Liquid ejection device, control method for liquid ejection device and program

Abstract

To provide a liquid ejection device in which liquid ejection failure can be suppressed.SOLUTION: In a switching valve of a liquid ejection device, a fixed member includes: a main body supporting a flow path member; a cleaning liquid upstream port having a convex shape protruding from the main body and connected via a tube to a cleaning liquid tank; a cleaning liquid downstream port and a waste liquid port having convex shapes protruding from the main body and connected via tubes to a cap; and an air suction port having a convex shape protruding from the main body and connected to a tube provided with a suction pump. A rotary member rotates relative to the fixed member and has a first cleaning liquid passage. The flow path member includes: a second cleaning liquid passage that is mounted on the rotary member, rotates together with the rotary member relative to the fixed member, is connected to the first cleaning liquid passage, and forms a cleaning liquid passage communicating between the cleaning liquid upstream port and the cleaning liquid downstream port; and a waste liquid passage communicated between the waste liquid port and the air suction port.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a liquid ejection device that ejects liquid, and a control method and program for the liquid ejection device. [Background technology]

[0002] A known example of a conventional liquid ejection device is the liquid ejection device disclosed in Patent Document 1. This liquid ejection device includes a liquid ejection head and a maintenance unit. The liquid ejection head has nozzles that eject ink and an ejection surface where the nozzles open. The maintenance unit includes a cap that covers the ejection surface, a suction pump that sucks the inside of the cap, a waste liquid tank, and a switching valve. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-193552 Summary of the Invention [Problem to be solved by the invention]

[0004] In the liquid ejection device, the switching valve switches between communication and blocking between the cap, suction pump, and waste liquid tank, thereby performing a suction purge in which the suction pump sucks the inside of the cap that covers the ejection surface. This suction purge causes ink to be ejected from the nozzles, which can cause the ink to adhere to the ejection surface where the nozzles open. If the ink used here has good fixability, and the ink adheres to the ejection surface and dries, this can cause problems with ejection of the ink from the nozzles.

[0005] In view of such circumstances, the present disclosure aims to provide a liquid ejection device, a control method for a liquid ejection device, and a program that can suppress poor liquid ejection from nozzles caused by adhesions on the ejection surface. [Means for solving the problem]

[0006] A liquid ejection device according to the present disclosure includes a liquid ejection head having an ejection surface where nozzles open, a cap that covers the ejection surface, a suction pump, a cleaning liquid tank that stores cleaning liquid, and a switching valve that has a fixed member, a rotating member, and a flow path member, and the fixed member includes a main body that supports the flow path member, a cleaning liquid upstream port that has a convex shape that protrudes from the main body and is connected to the cleaning liquid tank via a tube, a cleaning liquid downstream port and a waste liquid port that have a convex shape that protrudes from the main body and are connected to the cap via a tube, the flow path member is attached to the rotating member and rotates together with the rotating member relative to the fixed member, and has a second cleaning liquid passage connected to the first cleaning liquid passage and forming a cleaning liquid passage communicating between the cleaning liquid upstream port and the cleaning liquid downstream port, and a waste liquid passage communicating between the waste liquid port and the intake port.

[0007] A method for controlling a liquid ejection device according to the present disclosure includes a liquid ejection head having an ejection surface where nozzles open, a cap that covers the ejection surface, a suction pump, a cleaning liquid tank that stores cleaning liquid, and a switching valve having a fixed member, a rotating member, and a flow path member, the fixed member rotating relative to the fixed member and including a main body that supports the flow path member, a cleaning liquid upstream port that has a convex shape protruding from the main body and is connected to the cleaning liquid tank via a tube, a cleaning liquid downstream port and a waste liquid port that have a convex shape protruding from the main body and are connected to the cap via a tube, and a cleaning liquid downstream port and a waste liquid port that have a convex shape protruding from the main body and are connected to the cap via a tube. a flow path member attached to the rotating member and rotating together with the rotating member relative to the fixed member, a second cleaning liquid passage connected to the first cleaning liquid passage and forming a cleaning liquid passage communicating between the cleaning liquid upstream port and the cleaning liquid downstream port, and a waste liquid passage communicating between the waste liquid port and the intake port; and a control method for a liquid ejection device, the method comprising: rotating the rotating member to change the communication state between the port and the cleaning liquid passage and the waste liquid passage;

[0008] The program according to the present disclosure includes a liquid ejection head having an ejection surface where nozzles open, a cap that covers the ejection surface, a suction pump, a cleaning liquid tank that stores cleaning liquid, and a switching valve that has a fixed member, a rotating member, and a flow path member, the fixed member rotating relative to the fixed member and including a main body that supports the flow path member, a cleaning liquid upstream port that has a convex shape that protrudes from the main body and is connected to the cleaning liquid tank via a tube, a cleaning liquid downstream port and a waste liquid port that have a convex shape that protrudes from the main body and are connected to the cap via a tube, and a cleaning liquid downstream port and a waste liquid port that have a convex shape that protrudes from the main body and are connected to the cap via a tube. a liquid ejection device having a port including an intake port connected to a tube provided with the suction pump, the rotating member rotating relative to the fixed member and having a first cleaning liquid passage, the flow path member being attached to the rotating member and rotating together with the rotating member relative to the fixed member, a second cleaning liquid passage connected to the first cleaning liquid passage and forming a cleaning liquid passage communicating between the cleaning liquid upstream port and the cleaning liquid downstream port, and a waste liquid passage communicating between the waste liquid port and the intake port, the liquid ejection device having a port including an intake port connected to the suction pump, the rotating member rotating relative to the fixed member and having a first cleaning liquid passage, the flow path member being attached to the rotating member and rotating together with the rotating member relative to the fixed member, [Effects of the Invention]

[0009] According to the present disclosure, the rotating member and the flow path member are rotated relative to the fixed member. This connects the cleaning liquid passage to the cleaning liquid upstream port and the cleaning liquid downstream port, and the waste liquid passage to the waste liquid port and the intake port. When the suction pump is driven in this state, the inside of the cap is suctioned via the intake port, the waste liquid passage, and the waste liquid port. Furthermore, cleaning liquid is sucked from the cleaning liquid tank via the cleaning liquid downstream port, the cleaning liquid passage, and the cleaning liquid upstream port, which are connected to the cap, and flows into the cap. This cleaning liquid cleans the ejection surface covered by the cap, thereby removing liquid adhering to the ejection surface. This makes it possible to suppress poor ejection of liquid from the nozzles due to deposits on the ejection surface. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a liquid ejection device according to an embodiment of the present disclosure, viewed from above; [Figure 2] FIG. 1 is a block diagram illustrating a configuration of a liquid ejection device. [Figure 3] FIG. 2 is a schematic view showing a maintenance unit. [Figure 4] FIG. 2 is a partially cutaway perspective view of a switching valve. [Figure 5] Fig. 5A is a schematic diagram showing a switching valve in which a cleaning liquid passage is connected between a first cleaning liquid upstream port and a first cleaning liquid downstream port, and Fig. 5B is a schematic diagram showing a switching valve in which a waste liquid passage is connected between a first waste liquid port and an intake port. [Figure 6] FIG. 4 is a cross-sectional view showing a switching valve in which a rotary member is disposed at a standby position. [Figure 7] 7A and 7B are cross-sectional views showing the switching valve with the rotary member positioned at a first purge position and a first cleaning position, respectively. [Figure 8] Figure 8A is a cross-sectional view showing the switching valve when the rotary member is positioned at the first pressure-increasing position, and Figure 8B is a cross-sectional view showing the switching valve when the rotary member is positioned at the first dry suction position. [Figure 9] 9A and 9B are cross-sectional views showing the switching valve with the rotary member positioned at a second purge position and a second cleaning position, respectively. [Figure 10] Figure 10A is a cross-sectional view showing the switching valve when the rotary member is positioned at the second pressure-increasing position, and Figure 10B is a cross-sectional view showing the switching valve when the rotary member is positioned at the second dry suction position. [Figure 11] 11A and 11B are cross-sectional views showing the switching valve with the rotary member positioned at the exhaust purge position and the exhaust purge suction position, respectively. [Figure 12] 10 is a flowchart illustrating an example of a maintenance process of the liquid ejection device. [Figure 13] 10 is a flowchart showing an example of a maintenance process of the liquid ejection device according to Modification 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Liquid discharge device> A liquid ejection device 10 according to an embodiment of the present disclosure is a device that ejects liquid, as shown in Fig. 1. In the following, a case where the liquid ejection device 10 is used in an inkjet printer that ejects ink as the liquid will be described, but the liquid ejection device 10 is not limited to this.

[0012] The liquid ejection device 10 includes a liquid ejection head 20 that ejects liquid. The liquid ejection head 20 includes a flow path forming body 21 and a plurality of drive elements 22 (FIG. 2). A plurality of nozzles are formed in the flow path forming body 21, and the plurality of nozzles include first nozzles 23a and second nozzles 23b.

[0013] The driving elements 22 are piezoelectric elements, heating elements, electrostatic actuators, etc., and are provided for each of the nozzles 23a, 23b, and apply pressure to the liquid inside the liquid ejection head 20 to eject droplets from the nozzles 23a, 23b. This pressure wave acts on the meniscus of the liquid formed in the nozzles 23a, 23b, causing the liquid to be ejected from the nozzles 23a, 23b. Details of the liquid ejection head 20 will be described later.

[0014] The liquid ejection device 10 further includes a platen 11. The platen 11 is positioned below the liquid ejection head 20 at a predetermined distance, and its upper surface faces the lower surface of the flow path forming body 21 of the liquid ejection head 20, supporting the print medium A from below.

[0015] Furthermore, the liquid ejection device 10 is equipped with cartridges 12 and a buffer tank 13 (FIG. 3). The cartridges 12 are detachably attached to the housing of the liquid ejection device 10, and the same number of cartridges 12 as the types of liquid to be ejected from the liquid ejection head 20 (four in the example of FIG. 1) are provided in the liquid ejection device 10. The cartridges 12 store liquid and supply it to a buffer tank 13 provided on the liquid ejection head 20. Details of the buffer tank 13 will be described later.

[0016] Furthermore, the liquid ejection device 10 includes a maintenance unit 30 that performs maintenance on the liquid ejection head 20. The maintenance unit 30 is disposed, for example, in the left-right direction, in a maintenance range to the right of the printing range in which the platen 11 is disposed. Details of the maintenance unit 30 will be described later.

[0017] Furthermore, the liquid ejection device 10 is equipped with a moving device 14 that moves the liquid ejection head 20 in the left-right direction, and a transport device 15 that transports the print medium A in the front-to-back direction. The moving device 14 moves the liquid ejection head 20 across the printing range and the maintenance range. The transport device 15 transports the print medium A in the front-to-back direction on the platen 11.

[0018] 2, the liquid ejection device 10 further includes a control device 40. The control device 40 is electrically connected to a communication interface 43, and is also electrically connected via drive circuits 44 to 49 to the drive element 22 of the liquid ejection head 20, the moving device 14, the transport device 15, and the displacement device 32, suction pump 36, and rotation device 38 provided in the maintenance unit 30. The communication interface 43 is capable of communicating with external devices such as computers and mobile terminal devices, and transmits and receives data to and from the external devices.

[0019] The control device 40 is configured, for example, by a computer, and has a calculation unit 41 and a storage unit 42. The storage unit 42 is a memory accessible from the calculation unit 41, and includes, for example, RAM and ROM. The storage unit 42 stores data input from the communication interface 43, as well as computer programs and various data used for data processing by the calculation unit 41. The data includes image data, such as raster data, that represents an image to be printed.

[0020] The calculation unit 41 includes circuits such as a processor such as a CPU, an integrated circuit such as an ASIC, or both. The calculation unit 41 executes a computer program while referring to the data stored in the storage unit 42, and the control device 40 controls the operation of each part of the liquid ejection device 10. In this way, the liquid ejection device 10 executes various processes such as a printing process for printing an image and a maintenance process for the liquid ejection head 20. These processes will be described later.

[0021] Furthermore, the control device 40 may be configured as a single device, or may be configured as a plurality of devices distributed in a distributed manner that cooperate to perform the operations of the control device 40. For example, the liquid ejection device 10 may be configured as an information processing unit such as a personal computer or a mobile terminal device, and a liquid ejection execution unit having the liquid ejection head 20. The information processing unit and the liquid ejection execution unit are formed as separate units that can communicate with each other. In this case, the control device 40 may be configured as a control device for the information processing unit and a control device for the liquid ejection execution unit. These control devices cooperate to perform the operations of the control device 40 of the liquid ejection device 10.

[0022] <Liquid ejection head> 1 and 3, the plurality of nozzles includes a plurality of first nozzles 23a that eject a first liquid and a plurality of second nozzles 23b that eject a second liquid. For example, the first liquid may be color ink, such as cyan ink, magenta ink, and yellow ink. The second liquid may be a liquid different from the first liquid, such as black ink. Details of the first liquid and the second liquid will be described later.

[0023] The nozzles 23a and 23b open to a discharge surface, which is the lower surface of the flow path forming body 21. The discharge surface has a first discharge surface 21a where the first nozzle 23a opens, and a second discharge surface 21b where the second nozzle 23b opens. For example, the second discharge surface 21b is located to the left of the first discharge surface 21a.

[0024] On the first ejection surface 21a, the multiple first nozzles 23a are aligned in the front-to-rear direction to form a first nozzle row, and the multiple first nozzle rows are aligned in the left-to-right direction. The multiple first nozzle rows include a row of first nozzles 23a that eject cyan ink, a row of first nozzles 23a that eject magenta ink, and a row of first nozzles 23a that eject yellow ink. On the second ejection surface 21b, the multiple second nozzles 23b are aligned in the front-to-rear direction to form a second nozzle row, and the second nozzle row is located, for example, to the left of the multiple first nozzle rows.

[0025] <First liquid and second liquid> Each of the first liquid and the second liquid is, for example, an ink such as an aqueous ink, containing resin particles, a colorant, an organic solvent, a surfactant, and water. In this case, the ink has wettability to hydrophobic recording media such as coated paper, plastic, film, and OHP sheets, but is not limited thereto. For example, the ink may be suitable for image recording on recording media other than hydrophobic recording media such as plain paper, glossy paper, and matte paper. "Coated paper" refers to plain paper, such as high-grade printing paper or medium-grade printing paper, that is coated with a coating agent to improve smoothness, whiteness, gloss, etc., specifically high-grade coated paper, medium-grade coated paper, etc.

[0026] The resin microparticles may contain, for example, at least one of methacrylic acid and acrylic acid as a monomer, and commercially available products may be used. The resin microparticles may further contain, for example, styrene, vinyl chloride, or the like as a monomer. The resin microparticles may be contained in, for example, an emulsion. The emulsion is composed of, for example, resin microparticles and a dispersion medium (e.g., water). The resin microparticles are not dissolved in the dispersion medium but are dispersed within a specific particle size range. Examples of resin microparticles include acrylic acid-based resins, maleic acid-based ester resins, vinyl acetate-based resins, carbonate-based resins, polycarbonate-based resins, styrene-based resins, ethylene-based resins, polyethylene-based resins, propylene-based resins, polypropylene-based resins, urethane-based resins, polyurethane-based resins, polyester-based resins, and copolymer resins thereof, with acrylic resins being preferred.

[0027] The resin particles used may have a glass transition temperature (Tg) in the range of 0° C. to 200° C. More preferably, the glass transition temperature (Tg) is 20° C. to 180° C., and even more preferably, 30° C. to 150° C.

[0028] The emulsion may be, for example, a commercially available product. Examples of commercially available products include "Superflex (registered trademark) 870" (Tg: 71°C) and "Superflex (registered trademark) 150" (Tg: 40°C) manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "Mowinyl (registered trademark) 6760" (Tg: -28°C) and "Mowinyl (registered trademark) DM774" (Tg: 33°C) manufactured by Japan Coating Resins Co., Ltd., "Polysol (registered trademark) AP-3270N" (Tg: 27°C) manufactured by Showa Denko K.K., and "Hi-Loss-X (registered trademark) KE-1062" (Tg: 112°C) and "Hi-Loss-X (registered trademark) QE-1042" (Tg: 69°C) manufactured by Seiko PMC Corporation.

[0029] The average particle diameter of the resin microparticles is, for example, in the range of 30 nm to 200 nm. The average particle diameter can be measured as an arithmetic mean diameter using, for example, a dynamic light scattering particle size distribution analyzer "LB-550" manufactured by Horiba, Ltd.

[0030] The content (R) of resin particles in the total amount of ink is, for example, preferably in the range of 0.1 wt% to 30 wt%, more preferably in the range of 0.5 wt% to 20 wt%, and particularly preferably in the range of 1.0 wt% to 15.0 wt%. One type of resin particles may be used alone, or two or more types may be used in combination.

[0031] The colorant is a pigment that can be dispersed in water using, for example, a pigment dispersing resin (resin dispersant). Examples of colorants include carbon black, inorganic pigments, and organic pigments. Examples of carbon black include furnace black, lamp black, acetylene black, and channel black. Examples of inorganic pigments include titanium oxide, iron oxide-based inorganic pigments, and carbon black-based inorganic pigments. Examples of organic pigments include azo pigments such as azo lake, insoluble azo pigments, condensed azo pigments, and chelate azo pigments; polycyclic pigments such as phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments; dye lake pigments such as basic dye lake pigments and acid dye lake pigments; nitro pigments; nitroso pigments; and aniline black daylight fluorescent pigments.

[0032] The solid content of the colorant in the total amount of ink is not particularly limited and can be appropriately determined, for example, depending on the desired optical density or saturation. The solid content of the colorant is, for example, preferably in the range of 0.1 wt% to 20.0 wt%, more preferably in the range of 1.0 wt% to 15.0 wt%. The solid content of the colorant is the weight of the pigment only and does not include the weight of resin microparticles. One type of colorant may be used alone, or two or more types may be used in combination.

[0033] The organic solvent is not particularly limited, and any organic solvent can be used. Examples of organic solvents include propylene glycol, ethylene glycol, 1,2-butanediol, propylene glycol monobutyl ether, dipropylene glycol monopropyl ether, triethylene glycol monobutyl ether, 1,2-hexanediol, and 1,6-hexanediol, with glycol ethers having a propylene oxide group being preferred. Other examples of organic solvents include alkyl alcohols having 1 to 4 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl alcohol; alkylene glycols having an alkylene group containing 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, and diethylene glycol; glycerin, ethylene glycol monomethyl (or ethyl, propyl, or butyl) ether, and diethylene glycol monomethyl (or ethyl, propyl, or butyl) ether. lower alkyl ethers of alkylene glycols such as ethylene glycol monomethyl (or ethyl, propyl, butyl, hexyl) ether, triethylene glycol monomethyl (or ethyl, propyl, butyl, hexyl) ether, tetraethylene glycol monomethyl (or ethyl, propyl, butyl, hexyl) ether, propylene glycol monomethyl (or ethyl, propyl, butyl) ether, dipropylene glycol monomethyl (or ethyl, propyl, butyl) ether, tripropylene glycol monomethyl (or ethyl, propyl, butyl) ether, and tetrapropylene glycol monomethyl (or ethyl) ether; N-methyl-2-pyrrolidone, 2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone.

[0034] The content of organic solvent in the total amount of ink, which exists as a liquid at 25° C. as a single organic solvent, is preferably 50 wt % or less, more preferably 40 wt % or less, based on the total amount of ink.

[0035] The water is preferably ion-exchanged water or pure water. The water content of the total ink is preferably, for example, in the range of 15 wt% to 95 wt%, more preferably 25 wt% to 85 wt%. The water content may be, for example, the remainder of the other components.

[0036] The ink may further contain conventional additives as needed. Examples of additives include surfactants, pH adjusters, viscosity adjusters, surface tension adjusters, preservatives, antifungals, leveling agents, antifoaming agents, light stabilizers, antioxidants, nozzle drying inhibitors, polymer components such as emulsions, and dyes. The surfactant may further include cationic surfactants, anionic surfactants, or nonionic surfactants. These surfactants may be commercially available products. Examples of commercially available products include "Olfine® E1010," "Olfine® E1006," "Olfine® E1004," "Silface SAG503A," and "Silface SAG002" manufactured by Nissin Chemical Industry Co., Ltd. The surfactant content of the total ink is, for example, 5 wt% or less, 3 wt% or less, or 0.1 wt% to 2 wt%. Examples of viscosity adjusters include polyvinyl alcohol, cellulose, and water-soluble resins.

[0037] The ink can be prepared, for example, by uniformly mixing resin fine particles, colorant, organic solvent, water, and, if necessary, other additives using a conventionally known method, and then removing any insoluble matter using a filter or the like.

[0038] <Buffer tank> The buffer tank 13 is connected to the cartridge 12 (FIG. 1) by a tube or the like, and liquid is supplied from the cartridge 12. The buffer tank 13 is also provided on the liquid ejection head 20, and is connected to the nozzles 23a, 23b by a liquid flow path. A filter 13a is provided in the liquid flow path. The liquid passes through the filter 13a, flows through the liquid flow path, and is supplied to the nozzles 23a, 23b. When this liquid passes through the filter 13a, air bubbles contained in the liquid are separated and stored above the buffer tank 13.

[0039] <Maintenance unit> The maintenance unit 30 is equipped with caps that cover the ejection surfaces of the liquid ejection head 20. The caps include a first cap 31a that covers the first ejection surface 21a and a second cap 31b that covers the second ejection surface 21b. The first cap 31a and the second cap 31b are made of an elastic material such as silicone rubber and are integrally formed. Each of the first cap 31a and the second cap 31b is box-shaped with an open top and has a through-hole that connects to a tube 39.

[0040] Furthermore, the maintenance unit 30 includes a displacement device 32 (FIG. 2) that displaces the caps 31a and 31b. The displacement device 32 displaces the caps 31a and 31b between a contact position and a separated position. Accordingly, the caps 31a and 31b change between a capped state and an uncapped state.

[0041] That is, in the capping state, the first cap 31a contacts the first ejection surface 21a at the abutting position and covers the first nozzles 23a opening to the first ejection surface 21a. In the capping state, the second cap 31b contacts the second ejection surface 21b at the abutting position and covers the second nozzles 23b opening to the second ejection surface 21b. This reduces drying of the first liquid from the first nozzles 23a and drying of the second liquid from the second nozzles 23b. Furthermore, in the uncapping state, the first cap 31a is separated from the first ejection surface 21a at the separated position, exposing the first ejection surface 21a. In the uncapping state, the second cap 31b is separated from the second ejection surface 21b at the separated position, exposing the second ejection surface 21b.

[0042] Furthermore, the maintenance unit 30 has an exhaust path 33a, an exhaust body 33b, and an exhaust cap 33c. The exhaust path 33a is connected to the top of the buffer tank 13 and opens to an exhaust surface 33b1, which is the bottom surface of the exhaust body 33b. Air bubbles stored in the top of the buffer tank 13 pass through the exhaust path 33a and are discharged from the buffer tank 13. The exhaust cap 33c is made of an elastic material such as silicone rubber, has a box shape with an open top, and has a through hole through which it is connected to a tube 39.

[0043] The exhaust cap 33c is displaced between an abutting position and a separated position by the displacement device 32. Accordingly, the exhaust cap 33c changes between a capping state and an uncapping state. In the capping state, the exhaust cap 33c contacts the exhaust surface 33b1 at the abutting position and covers the opening of the exhaust path 33a. On the other hand, in the separated position, the exhaust cap 33c is separated from the exhaust surface 33b1 and the opening of the exhaust path 33a is exposed to the outside.

[0044] The maintenance unit 30 further includes a cleaning liquid tank 34 for storing cleaning liquid, a waste liquid tank 35 for storing waste liquid, and a suction pump 36. The cleaning liquid tank 34 stores cleaning liquid and supplies it to the caps 31a and 31b. The cleaning liquid is a liquid that can clean (dilute) the first and second liquids and does not contain solids, but contains, for example, an organic solvent, a surfactant, and a water-soluble solvent containing water. In other words, the cleaning liquid may be a liquid obtained by removing the resin particles and colorant from the first and second liquids. The waste liquid tank 35 has a space for storing waste liquid, which is liquid discharged from the nozzles 23a and 23b and the caps 31a and 31b, and this space is open to the atmosphere.

[0045] The suction pump 36 is, for example, a tube pump, and is provided in a tube 39 (tube 39a) connected to the switching valve 37 and the waste liquid tank 35. The suction pump 36 rotates while the roller is pressed against the tube 39a, thereby performing suction by sucking air from the switching valve 37 to the waste liquid tank 35. When the roller of the suction pump 36 is not pressed against the tube 39a, the tube 39a is in an open-to-atmosphere state in which it is open to the atmosphere via the waste liquid tank 35.

[0046] The maintenance unit 30 further includes a switching valve 37 and a rotating device 38 (FIG. 2). The switching valve 37 has a fixed member 50 (FIG. 4) and a rotating member 60 (FIG. 4), and is connected to the first cap 31a, the second cap 31b, the exhaust cap 33c, the suction pump 36, the cleaning liquid tank 34, and the waste liquid tank 35 via a tube 39. The rotating device 38 rotates the rotating member 60 relative to the fixed member 50, causing the switching valve 37 to change the communication state among the first cap 31a, the second cap 31b, the exhaust cap 33c, the suction pump 36, the cleaning liquid tank 34, and the waste liquid tank 35.

[0047] <Switching valve> As shown in Fig. 4, the switching valve 37 has a fixed member 50, a rotating member 60, and a flow path member 70. The rotating member 60 is made of, for example, resin, and has a gear portion 61 and a passage portion 62. The gear portion 61 is disk-shaped and connected to a rotating device 38 (Fig. 2). When the rotating device 38 is driven, the rotating member 60 rotates relative to the fixed member 50. The central axis of the rotating member 60 and the central axis of the fixed member 50 coincide with each other, and the rotating member 60 rotates around this central axis.

[0048] The passage portion 62 is cylindrical, has a central axis coinciding with the central axis of the gear portion 61, and protrudes downward from the gear portion 61. The passage portion 62 has a first cleaning liquid passage 64. The first cleaning liquid passage 64 extends linearly along the radial direction of the passage portion 62, penetrates the passage portion 62, and opens onto the outer circumferential surface of the passage portion 62. The passage portion 62 is also provided with a plurality of protrusions 65 that protrude from the outer circumferential surface. The protrusions 65 extend in a direction parallel to the central axis of the passage portion 62, for example, in the up-and-down direction.

[0049] The flow path member 70 is made of an elastic material such as rubber and has a second main body 71. The second main body 71 includes a second side wall 71a and a second bottom wall 71b. The second side wall 71a is cylindrical, and the passage portion 62 is inserted into the second side wall 71a. The central axis of the second side wall 71a coincides with the central axis of the passage portion 62, and the inner peripheral surface of the second side wall 71a makes watertight contact with the outer peripheral surface of the passage portion 62.

[0050] Additionally, a recess 73 is provided on the outer peripheral surface of the second side wall 71a. The recess 73 extends in a direction parallel to the central axis of the second side wall 71a, for example, in the up-and-down direction. The convex portion 65 of the passage portion 62 is fitted into the recess 73 of the second side wall 71a, and the flow path member 70 is attached to the rotating member 60. The flow path member 70 engages with the passage portion 62 in the circumferential direction around the central axis, and thereby the flow path member 70 rotates together with the rotating member 60 relative to the fixed member 50.

[0051] Further, two second cleaning liquid passages 74 are provided in the second side wall 71a. The second cleaning liquid passages 74 extend radially of the second side wall 71a and penetrate the second side wall 71a. As shown in FIGS. 5A and 6, the first cleaning liquid passage 64 is disposed between the two second cleaning liquid passages 74, and these passages extend along the same straight line. In the radial direction of the flow path member 70, the opening of the second cleaning liquid passage 74 and the opening of the first cleaning liquid passage 64 face each other, and the second cleaning liquid passage 74 is connected to the first cleaning liquid passage 64. As a result, the first cleaning liquid passage 64 and the two second cleaning liquid passages 74 form a cleaning liquid passage 75. The cleaning liquid passage 75 extends linearly radially of the flow path member 70 and opens on the outer circumferential surface of the flow path member 70.

[0052] 5B and 6, a plurality of grooves are provided on the outer peripheral surface of the second side wall 71a and the lower surface of the second bottom wall 71b. These grooves form a plurality of waste liquid passages, such as a first waste liquid passage 76a, a second waste liquid passage 76b, a third waste liquid passage 76c, and a fourth waste liquid passage 76d. These waste liquid passages 76a to 76d extend from the center of the lower surface of the second bottom wall 71b to the outer peripheral surface of the second side wall 71a along the radial direction of the lower surface of the second bottom wall 71b, and further extend upward from the lower surface of the second bottom wall 71b on the outer peripheral surface of the second side wall 71a.

[0053] As a result, these waste liquid passages 76a to 76d overlap and communicate with one another at the center of the lower surface of the flow path member 70. Furthermore, these waste liquid passages 76a to 76d are arranged on the outer circumferential surface of the second bottom wall 71b so as to be shifted from one another in the circumferential direction of the central axis of the flow path member 70. Furthermore, the waste liquid passages 76a to 76d are arranged below the cleaning liquid passage 75 in the up-down direction, and therefore do not communicate with the cleaning liquid passage 75.

[0054] 4, the fixing member 50 has a first main body 51 that supports the flow path member 70. The first main body 51 is made of, for example, resin, and has a first side wall 51a and a first bottom wall 51b. The first side wall 51a is cylindrical, and the first bottom wall 51b is circular, covering a lower opening of the first side wall 51a.

[0055] The flow path member 70 is housed within this first side wall 51a, and the central axis of the first side wall 51a coincides with the central axis of the flow path member 70. The flow path member 70 is rotatable relative to this first side wall 51a, and the inner circumferential surface of the first side wall 51a makes watertight contact with the outer circumferential surface of the second side wall 71a. Furthermore, the upper surface of the first bottom wall 51b makes watertight contact with the lower surface of the second bottom wall 71b. As a result, the waste liquid passages 76a to 76d formed in the outer circumferential surface of the second side wall 71a and the lower surface of the second bottom wall 71b of the flow path member 70 are covered by the inner circumferential surface of the first side wall 51a and the upper surface of the first bottom wall 51b of the fixing member 50.

[0056] The fixing member 50 further has a cleaning liquid upstream port. As shown in Fig. 6, the cleaning liquid upstream port includes a first cleaning liquid upstream port 52a and a second cleaning liquid upstream port 52b. The cleaning liquid upstream ports 52a and 52b are cylindrical, penetrate the first side wall 51a of the main body, and open to the inner circumferential surface of the first side wall 51a. The first cleaning liquid upstream port 52a and the second cleaning liquid upstream port 52b are disposed at the same height in the vertical direction, and the opening of the first cleaning liquid upstream port 52a and the opening of the second cleaning liquid upstream port 52b face each other in the radial direction of the first side wall 51a.

[0057] The cleaning liquid upstream ports 52a, 52b have a convex shape that protrudes from the outer peripheral surface of the first side wall 51a. The cleaning liquid upstream ports 52a, 52b are connected to one end of a tube 39, and the other end of the tube 39 is connected to the cleaning liquid tank 34. As a result, the cleaning liquid upstream ports 52a, 52b are in communication with the cleaning liquid tank 34 via the tube 39.

[0058] The fixing member 50 further has a cleaning liquid downstream port. As shown in FIGS. 4 and 6, the cleaning liquid downstream port includes a first cleaning liquid downstream port 53a and a second cleaning liquid downstream port 53b. The cleaning liquid downstream ports 53a and 53b are cylindrical, penetrate the first side wall 51a of the main body, and open to the inner circumferential surface of the first side wall 51a. The first cleaning liquid downstream port 53a and the second cleaning liquid downstream port 53b are disposed at the same height in the vertical direction, and the opening of the first cleaning liquid downstream port 53a and the opening of the second cleaning liquid downstream port 53b face each other in the radial direction of the first side wall 51a.

[0059] The cleaning liquid downstream ports 53a, 53b have a convex shape that protrudes from the outer peripheral surface of the first side wall 51a. The first cleaning liquid downstream port 53a is connected to one end of a tube 39, and the other end of the tube 39 is connected to the first cap 31a. As a result, the first cleaning liquid downstream port 53a is in communication with the first cap 31a via the tube 39. Furthermore, the second cleaning liquid downstream port 53b is connected to one end of a tube 39, and the other end of the tube 39 is connected to the second cap 31b. As a result, the second cleaning liquid downstream port 53b is in communication with the second cap 31b via the tube 39.

[0060] The cleaning liquid upstream ports 52a, 52b and the cleaning liquid downstream ports 53a, 53b are disposed at the same height in the vertical direction as the rotating member 60 and the cleaning liquid passage 75 of the flow path member 70. When the rotating member 60 and the flow path member 70 rotate relative to the fixed member 50, the state of communication between the cleaning liquid passage 75 and the cleaning liquid upstream ports 52a, 52b and the cleaning liquid downstream ports 53a, 53b changes.

[0061] 5A and 7B, the cleaning liquid passage 75 is aligned on the same straight line as the first cleaning liquid upstream port 52a and the first cleaning liquid downstream port 53a. The opening of the cleaning liquid passage 75 faces the opening of the first cleaning liquid upstream port 52a and the opening of the first cleaning liquid downstream port 53a in the radial direction of the flow path member 70. This allows the cleaning liquid passage 75 to communicate with the first cleaning liquid upstream port 52a and the first cleaning liquid downstream port 53a. In this case, the cleaning liquid passage 75 does not communicate with the second cleaning liquid upstream port 52b and the second cleaning liquid downstream port 53b.

[0062] 5A and 9B, the cleaning liquid passage 75 is aligned on the same straight line as the second cleaning liquid upstream port 52b and the second cleaning liquid downstream port 53b. The opening of the cleaning liquid passage 75 faces the opening of the second cleaning liquid upstream port 52b and the opening of the second cleaning liquid downstream port 53b in the radial direction of the flow path member 70. This allows the cleaning liquid passage 75 to communicate with the second cleaning liquid upstream port 52b and the second cleaning liquid downstream port 53b. In this case, the cleaning liquid passage 75 does not communicate with the first cleaning liquid upstream port 52a and the first cleaning liquid downstream port 53a.

[0063] 4, 5B, and 6, the fixing member 50 has an intake port 54. The intake port 54 is generally cylindrical and passes through the center of the first bottom wall 51b in the vertical direction. At the center of the second bottom wall 71b opposite the center of the first bottom wall 51b, the intake port 54 is connected to waste liquid passages 76a to 76d provided on the underside of the second bottom wall 71b.

[0064] The intake port 54 has a convex shape that protrudes from the lower surface of the first bottom wall 51b of the main body. The intake port 54 extends from the center of the first bottom wall 51b along the radial direction of the first bottom wall 51b beyond the outer circumferential surface of the first side wall 51a. The intake port 54 is connected to one end of a tube 39, the other end of which is connected to the waste liquid tank 35. The intake port 54 is thereby connected to the waste liquid tank 35 by the tube 39. A suction pump 36 is provided in the tube 39a between the intake port 54 and the waste liquid tank 35.

[0065] Furthermore, the fixing member 50 has waste liquid ports. The waste liquid ports include a first waste liquid port 55a and a second waste liquid port 55b. The waste liquid ports 55a and 55b are cylindrical, penetrate the first side wall 51a, and open to the inner circumferential surface of the first side wall 51a.

[0066] The first waste liquid port 55a has a convex shape that protrudes from the outer peripheral surface of the first side wall 51a and is connected to one end of a tube 39. The other end of the tube 39 is connected to the first cap 31a, so that the first waste liquid port 55a is in communication with the first cap 31a via the tube 39. The second waste liquid port 55b has a convex shape that protrudes from the outer peripheral surface of the first side wall 51a and is connected to one end of the tube 39. The other end of the tube 39 is connected to the second cap 31b, so that the second waste liquid port 55b is in communication with the second cap 31b via the tube 39.

[0067] Furthermore, the fixing member 50 has an exhaust port 57. The exhaust port 57 is cylindrical, penetrates the first side wall 51a of the main body, and opens to the inner circumferential surface of the first side wall 51a. The exhaust port 57 has a convex shape that protrudes from the outer circumferential surface of the first side wall 51a, and is connected to one end of a tube 39. The other end of the tube 39 is connected to the exhaust cap 33c, so that the exhaust port 57 communicates with the exhaust cap 33c via the tube 39.

[0068] Furthermore, the fixing member 50 has an atmospheric port 56. The atmospheric port 56 is cylindrical, penetrates the first side wall 51a of the main body, and opens to the inner circumferential surface of the first side wall 51a. The atmospheric port 56 has a convex shape that protrudes from the outer circumferential surface of the first side wall 51a, and is connected to one end of a tube 39. The tube 39 is connected to a waste liquid tank 35, which is open to the atmosphere. When an intake port 54 provided in the tube 39 is open to the atmosphere, the atmospheric port 56 is open to the atmosphere via the tube 39 and the waste liquid tank 35.

[0069] The waste liquid ports 55a, 55b, exhaust port 57, and atmosphere port 56 are disposed vertically below the cleaning liquid upstream ports 52a, 52b and cleaning liquid downstream ports 53a, 53b. The ports 55a to 57 open to the inner circumferential surface of the first side wall 51a at different positions in the circumferential direction of the first side wall 51a. The waste liquid passages 76a to 76d of the flow path member 70 open to the outer circumferential surface of the second side wall 71a at different positions in the circumferential direction of the second side wall 71a.

[0070] The rotating member 60 and the flow path member 70 rotate relative to the fixed member 50 while the inner circumferential surface of the first side wall 51a and the outer circumferential surface of the second side wall 71a face each other. This changes the state of communication between the ports 55a-57 and the waste liquid passages 76a-76d. Note that while the state of communication between one opening of each of the waste liquid passages 76a-76d and the ports 55a-57 changes as the rotating member 60 rotates, the other opening of each of the waste liquid passages 76a-76d remains in communication with the intake port 54 regardless of the rotation of the rotating member 60.

[0071] 5B, 7A, and 7B, the opening of the second waste liquid passage 76b faces the opening of the first waste liquid port 55a in the radial direction of the flow path member 70. This allows the second waste liquid passage 76b to communicate with the first waste liquid port 55a. Therefore, the first cap 31a is connected to the waste liquid tank 35 via the tube 39, the first waste liquid port 55a, the second waste liquid passage 76b, and the intake port 54.

[0072] 5B, 9A, and 9B, the opening of the third waste liquid passage 76c faces the opening of the second waste liquid port 55b in the radial direction of the flow path member 70. This places the third waste liquid passage 76c in communication with the second waste liquid port 55b. Therefore, the second cap 31b is in communication with the waste liquid tank 35 via the tube 39, the second waste liquid port 55b, the third waste liquid passage 76c, and the intake port 54.

[0073] 5B and 10A, the opening of the fourth waste liquid passage 76d faces the opening of the atmosphere port 56 in the radial direction of the flow path member 70. This allows the fourth waste liquid passage 76d to communicate with the atmosphere port 56. Therefore, the waste liquid tank 35 is communicated with the waste liquid tank 35 via the tube 39, the atmosphere port 56, the fourth waste liquid passage 76d, and the intake port 54.

[0074] 5B and 11B, the opening of the fourth waste liquid passage 76d faces the opening of the exhaust port 57 in the radial direction of the flow path member 70. This allows the fourth waste liquid passage 76d to communicate with the exhaust port 57. Therefore, the exhaust cap 33c is connected to the waste liquid tank 35 via the tube 39, the exhaust port 57, the fourth waste liquid passage 76d, and the intake port 54.

[0075] 7A and 7B, the dimension B of the second waste liquid passage 76b in the direction perpendicular to the radial direction of the flow path member 70 and the direction parallel to the central axis is equal to or greater than the sum of the dimension C of the first waste liquid port 55a and the dimension D of the first cleaning liquid downstream port 53a (C + D) in the direction perpendicular to the radial direction of the fixing member 50 and the direction parallel to the central axis. For example, the dimension B of the second waste liquid passage 76b is 2.0 mm, and the dimension C of the first waste liquid port 55a and the dimension D of the first cleaning liquid downstream port 53a are each 0.8 mm. Therefore, by rotating the rotating member 60 by, for example, 6°, the state in which the cleaning liquid passage 75 is not communicated with the first cleaning liquid downstream port 53a as shown in FIG. 7A can be changed to the state in which the cleaning liquid passage 75 is communicated with the first cleaning liquid downstream port 53a as shown in FIG. 7B, while maintaining the state in which the second waste liquid passage 76b is communicated with the first waste liquid port 55a.

[0076] 9B and 9C, the dimension E of the third waste liquid passage 76c in the direction perpendicular to the radial direction of the flow path member 70 and the direction parallel to the central axis is equal to or greater than the sum of the dimension F of the second waste liquid port 55b and the dimension G of the second cleaning liquid downstream port 53b (F+G) in the direction perpendicular to the radial direction of the fixing member 50 and the direction parallel to the central axis. For example, the dimension E of the third waste liquid passage 76c is 2.0 mm, and the dimension F of the second waste liquid port 55b and the dimension G of the second cleaning liquid downstream port 53b are each 0.8 mm. Therefore, by rotating the rotating member 60 by, for example, 6°, the cleaning liquid passage 75 can be switched between a state in which the cleaning liquid passage 75 is not connected to the second cleaning liquid downstream port 53b as shown in FIG. 9A and a state in which the cleaning liquid passage 75 is connected to the second cleaning liquid downstream port 53b as shown in FIG. 9B, while maintaining the state in which the third waste liquid passage 76c is connected to the second waste liquid port 55b.

[0077] <Printing process> The control device 40 acquires image data of the image to be printed from the storage unit 42 or the communication interface 43, and executes the printing process based on the image data. In this printing process, the control device 40 executes a pass operation based on partial image data of the image data, and ejects liquid from the nozzles 23a, 23b of the liquid ejection head 20 onto the print medium A while moving the liquid ejection head 20 to the right or left. The control device 40 also executes a transport operation to transport the print medium A forward. In this way, the control device 40 executes the pass operation and transport operation, so that multiple partial images are formed along the front-to-back direction, and an image composed of the multiple partial images is printed on the print medium A.

[0078] <Maintenance processing> The maintenance process for the liquid ejection head 20 is performed by the control device 40 in accordance with the flowchart of Fig. 12. This maintenance process is performed, for example, periodically or in response to a command from an input device or external device that can communicate with the control device 40.

[0079] In the liquid ejection device 10, in a standby state in which no printing process or maintenance process is being performed, the first cap 31a, the second cap 31b, and the exhaust cap 33c are in a capping state. The rotating member 60 is positioned in the standby position shown in FIG. 6. In this standby position, the first waste liquid passage 76a is in communication with the first waste liquid port 55a, and the second waste liquid passage 76b is in communication with the second waste liquid port 55b. The suction pump 36 is open to the atmosphere.

[0080] As a result, the first cap 31a and the second cap 31b are open to the atmosphere via the suction pump 36 and the waste liquid tank 35. This reduces pressure fluctuations within the first cap 31a and the second cap 31b, making it possible to suppress unnecessary liquid ejection from the first nozzle 23a and the second nozzle 23b.

[0081] In the maintenance process, the control device 40 executes a first purge process (step S10). In the first purge process, the control device 40 rotates the rotating member 60 from the standby position to the first purge position shown in FIG. 7A. As a result, the second waste liquid passage 76b is connected to the first waste liquid port 55a and the suction port 54, and the cleaning liquid passage 75 is not connected to the first cleaning liquid upstream port 52a and the first cleaning liquid downstream port 53a. In addition, the other waste liquid passages 76a, 76c, and 76d are not connected to the other ports 55b to 57, and the cleaning liquid passage 75 is not connected to the other ports 52b and 53b. In this case, the first cap 31a is connected to the tube 39a to which the suction pump 36 is provided.

[0082] Then, with the first cap 31a in the capping state and the rotating member 60 positioned at the first purge position, the control device 40 drives the suction pump 36. This causes suction to be applied to the inside of the first cap 31a covering the first ejection surface 21a, and the first liquid is sucked through the first nozzle 23a opening onto the first ejection surface 21a. This first liquid flows from the first cap 31a through the tube 39, the first waste liquid port 55a, the second waste liquid passage 76b, the intake port 54, and the tube 39a in this order, and is then discharged into the waste liquid tank 35 and stored therein. This first purge process discharges the first liquid, which has thickened due to drying, from the first nozzle 23a, thereby reducing ejection failures from the first nozzle 23a.

[0083] After the first purge process is performed, the control device 40 performs a first cleaning process (step S11). In the first cleaning process, the control device 40 rotates the rotatable member 60 from the first purge position to the first cleaning position shown in FIG. 7B. As a result, the second waste liquid passage 76b is connected to the first waste liquid port 55a and the suction port 54, and the cleaning liquid passage 75 is connected to the first cleaning liquid upstream port 52a and the first cleaning liquid downstream port 53a. The other waste liquid passages 76a, 76c, and 76d are not connected to the other ports 55b to 57, and the cleaning liquid passage 75 is not connected to the other ports 52b and 53b. In this case, the first cap 31a is connected to the tube 39a provided with the suction pump 36 and to the cleaning liquid tank 34.

[0084] Then, with the first cap 31a in the capping state and the rotating member 60 in the first cleaning position, the control device 40 drives the suction pump 36. As a result, the inside of the first cap 31a covering the first discharge surface 21a is suctioned, and the space surrounded by the first discharge surface 21a and the first cap 31a becomes negative pressure.

[0085] The diameter of the first nozzle 23a opening to the first discharge surface 21a is smaller than the diameters of the tube 39, the first cleaning liquid upstream port 52a, the first cleaning liquid downstream port 53a, and the cleaning liquid passage 75, which are connected to the first cap 31a. Therefore, the flow path resistance of the first nozzle 23a is high, and the cleaning liquid is more likely to be sucked from the cleaning liquid tank 34 than the first liquid is sucked from the first nozzle 23a into the first cap 31a. In other words, the cleaning liquid is more likely to flow from the cleaning liquid tank 34 into the first cap 31a. Therefore, while the inflow of the first liquid from the first nozzle 23a is suppressed, the cleaning liquid flows from the cleaning liquid tank 34 through the tube 39, the first cleaning liquid upstream port 52a, the cleaning liquid passage 75, the first cleaning liquid downstream port 53a, and the tube 39 in this order, and then flows into the first cap 31a.

[0086] The cleaning liquid then accumulates on the first ejection surface 21a, which is covered by the first cap 31a, and contacts the first ejection surface 21a. For example, if solidified first liquid is present on the first ejection surface 21a, the solidified first liquid on the first ejection surface 21a comes into contact with the cleaning liquid, which has a similar composition, and is therefore easily dissolved in the cleaning liquid. Furthermore, even if deposits on the first ejection surface 21a are insoluble in the cleaning liquid, they can be transferred from the first ejection surface 21a to the cleaning liquid. In other words, the cleaning liquid cleans the first ejection surface 21a. The cleaning liquid then flows from the first cap 31a through the tube 39, the first waste liquid port 55a, the second waste liquid passage 76b, the intake port 54, and the tube 39a in this order, and is then discharged into the waste liquid tank 35 and stored there. This first cleaning process removes deposits from the first ejection surface 21a with the cleaning liquid, thereby preventing ejection problems of the first liquid from the first nozzle 23a caused by the deposits.

[0087] After the first cleaning process is performed, the controller 40 performs a first pressure increase process (step S12). In the first pressure increase process, the controller 40 rotates the rotatable member 60 from the first cleaning position to the first pressure increase position shown in Fig. 8A. As a result, the waste liquid passages 76a-76d do not communicate with any of the ports 55a-57, and the cleaning liquid passage 75 does not communicate with any of the ports 52a, 52b, 53a, and 53b.

[0088] Then, with the first cap 31a in the capping state and the rotating member 60 in the first pressurization position, the control device 40 opens the suction pump 36 to the atmosphere. This causes air to flow from the waste liquid tank 35 through the tube 39a in which the suction pump 36 is provided and the intake port 54, and into the waste liquid passages 76a-76d. The pressure in the waste liquid passages 76a-76d then reaches or approaches atmospheric pressure. This may temporarily cause the waste liquid passages 76a-76d to communicate with the second waste liquid port 55b while the flow path member 70 is rotating. Even in this case, it is possible to prevent the second liquid from being unnecessarily sucked through the second nozzle 23b covered by the second cap 31b that is connected to the second waste liquid port 55b.

[0089] After the first pressure increase process is performed, the controller 40 performs a first dry suction process (step S13). In the first dry suction process, the controller 40 rotates the rotating member 60 from the first pressure increase position to the first dry suction position shown in FIG. 8B. As a result, the third waste liquid passage 76c is connected to the first waste liquid port 55a and the suction port 54, and the cleaning liquid passage 75 is not connected to the first cleaning liquid upstream port 52a and the first cleaning liquid downstream port 53a. Furthermore, the other waste liquid passages 76a, 76b, and 76d are not connected to the other ports 55b to 57, and the cleaning liquid passage 75 is not connected to the other ports 52b and 53b. In this case, the first cap 31a is connected to the tube 39a to which the suction pump 36 is provided.

[0090] Then, the control device 40 changes the first cap 31a from the capping state to the uncapping state, and drives the suction pump 36 with the rotating member 60 positioned at the first dry suction position. As a result, the first liquid and cleaning liquid remaining in the first cap 31a, together with air, are discharged from the first cap 31a through the tube 39, the first waste liquid port 55a, the third waste liquid passage 76c, the suction port 54, and the tube 39a into the waste liquid tank 35. This reduces the amount of the first liquid that dries within the first cap 31a, suppresses water absorption from the first liquid in the first nozzle 23a by this dried matter, and prevents the first liquid from drying due to water absorption and resulting poor discharge of the first liquid from the first nozzle 23a.

[0091] After the first dry suction process is performed, the control device 40 performs a second purge process (step S14). In the second purge process, the control device 40 rotates the rotating member 60 from the first dry suction position to the second purge position shown in FIG. 9A. As a result, the third waste liquid passage 76c is connected to the second waste liquid port 55b and the suction port 54, and the cleaning liquid passage 75 is not connected to the second cleaning liquid upstream port 52b and the second cleaning liquid downstream port 53b. Furthermore, the other waste liquid passages 76a, 76b, and 76d are not connected to the other ports 55a, 56, and 57, and the cleaning liquid passage 75 is not connected to the other ports 52a and 53a. In this case, the second cap 31b is connected to the tube 39a to which the suction pump 36 is provided.

[0092] Then, the control device 40 places the second cap 31b in the capping state, and drives the suction pump 36 with the rotating member 60 in the second purge position. This causes suction to be applied to the inside of the second cap 31b covering the second discharge surface 21b, and the second liquid is sucked through the second nozzle 23b opening on the second discharge surface 21b. This second liquid flows from the second cap 31b through the tube 39, the second waste liquid port 55b, the third waste liquid passage 76c, the intake port 54, and the tube 39a in this order, and is then discharged into the waste liquid tank 35 and stored there. This second purge process allows the second liquid, which has thickened due to drying, to be discharged from the second nozzle 23b, thereby reducing discharge problems from the second nozzle 23b.

[0093] After the second purge process is performed, the control device 40 performs a second cleaning process (step S15). In the second cleaning process, the control device 40 rotates the rotatable member 60 from the second purge position to the second cleaning position shown in FIG. 9B. As a result, the third waste liquid passage 76c is connected to the second waste liquid port 55b and the suction port 54, and the cleaning liquid passage 75 is connected to the second cleaning liquid upstream port 52b and the second cleaning liquid downstream port 53b. The other waste liquid passages 76a, 76b, and 76d are not connected to the other ports 55a, 56, and 57, and the cleaning liquid passage 75 is not connected to the other ports 52a and 53a. In this case, the second cap 31b is connected to the tube 39a provided with the suction pump 36 and to the cleaning liquid tank 34.

[0094] Then, with the second cap 31b in the capping state and the rotating member 60 in the second cleaning position, the control device 40 drives the suction pump 36. As a result, the inside of the second cap 31b covering the second discharge surface 21b is suctioned, and the space surrounded by the second discharge surface 21b and the second cap 31b becomes negative pressure.

[0095] The diameter of the second nozzle 23b that opens to this second discharge surface 21b is smaller than the diameters of the tube 39, ports 52b and 53b, and cleaning liquid passage 75 that are connected to the second cap 31b. Therefore, the flow path resistance of the second nozzle 23b is high, and the cleaning liquid is more likely to be sucked from the cleaning liquid tank 34 than the second liquid is sucked from the second nozzle 23b into the second cap 31b. In other words, the cleaning liquid is more likely to flow from the cleaning liquid tank 34 into the second cap 31b. Therefore, while the inflow of the second liquid from the second nozzle 23b is suppressed, the cleaning liquid flows from the cleaning liquid tank 34 through the tube 39, the second cleaning liquid upstream port 52b, the cleaning liquid passage 75, the second cleaning liquid downstream port 53b, and the tube 39 in this order, and then flows into the second cap 31b.

[0096] The cleaning liquid then accumulates on the second ejection surface 21b, which is covered by the second cap 31b, and contacts the second ejection surface 21b. For example, if solidified second liquid is present on the second ejection surface 21b, the solidified second liquid on the second ejection surface 21b comes into contact with the cleaning liquid, which has a similar composition, and is therefore easily dissolved in the cleaning liquid. Furthermore, even if deposits on the second ejection surface 21b are insoluble in the cleaning liquid, they can be transferred from the second ejection surface 21b to the cleaning liquid. In other words, the cleaning liquid cleans the second ejection surface 21b. The cleaning liquid then flows from the second cap 31b through the tube 39, the second waste liquid port 55b, the third waste liquid passage 76c, the intake port 54, and the tube 39a in this order, and is then discharged into the waste liquid tank 35 and stored there. This second cleaning process removes deposits from the second ejection surface 21b with the cleaning liquid, thereby preventing poor ejection of liquid from the second nozzle 23b due to the deposits.

[0097] After the second cleaning process is performed, the controller 40 performs a second pressurization process (step S16). In the second pressurization process, the controller 40 rotates the rotatable member 60 from the second cleaning position to the second pressurization position shown in Fig. 10A. As a result, the fourth waste liquid passage 76d is connected to the atmosphere port 56, the other waste liquid passages 76a to 76c are not connected to the ports 55a, 55b, and 57, and the cleaning liquid passage 75 is not connected to any of the ports 52a, 52b, 53a, and 53b.

[0098] Then, with the second cap 31b in the capping state and the rotating member 60 in the second pressurization position, the control device 40 places the suction pump 36 in an open-to-atmosphere state. This causes air to flow from the waste liquid tank 35 through the tube 39 and the atmospheric port 56 into the waste liquid passages 76a-76d. Air also flows from the waste liquid tank 35 through the tube 39a to which the suction pump 36 is attached and the air intake port 54 into the waste liquid passages 76a-76d. The pressure in the waste liquid passages 76a-76d then reaches or approaches atmospheric pressure. This may temporarily cause the waste liquid passages 76a-76d to communicate with the first waste liquid port 55a while the flow path member 70 is rotating. Even in this case, it is possible to prevent the first liquid from being unnecessarily sucked through the first nozzle 23a covered by the first cap 31a that is connected to the first waste liquid port 55a.

[0099] After the second pressurization process is completed, the controller 40 executes a second dry suction process (step S17). In the second dry suction process, the controller 40 rotates the rotating member 60 from the second pressurization position to the second dry suction position shown in FIG. 10B. As a result, the fourth waste liquid passage 76d is connected to the second waste liquid port 55b and the suction port 54, the other waste liquid passages 76a-76c are not connected to the other ports 55a, 56, and 57, and the cleaning liquid passage 75 is not connected to the ports 52a, 52b, 53a, and 53b. In this case, the second cap 31b is connected to the tube 39a to which the suction pump 36 is attached.

[0100] Then, the control device 40 changes the second cap 31b from the capping state to the uncapping state, and drives the suction pump 36 with the rotating member 60 positioned at the second dry suction position. As a result, the second liquid and cleaning liquid remaining in the second cap 31b, together with air, are discharged from the second cap 31b through the tube 39, the second waste liquid port 55b, the fourth waste liquid passage 76d, and the tube 39a into the waste liquid tank 35. This reduces the amount of the second liquid that dries within the second cap 31b, suppresses water absorption from the second liquid in the second nozzles 23b due to this dried matter, and prevents the second liquid from drying due to water absorption and resulting poor discharge of the second liquid from the second nozzles 23b.

[0101] After the second dry suction process is performed, the control device 40 performs an exhaust purge process (step S18). In the exhaust purge process, the control device 40 rotates the rotating member 60 from the second dry suction position to the exhaust purge position shown in FIG. 11A. As a result, the second waste liquid passage 76b is connected to the exhaust port 57 and the intake port 54, the other waste liquid passages 76a, 76c, and 76d are not connected to the other ports 55a, 55b, and 56, and the cleaning liquid passage 75 is not connected to the ports 52a, 52b, 53a, and 53b. In this case, the exhaust cap 33c is connected to the tube 39a to which the suction pump 36 is attached.

[0102] The control device 40 then places the exhaust cap 33c in the capping state, positions the rotating member 60 in the exhaust purge position, and drives the suction pump 36. As a result, as shown in FIGS. 3 and 11A, the inside of the exhaust cap 33c covering the exhaust surface 33b1 is suctioned, creating a negative pressure in the space surrounded by the exhaust surface 33b1 and the exhaust cap 33c. The exhaust path 33a opening to the exhaust surface 33b1 sucks in air bubbles accumulated in the upper part of the buffer tank 13. The air bubbles then flow from the buffer tank 13 through the exhaust path 33a, the exhaust cap 33c, the tube 39, the exhaust port 57, the second waste liquid passage 76b, the intake port 54, and the tube 39a, and are discharged into the waste liquid tank 35. This exhaust purge process discharges air bubbles from the liquid ejection head 20, thereby reducing ejection defects from the liquid ejection head 20 caused by air bubbles.

[0103] After the exhaust purge process is performed, the control device 40 performs an exhaust empty suction process (step S19). In the exhaust empty suction process, the control device 40 rotates the rotating member 60 from the exhaust pressure boost position to the exhaust empty suction position shown in FIG. 11B. As a result, the fourth waste liquid passage 76d is connected to the exhaust port 57 and the intake port 54, the other waste liquid passages 76a-76c are not connected to the other ports 55a, 55b, and 56, and the cleaning liquid passage 75 is not connected to the ports 52a, 52b, 53a, and 53b. In this case, the exhaust cap 33c is connected to the tube 39a to which the suction pump 36 is attached.

[0104] Then, the control device 40 changes the exhaust cap 33c from the capping state to the uncapping state, and with the rotating member 60 positioned at the exhaust / empty suction position, drives the suction pump 36. As a result, the liquid that was discharged from the liquid discharge head 20 together with the air bubbles and remained in the exhaust cap 33c is discharged together with the air from the exhaust cap 33c through the tube 39, the exhaust port 57, the fourth waste liquid passage 76d, the suction port 54, and the tube 39a into the waste liquid tank 35.

[0105] <Variation 1> In the liquid ejection device 10 according to the first modification, the control device 40 further executes a first preliminary cleaning process and a second preliminary cleaning process in addition to the above-described embodiment. For example, the control device 40 executes a maintenance process according to the flowchart shown in FIG. 13. In the flowchart of FIG. 13, the first preliminary cleaning process in step S20 is executed before the first purge process in step S10 in the flowchart of FIG. 12. Also, in the flowchart of FIG. 13, the second preliminary cleaning process in step S21 is executed before the second purge process in step S14 in the flowchart of FIG. 12.

[0106] Specifically, the control device 40 executes a first preliminary cleaning process (S20) before executing the first purging process (step S10). In the first preliminary cleaning process, the control device 40 rotates the rotating member 60 from the standby position shown in FIG. 6 to the first cleaning position shown in FIG. 7B. Then, with the first cap 31a in the capping state and the rotating member 60 at the first cleaning position, the control device 40 drives the suction pump 36. As a result, the inside of the first cap 31a covering the first discharge surface 21a is suctioned, and a negative pressure is created in the space surrounded by the first discharge surface 21a and the first cap 31a.

[0107] Therefore, the cleaning liquid flows from the cleaning liquid tank 34 through the first cleaning liquid upstream port 52a, the cleaning liquid passage 75, and the first cleaning liquid downstream port 53a in this order, and then into the first cap 31a. The cleaning liquid then flows from the first cap 31a through the first waste liquid port 55a, the second waste liquid passage 76b, and the intake port 54 in this order, and is then discharged into the waste liquid tank 35. This first preliminary cleaning process causes the cleaning liquid to adhere to the inside of the first cap 31a and the waste liquid flow path, which includes the first waste liquid port 55a, the second waste liquid passage 76b, and the intake port 54. Since the cleaning liquid is already adhered to the inside of the first cap 31a and the waste liquid flow path, the cleaning liquid is scattered throughout the first cap 31a and the waste liquid flow path, and when the first liquid comes into contact with the cleaning liquid, the first liquid is diluted by the cleaning liquid. By diluting the first liquid, the first liquid becomes less likely to solidify, and therefore the first liquid can be made less likely to solidify in the first cap 31a and the waste liquid flow path.

[0108] Therefore, even if the first liquid is sucked into the first cap 31a by performing the first purge process (step S10) after the first preliminary cleaning process, the first liquid is not stuck in the first cap 31a or the waste liquid flow path, and is easily discharged from the first cap 31a via the waste liquid flow path. Note that the first liquid may be discharged from the first cap 31a without being accumulated on the first ejection surface 21a in the first cap 31a. This allows the time required for the first preliminary cleaning process to be shortened.

[0109] Furthermore, the control device 40 performs a second preliminary cleaning process (S21) after the first empty suction process (step S13) and before the second purging process (step S14). In the second preliminary cleaning process, the control device 40 rotates the rotating member 60 from the standby position to the second cleaning position shown in FIG. 9B. Then, with the second cap 31b in the capping state and the rotating member 60 at the second cleaning position, the control device 40 drives the suction pump 36. As a result, the inside of the second cap 31b covering the second discharge surface 21b is suctioned, and a negative pressure is created in the space surrounded by the second discharge surface 21b and the second cap 31b.

[0110] Therefore, the cleaning liquid flows from the cleaning liquid tank 34 through the second cleaning liquid upstream port 52b, the cleaning liquid passage 75, and the second cleaning liquid downstream port 53b in this order, and then into the second cap 31b. The cleaning liquid then flows from the second cap 31b through the second waste liquid port 55b, the third waste liquid passage 76c, and the intake port 54 in this order, and is then discharged into the waste liquid tank 35. This second preliminary cleaning process causes the cleaning liquid to adhere to the inside of the second cap 31b and the waste liquid flow path, which includes the second waste liquid port 55b, the third waste liquid passage 76c, and the intake port 54. As a result of the cleaning liquid being pre-adhered to the inside of the second cap 31b and the waste liquid flow path, the cleaning liquid is scattered throughout the second cap 31b and the waste liquid flow path, and when the second liquid comes into contact with the cleaning liquid, the second liquid is diluted by the cleaning liquid. By diluting the second liquid, the second liquid becomes less likely to solidify, and therefore the second liquid can be made less likely to solidify in the second cap 31b and the waste liquid flow path.

[0111] Therefore, even if the second liquid is sucked into the second cap 31b by the execution of the second purge process (step S14) after the execution of the second preliminary cleaning process, the second liquid is not stuck in the second cap 31b or the waste liquid flow path, and is easily discharged from the second cap 31b via the waste liquid flow path. Note that the second liquid may be discharged from the second cap 31b without being accumulated in the second cap 31b up to the second ejection surface 21b. This allows the time for the second preliminary cleaning process to be shortened.

[0112] <Variation 2> In the liquid discharger 10 according to the second modification, the suction pump 36 performs suction with a first suction force or a second suction force that is greater than the first suction force. For example, as shown in FIG. 2, the suction pump 36 has a pump motor 36a. The suction force of the suction pump 36 can be increased by increasing the rotational speed of the pump motor 36a. The rotational speed of the pump motor 36a is controlled by the control device 40. The control device 40 drives the pump motor 36a at the first rotational speed, causing the suction pump 36 to perform suction with the first suction force. The control device 40 also drives the pump motor 36a at a second rotational speed that is greater than the first rotational speed, causing the suction pump 36 to perform suction with the second suction force that is greater than the first suction force.

[0113] When executing the first preliminary cleaning process in step S20 in the example flowchart of FIG. 13, the control device 40 drives the pump motor 36a at a first rotational angle and causes the suction pump 36 to perform suction with a first suction force. This causes cleaning liquid to flow from the cleaning liquid tank 34 into the first cap 31a, clean the first cap 31a, and then be discharged into the waste liquid tank 35. This cleaning liquid does not contain solids and has a lower viscosity than the first liquid, which does contain solids. Therefore, power consumption can be reduced by driving the pump motor 36a at a small first rotational angle, while the suction pump 36 can suction the cleaning liquid at a small first suction force to clean the first cap 31a.

[0114] Furthermore, when performing the first purge process in step S10 after step S20, the control device 40 drives the pump motor 36a at a second rotational speed and causes the suction pump 36 to perform suction with a second suction force. The first liquid contains solids, including resin particles and solid colorant. For example, the first liquid contains resin particles in a range of 0.1 wt% to 30 wt% and solid colorant in a range of 0.1 wt% to 20 wt%. The viscosity of the first liquid is higher than that of the cleaning liquid. Even in such a case, the suction pump 36 can suck the first liquid from the first nozzle 23a into the first cap 31a and discharge it from the first cap 31a into the waste liquid tank 35 by suction with the second, larger suction force.

[0115] Furthermore, when performing the second preliminary cleaning process in step S21, the control device 40 drives the pump motor 36a at a first rotational angle and causes the suction pump 36 to perform suction with a first suction force. This causes the cleaning liquid to flow from the cleaning liquid tank 34 into the second cap 31b, clean the second cap 31b, and then be discharged into the waste liquid tank 35. This cleaning liquid does not contain solids and has a lower viscosity than the second liquid, which does contain solids. Therefore, power consumption can be reduced by driving the pump motor 36a at a small first rotational angle, while the suction pump 36 can suction the cleaning liquid at a small first suction force to clean the second cap 31b.

[0116] Furthermore, when performing the second purge process in step S14 after step S21, the control device 40 drives the pump motor 36a at a second rotational speed and causes the suction pump 36 to perform suction with a second suction force. The second liquid contains solids, including resin particles and solid colorant. For example, the second liquid contains resin particles in a range of 0.1 wt% to 30 wt% and solid colorant in a range of 0.1 wt% to 20 wt%. The viscosity of the second liquid is higher than that of the cleaning liquid. Even in such a case, the second liquid can be sucked from the second nozzle 23b to the second cap 31b by the suction of the suction pump 36 with a larger second suction force, and then discharged from the second cap 31b to the waste liquid tank 35.

[0117] <Other variations> In the above-described embodiment and Modification 1, the waste liquid passages 76a to 76d are opened to the atmosphere via the intake port 54 during the first pressure increase process, and the waste liquid passages 76a to 76d are opened to the atmosphere via the atmosphere port 56 during the second pressure increase process. However, the method of opening the waste liquid passages 76a to 76d to the atmosphere during the first pressure increase process and the second pressure increase process is not limited to this. For example, the waste liquid passages 76a to 76d may be opened to the atmosphere via the atmosphere port 56 during the first pressure increase process, and the waste liquid passages 76a to 76d may be opened to the atmosphere via the intake port 54 during the second pressure increase process. Furthermore, the waste liquid passages 76a to 76d may be opened to the atmosphere via the intake port 54 during both the first pressure increase process and the second pressure increase process, or the waste liquid passages 76a to 76d may be opened to the atmosphere via the atmosphere port 56.

[0118] In the above-described embodiment and modified examples, an on-off valve 33d that opens and closes the exhaust path 33a may be provided in the exhaust body 33b. In this case, a cam 61a that opens and closes the on-off valve 33d may be provided in the gear portion 61 of the rotating member 60. When the cam 61a rotates due to the rotation of the rotating member 60 and the on-off valve 33d closes, the exhaust path 33a is blocked. This prevents the air from entering the buffer tank 13 and the liquid ejection head 20 via the exhaust path 33a.

[0119] Meanwhile, when the rotation of the rotary member 60 rotates the cam 61a and opens the on-off valve 33d, the exhaust passage 33a is opened. As a result, in a capping state in which the exhaust surface 33b1 where the exhaust passage 33a opens is covered by the exhaust cap 33c, the buffer tank 13 and the exhaust cap 33c are in communication with each other via the exhaust passage 33a. The exhaust cap 33c is in communication with the tube 39a to which the suction pump 36 is attached. Therefore, by driving the suction pump 36, an exhaust purge process is performed. This exhaust purge process can reduce the amount of waste liquid discharged while shortening the processing time compared to a bubble discharge method that uses liquid suction. Furthermore, since the cam 61a is provided on the rotary member 60, the on-off valve 33d can be opened and closed while changing the communication state between the ports 52a-53b, 55a-57 and the cleaning liquid passage 75 and the waste liquid passages 76a-76d. [Explanation of symbols]

[0120] 10:Liquid discharge device 20: Liquid ejection head 23a: First nozzle (nozzle) 23b: Second nozzle (nozzle) 21a: 1st discharge surface (discharge surface) 21b: Second discharge surface (discharge surface) 31a: 1st Cap (Cap) 31b: Second cap (cap) 34: Cleaning liquid tank 36: Suction pump 37: Switching valve 38: Rotating device 39: Tube 39a: Tube 40: Control device 50: Fixing member 51: First body (body) 52a: First cleaning fluid upstream port (cleaning fluid upstream port) 52b: Second cleaning fluid upstream port (cleaning fluid upstream port) 53a: First cleaning fluid downstream port (cleaning fluid downstream port) 53b: Second cleaning liquid downstream port (cleaning liquid downstream port) 54: Intake port 60: Rotating member 64: First cleaning fluid passage 70: Flow path member 74: Second cleaning fluid passage 75: Cleaning fluid passage 76a: First waste liquid passage (waste liquid passage) 76b: Second waste liquid passage (waste liquid passage) 76c: Third waste passage (waste passage) 76d: 4th waste liquid passage (waste liquid passage)

Claims

1. a liquid ejection head having an ejection surface on which nozzles are opened; a cap that covers the ejection surface; A suction pump; a cleaning liquid tank for storing a cleaning liquid; a switching valve having a fixed member, a rotating member, and a flow path member; Equipped with The fixing member is a main body supporting the flow path member; a cleaning liquid upstream port having a convex shape protruding from the main body and communicating with the cleaning liquid tank via a tube; a downstream port for cleaning liquid and a waste port, each having a convex shape protruding from the main body and connected to the cap via a tube; an intake port having a convex shape protruding from the main body and communicating with a tube provided with the suction pump; and The rotating member is Rotating relative to the fixed member, a first cleaning fluid passage; The flow path member is a rotating member attached to the rotating member and rotating together with the rotating member relative to the fixed member; a second cleaning liquid passage connected to the first cleaning liquid passage and forming a cleaning liquid passage communicating between the cleaning liquid upstream port and the cleaning liquid downstream port; a waste liquid passage communicating between the waste liquid port and the intake port; having Liquid discharge device.

2. the nozzles include a first nozzle that ejects a first liquid and a second nozzle that ejects a second liquid; the ejection surface includes a first ejection surface and a second ejection surface, the caps include a first cap that covers the first ejection surface and a second cap that covers the second ejection surface; the cleaning liquid upstream port includes a first cleaning liquid upstream port and a second cleaning liquid upstream port that are in communication with the cleaning liquid tank; the cleaning liquid downstream port includes a first cleaning liquid downstream port communicating with the first cap and a second cleaning liquid downstream port communicating with the second cap; the waste liquid port includes a first waste liquid port communicating with the first cap and a second waste liquid port communicating with the second cap; The liquid ejection device according to claim 1 .

3. the rotating member is disposed at a first cleaning position where the waste liquid passage is communicated with the first waste liquid port and the intake port, and the cleaning liquid passage is communicated with the first cleaning liquid upstream port and the first cleaning liquid downstream port; The liquid ejection device according to claim 2 .

4. the rotating member is disposed at a first purge position where the waste liquid passage is communicated with the first waste liquid port and the intake port, and the cleaning liquid passage is not communicated with the first cleaning liquid upstream port and the first cleaning liquid downstream port; The liquid ejection device according to claim 2 .

5. a dimension of the waste liquid passage in a direction perpendicular to the radial direction of the flow path member is equal to or greater than a sum of a dimension of the first waste liquid port and a dimension of the first cleaning liquid downstream port in a direction perpendicular to the radial direction of the fixing member; The liquid ejection device according to claim 2 .

6. the rotating member is disposed at a second cleaning position where the waste liquid passage is communicated with the second waste liquid port and the intake port, and the cleaning liquid passage is communicated with the second cleaning liquid upstream port and the second cleaning liquid downstream port; The liquid ejection device according to claim 2 .

7. the rotating member is disposed at a second purge position where the waste liquid passage is communicated with the second waste liquid port and the intake port, and the cleaning liquid passage is not communicated with the second cleaning liquid upstream port and the second cleaning liquid downstream port. The liquid ejection device according to claim 2 .

8. a dimension of the waste liquid passage in a direction perpendicular to the radial direction of the flow path member is equal to or greater than a sum of a dimension of the second waste liquid port and a dimension of the second cleaning liquid downstream port in a direction perpendicular to the radial direction of the fixing member; The liquid ejection device according to claim 2 .

9. a rotation device that rotates the rotation member relative to the fixed member; a control device; The control device a first cleaning process is performed by driving the suction pump while the rotating member is disposed at the first cleaning position, to clean the first ejection surface covered by the first cap; The liquid ejection device according to claim 3 .

10. The control device before the first cleaning process is performed, the rotary member is placed at a first purge position where the waste liquid passage is connected to the first waste liquid port and the suction port and the cleaning liquid passage is not connected to the first cleaning liquid upstream port and the first cleaning liquid downstream port, and the suction pump is driven to perform a first purge process in which the inside of the first cap covering the first ejection surface is sucked; before the first purge process is performed, the suction pump is driven with the rotating member disposed at the first cleaning position to perform a first preliminary cleaning process in which a cleaning liquid is applied in advance to the first cap covering the first ejection surface; The liquid ejection device according to claim 9 .

11. the first liquid contains solids, the solid content includes resin fine particles and solid content of a colorant, the resin fine particles are contained in the first liquid in a range of 0.1 wt % to 30 wt %; the solid content of the coloring material is contained in the first liquid in a range of 0.1 wt % to 20 wt %; The cleaning liquid does not contain the solid content, the suction pump suctions with a first suction force or a second suction force that is greater than the first suction force; The control device before the first cleaning process is performed, the rotary member is placed at a first purge position where the waste liquid passage is connected to the first waste liquid port and the suction port and the cleaning liquid passage is not connected to the first cleaning liquid upstream port and the first cleaning liquid downstream port, and the suction pump is driven to perform a first purge process in which the inside of the first cap covering the first ejection surface is sucked; before the first purge process is performed, the suction pump is driven with the rotating member disposed at the first cleaning position to perform a first preliminary cleaning process in which the first cap covering the first ejection surface is cleaned; the suction pump performs suction with the first suction force when the first preliminary cleaning process is performed, and performs suction with the second suction force when the first purging process is performed. The liquid ejection device according to claim 9 .

12. a rotation device that rotates the rotation member relative to the fixed member; a control device; The control device a second cleaning process is performed by driving the suction pump while the rotating member is disposed at the second cleaning position, to clean the second ejection surface covered by the second cap; The liquid ejection device according to claim 6 .

13. The control device before the second cleaning process is performed, the rotary member is placed at a second purge position where the waste liquid passage is connected to the second waste liquid port and the suction port and the cleaning liquid passage is not connected to the second cleaning liquid upstream port and the second cleaning liquid downstream port, and the suction pump is driven to perform a second purge process in which the inside of the second cap covering the second ejection surface is sucked, before the second purge process is performed, the suction pump is driven with the rotating member disposed at the second cleaning position to perform a second preliminary cleaning process in which a cleaning liquid is applied in advance to the second cap covering the second ejection surface. The liquid ejection device according to claim 12.

14. the second liquid contains solids, the solid content includes resin fine particles and solid content of a colorant, the resin fine particles are contained in the second liquid in a range of 0.1 wt % to 30 wt %; the solid content of the coloring material is contained in the second liquid in a range of 0.1 wt % to 20 wt %; The cleaning liquid does not contain the solid content, the suction pump suctions with a first suction force or a second suction force that is greater than the first suction force; The control device before the second cleaning process is performed, the rotary member is placed at a second purge position where the waste liquid passage is connected to the second waste liquid port and the suction port and the cleaning liquid passage is not connected to the second cleaning liquid upstream port and the second cleaning liquid downstream port, and the suction pump is driven to perform a second purge process in which the inside of the second cap covering the second ejection surface is sucked, before the second purge process is performed, the suction pump is driven with the rotating member disposed at the second cleaning position to perform a second preliminary cleaning process in which the second cap covering the second ejection surface is cleaned; the suction pump performs suction with the first suction force when the second preliminary cleaning process is performed, and performs suction with the second suction force when the second purging process is performed. The liquid ejection device according to claim 12.

15. a liquid ejection head having an ejection surface on which nozzles are opened; a cap that covers the ejection surface; A suction pump; a cleaning liquid tank for storing a cleaning liquid; a switching valve having a fixed member, a rotating member, and a flow path member; Equipped with The fixing member is Rotating relative to the fixed member, a main body supporting the flow path member; the cleaning liquid upstream port has a convex shape protruding from the main body and is connected to the cleaning liquid tank via a tube; the cleaning liquid downstream port and a waste liquid port have a convex shape protruding from the main body and are connected to the cap via a tube; and the cleaning liquid downstream port and a waste liquid port have a convex shape protruding from the main body and are connected to the cap via a tube; and the cleaning liquid downstream port has a convex shape protruding from the main body and is connected to a tube provided with the suction pump; The rotating member is Rotating relative to the fixed member, a first cleaning fluid passage; The flow path member is a rotating member attached to the rotating member and rotating together with the rotating member relative to the fixed member; a second cleaning liquid passage connected to the first cleaning liquid passage and forming a cleaning liquid passage communicating between the cleaning liquid upstream port and the cleaning liquid downstream port; a waste liquid passage communicating between the waste liquid port and the intake port; A method for controlling a liquid ejection device, comprising: The rotation of the rotary member changes the communication state between the port and the cleaning liquid passage and the waste liquid passage. A method for controlling a liquid ejection device.

16. a liquid ejection head having an ejection surface on which nozzles are opened; a cap that covers the ejection surface; A suction pump; a cleaning liquid tank for storing a cleaning liquid; a switching valve having a fixed member, a rotating member, and a flow path member; Equipped with The fixing member is Rotating relative to the fixed member, a main body supporting the flow path member; the cleaning liquid upstream port has a convex shape protruding from the main body and is connected to the cleaning liquid tank via a tube; the cleaning liquid downstream port and a waste liquid port have a convex shape protruding from the main body and are connected to the cap via a tube; and the cleaning liquid downstream port and a waste liquid port have a convex shape protruding from the main body and are connected to the cap via a tube; and the cleaning liquid downstream port has a convex shape protruding from the main body and is connected to a tube provided with the suction pump; The rotating member is Rotating relative to the fixed member, a first cleaning fluid passage; The flow path member is a rotating member attached to the rotating member and rotating together with the rotating member relative to the fixed member; a second cleaning liquid passage connected to the first cleaning liquid passage and forming a cleaning liquid passage communicating between the cleaning liquid upstream port and the cleaning liquid downstream port; a waste liquid passage communicating between the waste liquid port and the intake port; The liquid ejection device includes: The rotation of the rotary member changes the communication state between the port and the cleaning liquid passage and the waste liquid passage. program.

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