acetylenic diol with an adduct number of 4 to 30 as the surfactant, and to adjust the content of the adduct to 0.1 to 3.0 wt% based on the total weight of the cleaning solution. Furthermore, to achieve the above-mentioned preferred range of foam heights immediately after foaming and 5 minutes after foaming using the Ross-Miles method (foam height of 100 mm or more immediately after foaming and 5 mm or less 5 minutes after foaming), it is preferable to use an adduct of ethylene oxide (EO) added to acetylenic diol with an adduct number of 10 to 20 as the surfactant, and to adjust the content of the adduct to 0.5 to 1.5 wt% based on the total weight of the cleaning solution. However, if the content of the ethylene oxide adduct of acetylenic diol is too high, the critical micelle concentration may be reached, resulting in the formation of an emulsion.

[0175] The surfactant functions to facilitate wetting and spreading of the aqueous ink on the recording medium. The surfactant that can be used in the present invention is not particularly limited, and examples thereof include anionic surfactants such as dialkyl sulfosuccinates, alkyl naphthalene sulfonates, and fatty acid salts; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, and polyoxyethylene-polyoxypropylene block copolymers; cationic surfactants such as alkylamine salts and quaternary ammonium salts; silicone surfactants; and fluorine-based surfactants.

[0176] The surfactant has the effect of breaking down and dispersing the aggregates due to the interfacial activity between the humidifying fluid L1a and the aggregates. It also has the effect of lowering the surface tension of the cleaning liquid, making it easier for the cleaning liquid to penetrate between the aggregates and the nozzle surface 23, and making it easier to peel the aggregates from the nozzle surface 23.

[0177] Any surfactant can be suitably used as long as it is a compound having a hydrophilic portion and a hydrophobic portion in the same molecule. Specific examples of surfactants that are preferred are those represented by the following formulas (I) to (IV). That is, examples thereof include polyoxyethylene alkyl phenyl ether surfactants of the following formula (I), acetylene glycol surfactants of the following formula (II), polyoxyethylene alkyl ether surfactants of the following formula (III), and polyoxyethylene polyoxypropylene alkyl ether surfactants of the following formula (IV).

[0178] [ka] (R is an optionally branched hydrocarbon chain having 6 to 14 carbon atoms, and k is 5 to 20).

[0179] [ka] (m, n≦20,0 <m+n≦40)

[0180] [ka] (R is a hydrocarbon chain with 6 to 14 carbon atoms that may be branched, and n is 5 to 20.)

[0181] [ka] (R is a hydrocarbon chain with 6 to 14 carbon atoms, and m and n are numbers up to 20.) In addition to the compounds of the formulae (I) to (IV), alkyl and aryl ethers of polyhydric alcohols such as diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, and tetraethylene glycol chlorophenyl ether, nonionic surfactants such as polyoxyethylene polyoxypropylene block copolymers, fluorine-containing surfactants, and lower alcohols such as ethanol and 2-propanol can be used, with diethylene glycol monobutyl ether being particularly preferred.

[0182] The operation of this embodiment will be described. After the liquid ejection device 11 is assembled, the flow of the moisturizing fluid filling operation shown in FIG. 22 is carried out before it is shipped from the factory.

[0183] 21, during the humidifying fluid filling operation, with the clamp 69 preventing the humidifying fluid L1a in the humidifying fluid storage unit 61 from being supplied into the circulation path 62 and with the first on-off valve 66c open, the control unit 90 drives the first pump 63 to cause the humidifying fluid L1a to flow through the circulation path 62 in the direction of the solid arrow shown in FIG. 21. By driving the first pump 63 until the detection unit 61a detects that the liquid level in the humidifying fluid storage unit 61 is above the first predetermined height H1, a predetermined amount of humidifying fluid L1a in the humidifying fluid pack 68 can be stored in the humidifying fluid storage unit 61. Therefore, the liquid ejector 11 can be shipped from the factory with a predetermined amount of humidifying fluid L1a stored in the humidifying fluid storage unit 61.

[0184] At the end of the humidifying fluid filling operation, the control unit 90 executes a cap replacement preparation operation, which causes most of the humidifying fluid L1a in the unit cap 51a to be discharged to the outside of the unit cap 51a. Therefore, the liquid ejector 11 can be shipped from the factory with almost no humidifying fluid L1a remaining in the unit cap 51a.

[0185] The liquid ejection device 11 shipped from the factory is installed by the user, and the user begins to use the liquid ejection device 11. Before the liquid ejection device 11 is installed and performs recording on the medium M for the first time, the control unit 90 executes the circulation operation flow shown in FIG.

[0186] 13, during circulation operation, with the first on-off valve 66c in a closed state, the control unit 90 drives the first pump 63 to cause the humidifying fluid L1a to flow in the circulation path 62 in the direction of the solid arrows shown in Fig. 13. This allows the humidifying fluid L1a to circulate inside the unit cap 51a, which was almost empty of humidifying fluid L1a at the time of shipment. This allows the humidifying chamber 55 of the unit cap 51a to be filled with humidifying fluid L1a.

[0187] 7, humidification fluid L1a can be circulated within humidification chamber 55, which is formed as a single flow path connecting inlet 55a and outlet 55b by groove 55c and first moisture permeable membrane 54 covering groove 55c. That is, groove 55c of humidification chamber 55, which is almost empty of humidification fluid L1a at the time of shipment, can be filled with humidification fluid L1a.

[0188] By forming the humidifying chamber 55 in the shape of a single flow path, it is possible to facilitate the circulation of the humidifying fluid L1a into the humidifying chamber 55. Furthermore, because the humidifying chamber 55 is formed in the shape of a winding flow path, it is possible to prevent the humidifying fluid L1a, which has been filled into the humidifying chamber 55 by the circulation, from flowing out of the humidifying chamber 55 from the inlet 55a or the outlet 55b.

[0189] As shown in Fig. 3, the capping device 50 is configured with a plurality of unit caps 51a lined up. As described above, the outlet 55b of one of the plurality of unit caps 51a is connected to the inlet 55a of another unit cap 51a adjacent to that unit cap 51a. As shown in Fig. 11, the inlet 55a located most upstream is connected to the supply flow path 62a, and the outlet 55b located most downstream is connected to the recovery flow path 62b. This allows the humidifying fluid L1a to be filled into a plurality of unit caps 51a using only one supply flow path 62a and one recovery flow path 62b.

[0190] 8, humidifying chamber 55 is disposed at an angle relative to the horizontal. Inflow port 55a and outflow port 55b are disposed above the vertical center of humidifying chamber 55. This prevents humidifying fluid L1a, which has been filled into humidifying chamber 55 by circulation, from flowing out of humidifying chamber 55 from inflow port 55a or outflow port 55b due to head pressure.

[0191] 2, in the liquid ejection device 11, when the liquid ejection head 21 records on the medium M, the medium M in the medium storage unit 16 shown in FIG. 1 is fed, and the medium M travels along a transport path 19 toward the recording unit 20. Then, in the recording unit 20, the liquid ejection head 21 ejects liquid toward the medium M transported in a first transport direction Z1. Then, the liquid ejection device 11 alternately repeats a transport operation for transporting the medium M to the next recording position and a recording operation for ejecting liquid from the liquid ejection head 21, thereby recording characters, images, and the like on the medium M.

[0192] 8, when the liquid ejection head 21 is not ejecting liquid, the liquid ejection device 11 performs capping, which is an operation in which the cap unit 51 comes into contact with the nozzle surface 23 of the liquid ejection head 21 so as to surround the nozzles 22. In other words, when the liquid ejection head 21 is not ejecting liquid, the unit cap 51a is kept in contact with the nozzle surface 23 of the liquid ejection head 21 so as to surround the nozzles 22.

[0193] 2, during capping, the cap unit 51 moves from the retracted position in the third direction D3 to the maintenance position, and then the head unit 24 moves from the recording position in the first direction D1 to the maintenance position. This causes the cap unit 51 to cap the head unit 24. That is, the cap device 50 and the liquid ejection head 21 come into contact with each other. This allows the contact surface 56f of the unit cap 51a to come into contact with the nozzle surface 23 of the liquid ejection head 21, allowing the seal portion 56e to seal the nozzle surface 23.

[0194] As shown in FIG. 10, the humidification chamber 55 is filled with a humidification fluid L1a. The moisture evaporated from the humidification fluid L1a, together with moist air containing the moisture, passes through the first moisture-permeable membrane 54 and the absorber 53 and reaches the recess 57. The moisture can then humidify the interior of the recess 57. This humidifies the space SP surrounding the opening of the nozzle 22 when the unit cap 51a comes into contact with the liquid ejection head 21, thereby enabling the opening of the nozzle 22 to be humidified. Furthermore, because the viscosity of the liquid in the nozzle 22 is suppressed, ejection defects can be prevented.

[0195] 8, in the humidifying chamber 55, the flow path is routed over the entire bottom surface of the unit cap 51a, so that the entire inside of the recess 57 can be humidified. This allows the openings of the multiple nozzles 22 of the liquid ejection head 21 to be humidified more uniformly.

[0196] 8, the liquid ejection device 11 periodically performs flushing, which is an ejection operation for ejecting droplets unrelated to printing into the space SP within the unit cap 51a from the nozzles 22. Even during flushing, the unit cap 51a is kept in contact with the nozzle surface 23 of the liquid ejection head 21 so as to surround the nozzles 22.

[0197] 2, during flushing or cleaning, the cap unit 51 moves from the retracted position in the third direction D3 to the maintenance position, and then the head unit 24 moves from the recording position in the first direction D1 to the maintenance position. This brings the cap device 50 into contact with the liquid ejection head 21. This allows the contact surface 56f of the unit cap 51a to come into contact with the nozzle surface 23 of the liquid ejection head 21, allowing the seal portion 56e to seal the nozzle surface 23.

[0198] As shown in FIG. 9, waste liquid L2 discharged from nozzle 22 into recess 57 by flushing or cleaning passes through restriction member 52 and absorber 53. The waste liquid L2 is absorbed by absorber 53. The waste liquid L2 absorbed by absorber 53 spreads throughout the entire absorber 53. When absorber 53 approaches a state where it can no longer absorb the waste liquid L2, gravity causes the waste liquid L2 to flow vertically within absorber 53. Because first moisture-permeable membrane 54 is not liquid-permeable, waste liquid L2 does not flow into humidification chamber 55. Because recess 57 has discharge hole 56b, waste liquid L2 that cannot be absorbed by absorber 53 within recess 57 can be discharged through discharge hole 56b to the outside of unit cap 51a.

[0199] The discharge hole 56b may be provided in the recess 57 at a position lower than the first moisture-permeable membrane 54. The waste liquid L2 can be discharged to the outside of the unit cap 51a through the discharge hole 56b by gravity. This prevents the surface of the first moisture-permeable membrane 54 from being blocked by the waste liquid L2, preventing gas from passing through.

[0200] The drain hole 56b may be provided at the bottom of the recess 57. The waste liquid L2 can be drained to the outside of the unit cap 51a through the drain hole 56b by gravity. This makes it possible to prevent the waste liquid L2 from remaining in the recess 57.

[0201] 11, the recess 57 has an atmosphere communication hole 56a for communicating the space SP with the atmosphere. As described above, in this embodiment, the third on-off valve 58b, which communicates the space SP with the atmosphere, is opened and closed by movement of the cap unit 51. This makes it possible to open and close the third on-off valve 58b to communicate the space SP with the atmosphere without using an actuator dedicated to the third on-off valve.

[0202] When the third on-off valve 58b is opened or closed, the space SP is connected to the atmosphere. As a result, even when the space SP is formed surrounding the opening of the nozzle 22, the atmosphere flows into the space SP, making it easier to discharge the waste liquid L2 in the recess 57 to the outside of the unit cap 51a through the discharge hole 56b.

[0203] During flushing or cleaning, the first atmosphere-communicating passage 58a is open, and the liquid ejection head 21 discharges liquid into the unit cap 51a. The first atmosphere-communicating passage 58a is also open during capping, when the liquid ejection head 21 is not ejecting liquid. In other words, because the first atmosphere-communicating passage 58a is open most of the time, it is possible to prevent the waste liquid L2 from remaining in the recess 57.

[0204] 10, the atmosphere communication hole 56a may be provided above the vertical center of the recess 57. This can prevent the atmosphere communication hole 56a from being blocked by the waste liquid L2, preventing the waste liquid L2 from being discharged from inside the recess 57.

[0205] The atmosphere communication hole 56a may be provided at a position in the recess 57 that is higher than the first moisture permeable membrane 54. This can prevent the atmosphere communication hole 56a from being blocked by the waste liquid L2 flowing over the surface of the first moisture permeable membrane 54, preventing the waste liquid L2 from being discharged from inside the recess 57.

[0206] As shown in Fig. 9, the waste liquid L2 discharged from the nozzle 22 into the recess 57 by flushing or cleaning is absorbed by the absorber 53. Furthermore, as shown in Fig. 10, the moisture that evaporates from the humidifying fluid L1a and passes through the first moisture-permeable membrane 54 humidifies the waste liquid L2 absorbed in the absorber 53. As a result, when the viscosity of the waste liquid L2 absorbed in the absorber 53 is high, the viscosity of the waste liquid L2 is adjusted by the moisture evaporated from the humidifying fluid L1a. The moisture evaporated from the humidifying fluid L1a and the waste liquid L2 with adjusted viscosity can more efficiently humidify the space SP.

[0207] In this embodiment, the moisturizing power of the moisturizing fluid L1a is equivalent to that of fresh ink, so when the ink absorbed in the absorber 53 is thickened, the ink absorbed in the absorber 53 can be moisturized, and the moisturizing power of the ink absorbed in the absorber 53 can be maintained at a moisturizing power equivalent to that of fresh ink.

[0208] The waste liquid L2 absorbed by the absorber 53 spreads throughout the entire absorber 53. This allows the distribution of the waste liquid L2 absorbed by the absorber 53 to become more uniform, making it possible to more uniformly humidify the entire space SP. This also allows the openings of the multiple nozzles 22 of the liquid ejection head 21 to be more uniformly humidified.

[0209] When flushing or cleaning is performed, the liquid discharged from the nozzles 22 of the liquid ejection head 21 adheres to the nozzle surface 23. Therefore, after flushing or cleaning is performed, the liquid ejection device 11 performs wiping.

[0210] 4, after the head unit 24 moves from the recording position in the first direction D1 to the maintenance position, the wiper carriage 41 moves from the retracted position in the fifth direction D5 to the turning back position. This allows the nozzle surface 23 of the head unit 24 to be wiped by the wiper members 42 of the wiper carriage 41. The liquid adhering to the nozzle surface 23 can then be collected into the wiper carriage 41 as waste liquid L2. This allows the liquid adhering to the nozzle surface 23 of the liquid ejection head 21, as well as dirt such as dust, to be removed.

[0211] 11, the waste liquid recovery mechanism 80 causes the third pump 82 to cause the waste liquid L2 recovered by flushing or cleaning and the waste liquid L2 recovered by wiping to flow out into the waste liquid storage section 86 through the waste liquid recovery path 81. This allows both the waste liquid L2 recovered by flushing or cleaning and the waste liquid L2 recovered by wiping to be stored together in the waste liquid storage section 86.

[0212] The fourth pump 84 is a decompression pump. Therefore, in the first waste liquid recovery path 81a, the fourth pump 84 lowers the air pressure inside the buffer chamber 83 by discharging the air inside the buffer chamber 83 to the outside of the buffer chamber 83. This makes it easier for the waste liquid L2 recovered by flushing or cleaning to flow into the buffer chamber 83. Furthermore, it makes it easier for the waste liquid L2 recovered by flushing or cleaning to flow into the waste liquid storage section 86. In other words, it is possible to prevent the waste liquid L2 from remaining in the recess 57.

[0213] 10, during capping, the moisture contained in the humidifying fluid L1a filled in the humidifying chamber 55 humidifies the space SP surrounding the opening of the nozzle 22 when the unit cap 51a comes into contact with the liquid ejection head 21. This reduces the amount of moisture contained in the humidifying fluid L1a filled in the humidifying chamber 55. In other words, the concentration of the humidifying fluid L1a filled in the humidifying chamber 55 becomes greater than the concentration of the humidifying fluid L1a contained in the humidifying fluid container 61.

[0214] As shown in Fig. 13, in a capping device 50 including a humidifying fluid storage portion 61, a supply flow path 62a, a recovery flow path 62b, and a first pump 63, the humidifying fluid L1a is circulated within the circulation path 62 by a circulation operation. This makes it possible to agitate the humidifying fluid L1a within the circulation path 62. By agitating the humidifying fluid L1a within the circulation path 62, it is possible to make the concentration of the humidifying fluid L1a throughout the circulation path 62 uniform. In other words, the circulation operation makes it possible to return the amount of moisture contained in the humidifying fluid L1a filled within the humidifying chamber 55 to an amount close to the amount at the time of shipment.

[0215] The control unit 90 manages time using a timer or the like and periodically executes the circulation operation. This makes it possible to uniformize the concentration of the humidifying fluid L1a throughout the circulation path 62 at the appropriate timing. That is, it is possible to prevent the concentration of the humidifying fluid L1a filled in the humidifying chamber 55 from remaining higher than the concentration of the humidifying fluid L1a contained in the humidifying fluid container 61. More specifically, even if the amount of moisture contained in the humidifying fluid L1a filled in the humidifying chamber 55 decreases, it is possible to restore the amount of moisture to an amount close to the amount at the time of shipment at the appropriate timing. This makes it possible to prevent ejection defects caused by insufficient humidification of the opening of the nozzle 22.

[0216] As described above, the outlet 55b of one of the multiple unit caps 51a is connected to the inlet 55a of another unit cap 51a adjacent to that unit cap 51a, with the most upstream inlet 55a connected to the supply flow path 62a and the most downstream outlet 55b connected to the recovery flow path 62b. This makes it possible to agitate the humidifying fluid L1a in the circulation path 62, which includes the humidifying chambers 55 of the multiple unit caps 51a, using only one supply flow path 62a and recovery flow path 62b. Furthermore, it is possible to make the concentration of the humidifying fluid L1a uniform in the circulation path 62, which includes the humidifying chambers 55 of the multiple unit caps 51a, using only one supply flow path 62a and recovery flow path 62b.

[0217] The cap device 50 humidifies the space SP with the moisture contained in the humidifying fluid L1a filled in the humidifying chamber 55, and periodically performs a circulation operation, thereby reducing the volume of the humidifying fluid L1a contained in the humidifying fluid storage unit 61 by the amount of evaporated moisture. The humidifying fluid storage unit 61 has a detection unit 61a that detects the liquid level within the humidifying fluid storage unit 61, so it can be determined that the concentration of the humidifying fluid L1a has become greater than a predetermined concentration.

[0218] During the circulation operation, when the liquid level in the humidifying fluid storage section 61 is detected by the detection section 61a to be below the first predetermined height H1, it is determined that the concentration of the humidifying fluid L1a in the circulation path 62 has become greater than the predetermined concentration, and the concentration adjustment operation flow shown in Figure 16 is executed.

[0219] 15, by further providing a moisture supply unit 66 capable of supplying moisture into the circulation path 62, when moisture evaporates from the humidifying fluid L1a, moisture L1b can be replenished to the humidifying fluid L1a, thereby optimizing the concentration of the humidifying fluid L1a. In other words, the amount of moisture contained in the humidifying fluid L1a can be returned to the amount of moisture at the time of shipment.

[0220] The pressure loss in the flow path on the moisture supply unit 66 side is set to be equal to or greater than the pressure loss in the flow path on the humidifying fluid storage unit 61 side. This slows down the rate of change in the liquid level in the humidifying fluid storage unit 61, reducing variability in liquid level detection, allowing the liquid level to be detected in a timely manner.

[0221] When performing the concentration adjustment operation when the detection unit 61a detects that the liquid level in the humidifying fluid storage unit 61 is below the first predetermined height H1, the capping device 50 supplies moisture from the moisture storage unit 66a into the circulation path 62 until the liquid level is detected to be equal to or greater than the first predetermined height H1. The capping device 50 then causes the humidifying fluid L1a to flow in the circulation path 62. This replenishes the humidifying fluid L1a with the moisture that has evaporated, and then circulates the humidifying fluid L1a in the circulation path 62, thereby optimizing the concentration of the humidifying fluid L1a.

[0222] During the concentration adjustment operation, when the detection unit 61a detects that the liquid level in the humidifying fluid storage unit 61 is above the first predetermined height H1, the capping device 50 closes the first on-off valve 66c and performs the circulation operation described above. In other words, when the concentration adjustment operation is performed, the circulation operation is performed before the concentration adjustment operation is finished. This agitates the humidifying fluid L1a in the circulation path 62, so that the concentration of the humidifying fluid L1a throughout the circulation path 62 can be made uniform even when the concentration adjustment operation is performed.

[0223] The cap device 50 replenishes the humidifying fluid L1a in the circulation path 62 with the evaporated moisture, thereby increasing the volume of the humidifying fluid L1a in the circulation path 62. Furthermore, the second moisture-permeable membrane 61e, located at the connection between the humidifying fluid storage unit 61 and the second atmosphere-communicating passage 61d, allows gas to pass between the humidifying fluid storage unit 61 and the second atmosphere-communicating passage 61d. This allows a volume of air equal to the increased volume of the humidifying fluid L1a to flow from the humidifying fluid storage unit 61 to the second atmosphere-communicating passage 61d as the volume of the humidifying fluid L1a increases. This facilitates the replenishment of moisture to the humidifying fluid L1a in the circulation path 62. Furthermore, by making the area of ​​the second moisture-permeable membrane 61e larger than the volume of the humidifying fluid storage unit 61, the amount of air flowing out from the second atmosphere-communicating passage 61d to the atmosphere can be increased. This allows the humidifying fluid L1a to be efficiently replenished with the evaporated moisture.

[0224] 15, the capping device 50 performs a concentration adjustment operation that includes supplying moisture L1b into the circulation path 62 by the moisture supply unit 66 and causing humidifying fluid L1a to flow within the circulation path 62. The capping device 50 also performs a concentration adjustment operation that includes opening the first on-off valve 66c when supplying moisture L1b from the moisture storage unit 66a into the circulation path 62, and closing the first on-off valve 66c when causing humidifying fluid L1a to flow within the circulation path 62. Depending on the state of the first on-off valve 66c, it is possible to supply evaporated moisture into the circulation path 62 and to cause the humidifying fluid L1a to flow within the circulation path 62, as necessary. In this way, by replenishing the evaporated moisture to the humidifying fluid L1a and then circulating the humidifying fluid L1a within the circulation path 62, it is possible to optimize the concentration of the humidifying fluid L1a.

[0225] In the liquid ejection device 11, when recording on the medium M is repeated using the liquid ejection head 21, the seal portion 56e of the unit cap 51a may lose its adhesion to the nozzle surface 23 due to deterioration or fatigue caused by repeated stress over a long period of time. Also, a malfunction may occur in the components that make up the cap unit 51. In such a case, the cap unit 51 that has been used until then is replaced with a new cap unit 51. The cap unit 51 may be configured so that the unit caps 51a are replaced one by one.

[0226] As shown in Figure 17, when replacing the cap unit 51, a cap replacement preparation operation is performed. Pressurized air is supplied from the pressurized air supply unit 67 into the unit cap 51a, and the humidifying fluid L1a in the unit cap 51a is discharged into the humidifying fluid storage unit 61. This allows the humidifying fluid L1a in the unit cap 51a to be discharged outside the unit cap 51a. Furthermore, the humidifying fluid L1a in the unit cap 51a can be recovered in the humidifying fluid storage unit 61. In other words, the humidifying fluid L1a in the cap unit 51 that has been used until now can be used as the humidifying fluid L1a in the cap unit 51 that will be used next.

[0227] The cap device 50 may have an air supply unit that supplies air to the circulation path 62, in which the humidifying fluid L1a flows, between a first junction 62c where the moisture supply unit 66 and the circulation path 62 join and the inlet 55a of the unit cap 51a. The cap device 50 may further have a pump that sends the air to the circulation path 62. This allows the humidifying fluid L1a in the unit cap 51a to be discharged outside the unit cap 51a. Furthermore, the humidifying fluid L1a in the unit cap 51a can be recovered in the humidifying fluid storage unit 61.

[0228] 7, humidification chamber 55 is formed as a single flow path that connects inlet 55a and outlet 55b by groove 55c and first moisture permeable membrane 54 covering groove 55c. Therefore, in the cap replacement preparation operation, supplying pressurized air to inlet 55a of the single flow path in humidification chamber 55 makes it easier to discharge humidified fluid L1a from outlet 55b in humidification chamber 55.

[0229] As described above, the outlet 55b of one of the multiple unit caps 51a is connected to the inlet 55a of another unit cap 51a adjacent to that unit cap 51a, with the most upstream inlet 55a connected to the supply flow path 62a and the most downstream outlet 55b connected to the recovery flow path 62b. This allows the humidifying fluid L1a in the humidifying chambers 55 of the multiple unit caps 51a to be discharged through one supply flow path 62a, one recovery flow path 62b, and one pressurized air supply unit 67 during the cap replacement preparation operation.

[0230] 17, the humidifying fluid storage portion 61 has a second atmosphere-communicating passage 61d. The second atmosphere-communicating passage 61d connects the humidifying fluid storage portion 61 to the atmosphere via a labyrinth-like thin tube structure. Even when pressurized air is supplied into the humidifying fluid storage portion 61 during the cap replacement preparation operation, the labyrinth-like thin tube structure of the second atmosphere-communicating passage 61d can prevent the humidifying fluid L1a from flowing out of the humidifying fluid storage portion 61 from the humidifying fluid storage portion 61 through the second atmosphere-communicating passage 61d.

[0231] 17, the humidifying fluid storage portion 61 has a second moisture-permeable membrane 61e. The second moisture-permeable membrane 61e allows gas to pass through but restricts liquid from passing through. Even when pressurized air is supplied into the humidifying fluid storage portion 61 during the cap replacement preparation operation, the outflow of humidifying fluid L1a from the humidifying fluid storage portion 61 to the outside of the humidifying fluid storage portion 61 through the second atmosphere-communicating passage 61d can be prevented.

[0232] Before the cap unit 51 that has been used is replaced with a new cap unit 51 and recording is first performed on the medium M, the above-mentioned circulation operation is performed, and the humidifying chamber 55 of the unit cap 51a of the new cap unit 51 is filled with the humidifying fluid L1a. As a result, even in the replaced cap unit 51, the space SP surrounding the opening of the nozzle 22 when the unit cap 51a comes into contact with the liquid ejection head 21 is humidified, so that the opening of the nozzle 22 can be humidified.

[0233] In the liquid ejection device 11, even in the replaced cap unit 51, the space SP surrounding the opening of the nozzle 22 is humidified when the unit cap 51a comes into contact with the liquid ejection head 21, thereby using the moisture in the humidifying fluid L1a. The used moisture is replenished into the humidifying fluid L1a from the moisture storage section 66a during the concentration adjustment operation. In other words, even in the replaced cap unit 51, the opening of the nozzle 22 of the liquid ejection head 21 can be humidified without newly replenishing the circulation path 62 with humidifying fluid L1a.

[0234] 15, during the concentration adjustment operation, when the first pump 63 has been driven for a third predetermined time T3 and the detection unit 61a detects that the liquid level in the humidifying fluid storage unit 61 has fallen below the first predetermined height H1, the control unit 90 determines that the moisture in the moisture storage unit 66a has run out. Because the humidifying fluid storage unit 61 has the detection unit 61a that detects the liquid level in the humidifying fluid storage unit 61, it can detect that the amount of moisture in the moisture storage unit 66a has reached a level at which it is determined that replacement of the moisture storage unit 66a is necessary.

[0235] When the amount of moisture in the moisture storage unit 66a used to humidify the opening of the nozzle 22 reaches an amount that determines that replacement of the moisture storage unit 66a is necessary, the moisture storage unit 66a that has been in use is replaced with a full moisture storage unit 66a. However, if the user does not have a replacement moisture storage unit 66a, the opening of the nozzle 22 cannot be humidified with the humidifying fluid L1a until a replacement moisture storage unit 66a arrives. Furthermore, if the moisture storage unit 66a is configured so that it cannot be replaced by the user, the opening of the nozzle 22 cannot be humidified with the humidifying fluid L1a until the moisture storage unit 66a is replaced by a service technician.

[0236] Until the moisture storage unit 66a is replaced, the first parameter table for flushing is switched to the second parameter table used when the moisture L1b in the moisture storage unit 66a is depleted. This allows the openings of the nozzles 22 to be humidified by flushing. In other words, the space SP can be humidified by performing idle ejection from the liquid ejection head 21 into the unit cap 51a until the moisture storage unit 66a is replaced. This allows the user to continue printing.

[0237] 19, when the moisture containing portion 66a is replaced, a cap replacement preparation operation is performed. Pressurized air is supplied from the pressurized air supply portion 67 into the unit cap 51a, so that the humidifying fluid L1a in the unit cap 51a is discharged to the humidifying fluid containing portion 61 and the pressurized air is supplied into the unit cap 51a. This allows the humidifying fluid L1a in the unit cap 51a to be discharged.

[0238] 9, the recess 57 has an absorber 53 capable of absorbing liquid at a position in contact with the first moisture permeable membrane 54. Since the amount of waste liquid L2 discharged into the unit cap 51a increases due to flushing or cleaning, a larger amount of waste liquid L2 than usual is absorbed by the absorber 53. The waste liquid L2 absorbed by the absorber 53 then spreads over the entire absorber 53. The large amount of waste liquid L2 absorbed by the absorber 53 can more effectively humidify the space SP until the moisture storage section 66a is replaced. Furthermore, the openings of the nozzles 22 of the liquid ejection head 21 can be more effectively humidified.

[0239] As in this embodiment, even when the humidification chamber 55 is provided in an inclined position relative to the horizontal, the waste liquid L2 absorbed by the absorber 53 spreads throughout the entire absorber 53. In other words, by the absorber 53 absorbing the waste liquid L2, the influence of gravity on the uneven distribution of the waste liquid L2 within the recess 57 can be suppressed. This makes it possible to more uniformly humidify the entire space SP, even when the humidification chamber 55 is provided in an inclined position relative to the horizontal. This also makes it possible to more uniformly humidify the openings of the multiple nozzles 22 of the liquid ejection head 21.

[0240] The absorbent body 53 is located in a position where it contacts the first moisture-permeable membrane 54. Therefore, by restricting only the surface of the absorbent body 53 that is not in contact with the first moisture-permeable membrane 54 by the restricting member 52, the position of the absorbent body 53 can be restricted.

[0241] The sealing portion 56e is made of a material that repels the liquid ejected from the liquid ejection head 21, so that even when the amount of waste liquid L2 discharged into the unit cap 51a due to flushing or cleaning increases, the liquid inside the unit cap 51a can be prevented from dripping out of the unit cap 51a from the sealing portion 56e.

[0242] When the water storage unit 66a is replaced, the second parameter table for flushing is restored to the normal first parameter table, and the concentration adjustment operation is performed. The amount of waste liquid L2 discharged into the unit cap 51a increases only until the water storage unit 66a is replaced, so the amount of liquid used by flushing can be reduced.

[0243] As described above, the cap device 50 includes a unit cap 51a having a recess 57 that forms the space SP, a humidification chamber 55, and a first moisture-permeable membrane 54. Furthermore, the recess 57 has a discharge hole 56b, so that a single unit cap 51a can receive and discharge liquid discharged from the nozzles 22 and humidify the nozzles 22 as needed. By circulating the humidification fluid L1a within the circulation path 62 while replenishing the humidification fluid L1a with evaporated moisture, the humidification fluid L1a can be agitated and its concentration optimized. In other words, the humidification fluid L1a throughout the circulation path 62 can be maintained in a state suitable for humidifying the nozzles 22 of the liquid ejection head 21.

[0244] The effects of this embodiment will be described. (1) The cap device 50 includes a unit cap 51a having a recess 57 that forms a space SP when the unit cap 51a contacts the liquid ejection head 21, a humidification chamber 55 through which humidification fluid L1a flows, and a first moisture-permeable membrane 54 that is gas-permeable and separates the recess 57 from the humidification chamber 55. The recess 57 has a discharge hole 56b that can discharge waste liquid L2 discharged into the unit cap 51a from the nozzle 22 of the liquid ejection head 21. Moisture evaporated from the humidification fluid L1a in the humidification chamber 55 passes through the first moisture-permeable membrane 54 and reaches the recess 57, thereby humidifying the space SP formed by the recess 57 and humidifying the opening of the nozzle 22. Furthermore, the first moisture-permeable membrane 54 prevents the waste liquid L2 discharged into the unit cap 51a from flowing into the humidification chamber 55, and therefore the waste liquid L2 is discharged to the outside of the unit cap 51a through the discharge hole 56b in the recess 57. As a result, one unit cap 51a can receive and discharge the waste liquid L2 discharged from the nozzle 22 and humidify the nozzle 22. In other words, in the liquid ejection device 11, the space required to accommodate both the cap of the capping mechanism that prevents clogging of the nozzle 22 and the cap of the capping device that prevents the nozzle 22 from drying out can be reduced to the space required to accommodate only one of the caps. This makes it possible to prevent the liquid ejection device 11 from becoming larger.

[0245] (2) The discharge hole 56b is provided in the recess 57 at a position lower than the first moisture-permeable membrane 54. The waste liquid L2 in the recess 57 can be discharged to the outside of the unit cap 51a through the discharge hole 56b by gravity. This reduces the amount of waste liquid L2 remaining in the recess 57. Furthermore, blocking the surface of the first moisture-permeable membrane 54 with the waste liquid L2 prevents moisture evaporated from the humidifying fluid L1a in the humidifying chamber 55 from being unable to pass through the first moisture-permeable membrane 54. In other words, it is possible to prevent the opening of the nozzle 22 of the liquid ejection head 21 from being unable to be humidified.

[0246] (3) The drain hole 56b is provided at the bottom of the recess 57. The waste liquid L2 in the recess 57 can be drained to the outside of the unit cap 51a through the drain hole 56b by gravity. This makes it possible to prevent the waste liquid L2 from remaining in the recess 57.

[0247] (4) The recess 57 has an absorber 53 capable of absorbing liquid at a position in contact with the first moisture-permeable membrane 54. The waste liquid L2 discharged into the recess 57 is absorbed by the absorber 53. Furthermore, the moisture that evaporates from the humidifying fluid L1a and passes through the first moisture-permeable membrane 54 humidifies the waste liquid L2 absorbed by the absorber 53. The waste liquid L2 absorbed by the absorber 53 spreads throughout the entire absorber 53. This makes it possible to make the distribution of the waste liquid L2 absorbed by the absorber 53 more uniform. In other words, the entire space SP can be more uniformly humidified. Furthermore, the openings of the multiple nozzles 22 of the liquid ejection head 21 can be more uniformly humidified.

[0248] (5) The humidification chamber 55 has a groove 55c through which the humidifying fluid L1a flows. The humidification chamber 55 is formed into a flow path connecting the inlet 55a and the outlet 55b by the groove 55c and the first moisture-permeable membrane 54 covering the groove 55c. By flowing the humidifying fluid L1a through the humidification chamber 55, which is formed into a single flow path connecting the inlet 55a and the outlet 55b, the humidifying fluid L1a can be filled into or discharged from the humidification chamber 55 as needed. Furthermore, because the humidification chamber 55 is formed into such a flow path, unnecessary outflow of the humidifying fluid L1a filled into the humidification chamber 55 outside the humidification chamber 55 can be prevented. Furthermore, because the flow path extends across the entire bottom surface of the unit cap 51a, the entire recess 57 can be humidified. This allows the openings of the multiple nozzles 22 of the liquid ejection head 21 to be more uniformly humidified.

[0249] (6) The humidifying chamber 55 is provided at an angle relative to the horizontal, and the inlet 55a and outlet 55b are provided above the vertical center of the humidifying chamber 55. This prevents the humidifying fluid L1a filled in the humidifying chamber 55 from flowing out of the humidifying chamber 55 from the inlet 55a or outlet 55b due to head pressure.

[0250] (7) The recess 57 has an atmosphere communication hole 56a for communicating the space SP with the atmosphere, and the atmosphere communication hole 56a is provided above the vertical center of the recess 57. This prevents the atmosphere communication hole 56a from being blocked by the waste liquid L2, preventing the waste liquid L2 from being discharged from inside the recess 57.

[0251] (8) The capping device 50 further includes a humidifying fluid container 61, a supply flow path 62a, a recovery flow path 62b, and a first pump 63 that is capable of causing the humidifying fluid L1a to flow within the circulation path 62. This allows the humidifying fluid L1a in the circulation path 62 to be agitated. To humidify the space SP, a large amount of moisture evaporates from the humidifying fluid L1a filled in the humidifying chamber 55. Therefore, by agitating the humidifying fluid L1a in the circulation path 62, the concentration of the humidifying fluid L1a throughout the circulation path 62 can be made uniform. In other words, the amount of moisture contained in the humidifying fluid L1a filled in the humidifying chamber 55 can be returned to an amount close to the amount when the liquid ejector 11 was shipped.

[0252] (9) The capping device 50 further includes a moisture supply unit 66 that can supply moisture into the circulation path 62. As a result, when moisture evaporates from the humidifying fluid L1a, moisture L1b can be replenished to the humidifying fluid L1a, thereby optimizing the concentration of the humidifying fluid L1a. In other words, the amount of moisture contained in the humidifying fluid L1a can be restored to the amount at the time the liquid ejection device was shipped.

[0253] (10) The capping device 50 is configured with a plurality of unit caps 51a lined up. The outlet 55b of one of the plurality of unit caps 51a is connected to the inlet 55a of another unit cap 51a adjacent to that unit cap 51a. The inlet 55a located most upstream is connected to the supply flow path 62a, and the outlet 55b located most downstream is connected to the recovery flow path 62b. This allows the humidifying fluid L1a to be filled, stirred, and discharged from the plurality of unit caps 51a using only one supply flow path 62a and one recovery flow path 62b.

[0254] (11) A maintenance method for the capping device 50 performs a concentration adjustment operation that includes supplying moisture into the circulation path 62 using the moisture supply unit 66 and flowing the humidifying fluid L1a within the circulation path 62. This allows the humidifying fluid L1a to be replenished with the moisture that has evaporated, and then circulating the humidifying fluid L1a within the circulation path 62, thereby optimizing the concentration of the humidifying fluid L1a. In other words, the humidifying fluid L1a throughout the circulation path 62 can be maintained in a state suitable for humidifying the nozzles 22 of the liquid ejection head 21.

[0255] (12) A maintenance method for the capping device 50 performs a concentration adjustment operation that includes opening the first on-off valve 66c when supplying moisture from the moisture storage section 66a into the circulation path 62 and closing the first on-off valve 66c when flowing the humidifying fluid L1a through the circulation path 62. Depending on the state of the first on-off valve 66c, it is possible to supply evaporated moisture into the circulation path 62 and flow the humidifying fluid L1a through the circulation path 62, as needed. This makes it possible to optimize the concentration of the humidifying fluid L1a by replenishing the evaporated moisture to the humidifying fluid L1a and circulating the humidifying fluid L1a through the circulation path 62. In other words, it is possible to maintain the humidifying fluid L1a throughout the circulation path 62 in a state suitable for humidifying the nozzles 22 of the liquid ejection head 21.

[0256] (13) In a maintenance method for the cap device 50, when replacing a unit cap 51a, pressurized air is supplied from the pressurized air supply unit 67 into the unit cap 51a, thereby performing a cap replacement preparation operation in which the humidifying fluid L1a in the unit cap 51a is discharged to the humidifying fluid storage unit 61 and pressurized air is supplied into the unit cap 51a. This allows the humidifying fluid L1a in the unit cap 51a to be discharged outside the unit cap 51a. Furthermore, the humidifying fluid L1a in the unit cap 51a can be recovered in the humidifying fluid storage unit 61. In other words, the humidifying fluid L1a in the cap unit 51 that has been used until now can be used as the humidifying fluid L1a in the cap unit 51 that will be used next. Furthermore, the replaced cap unit 51 can still humidify the openings of the nozzles 22 of the liquid ejection head 21.

[0257] (14) A maintenance method for the cap device 50 includes the cap replacement preparation operation described above and a moisture storage unit pre-replacement operation that includes humidifying the nozzles 22 by performing idle ejection, which is ejection of liquid unrelated to printing, from the liquid ejection head 21 into the space SP within the unit cap 51a until the moisture storage unit 66a is replaced. This allows the humidifying fluid L1a within the unit cap 51a to be discharged. Then, with the humidifying fluid L1a within the unit cap 51a having been discharged, idle ejection can be performed from the liquid ejection head 21 into the unit cap 51a to humidify the space SP. This allows the user to continue printing operations.

[0258] (15) In a maintenance method for the capping device 50, when the concentration adjustment operation is performed while the liquid level in the humidifying fluid storage unit 61 is detected to be below the first predetermined height H1, moisture in the moisture storage unit 66a is supplied into the circulation path 62 until the liquid level is detected to be equal to or greater than the first predetermined height H1, and then the humidifying fluid L1a is caused to flow within the circulation path 62. This allows the humidifying fluid L1a to be replenished with the moisture that has evaporated, and then the humidifying fluid L1a is circulated within the circulation path 62, thereby optimizing the concentration of the humidifying fluid L1a. In other words, the humidifying fluid L1a throughout the circulation path 62 can be maintained in a state suitable for humidifying the nozzles 22 of the liquid ejection head 21.

[0259] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. The capping device 50 may be provided in a liquid ejection device that ejects liquid vertically from the liquid ejection head 21 toward the medium M. The contact surface 56f of the unit cap 51a that comes into contact with the nozzle surface 23 of the liquid ejection head 21 during capping, the absorber 53, the first moisture-permeable membrane 54, and the humidification chamber 55 may be provided horizontally. That is, the unit cap 51a of this embodiment may be provided horizontally in a liquid ejection device that ejects liquid vertically from the liquid ejection head 21 toward the medium M. Alternatively, the absorber 53, the first moisture-permeable membrane 54, and the humidification chamber 55 may be provided at an angle relative to the horizontal, as in this embodiment, with only the contact surface 56f provided horizontally.

[0260] The angle at which the humidifying chamber 55 is inclined relative to the horizontal does not have to be the same as the angle at which the nozzle surface 23, on which the nozzles 22 of the liquid ejection head 21 are arranged, is inclined relative to the horizontal. The angle at which the humidifying chamber 55 is inclined relative to the horizontal may be larger or smaller than the angle at which the nozzle surface 23 is inclined relative to the horizontal.

[0261] The capping device 50 may be provided in a serial-type liquid ejection device, which is an inkjet printer, in which a liquid ejection head supported by a carriage that moves back and forth in the width direction X ejects liquid toward a medium M to perform printing. When the reciprocating carriage moves in the width direction X from an ejection area where printing is performed on the medium M to a maintenance area outside the ejection area for maintenance, a cap of the capping device 50 positioned in the maintenance area may cap the nozzle face of the liquid ejection head. In this case, the capping device 50 may be configured so that when the carriage moves to the maintenance area and the liquid ejection head is positioned at the maintenance position, the cap moves toward the nozzle face of the liquid ejection head and makes close contact with the nozzle face, thereby performing capping. This allows a single cap to receive and discharge waste liquid discharged from the nozzles and humidify the nozzles, even in a serial-type liquid ejection device. Furthermore, even in a serial-type liquid ejection device, the space required to accommodate both the cap of the capping mechanism that prevents nozzle clogging and the cap of the capping device that prevents nozzle drying is limited to the space required to accommodate only one of the caps. This makes it possible to prevent the serial liquid ejection device 11 from becoming large.

[0262] The cap device 50 may have a plurality of unit caps 51 a or may have only one unit cap 51 a. When the cap device 50 has only one unit cap 51 a, the unit cap 51 a may have one restricting member 52, one absorber 53, one first moisture-permeable membrane 54, one humidifying chamber 55, and one case 56.

[0263] As in the above embodiment, even in a line-type inkjet printer that uses a liquid ejection head 21 made up of five unit ejection heads 21a, the capping device 50 may have only one unit cap 51a. Also, in the above-mentioned serial-type liquid ejection device, the capping device 50 may have only one unit cap 51a.

[0264] The capping device 50 does not have to have the same number of restricting members 52, absorbers 53, first moisture-permeable membranes 54, and humidification chambers 55. For example, the capping device 50 may have only one unit cap 51a, and the unit cap 51a may have one restricting member 52, one absorber 53, one first moisture-permeable membrane 54, and multiple humidification chambers 55. Alternatively, the capping device 50 may have multiple unit caps 51a, and each of the multiple unit caps 51a may have one restricting member 52, one absorber 53, one first moisture-permeable membrane 54, and multiple humidification chambers 55.

[0265] The unit cap 51 a may have a plurality of recesses 57 . The recess 57 may have a plurality of drain holes 56b. The recess 57 may have a plurality of air communication holes 56a.

[0266] When the cap device 50 has a plurality of unit caps 51a, the recesses 57 of the unit caps 51a may be configured so that the spaces SP formed by the recesses 57 communicate with each other without passing through the discharge holes 56b. For example, the unit caps 51a may be configured so that the bottom of one unit cap 51a communicates with the bottom of another unit cap 51a adjacent to that unit cap 51a inside the cap unit 51. In this case, the number of discharge holes 56b in the cap unit 51 may be one.

[0267] The absorber 53 does not have to be in contact with the first moisture permeable membrane 54. For example, a configuration may be adopted in which the position of the surface of the absorber 53 on the −Y1 side is regulated by a regulating member different from the regulating member 52 that regulates the position of the surface of the absorber 53 on the +Y1 side, and there is a space between the first moisture permeable membrane 54 and the absorber 53.

[0268] In the above embodiment, the flow path of the humidifying chamber 55 is formed in a maze shape with a single path from the inlet 55a to the outlet 55b, but it may be a two-path or three-path flow path as long as it is connected from the inlet 55a to the outlet 55b.

[0269] The arrangement of the unit ejection heads 21a that make up the liquid ejection head 21 can be changed as appropriate. It is not limited to the configuration in which the unit ejection heads 21a are arranged diagonally as in the above embodiment, but may also be a configuration in which, for example, the unit ejection heads 21a are arranged in two rows at a fixed interval in the width direction X, and are arranged in a staggered arrangement in which the positions of the rows are shifted in the width direction by half the interval between the rows.

[0270] In the above embodiment, the supply flow path 62a in the circulation path 62 is provided with the water supply unit 66 capable of supplying water, but the recovery flow path 62b in the circulation path 62 may also be provided with the water supply unit 66. In this case, the capping device 50 may further include a pump for supplying water to the recovery flow path 62b.

[0271] In the above embodiment, the third on-off valve 58b, which connects the space SP to the atmosphere, is opened and closed by the movement of the cap unit 51. An actuator-type on-off valve that can be opened and closed by the control unit 90 regardless of the position of the cap unit 51 may be provided in the first atmosphere-communicating passage 58a.

[0272] The capping device 50 may have a second detector that detects the amount of moisture L1b in the moisture storage unit 66a. Based on the detection result of the second detector, the control unit 90 may determine whether the amount of moisture L1b in the moisture storage unit 66a has reached a level that requires replacement of the moisture storage unit.

[0273] The capping device 50 may be configured so that the moisture in the moisture containing portion 66a can be replenished. Also, the capping device 50 may be configured so that the humidifying fluid containing portion 61 can be replaced. The timing at which the cyclical action is performed may be changed by an administrator or user.

[0274] The first predetermined time T1, the second predetermined time T2, the third predetermined time T3, and the fourth predetermined time T4 do not have to be constant. The values ​​may be changed depending on the temperature and humidity environment. Furthermore, the values ​​may be changed by an administrator or a user.

[0275] The liquid ejection device 11 may have a third parameter table for flushing, which specifies an even larger amount of liquid to be ejected. If the interval between concentration adjustment operations is short, the control unit 90 may switch to the third parameter table when switching the flushing table in the pre-water storage unit replacement operation. That is, liquid ejection device 11 may have multiple parameter tables for different liquid ejection amounts as flushing parameter tables. Then, when switching the flushing table in the pre-water storage unit replacement operation, control unit 90 may switch to an appropriate parameter table from the multiple parameter tables depending on the time interval between concentration adjustment operations.

[0276] The liquid ejection device 11 may be a liquid ejection device that ejects or ejects liquids other than ink. The state of the liquid ejected as minute droplets from the liquid ejection device includes granular, teardrop-like, and string-like tails. The liquid referred to here may be any material that can be ejected from the liquid ejection device. For example, the liquid may be any state in which a substance is in a liquid phase, including fluids such as high or low viscosity liquids, sols, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals, and metal melts. The liquid may not only refer to a liquid as a single state of matter, but also to particles of solid functional materials, such as pigments and metal particles, dissolved, dispersed, or mixed in a solvent. Typical examples of the liquid include ink and liquid crystal as described in the above embodiments.

[0277] The technical concepts and effects that can be understood from the above-described embodiment and modified examples will be described below. (A) A cap device is a cap device that can form a space surrounding the opening of a nozzle when it comes into contact with a liquid ejection head having a nozzle that ejects liquid, and is equipped with a cap having a recess that forms the space, a humidification chamber having an inlet through which humidification fluid flows in to humidify the space, and an outlet through which the humidification fluid flows out, and a gas-permeable partition that separates the recess from the humidification chamber, and the recess has a hole that can discharge liquid that has been ejected from the liquid ejection head into the cap.

[0278] With this configuration, moisture evaporated from the humidifying fluid in the humidifying chamber passes through the partition wall and reaches the recess, humidifying the space formed by the recess and thereby humidifying the nozzle openings of the liquid ejection head. Furthermore, liquid discharged into the cap is prevented from flowing into the humidifying chamber by the partition wall and is instead discharged out of the cap through the hole in the recess. This allows a single cap to receive and discharge liquid discharged from the nozzles and humidify the nozzles. In other words, in a liquid ejection device, the space required to accommodate both the cap of the capping mechanism that prevents nozzle clogging and the cap of the capping device that prevents nozzle drying is reduced to the space required to accommodate only one of the caps. This reduces the size of the liquid ejection device.

[0279] (B) In the capping device, the hole may be provided in the recess at a position lower than the partition wall. This configuration allows the liquid in the recess to be discharged out of the cap through the hole by gravity, thereby reducing the amount of liquid remaining in the recess. Furthermore, by blocking the surface of the partition with liquid, it is possible to prevent moisture evaporated from the humidifying fluid in the humidifying chamber from being unable to pass through the partition. In other words, it is possible to prevent the nozzle opening of the liquid ejection head from being unable to be humidified.

[0280] (C) In the capping device, the hole may be provided at the bottom of the recess. With this configuration, the liquid in the recess can be discharged to the outside of the cap through the hole by gravity, and the liquid can be prevented from remaining in the recess.

[0281] (D) In ​​the capping device, the recess may have an absorbent capable of absorbing liquid at a position where the recess contacts the partition wall. With this configuration, the liquid discharged into the recess is absorbed by the absorbent. Furthermore, the moisture that evaporates from the humidifying fluid and passes through the partition humidifies the liquid absorbed by the absorbent. The liquid absorbed by the absorbent spreads throughout the absorbent. This allows the distribution of the liquid absorbed by the absorbent to approach uniformity. In other words, the entire space can be more uniformly humidified. Furthermore, the openings of the multiple nozzles in the liquid ejection head can be more uniformly humidified.

[0282] (E) In the above cap device, the humidifying chamber may have a groove through which the humidifying fluid flows, and the humidifying chamber may be formed into a flow path connecting the inlet and the outlet by the groove and the partition wall covering the groove.

[0283] With this configuration, the humidifying fluid is caused to flow within the humidifying chamber, which is formed into a flow path that connects the inlet and outlet, so that the humidifying fluid can be filled into the humidifying chamber or discharged from the humidifying chamber as needed.Furthermore, because the humidifying chamber is formed into a flow path, it is possible to prevent the humidifying fluid filled within the humidifying chamber from unnecessarily leaking out of the humidifying chamber. Furthermore, since the flow path is routed around the entire bottom surface of the cap, the entire recess can be humidified, thereby enabling the openings of the multiple nozzles in the liquid ejection head to be humidified more uniformly.

[0284] (F) In the capping device, the humidifying chamber may be provided at an angle relative to the horizontal, and the inlet and the outlet may be provided above the vertical center of the humidifying chamber.

[0285] With this configuration, the humidifying fluid filled in the humidifying chamber can be prevented from flowing out of the humidifying chamber from the inlet or outlet due to head pressure. (G) In the capping device, the recess may have an air vent hole for connecting the space to the atmosphere, and the air vent hole may be provided above the center of the recess in the vertical direction.

[0286] This configuration can prevent the atmosphere communication hole from being blocked by liquid, preventing the liquid from being discharged from inside the recess. (H) The cap device may further include a humidifying fluid storage section that stores the humidifying fluid, a supply flow path that connects the humidifying fluid storage section to the inlet, a recovery flow path that connects the outlet to the humidifying fluid storage section, and a pump that can cause the humidifying fluid to flow within a circulation path that includes the humidifying fluid storage section, the supply flow path, and the recovery flow path.

[0287] This configuration allows the humidifying fluid in the circulation path to be agitated. To humidify the space, a large amount of moisture evaporates from the humidifying fluid filled in the humidifying chamber. Therefore, by agitating the humidifying fluid in the circulation path, the concentration of the humidifying fluid throughout the circulation path can be made uniform. In other words, the amount of moisture contained in the humidifying fluid filled in the humidifying chamber can be returned to a level close to the amount at the time the liquid ejection device was shipped.

[0288] (I) The capping device may further include a moisture supply unit capable of supplying moisture into the circulation path. With this configuration, when moisture evaporates from the humidifying fluid, moisture can be replenished to the humidifying fluid to optimize its concentration, i.e., the amount of moisture contained in the humidifying fluid can be restored to the amount at the time the liquid ejection device was shipped.

[0289] (J) In the above capping device, the capping device may be configured with a plurality of caps lined up, and the outlet of one of the plurality of caps may be connected to the inlet of a second cap adjacent to the first cap, the inlet located most upstream may be connected to the supply flow path, and the outlet located most downstream may be connected to the recovery flow path.

[0290] According to this configuration, it is possible to fill, agitate, and discharge the humidifying fluid for a plurality of caps using only one supply flow path and one recovery flow path. [Explanation of symbols]

[0291] 11...liquid ejection device, 12...main body portion, 13...image reading portion, 14...automatic feeding portion, 15...operation portion, 16...medium storage portion, 17...placing portion, 17a...placing surface, 19...transport path, 20...recording portion, 21...liquid ejection head, 21a...unit ejection head, 21b...nozzle row, 22...nozzle, 22a...opening, 23...nozzle surface, 24...head unit, 25...support portion, 40...wiper device, 41...wiper carriage, 42...wiper member, 43...waste liquid outlet, 50...capping device, 51...cap unit, 51a...unit cap which is an example of a cap, 52...regulating member, 52a... Restriction surface, 52b...communication hole, 52c...positioning engaged portion, 53...absorber, 54...first moisture permeable membrane which is an example of a partition wall, 54a...communication portion, 55...humidification chamber, 55a...inlet, 55b...outlet, 55c...groove, 55d...positioning engaged portion, 55e...communication portion, 55f...communication hole, 55g...engaging portion, 55h...positioning engaged portion, 55i...groove wall, 55j...communication hole, 56...case, 56a...atmosphere communication hole, 56b...discharge hole which is an example of a hole, 56c...engaged portion, 56d...positioning engaged portion, 56e...seal portion, 56f...contact surface, 57...recess, 58...atmosphere release mechanism, 58a...first atmosphere communication passage, 58 b...third on-off valve, 59...holding section, 60...humidified fluid circulation mechanism, 61...humidified fluid storage section, 61a...detection section, 61b...first electrode, 61c...second electrode, 61d...second atmosphere communication passage, 61e...second moisture permeable membrane, 61f...inlet section, 61g...outlet section, 62...circulation path, 62a...supply flow path, 62b...recovery flow path, 62c...first junction section, 62d...clamp section, 63...first pump which is an example of a pump, 64...first check valve, 65...pressure adjustment valve, 66...moisture supply section, 66a...moisture storage section, 66b...moisture supply flow path, 66c...first on-off valve which is an example of an on-off valve, 66d...second check valve, 66e...second junction Flow section, 66f...outflow section, 67...pressurized air supply section, 68...humidified fluid pack, 68a...outflow section, 69...clamp, 67a...pressurized air supply path, 67b...second on-off valve, 67c...second pump, 80...waste liquid recovery mechanism, 81...waste liquid recovery path, 81a...first waste liquid recovery path, 81b...second waste liquid recovery path, 82...third pump, 83...buffer chamber, 84...fourth pump, 85...third atmosphere communication path, 86...waste liquid storage section, 90...control section, 91 detector group, 94...interface section, 95...CPU, 96...memory, 97...control circuit, 98...drive circuit, 99...computer, θ1...first predetermined angle,θ2...second predetermined angle, D1...first direction, D2...second direction, D3...third direction, D4...fourth direction, D5...fifth direction, D6...sixth direction, H1...first predetermined height which is an example of a predetermined height, H2...second predetermined height, L1a...humidifying fluid, L1b...moisture, L2...waste liquid, M...medium, P1...first predetermined pitch, SP...space, T1...first predetermined time, T2...second predetermined time, T3...third predetermined time, T4...fourth predetermined time, X...width direction, Y...depth direction, Y1...discharge direction, Z1...first transport direction, Z...vertical direction.

Claims

1. When the liquid ejection head has a nozzle for ejecting liquid, the nozzle opening is opened. A cap device capable of forming an enclosing space, a recessed portion that forms the space; a humidifying chamber for humidifying the recess; a gas-permeable partition wall that separates the recess and the humidifying chamber; a cap having The humidifying chamber has an inlet through which humidifying fluid flows in and an outlet through which the humidifying fluid flows out. death, The liquid in the recess is discharged without passing through the outlet, the humidifying chamber has a groove through which the humidifying fluid flows; The humidifying chamber has the inlet and the outlet separated by the groove and the partition wall covering the groove. A capping device characterized in that it is formed in the shape of a communicating flow channel.

2. When the liquid ejection head has a nozzle for ejecting liquid, the nozzle opening is opened. A cap device capable of forming an enclosing space, a recessed portion that forms the space; a cap having a humidifying chamber for humidifying the recess, The humidifying chamber has an inlet through which humidifying fluid flows in and an outlet through which the humidifying fluid flows out. death, The liquid in the recess is discharged without passing through the outlet, the recessed portion has a hole through which liquid discharged from the liquid ejection head into the recessed portion can be discharged; an atmosphere communication hole for communicating the space with the atmosphere; The cap is characterized in that the atmosphere communication hole is provided vertically above the hole. Pup device.

3. When the liquid ejection head has a nozzle for ejecting liquid, the nozzle opening is opened. A cap device capable of forming an enclosing space, a recessed portion that forms the space; a cap having a humidifying chamber for humidifying the recess, The humidifying chamber has an inlet through which humidifying fluid flows in and an outlet through which the humidifying fluid flows out. death, The liquid in the recess is discharged without passing through the outlet, the recessed portion has a hole through which liquid discharged from the liquid ejection head into the recessed portion can be discharged; an absorbent body capable of absorbing liquid, the humidifying chamber is partitioned from the recess and is adjacent to and below the absorbent body; the inlet and the outlet are spaced apart from the absorber; The hole is provided at a position lower than the absorber and the outlet. Capping device.

4. 4. The method according to claim 2 or 3, wherein the hole is provided at the bottom of the recess. The capping device described herein.

5. the cap has a gas-permeable film that separates the recess and the humidifying chamber, 4. The carrier according to claim 3, wherein the membrane is positioned so as to contact the absorbent body. Top device.

6. The cap has a gas-permeable film that separates the recess and the humidifying chamber. The capping device according to any one of claims 2 to 4, characterized in that:

7. The hole is provided in the recess at a position lower than the membrane in the vertical direction.

7. The capping device according to claim 5 or 6, wherein:

8. 10. The method according to claim 1, wherein the outlet is provided at a lower position than the inlet. The capping device according to any one of claims 7 to 9.

9. The humidifying chamber is provided at an angle relative to the horizontal, The inlet and the outlet are provided above the vertical center of the humidifying chamber. The capping device according to any one of claims 1 to 8, characterized in that

10. The atmosphere communication hole is preferably provided above the center of the recess in the vertical direction.

3. The capping device according to claim 2.

11. a humidifying fluid storage section that stores the humidifying fluid; a supply flow path that communicates the humidifying fluid storage portion with the inlet; a recovery flow path that connects the outlet and the humidifying fluid storage portion; The humidifying fluid is supplied to the humidifying fluid storage portion, the supply flow path, and the recovery flow path through a circulation path.

11. The method according to claim 1, further comprising: The capping device according to any one of claims 1 to 4.

12. The supply flow path allows the liquid to flow from the humidifying fluid storage portion to the inlet, a valve for preventing the flow of liquid from the inlet to the humidifying fluid reservoir; Item 12. A capping device according to item 11.

13. 2. The method according to claim 1, further comprising: providing a water supply unit capable of supplying water into the circulation path.

13. The capping device of claim 1 or claim 12.

14. The cap device is configured by arranging a plurality of the caps, The outlet of one of the caps is adjacent to the cap. connected to the inlet of the second cap, The inlet located at the most upstream side is connected to the supply flow path, and the inlet located at the most downstream side is connected to the supply flow path.

14. The method according to claim 11, wherein the outlet is connected to the recovery flow path. Item 1. A capping device according to item 1.

15. a liquid ejection head having nozzles for ejecting liquid; a carrier that can form a space surrounding the nozzle opening when the carrier comes into contact with the liquid ejection head; It is equipped with The cap is a recessed portion that forms the space; a humidifying chamber for humidifying the recess; a gas-permeable partition wall that separates the recess and the humidifying chamber, The humidifying chamber has an inlet through which humidifying fluid flows in and an outlet through which the humidifying fluid flows out. death, The liquid in the recess is discharged without passing through the outlet, the humidifying chamber has a groove through which the humidifying fluid flows; The humidifying chamber has the inlet and the outlet separated by the groove and the partition wall covering the groove. A liquid ejection device characterized in that the liquid ejection device is formed in the shape of a communicating flow path.

16. a liquid ejection head having nozzles for ejecting liquid; a carrier that can form a space surrounding the nozzle opening when the carrier comes into contact with the liquid ejection head; It is equipped with The cap is a recessed portion that forms the space; a humidifying chamber for humidifying the recessed portion, The humidifying chamber has an inlet through which humidifying fluid flows in and an outlet through which the humidifying fluid flows out. death, The liquid in the recess is discharged without passing through the outlet, the recessed portion has a hole through which liquid discharged from the liquid ejection head into the recessed portion can be discharged; an atmosphere communication hole for communicating the space with the atmosphere; the atmosphere communication hole is provided vertically above the hole. Output device.

17. a liquid ejection head having nozzles for ejecting liquid; a carrier that can form a space surrounding the nozzle opening when the carrier comes into contact with the liquid ejection head; It is equipped with The cap is a recessed portion that forms the space; a humidifying chamber for humidifying the recessed portion, The humidifying chamber has an inlet through which humidifying fluid flows in and an outlet through which the humidifying fluid flows out. death, The liquid in the recess is discharged without passing through the outlet, the recessed portion has a hole through which liquid discharged from the liquid ejection head into the recessed portion can be discharged; an absorbent body capable of absorbing liquid, the humidifying chamber is partitioned from the recess and is adjacent to and below the absorbent body; the inlet and the outlet are spaced apart from the absorber; The hole is provided at a position lower than the absorber and the outlet. Liquid discharge device.

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