Cover device

Abstract

A cap device is provided that can suppress the enlargement of a liquid ejecting device by using a single cap to accommodate and discharge liquid ejected from a nozzle and to humidify the nozzle. The cap device (50) is a cap device that, when in contact with a liquid ejecting head (21) having a nozzle (22) for ejecting liquid, can form a space (SP) surrounding an opening (22a) of the nozzle. The cap device includes a unit cap (51a) as an example of a cap, the unit cap having: a recess (57) that forms the space (SP); a humidifying chamber (55) having an inlet (55a) for inflow of a humidifying fluid (L1a) for humidifying the space and an outlet (55b) for outflow of the humidifying fluid; and a first moisture-permeable membrane (54) that is an example of a partition wall that divides the recess and the humidifying chamber and has air permeability. The recess has a discharge hole (56b) that is an example of a hole that can discharge liquid ejected from the liquid ejecting head into the unit cap as an example of a cap.

Description

Technical Field

[0001] The present invention relates to a cap device used in a liquid ejecting device for ejecting liquid into a medium. Background Art

[0002] Patent Document 1 discloses a liquid ejection device, one example of which includes a cap mechanism that contacts the liquid ejection head to form a space surrounding the nozzle and is used to expel thickened liquid and bubbles within the liquid ejection head by suction. Furthermore, the liquid ejection device includes a cap device that contacts the liquid ejection head to form a space surrounding the nozzle and is used to supply a moisturizing liquid, an example of a humidifying fluid, from a moisturizing liquid reservoir, an example of a humidifying fluid storage unit, through a connecting flow path, thereby humidifying the nozzle. Specifically, a liquid ejection device is disclosed that includes the cap mechanism and the cap device for maintenance purposes, thereby preventing nozzle clogging and suppressing nozzle drying.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-38159

[0004] In the liquid ejecting device described in Patent Document 1, the liquid ejecting head is moved from the ejecting area where printing is performed on the medium to a maintenance area outside the ejecting area for maintenance. Specifically, the cap of the capping mechanism and the cap of the capping device are arranged side by side in the direction of movement of the liquid ejecting head in the maintenance area. Consequently, the space required to accommodate both caps increases the size of the liquid ejecting device. Summary of the Invention

[0005] A cover device that solves the above-mentioned problem is a cover device that can form a space surrounding the opening of a liquid ejecting head having a nozzle for ejecting liquid when it comes into contact with the liquid ejecting head, the cover device comprising a cover, the cover having: a recess that forms the space; a humidifying chamber that has an inlet for a humidifying fluid for humidifying the space and an outlet for the humidifying fluid to flow out; and a partition wall that divides the recess and the humidifying chamber and is air-permeable, the recess having a hole that can discharge the liquid discharged from the liquid ejecting head into the cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is a perspective view showing the liquid ejecting device in the first embodiment.

[0007] Figure 2 It is a schematic diagram showing the arrangement of components around the liquid ejecting head.

[0008] Figure 3 is Figure 2 Schematic front view of the components viewed from the direction along the ejection direction.

[0009] Figure 4 is Figure 2 Schematic front view of the components viewed from the direction along the first conveying direction.

[0010] Figure 5 is Figure 3 Exploded perspective view of the unit cover viewed from above.

[0011] Figure 6 is Figure 3 Exploded perspective view of the unit cover viewed diagonally from below.

[0012] Figure 7 is Figure 5 FIG. 7 is a top view of the humidification chamber as viewed from the direction along the ejection direction.

[0013] Figure 8 It is a schematic diagram of the main cross-sectional view of the unit cover.

[0014] Figure 9 It is indicated by arrows Figure 8 Schematic diagram of the flow of liquid in.

[0015] Figure 10 It is indicated by arrows Figure 8 Schematic diagram of the gas flow in .

[0016] Figure 11 It is a schematic diagram showing the structure of the cover device.

[0017] Figure 12 This is a block diagram showing the electrical structure of the liquid ejecting device.

[0018] Figure 13 Schematic diagram showing the state of the humidification fluid during the circulation operation.

[0019] Figure 14 It is a flowchart showing the loop operation.

[0020] Figure 15 Schematic diagram showing the state of the humidification fluid when the concentration adjustment operation is performed.

[0021] Figure 16 This is a flow chart showing the concentration adjustment operation.

[0022] Figure 17 Schematic diagram showing the state of the humidification fluid when the cap replacement preparation operation is performed.

[0023] Figure 18 This is a flowchart showing the cap replacement preparation operation.

[0024] Figure 19It is a schematic diagram showing the state of the humidification fluid when the operation before the moisture storage unit replacement is performed.

[0025] Figure 20 This is a flowchart showing the operation before the moisture storage unit is replaced.

[0026] Figure 21 Schematic diagram showing the state of the humidification fluid when the humidification fluid filling operation is performed.

[0027] Figure 22 This is a flowchart showing the humidification fluid filling operation.

[0028] Figure 23 It is a perspective view showing a liquid ejecting device in a second embodiment.

[0029] Figure 24 Yes Figure 23 Schematic diagram of the outline structure of the liquid ejection device.

[0030] Figure 25 is Figure 24 Schematic diagram of cleaning performed in the liquid ejection device.

[0031] Figure 26 is Figure 24 Schematic diagram of performing pressure wiping in a liquid ejection device.

[0032] Figure 27 yes Figure 24 Schematic diagram of the hydraulic adjustment mechanism and valve opening mechanism of the liquid ejection device.

[0033] Figure 28 Yes Figure 24 A schematic diagram showing the schematic structure of a suction mechanism of a liquid ejecting device.

[0034] Figure 29 yes Figure 24 Block diagram of a liquid ejection device.

[0035] Figure 30 This is a schematic diagram showing the general configuration of a suction mechanism of a liquid ejection device according to a third embodiment.

[0036] Figure 31 This is a schematic diagram showing the general structure of a suction mechanism of a liquid ejection device according to a fourth embodiment.

[0037] Figure 32 It is a schematic diagram showing a modified example of the liquid ejection device of the second embodiment.

[0038] Description of reference numerals:

[0039] 11…Liquid ejection device, 12…Main unit, 13…Image reading unit, 14…Automatic feed unit, 15…Operation unit, 16…Media storage unit, 17…Loading unit, 17a…Loading surface, 19…Conveyance path, 20…Recording unit, 21…Liquid ejection head, 21a…Unit ejection head, 21b…Nozzle array, 22…Nozzle, 22a…Opening, 23…Nozzle surface, 24…Head unit, 25…Support unit, 40…Wiper device, 41…Wiper carriage, 42…Wiper member, 43…Waste liquid outflow port, 50…Cap device, 51…Cap unit, 51a…Unit cap as an example of a cap, 52…Restriction member, 52a…Restriction surface, 52b…Communication hole, 52c…Positioning engagement portion, 53…Absorbent body , 54…a first moisture-permeable membrane as an example of a partition wall, 54a…a communicating portion, 55…a humidifying chamber, 55a…an inlet, 55b…an outlet, 55c…a groove, 55d…a positioning engaging portion, 55e…a communicating portion, 55f…a communicating hole, 55g…an engaging portion, 55h…a positioning engaging portion, 55i…a groove wall, 55j…a communicating hole, 56…a housing, 56a…an atmosphere communicating hole, 56b…an exhaust hole as an example of a hole, 56c…an engaged portion, 56d…a positioning engaged portion, 56e…a sealing portion, 56f…a close contact surface, 57…a recessed portion, 58…an atmosphere opening mechanism, 58a…a first atmosphere communicating passage, 58b…a third on-off valve, 59…a retaining portion, 60…a humidifying fluid circulating mechanism, 61…a humidifying fluid storing portion, 61a…Detection unit, 61b…First electrode, 61c…Second electrode, 61d…Second atmosphere communication path, 61e…Second moisture-permeable membrane, 61f…Inflow unit, 61g…Outflow unit, 62…Circulation path, 62a…Supply flow path, 62b…Recovery flow path, 62c…First confluence unit, 62d…Flow rate regulator, 63…First pump as an example of a pump, 64…First check valve, 65…Pressure regulating valve, 66…Water supply unit, 66a…Water storage unit, 66b…Water supply flow path, 66c…First on-off valve as an example of an on-off valve, 66d…Second check valve, 66e…Second confluence unit, 66f…Outflow unit, 67…Pressurized air supply unit, 68…Humidification fluid bag, 68a…Outflow unit, 69… 9...flow regulator, 67a...pressurized air supply path, 67b...second on-off valve, 67c...second pump, 80...waste liquid recovery mechanism, 81...waste liquid recovery path, 81a...first waste liquid recovery path, 81b...second waste liquid recovery path, 82...third pump, 83...buffer chamber, 84...fourth pump, 85...third atmosphere communication path, 86...waste liquid storage portion, 90...control unit, 91...detector group, 94...interface unit, 95...CPU, 96...memory, 97...control circuit, 98...drive circuit, 99...computer, θ1...first predetermined angle, θ2...second predetermined angle, D1...first direction, D2...second direction, D3...third direction, D4...fourth direction, D5...fifth direction, D6...sixth direction,H1…a first predetermined height as an example of a predetermined height, H2…a second predetermined height, L1a…humidified fluid, L1b…water, L2…waste liquid, M…medium, P1…a first predetermined distance, SP…space, T1…a first predetermined time, T2…a second predetermined time, T3…a third predetermined time, T4…a fourth predetermined time, X…width direction, Y…depth direction, Y1…discharge direction, Z1…a first conveying direction, Z…vertical direction, 111…liquid discharge device, 112…nozzle, 112a…nozzle surface, 113…liquid discharge portion, 113a…liquid discharge head, 114…liquid container, 114f…a first liquid container, 114s…a second liquid container, 120…liquid container, 121…a first liquid container, 122…a second liquid container, 123…a liquid container, 124…a second liquid container, 125…a liquid container, 126…a liquid container, 127…a liquid container, 128…a liquid container, 129…a liquid container, 130…a liquid container, 131…a liquid container, 132…a liquid container, 133…a liquid container, 134…a liquid container, 135…a liquid container, 136…a liquid container, 137…a liquid container, 138…a liquid container, 139…a liquid container, 140…a liquid container, 141…a liquid container, 142…a liquid container, 143…a liquid container, 144…a liquid container, 145…a liquid container, 146…a liquid container, 147…a liquid container, 148…a liquid container, 149…a liquid container, 150…a liquid container, 151…a liquid container, 152…a liquid 1... Storage Container, 122... Delivering Flow Path, 123... Merging Flow Path, 124f... First Valve, 124s... Second Valve, 125... Storage Portion, 126... Connecting Flow Path, 128... Gas Delivery Path, 129... Delivery Valve, 129f... First Delivery Valve, 129s... Second Delivery Valve, 131... Detection Portion, 132... Movable Wall, 133... Moving Body, 134... First Force Applying Member, 135... Rod, 136... Second Force Applying Member, 140... Supply Mechanism, 141... First Delivery Flow Path, 142... Second Delivery Flow Path, 143... Third Delivery Flow Path, 144... Supply Pump, 145... Third Delivery Valve, 146... Fourth Delivery Valve, 147... Delivery Flow Path, 150... Pressure Regulator, 160... Supply Limiter 161...Gas chamber, 162...Liquid chamber, 163...Protrusion, 164...Thin film member, 165...Force member, 166...First opening valve, 167...Opening, 170...Liquid pressurizing unit, 171...Gas chamber, 172...Liquid chamber, 173...Thin film member, 174...Force member, 175...Second opening valve, 180...Maintenance unit, 181...Cleaning mechanism, 182...Wiping mechanism, 183...Lid, 184...Suction mechanism, 185...Discharge flow path, 186...Suction valve, 188...Wiper, 189...Wiper support, 190...Supply flow path, 191...First supply flow path, 192...Second supply flow path, 193...Third supply flow path, 194...Fourth supply flow path, 195... Fifth supply flow path, 1100...control unit, 1102...main unit, 1103...image reading unit, 1104...automatic feed unit, 1105...operation unit, 1106...medium storage unit, 1107...loading unit, 1107a...loading surface, 1111...pressure chamber, 1112...discharge valve, 1113...pressure sensor, 1114...release valve, 1115...waste liquid tank, 1116...cleaning pump, 1117...decompression flow path, 1118...decompression valve, 1119...decompression flow path release valve, 1127...pressurization flow path, 1128...pressurization valve, 1129...pressurization flow path release valve, 1130...drive mechanism, 1131...first storage container, 1134...second storage container, 1142...CPU,1143... Storage unit, 1146... Discharge failure detection unit, 1147... Piezoelectric element drive circuit, 1148... Cap drive circuit, 1149... Cleaning pump drive circuit, 1150... Supply pump drive circuit, 1151... Suction valve drive circuit, 1152... Pressurizing valve drive circuit, 1153... Pressure reducing valve drive circuit, 1154... Release valve drive circuit, 1155... Discharge valve drive circuit, 1220... Filter unit, 1221... Filter, 1222... Upstream filter chamber, 1223... Downstream filter chamber, 1280... Hydraulic adjustment mechanism, 1281... Communication hole, 1282... Liquid chamber, 1283... Valve core, 1284... 284…pressure-bearing member, 1285…flexible wall, 1286…first pressing member, 1287…second pressing member, 1290…valve opening mechanism, 1291…accommodation chamber, 1292…pressurization bag, 1293…ventilation flow path, 1328…installation portion, 1329…accommodation chamber, 1330…delivery portion, 1331…valve, 1334…communication path, 1336…first valve, 1337…supply flow path, 1338…second valve, 1339…recovery flow path, 1340…third valve, 1341…liquid chamber, 1342…flexible member, 1344…first connecting portion, 1345…second connecting portion, 1348…switching mechanism , 1349…pressure sensor, 1350…atmosphere release path, 1351…pressurization path, 1352…connection path, 1353…air chamber, 1354…spring, 1355…air path, 1357…pressurization mechanism, 1358…micro-pressurization unit, 1360…introduction unit, 1361…device-side valve, 1362…first storage chamber, 1363…liquid volume sensor, 1364…first gas-liquid separation membrane, 1365…top portion, 1366…first liquid level, 1368…second storage chamber, 1369…second gas-liquid separation membrane, 1370…second liquid level, 1372…capillary portion, 1373a…first selector valve, 1373 b…second selector valve, 1373c…third selector valve, 1373d…fourth selector valve, 1373e…fifth selector valve, 1373f…sixth selector valve, 1373g…seventh selector valve, 1373h…eighth selector valve, 1373i…ninth selector valve, 1373j…tenth selector valve, 1373k…eleventh selector valve, CS…enclosed space, M…medium, np…number of injections, ns…number of suction cleanings, nw…number of pressurized wipes, PL…pressurization threshold, Q1…capacity, Q2…total discharge volume, Q2p…discharge volume, Q2s…suction volume, Q2w…leakage volume, Q3…remaining volume, QL1…first threshold. DETAILED DESCRIPTION

[0040] A first embodiment of a liquid ejection device, a cap device used in the liquid ejection device, and a maintenance method for the cap device used in the liquid ejection device will be described below with reference to the accompanying drawings. The liquid ejection device is, for example, an inkjet printer that ejects ink, an example of a liquid, onto a medium such as paper to perform printing.

[0041] In the accompanying drawings, the liquid ejection device 11 is arranged on a plane, and the width direction and depth direction are substantially horizontal. In addition, the Z axis represents the vertical direction, and the X axis and Y axis represent the directions along the plane intersecting the Z axis. The X axis, Y axis, and Z axis are preferably orthogonal to each other. In the following description, the X axis direction is also referred to as the width direction X, the Y axis direction is referred to as the depth direction Y, and the Z axis direction is referred to as the vertical direction Z.

[0042] Regarding the structure of the liquid ejection device

[0043] like Figure 1 As shown, the liquid ejecting device 11 includes a main body 12 having a rectangular parallelepiped shape, an image reader 13 mounted on top of the main body 12, and an automatic feeder 14. The liquid ejecting device 11 has a structure in which the main body 12, the image reader 13, and the automatic feeder 14 are stacked in this order from the bottom in the vertical direction Z.

[0044] The image reading unit 13 is configured to read images such as text and photos recorded on a document. The automatic feed unit 14 is configured to feed the document to the image reading unit 13. The image reading unit 13 also includes an operating unit 15 that is operated when giving instructions to the liquid ejecting device 11. The operating unit 15 includes, for example, a touch-panel liquid crystal screen and operating buttons.

[0045] The main body 12 has a plurality of medium storage sections 16 capable of storing media such as paper. The main body 12 in this embodiment has a total of four medium storage sections 16. The medium storage section 16 is configured to be pulled out relative to the main body 12. In addition, the main body 12 has a recording section 20 for recording on the medium M inside the main body 12. The recording section 20 has a head unit 24 having a liquid ejection head 21 capable of ejecting liquid. In addition, the main body 12 has a loading section 17 on the upper portion thereof for loading the recorded medium M. The loading section 17 has a loading surface 17a for loading the medium M. It should be noted that the number of the medium storage section 16 may be only one.

[0046] The medium M stored in the medium accommodating section 16 is conveyed along the conveyance path 19 from the medium accommodating section 16 through the recording section 20 to the receiving section 17. A feed roller (not shown) contacts and rotates the topmost medium M among the multiple media M stored in the medium accommodating section 16, thereby feeding the topmost medium M from the medium accommodating section 16 to the recording section 20 located above the medium accommodating section 16. As the medium M passes through the recording section 20, the liquid ejection head 21 ejects liquid onto the medium M, causing the ejected liquid to adhere to the medium M, thereby performing recording. The recorded medium M is then ejected toward the receiving section 17 by an ejection roller (not shown).

[0047] like Figure 2 As shown, a cap unit 51 and a wiper carriage 41 of a capping device (described later) are arranged around the liquid ejecting head 21 included in the recording section 20 on the side opposite to the side where the head unit 24 is located with respect to the transport path 19. The head unit 24 includes the liquid ejecting head 21 and a support portion 25 that holds the liquid ejecting head 21.

[0048] The liquid ejection head 21 is configured to eject liquid from a plurality of nozzles 22 forming a plurality of nozzle groups toward the medium M while extending in the width direction X. When the liquid ejection head 21 ejects liquid toward the medium M, the direction in which the liquid is ejected is referred to as an ejection direction Y1. Furthermore, when the liquid ejection head 21 ejects liquid toward the medium M, the direction in which the medium M is transported is referred to as a first transport direction Z1.

[0049] In this embodiment, the nozzle plane 23 on which the nozzles 22 are arranged is not horizontal, but rather has a first predetermined angle θ1 relative to the horizontal. That is, in this embodiment, the liquid ejection head 21 is arranged with the nozzle plane 23 at the first predetermined angle θ1 relative to the horizontal, and in this state, the liquid ejection head 21 ejects liquid toward the medium M. It should be noted that the nozzle plane 23 on which the nozzles 22 are arranged may also be arranged horizontally. That is, the liquid ejection head 21 may also be arranged with the nozzle plane 23 horizontal.

[0050] The liquid ejection head 21 of this embodiment is a line head having a number of nozzles 22 capable of simultaneously ejecting liquid across the entire width of the medium M in the width direction X intersecting the first conveying direction Z1 and the ejection direction Y1. The liquid ejection device 11 performs line printing by ejecting liquid from the plurality of nozzles 22 located across the entire width of the medium M onto the medium M being conveyed at a constant speed.

[0051] In the liquid ejection device 11 , maintenance operations such as capping, cleaning, flushing, and wiping are performed to prevent or resolve ejection defects caused by clogging of the nozzles 22 of the liquid ejection head 21 or adhesion of foreign matter.

[0052] Capping is the operation of bringing the cap unit 51 into contact with the nozzle surface 23 of the liquid ejection head 21 to surround the nozzle 22 when the liquid ejection head 21 is not ejecting liquid. Capping suppresses thickening of the liquid in the nozzle 22, thereby preventing ejection defects.

[0053] Cleaning is an operation of pressurizing the upstream side of the liquid ejecting head 21 to forcibly discharge liquid from the nozzles 22 , or applying suction force to the nozzles 22 of the liquid ejecting head 21 to forcibly discharge liquid from the nozzles 22 .

[0054] Flushing refers to the ejection action for discharging droplets not related to printing from the nozzle 22. Flushing is also called empty ejection. Since thickened ink, bubbles or foreign matter that cause poor ejection are discharged from the nozzle 22 by flushing, clogging of the nozzle 22 can be prevented. The liquid that is not used in printing among the liquid discharged from the liquid ejection head 21 is called waste liquid. The liquid discharged by flushing is waste liquid because it is not used in printing. The waste liquid discharged by flushing is contained in the cap unit 51. That is, flushing is performed by ejecting droplets from the nozzle 22 into the cap unit 51 through the liquid ejection head 21.

[0055] Wiping refers to the act of wiping the nozzle face 23 with a rubber wiper, cloth wiper, or the like. By wiping, liquid and dirt such as dust adhering to the nozzle face 23 of the liquid ejecting head 21 are removed. It should be noted that the liquid wiped by wiping is not used during printing and is therefore waste liquid.

[0056] The position of the head unit 24 when the liquid ejection head 21 ejects liquid onto the medium M, that is, when the liquid ejection head 21 records on the medium M, is referred to as the recording position. Furthermore, the position of the cap unit 51 when the liquid ejection head 21 ejects liquid onto the medium M is referred to as the retracted position. Furthermore, the position of the head unit 24 when the liquid ejection device 11 is undergoing maintenance is referred to as the maintenance position. The position of the cap unit 51 when the liquid ejection device 11 is undergoing maintenance is also referred to as the maintenance position.

[0057] like Figure 2 As shown, the head unit 24 is moved by a head moving mechanism (not shown). Figure 2 The recording position shown by the solid line is Figure 2 The direction in which the head unit 24 moves from the recording position to the maintenance position is referred to as a first direction D1. The direction in which the head unit 24 moves from the maintenance position to the recording position is referred to as a second direction D2.

[0058] The cover unit 51 is moved by a cover moving mechanism (not shown) Figure 2 The retreat position shown by the solid line is Figure 2The direction in which the cover unit 51 moves from the recording position to the maintenance position is referred to as a third direction D3. The direction in which the cover unit 51 moves from the maintenance position to the recording position is referred to as a fourth direction D4.

[0059] like Figure 2 As shown, the cover unit 51 is Figure 2 The retreat position indicated by the solid line moves toward the third direction D3 and is located at Figure 2 After the maintenance position shown by the two-dot chain line, the head unit 24 moves from Figure 2 The recording position indicated by the solid line moves in the first direction D1 and is located at Figure 2 The maintenance position is shown by the two-dot chain line in FIG. The head unit 24 is thus capped by the cap unit 51. In this embodiment, in this capped state, the liquid ejection head 21 is flushed by ejecting liquid droplets from the nozzle 22 into the cap unit 51. That is, in the liquid ejection device 11 of this embodiment, both capping and flushing are performed in the maintenance position. Flushing can also be performed while the liquid ejection head 21 is detached from the cap unit 51.

[0060] When maintenance is completed, the head unit 24 Figure 2 The maintenance position indicated by the double-dotted line moves in the second direction D2 and is located at Figure 2 Then, the cover unit 51 moves from Figure 2 The maintenance position indicated by the double-dot chain line moves in the fourth direction D4 and is located at Figure 2 The retracted position is indicated by the solid line. Note that, at this time, the wiper carriage 41 is located at a position that does not overlap with the head unit 24 and the cap unit 51 in the width direction X. The movement of the wiper carriage 41 will be described later.

[0061] Regarding the structure of the liquid ejection head and the cap unit

[0062] like Figure 3 As shown, the liquid ejection head 21 includes a plurality of unit ejection heads 21a. Figure 2 On the surfaces facing the transport path 19 shown, a plurality of unit ejection heads 21a are arranged at a first predetermined pitch P1 in the width direction X. The unit ejection heads 21a are composed of a plurality of nozzle rows 21b. The plurality of unit ejection heads 21a are arranged so as to be tilted at a second predetermined angle θ2 relative to the first transport direction Z1 in which the medium M is transported. In other words, the nozzle rows 21b are also arranged so as to be tilted at the second predetermined angle θ2 relative to the first transport direction Z1. In this embodiment, the liquid ejection head 21 includes five unit ejection heads 21a, each of which is composed of six nozzle rows 21b.

[0063] In this embodiment, the cover unit 51 includes a plurality of unit covers 51a and a holding portion 59 for holding the plurality of unit covers 51a. The unit cover 51a is an example of a cover. Figure 2 In the illustrated conveying path 19, on the side opposite to the side where the head unit 24 is located, a plurality of unit caps 51a are arranged at a first predetermined pitch P1 in the width direction X. The unit caps 51a are arranged at an inclination of a second predetermined angle θ2 relative to the first conveying direction Z1 of the conveyed medium M. In other words, when viewed from a direction along the ejection direction Y1, the unit caps 51a have a substantially parallelogram shape. In this embodiment, the cap unit 51 includes five unit caps 51a.

[0064] For each unit ejection head 21a, a unit cap 51a is arranged at an opposite position. Therefore, when the head unit 24 is capped by the cap unit 51, the multiple unit ejection heads 21a are respectively covered by their own unit caps 51a. That is, the multiple nozzles 22 possessed by the liquid ejection head 21 are covered by the same number of unit caps 51a as the unit ejection heads 21a. In this embodiment, the multiple nozzles 22 possessed by the liquid ejection head 21 composed of five unit ejection heads 21a are covered by the five unit caps 51a possessed by the cap unit 51. Thus, when capping, all the nozzles 22 possessed by the liquid ejection head 21 are covered by the cap unit 51.

[0065] like Figure 4 As shown, the head unit 24 moves in the Figure 4 The recording position shown by the solid line is Figure 4 Move between the maintenance positions shown by the two-dot chain lines.

[0066] The wiper carriage 41 is moved by a wiper moving mechanism (not shown) Figure 4 The retreat position shown by the solid line is Figure 4 The direction in which the wiper carriage 41 moves from the retracted position to the retracted position is referred to as a fifth direction D5. The direction in which the wiper carriage 41 moves from the retracted position to the retracted position is referred to as a sixth direction D6.

[0067] like Figure 4 As shown, the head unit 24 is Figure 4 The recording position indicated by the solid line moves in the first direction D1. Figure 4 After the maintenance position shown by the two-dot chain line, the wiper carriage 41 moves from Figure 4 The retreat position shown by the solid line moves in the fifth direction D5 to Figure 4 The folded position is shown by the two-dot chain line in FIG.

[0068] When wiping is finished, the head unit 24 Figure 4 The maintenance position indicated by the double-dotted line moves in the second direction D2 and is located at Figure 4 The recording position is shown by the solid line. After that, the wiper carriage 41 moves from Figure 4 The folded position indicated by the double-dot chain line moves in the sixth direction D6 and is located at Figure 4 The solid line shows the retreat position.

[0069] About the structure of the cover

[0070] like Figure 5 As shown, the unit cover 51a as an example of a cover includes a restricting member 52, an absorbent body 53, a first moisture-permeable membrane 54 as an example of a partition wall, a humidifying chamber 55, and a housing 56. The unit cover 51a has a relatively low prism shape with a substantially parallelogram-shaped bottom surface. In this embodiment, the unit cover 51a is arranged on the bottom surface of the substantially parallelogram-shaped unit cover. Figure 2 The XZ1 plane is used as shown. Figure 5 The unit cover 51a shown is used in a state where the bottom surface of the substantially parallelogram is tilted relative to the horizontal. Figure 4 The nozzle face 23 of the liquid ejection head 21 is shown to be parallel to the surface.

[0071] The restricting member 52 includes a substantially parallelogram-shaped restricting surface 52a for restricting the position of the surface 53a of the absorber 53 on the -Y1 direction side, and a positioning engaged portion 52c. The restricting member 52 is made of, for example, a thin metal plate such as stainless steel. Furthermore, the restricting member 52 maintains the flatness and strength of the restricting surface 52a by curving the four sides thereof toward the +Y1 direction, thereby restricting the position of the absorber 53.

[0072] The restricting surface 52a of the restricting member 52 is formed in a mesh shape. Specifically, the restricting surface 52a has a plurality of communication holes 52b. The -Y1 and +Y1 sides of the restricting surface 52a are connected via the plurality of communication holes 52b. Thus, the unit cover 51a is configured such that liquid can flow through the unit cover 51a from the -Y1 side to the +Y1 side, and vice versa.

[0073] like Figure 5 As shown, the absorber 53 is formed into a thin plate-like shape that is substantially parallelogram-shaped and extends in the XZ1 plane. The absorber 53 is configured to absorb liquid. Therefore, the absorber 53 may displace, i.e., swell, by increasing its volume due to absorption of liquid.

[0074] In order to expose the surface 53a of the absorber 53 widely and to make the surface 53a Figure 4 The distance to the nozzle surface 23 shown is constant, and the restriction member 52 restricts the absorber 53 at a predetermined position. That is, the restriction member 52 prevents the absorber 53 from being displaced in the -Y1 direction when the absorber 53 swells.

[0075] like Figure 5 As shown, the first moisture-permeable membrane 54 is formed into a roughly parallelogram-shaped sheet extending in the XZ1 plane. The first moisture-permeable membrane 54 is air-permeable. That is, it allows the passage of gas but restricts the passage of liquid. In this embodiment, the first moisture-permeable membrane 54 is made of a fluororesin-coated fabric. The material used for the first moisture-permeable membrane 54 can be any material, as long as it does not allow liquid to pass but allows gas to pass, and can be a thin film or an elastomeric film.

[0076] The first moisture-permeable membrane 54 has communication portions 54a on three of its four roughly parallelogram-shaped sides. The first moisture-permeable membrane 54 is configured so that the central portions of its three sides are slightly notched inward of the roughly parallelogram. This allows liquid to pass only near the three sides of the first moisture-permeable membrane 54, from the -Y1 side to the +Y1 side, and from the +Y1 side to the -Y1 side. The first moisture-permeable membrane 54 may also have a communication portion 54a on the side of its roughly parallelogram closest to the +Z direction.

[0077] As described above, in this embodiment, Figure 5 The unit cover 51a shown is positioned on an XZ1 plane, whose bottom surface is inclined relative to the horizontal. Because gravity exerts a force that causes liquid to flow vertically toward the -Z direction, liquid is less likely to flow along the side of the parallelogram closest to the +Z direction. Therefore, in this embodiment, the first moisture-permeable membrane 54 does not have a connecting portion 54a on the side of its parallelogram closest to the +Z direction.

[0078] like Figure 5 As shown, the humidifying chamber 55 has a substantially parallelogram-shaped bottom extending along the XZ1 plane. Furthermore, the humidifying chamber 55 has a groove 55c in the center of its bottom for passage of the humidifying fluid, described later. The humidifying chamber 55 is formed by resin molding or other means. In other words, the material used for the humidifying chamber 55 is liquid-impermeable. The groove 55c has a groove wall 55i. The end of the groove wall 55i on the -Y1 side is sealed to the first moisture-permeable membrane 54, for example, by welding or adhesive bonding. Thus, the groove 55c of the humidifying chamber 55 and the first moisture-permeable membrane 54 form a chamber.

[0079] The humidifying chamber 55 has a connecting portion 55e on three of the four sides of its roughly parallelogram shape and a positioning engaging portion 55d on two sides. The humidifying chamber 55 is configured so that, by slightly notching multiple portions of its three sides toward the inside of the roughly parallelogram, liquid can pass only near the three sides of the humidifying chamber 55, from the -Y1 direction side to the +Y1 direction side of the humidifying chamber 55, and from the +Y1 direction side to the -Y1 direction side. It should be noted that the humidifying chamber 55 may also have a connecting portion 55e on the side of its roughly parallelogram shape closest to the +Z direction side. The periphery of the humidifying chamber 55 is sealed, so the humidifying chamber 55 is not connected to the connecting portion 55e.

[0080] As described above, in this embodiment, Figure 5 The unit cover 51a shown is used with its roughly parallelogram-shaped bottom surface tilted relative to the horizontal. Because gravity exerts a force that causes liquid to flow vertically toward the -Z direction, liquid is less likely to flow along the side of the roughly parallelogram closest to the +Z direction. Therefore, in this embodiment, the humidification chamber 55 does not have a connecting portion 55e on the side of its roughly parallelogram closest to the +Z direction.

[0081] The humidification chamber 55 has a communication hole 55f in the communication portion 55e on the side of its substantially parallelogram shape closest to the -Z direction, slightly closer to the +X direction side than the center of the communication portion 55e, which communicates with the space within the housing 56. Thus, the humidification chamber 55 is configured so that liquid flowing due to gravity flows more evenly and efficiently through the communication hole 55f.

[0082] The housing 56 has an air communication hole 56a on one side of its substantially parallelogram shape closest to the +Z direction and slightly closer to the -X direction than the center of the side. In addition, the humidification chamber 55 has a space in communication with the air communication hole 56a. Figure 6 The communication hole 55j shown is provided. Thus, the space within the housing 56 communicates with the atmosphere (described later). To allow for more efficient circulation of the atmosphere within the housing 56, the atmosphere communication hole 56a is preferably located in the center of the housing 56. In this embodiment, the humidification chamber 55 has a substantially parallelogram-shaped bottom surface. Therefore, the atmosphere communication hole 56a is slightly located to the -X direction side relative to the width direction X.

[0083] like Figure 6As shown, the humidification chamber 55 has an inlet 55a, an outlet 55b, a locking portion 55g, and a positioning locking portion 55h on the +Y1 side of the bottom surface of the roughly parallelogram. The locking portion 55g is tubular, with the inlet 55a formed inside the locking portion 55g on the +X side, and the outlet 55b formed inside the locking portion 55g on the -X side. The inlet 55a and outlet 55b connect the +Y1 side and -Y1 side of the roughly parallelogram bottom surface. Furthermore, the inlet 55a and outlet 55b communicate within the humidification chamber 55 via a flow path formed by the groove 55c and the first moisture-permeable membrane 54. The flow path formed by the groove 55c and the first moisture-permeable membrane 54 will be described later.

[0084] The housing 56 includes an atmosphere communication hole 56a, a discharge hole 56b as an example of a hole, an engaged portion 56c, Figure 5 The shown positioning engaged portion 56d and the sealing portion 56e. The atmosphere communication hole 56a and the exhaust hole 56b connect the +Y1 direction side and the -Y1 direction side of the bottom surface of the substantially parallelogram.

[0085] The sealing portion 56e is formed in a frame shape along the surrounding wall on the surface closest to the -Y1 direction side of the surrounding wall forming the shell 56. The material used for the sealing portion 56e is, for example, a flexible material such as a rubber material or an elastomer. In order to prevent the liquid in the unit cover 51a from drooping from the sealing portion 56e to the outside of the unit cover 51a, the material of the sealing portion 56e may also be a waterproof elastomer material that repels the liquid ejected from the liquid ejection head 21. In this embodiment, the surface closest to the -Y1 direction side of the surrounding wall forming the shell 56 is located in the XZ1 plane inclined relative to the horizontal. The liquid moves in the vertical direction due to gravity. Therefore, the sealing portion 56e on the lower side of the center of the unit cover 51a in the vertical direction Z can be set to be more waterproof than the sealing portion 56e on the upper side, or only the sealing portion 56e on the lower side can be set to be waterproof.

[0086] The housing 56 is formed into a prism-shaped outer shape with a lower height having a substantially parallelogram-shaped bottom surface of the unit cover 51a, and houses the limiting member 52, the absorber 53, the first moisture-permeable membrane 54, and the humidifying chamber 55. The positioning engaging portion 55d of the humidifying chamber 55 engages with the positioning engaged portion 52c of the limiting member 52. The engaging portion 55g of the humidifying chamber 55 engages with the engaged portion 56c of the housing 56. The positioning engaging portion 55h of the humidifying chamber 55 engages with the engaged portion 56c of the housing 56. Figure 5The positioning engaging portion 56d shown is engaged. As a result, the restricting member 52, the absorber 53, the first moisture-permeable membrane 54, and the humidifying chamber 55 are retained by the housing 56. Furthermore, the communicating hole 55f of the humidifying chamber 55 communicates with the exhaust hole 56b of the housing 56. Furthermore, the communicating hole 55j of the humidifying chamber 55 communicates with the atmospheric communication hole 56a of the housing 56.

[0087] like Figure 7 As shown, the groove 55c of the humidifying chamber 55 is formed on the -Y1 side of the bottom surface of the substantially parallelogram. The groove 55c is curved in a serpentine shape so as to cover the entire surface, forming a labyrinthine shape of a single passage from the inlet 55a to the outlet 55b. The end portion of the groove wall 55i on the -Y1 side of the groove 55c and Figure 5 The first moisture permeable membrane 54 shown is sealed in the entire region from the inlet 55a to the outlet 55b. Therefore, a curved flow path having a complex meandering path is formed by the groove 55c and the first moisture permeable membrane 54, and the inlet 55a and the outlet 55b are connected. That is, the humidification chamber 55 is formed by the groove 55c through which the humidification fluid described later flows and the wall which is an example of the partition wall covering the groove 55c. Figure 5 The first moisture-permeable membrane 54 shown is formed in a flow path shape that connects the inlet 55a and the outlet 55b.

[0088] As will be described later, since the humidifying fluid flowing through the grooves 55c humidifies the space within the unit cover 51a, it is preferable that the area occupied by the grooves 55c within the unit cover 51a in the XZ1 plane be large. Specifically, in order to increase the area occupied by the grooves 55c on the bottom surface of the unit cover 51a, it is preferable to route the flow path across the entire bottom surface of the unit cover 51a.

[0089] Concave portion forming a space

[0090] like Figure 8 As shown in FIG. 1 , the liquid ejecting device 11 includes a cover device 50. The cover device 50 has a movable Figure 3 The cover unit 51 is shown. In addition, the cover unit 51 has a unit cover 51a.

[0091] When the cover unit 51 moves in the first direction D1 and is located Figure 8 After the maintenance position shown, when the head unit 24 moves to the third direction D3 and is located Figure 8When in the maintenance position shown, the unit cap 51a of the cap device 50 is in contact with the nozzle surface 23 of the liquid ejecting head 21. The surface on the -Y1 direction side of the sealing portion 56e located around the housing 56 is referred to as the close contact surface 56f. When the cap device 50 is in contact with the liquid ejecting head 21, the nozzle surface 23 is in close contact with the close contact surface 56f, and the nozzle surface 23 is sealed by the sealing portion 56e. That is, the cap device 50 is configured so that when the unit cap 51a as an example of a cap is in contact with the liquid ejecting head 21 having the nozzle 22 that ejects liquid, a space SP surrounding the opening 22a of the nozzle 22 can be formed. In other words, when the unit cap 51a as an example of a cap is in contact with the liquid ejecting head 21 having the nozzle 22 that ejects liquid, a space SP surrounding the opening 22a of the nozzle 22 can be formed.

[0092] The unit cover 51a has a recess 57 forming a space SP. In this embodiment, Figure 8 As shown, the recess 57 is formed by the inner surface of the housing 56, the outer surface of the outer periphery of the humidifying chamber 55, and the surface of the first moisture-permeable membrane 54 facing the absorbent body 53. The recess 57 includes the absorbent body 53 capable of absorbing liquid at a position in contact with the first moisture-permeable membrane 54, which serves as an example of a partition. The air-permeable first moisture-permeable membrane 54 divides the recess 57 and the humidifying chamber 55. Thus, when the cap device 50 is in contact with the liquid ejection head 21, the recess 57 forms a space SP surrounding the opening 22a of the nozzle 22. It should be noted that the recess 57 has a volume sufficient to prevent liquid ejected into the recess during flushing from overflowing from the sealing portion 56e.

[0093] In this embodiment, the nozzle surface 23 on which the nozzle 22 is arranged is not horizontal, but has a first predetermined angle θ1 relative to the horizontal. Therefore, the surface on the -Y1 direction side of the sealing portion 56e located around the housing 56 is also not horizontal, but has a first predetermined angle θ1 relative to the horizontal. Thus, when the unit cover 51a is tilted at the first predetermined angle θ1 relative to the horizontal, the nozzle surface 23 is in close contact with the sealing surface 56f of the sealing portion 56e, and the nozzle surface 23 is sealed by the sealing portion 56e. In this embodiment in which the unit cover 51a is tilted relative to the horizontal, the recess 57 also has a volume such that the liquid ejected into the recess by flushing during flushing does not overflow from the lower portion of the tilted sealing portion 56e.

[0094] The nozzle surface 23 where the nozzles 22 are arranged may be arranged horizontally with the surface of the sealing portion 56e on the -Y1 direction side. That is, the nozzle surface 23 may be sealed by the sealing portion 56e in a state where the liquid ejection head 21 and the unit cap 51a are arranged horizontally.

[0095] like Figure 9As shown, the restricting member 52 and the absorbent body 53 are liquid-permeable, while the first moisture-permeable membrane 54 is impermeable. Therefore, during flushing, liquid discharged from the nozzle 22 passes through the restricting member 52 and the absorbent body 53 from the -Y1 direction to the +Y1 direction, but does not pass through the first moisture-permeable membrane 54 from the -Y1 direction to the +Y1 direction. Furthermore, the liquid is absorbed by the absorbent body 53. Furthermore, the liquid absorbed by the absorbent body 53 spreads throughout the absorbent body 53. More specifically, if there is a portion within the absorbent body 53 where little liquid has been absorbed, surrounding a portion where much liquid has been absorbed, the liquid flows from the portion where much liquid has been absorbed to the portion where little liquid has been absorbed.

[0096] As more liquid is absorbed by the absorber 53, approaching a point where it can no longer absorb any more liquid, gravity causes the liquid to flow in the vertical -Z direction within the absorber 53. Consequently, when the liquid reaches the -Y1-side surface of the first moisture-permeable membrane 54, gravity causes it to flow in the -Z1 direction. Since the first moisture-permeable membrane 54 is impermeable to liquid, it restricts the passage of liquid. In other words, the liquid does not flow into the humidification chamber 55. Furthermore, gravity causes the liquid to flow through the communication portion 54a and the communication portion 55e, draining out of the unit cover 51a through the discharge hole 56b in the housing 56. Specifically, the recess 57 includes the discharge hole 56b, which is an example of a hole that allows the liquid discharged from the liquid ejection head 21 into the unit cover 51a to be discharged.

[0097] In this embodiment, the drain hole 56b, which is an example of a hole, is provided in the recess 57 at a position lower than the first moisture-permeable membrane 54, which is an example of a partition wall. That is, the drain hole 56b is provided closer to the -Z direction side than the first moisture-permeable membrane 54. Alternatively, the drain hole 56b, which is an example of a hole, may be provided at the lowest portion of the recess 57. That is, the drain hole 56b may be provided closest to the -Z direction side of the recess 57.

[0098] The humidification chamber 55 includes an inlet 55a for inflow of a humidification fluid (described later) for humidifying the space SP, and an outlet 55b for outflow of the humidification fluid. The first moisture-permeable membrane 54 is impermeable to liquid, and therefore restricts the passage of liquid within the humidification chamber 55 from the +Y1 direction side toward the -Y1 direction side. Consequently, in the humidification chamber 55, liquid flowing in through the inlet 55a flows out through the outlet 55b. It should be noted that the humidification chamber 55 is arranged in an inclined position relative to the horizontal. Furthermore, the inlet 55a and the outlet 55b are positioned above the center of the humidification chamber 55 in the vertical direction Z. In this embodiment, the inlet 55a and the outlet 55b are located closer to the +Z direction side than the center of the humidification chamber 55 in the vertical direction Z. By providing the inlet 55a and the outlet 55b on the +Z direction side of the humidification chamber 55, it is possible to suppress the liquid in the humidification chamber 55 from flowing out of the humidification chamber 55 from the inlet 55a or the outlet 55b due to the water level pressure.

[0099] like Figure 10 As shown, the restricting member 52, the absorbent body 53, and the first moisture-permeable membrane 54 are air-permeable. Therefore, atmospheric air and water vapor, as gases, pass through the restricting member 52, the absorbent body 53, and the first moisture-permeable membrane 54 from the -Y1 direction to the +Y1 direction, and vice versa. Thus, the cap device 50 is configured such that, within the unit cap 51a, water vapor evaporated from the humidification fluid (described later) can flow from the humidification chamber 55 into the recess 57.

[0100] The recessed portion 57 includes an atmospheric communication hole 56a for communicating the space SP with the atmosphere. The atmospheric communication hole 56a is located above the vertical center of the unit cover 51a. In this embodiment, the atmospheric communication hole 56a is located closer to the +Z direction than the center of the recessed portion 57 in the vertical direction Z. By positioning the atmospheric communication hole 56a above the vertical center of the unit cover 51a, clogging of the atmospheric communication hole 56a by liquid can be prevented. Alternatively, the atmospheric communication hole 56a may be located higher than the first moisture-permeable membrane 54, that is, closer to the +Z direction than the first moisture-permeable membrane 54.

[0101] Regarding the structure of the humidification fluid circulation mechanism provided in the cap device

[0102] like Figure 11 As shown, the cap device 50 includes a cap unit 51 having a unit cap 51 a , a cap moving mechanism (not shown), a humidification fluid circulation mechanism 60 , and a waste liquid recovery mechanism 80 .

[0103] The humidification fluid circulation mechanism 60 included in the cap device 50 includes a humidification fluid storage section 61 that stores the humidification fluid L1a, a supply flow path 62a, and a recovery flow path 62b. The supply flow path 62a connects the humidification fluid storage section 61 with the inlet 55a. That is, the supply flow path 62a connects the humidification fluid storage section 61 with the unit cap 51a as an example of a cap. The recovery flow path 62b connects the outlet 55b with the humidification fluid storage section 61. That is, the recovery flow path 62b connects the unit cap 51a as an example of a cap with the humidification fluid storage section 61. In addition, the humidification fluid circulation mechanism 60 includes a circulation path 62 that includes the humidification fluid storage section 61, the supply flow path 62a, and the recovery flow path 62b.

[0104] The humidifying fluid storage section 61 includes an inflow section 61f and an outflow section 61g. The inflow section 61f of the humidifying fluid storage section 61 communicates with the recovery flow path 62b. The outflow section 61g of the humidifying fluid storage section 61 communicates with the supply flow path 62a.

[0105] In the humidification fluid circulation mechanism 60, the humidification fluid L1a flowing in the circulation path 62 contains Figure 8 The space SP shown is humidified with water. The moisturizing power of the humidifying fluid L1a is preferably the same as the moisturizing power of the liquid ejected from the liquid ejection head 21. Moisturizing power refers to the concentration of the moisturizing agent contained in the humidifying fluid L1a, the liquid ejected from the liquid ejection head 21. For example, when the liquid ejection head 21 ejects ink, an example of a liquid, onto a medium such as paper for printing, the moisturizing power of the humidifying fluid L1a is preferably the same as the moisturizing power of fresh ink. In addition, the moisturizing power of the ink is preferably balanced for each color. It should be noted that the details of the humidifying fluid L1a will be described later.

[0106] like Figure 3 As shown, the cover unit 51 of the cover device 50 of this embodiment has five Figure 6 The unit cover 51a shown. That is, the cover device 50 is configured by arranging a plurality of unit covers 51a as an example of a cover. In addition, the five unit covers 51a of the cover device 50 each have Figure 6 The inlet 55a and Figure 6 The outflow outlet 55b shown. Therefore, in this embodiment, the outflow outlet 55b of one unit cover 51a among the multiple unit covers 51a is connected to the inflow inlet 55a of another unit cover 51a adjacent to the unit cover 51a. For example, the outflow outlet 55b of one unit cover 51a is connected to the inflow inlet 55a of another unit cover 51a adjacent to the unit cover 51a through a pipe not shown in the figure, and its outflow outlet 55b is connected to the inflow inlet 55a. As a result, the inflow inlet 55a located at the farthest upstream is connected to the outflow outlet 55b located at the farthest downstream. The inflow inlet 55a located at the farthest upstream is connected to Figure 11The supply flow path 62a shown in FIG. is connected. In addition, the outlet 55b located at the most downstream is connected to Figure 11 That is, the cap device 50 of this embodiment is configured such that Figure 11 The humidification fluid L1a flowing in the circulation path 62 shown can be Figure 7 The liquid flows through the groove 55c of the humidifying chamber 55. When the cap device 50 has only one unit cap 51a, the inlet 55a of the unit cap 51a is connected to the supply flow path 62a, and the outlet 55b of the unit cap 51a may be connected to the recovery flow path 62b.

[0107] like Figure 11 As shown, the humidifying fluid receiving portion 61 receives the humidifying fluid Figure 8 The space SP shown is humidified with a humidifying fluid L1a of water. The humidifying fluid storage section 61 includes a detection section 61a for detecting the liquid level in the humidifying fluid storage section 61. The detection section 61a includes a first electrode 61b and a second electrode 61c.

[0108] The humidifying fluid L1a contains a conductive additive. The detecting unit 61a detects the liquid level in the humidifying fluid storage unit 61 by means of the resistance between the first electrode 61b and the second electrode 61c. When the liquid level of the humidifying fluid L1a stored in the humidifying fluid storage unit 61 is higher than a first predetermined height H1, which is an example of a "predetermined height," electrical conduction occurs between the first electrode 61b and the second electrode 61c. When the liquid level of the humidifying fluid L1a stored in the humidifying fluid storage unit 61 is lower than the first predetermined height H1 and higher than a second predetermined height H2, electrical conduction occurs between the first electrode 61b and the second electrode 61c. In this manner, the detecting unit 61a is configured such that the output level changes between when the first electrode 61b is in contact with the liquid surface and when it is not in contact, thereby enabling determination of whether the liquid level of the humidifying fluid L1a is higher than the first predetermined height H1.

[0109] When the detection unit 61a detects that the liquid level of the humidifying fluid L1a exceeds the first predetermined height H1, it indicates that the humidifying fluid L1a is fully contained within the humidifying fluid storage unit 61, that is, the humidifying fluid storage unit 61 is fully filled with the humidifying fluid L1a. In this embodiment, the full state of the humidifying fluid storage unit 61 is detected. Alternatively, the detection unit 61 may detect not only the full state of the humidifying fluid storage unit 61 but also the empty state or nearly empty state of the humidifying fluid storage unit 61. Furthermore, the liquid level detection method is not limited to an electrode method and may also be an optical method or an electrostatic capacitance method.

[0110] The humidifying fluid storage section 61 includes a second atmosphere communication passage 61d and a second moisture-permeable membrane 61e. The second atmosphere communication passage 61d connects the humidifying fluid storage section 61 to the atmosphere. The second atmosphere communication passage 61d may also have a labyrinthine, narrow tube structure. A labyrinthine, narrow tube structure is a structure with narrow, winding, and complex tube paths, allowing air to flow in and out but significantly restricting the flow of liquid. This labyrinthine, narrow tube structure can suppress evaporation of the liquid within the humidifying fluid storage section 61.

[0111] The second moisture-permeable membrane 61e is provided at the connection between the humidifying fluid storage section 61 and the second atmosphere communication passage 61d. The second moisture-permeable membrane 61e allows gas to pass from the humidifying fluid storage section 61 to the second atmosphere communication passage 61d, while restricting the passage of liquid from the humidifying fluid storage section 61 to the second atmosphere communication passage 61d. To improve the efficiency of gas passage from the humidifying fluid storage section 61 to the second atmosphere communication passage 61d, the second moisture-permeable membrane 61e preferably has a large area.

[0112] like Figure 11 As shown, the humidification fluid circulation mechanism 60 included in the cap device 50 includes a first pump 63, an example of a pump, capable of flowing the humidification fluid L1a within the circulation path 62, a first check valve 64, and a pressure regulating valve 65. The first pump 63 causes the fluid to flow within the circulation path 62. When the first pump 63 is driven, the liquid flowing through the supply flow path 62a is delivered to the humidification chamber 55 within the unit cap 51a.

[0113] The first check valve 64 allows liquid to flow from the humidifying fluid storage section 61 side to the unit cover 51a side, and prevents liquid from flowing back from the unit cover 51a side to the humidifying fluid storage section 61 side due to the water level difference. It should be noted that an on-off valve can be provided instead of the first check valve 64. By driving the first pump 63 when the on-off valve is opened, liquid can also flow from the humidifying fluid storage section 61 side to the unit cover 51a side. It should be noted that the situation where the valve of the on-off valve is opened is referred to as an open valve or an open valve. In addition, the situation where the valve of the on-off valve is closed is referred to as a closed valve or a closed valve.

[0114] The pressure regulating valve 65 allows liquid to flow from the unit cover 51a side to the humidifying fluid storage unit 61 side when a predetermined negative pressure is reached on the humidifying fluid storage unit 61 side, while always preventing liquid from flowing back from the humidifying fluid storage unit 61 side to the unit cover 51a side. The pressure regulating valve 65 adjusts the pressure difference corresponding to the water level difference to prevent liquid from flowing from the unit cover 51a side to the humidifying fluid storage unit 61 side due to the water level pressure.

[0115] like Figure 11As shown, the humidification fluid circulation mechanism 60 included in the cap device 50 includes a moisture supply unit 66 capable of supplying moisture L1b into the circulation path 62. The moisture supply unit 66 includes a moisture storage portion 66a, a moisture supply flow path 66b, a first on-off valve 66c (an example of an on-off valve), and a second check valve 66d. The moisture storage portion 66a stores the moisture L1b that can be supplied into the circulation path 62. The moisture supply flow path 66b is connected to the circulation path 62. The first on-off valve 66c is configured to open and close the moisture supply flow path 66b.

[0116] The moisture storage portion 66a includes an outflow portion 66f. The moisture storage portion 66a communicates with the moisture supply flow path 66b at the outflow portion 61g. The moisture supply flow path 66b communicates with the circulation path 62 at the first confluence portion 62c of the circulation path 62. In other words, the moisture storage portion 66a communicates with the circulation path 62. It should be noted that the moisture storage portion 66a is preferably replaceable.

[0117] The water L1b supplied from the water storage portion 66a into the circulation path 62 is for replenishing the water evaporated from the humidification fluid L1a. The water L1b is composed of pure water and a small amount of preservative.

[0118] When the first on-off valve 66c is opened, the water storage portion 66a communicates with the circulation path 62 via the water supply flow path 66b. The second check valve 66d allows liquid to flow from the water storage portion 66a to the circulation path 62, while preventing liquid from flowing back from the circulation path 62 to the water storage portion 66a due to a water level difference. It should be noted that the second check valve 66d is not required. Even without the second check valve 66d, the first pump 63 can still flow water L1b from the water storage portion 66a to the unit cover 51a by driving the first pump 63 when the first on-off valve 66c is open.

[0119] like Figure 11 As shown, the humidification fluid circulation mechanism 60 of the cover device 50 also has a pressurized air supply unit 67. The pressurized air supply unit 67 is configured to be able to supply pressurized air into the circulation path 62. The pressurized air supply unit 67 includes a pressurized air supply path 67a connected to the circulation path 62, a second on-off valve 67b, and a second pump 67c. By opening the second on-off valve 67b, the second pump 67c and the circulation path 62 are connected through the pressurized air supply path 67a. The second pump 67c is, for example, a pressurizing pump. The second pump 67c applies pressure to the atmosphere to produce pressurized air, and supplies the pressurized air to the pressurized air supply path 67a.

[0120] In the circulation path 62, instead of providing the pressurized air supply portion 67 downstream of the first pump 63, an atmosphere supply portion may be provided upstream of the first pump 63 and closer to the downstream than the first confluence portion 62c. The atmosphere supply portion may also include an atmosphere communication path and an on-off valve that are connected to the atmosphere. In addition, the atmosphere may be delivered to the circulation path 62 by the first pump 63 when the circulation path 62 is connected to the atmosphere through the atmosphere communication path by opening the on-off valve. That is, the cover device 50 may also include an atmosphere supply portion in the circulation path 62 for the humidification fluid L1a to flow, and the atmosphere supply portion supplies atmosphere to the circulation path 62 between the first confluence portion 62c where the moisture supply portion 66 and the circulation path 62 merge and the inlet 55a of the unit cover 51a. In addition, the cover device 50 may also include a pump that delivers the atmosphere to the circulation path 62.

[0121] Regarding the structure of the waste liquid recovery mechanism provided in the cap device

[0122] like Figure 11 As shown, the waste liquid recovery mechanism 80 included in the cap device 50 includes a waste liquid recovery path 81 , a third pump 82 , a buffer chamber 83 , a fourth pump 84 , a third atmosphere communication path 85 , and a waste liquid storage portion 86 .

[0123] The waste liquid recovery path 81 includes a first waste liquid recovery path 81a and a second waste liquid recovery path 81b. The first waste liquid recovery path 81a is connected to the discharge hole 56b of the unit cover 51a and the inside of the unit cover 51a. Figure 8 The first waste liquid recovery path 81a connects the space SP formed by the recess 57 shown. Furthermore, the first waste liquid recovery path 81a connects the space SP to the waste liquid storage portion 86 via the buffer chamber 83. Furthermore, the second waste liquid recovery path 81b connects to the wiper carriage 41 at the waste liquid outflow port 43 provided on the wiper carriage 41. Furthermore, the second waste liquid recovery path 81b connects the wiper carriage 41 to the waste liquid storage portion 86.

[0124] During flushing or cleaning, liquid is discharged from the nozzle 22 of the liquid ejection head 21 as waste liquid L2. Waste liquid L2, as an example of liquid, is recovered from the unit cover 51a and circulates to the first waste liquid recovery path 81a. In addition, during wiping, liquid adhering to the nozzle surface 23 of the liquid ejection head 21 is wiped and recovered as waste liquid L2 in the wiper carriage 41. Waste liquid L2 is recovered from the wiper carriage 41 and circulates to the second waste liquid recovery path 81b. The waste liquid L2 recovered by flushing or cleaning and the waste liquid L2 recovered by wiping are transported to the waste liquid storage section 86 by the third pump 82. In addition, the waste liquid L2 is stored in the waste liquid storage section 86.

[0125] like Figure 3 As shown, the cover unit 51 of the cover device 50 of this embodiment has five Figure 6 The unit cover 51a shown is shown. Specifically, the cover assembly 50 is composed of a plurality of unit covers 51a arranged in an array, each of the five unit covers 51a having a discharge hole 56b. Therefore, in this embodiment, the five discharge holes 56b are connected to the first waste liquid recovery path 81a, and through the first waste liquid recovery path 81a, the five discharge holes 56b are connected to the waste liquid storage portion 86. If the cover assembly 50 has only one unit cover 51a, only the discharge hole 56b of that unit cover 51a may be connected to the first waste liquid recovery path 81a.

[0126] like Figure 11 As shown, in this embodiment, the fourth pump 84 is a pressure-reducing pump. The fourth pump 84 exhausts the air in the buffer chamber 83 to the outside of the buffer chamber 83 through the third atmospheric communication passage 85, thereby reducing the air pressure in the buffer chamber 83. This facilitates the flow of waste liquid L2 discharged from the nozzle 22 of the liquid ejection head 21 into the unit cover 51a during flushing or cleaning into the buffer chamber 83 through the first waste liquid recovery passage 81a. It should be noted that the buffer chamber 83, the fourth pump 84, and the third atmospheric communication passage 85 may also be omitted.

[0127] like Figure 11 As shown, the cover unit 51 having the unit cover 51a includes an atmosphere opening mechanism 58. The atmosphere opening mechanism 58 includes a first atmosphere communication passage 58a and a third on-off valve 58b.

[0128] The first atmospheric communication passage 58a connects the atmospheric communication holes 56a of each unit cover 51a in the cover unit 51 to the atmosphere. The third opening and closing valve 58b is an opening and closing valve that can open and close the first atmospheric communication passage 58a. In this embodiment, the atmospheric side of the first atmospheric communication passage 58a is open. Figure 11 The maintenance position indicated by the two-dot chain line is moved in the fourth direction D4 and is located at Figure 11 In the retracted position shown by the solid line, the released portion strikes a wall (not shown), causing the wall to block the first atmosphere communication passage 58a. Specifically, the movement of the cap unit 51 opens and closes the third on-off valve 58b. During flushing or cleaning, with the first atmosphere communication passage 58a open, the liquid ejection head 21 discharges liquid into the unit cap 51a.

[0129] Regarding the electrical structure of the liquid ejection device

[0130] like Figure 12 As shown, the liquid ejection device 11 includes a control unit 90 that controls the head unit 24, the wiper device 40, and the cap device 50. The cap device 50 includes a detector group 91 controlled by the control unit 90. The detector group 91 includes a detector 61a that detects the liquid level in the humidification fluid storage unit 61. The detector 61a outputs the detection result to the control unit 90.

[0131] The control unit 90 includes an interface unit 94, a CPU 95, a memory 96, a control circuit 97, and a drive circuit 98. The interface unit 94 transmits and receives data between a computer 99 (an external device) and the liquid ejection device 11. The drive circuit 98 generates a drive signal for driving the actuator of the liquid ejection head 21.

[0132] The CPU 95 is a processing unit. The memory 96 is a storage device that stores programs for the CPU 95 and a work area, and includes storage elements such as RAM and EEPROM. The CPU 95 controls the head unit 24, the wiper device 40, and the cap device 50, etc., via the control circuit 97, according to the programs stored in the memory 96.

[0133] About the circulation of humidification fluid

[0134] The cycle operation in the maintenance method of the cap device will be described.

[0135] like Figure 13 As shown, the cap device 50 performs a circulation operation. During the circulation operation, when the first opening and closing valve 66c is in the closed valve state, the control unit 90 controls the humidification fluid circulation mechanism 60 to make the humidification fluid L1a flow in the circulation path 62 to the Figure 13 Then, the control unit 90 checks the amount of water evaporated from the humidification fluid L1a.

[0136] Contains Figure 8 The humidifying fluid storage part 61 of the humidifying fluid L1a for humidifying the space SP shown, the supply flow path 62a connecting the humidifying fluid storage part 61 and the unit cover 51a, the recovery flow path 62b connecting the unit cover 51a and the humidifying fluid storage part 61, and the inner portion of the unit cover 51a. Figure 8 The humidifying chamber 55 shown constitutes a circulation path. It is preferable that the internal pressure in the unit cap 51a during the circulation operation is adjusted to be equal to or lower than the meniscus pressure of the liquid ejecting head 21 by adjusting the circulation flow rate of the first pump 63.

[0137] like Figure 13 As shown, in the circulation operation of the humidification fluid L1a, the humidification fluid L1a flows in the circulation path 62 to the Figure 13 The control unit 90 makes the humidification fluid L1a flow in the circulation path 62, thereby the humidification fluid L1a circulates in the humidification chamber 55. Figure 7The winding flow path of a channel with a complex, winding path is shown. Moisture from the humidifying fluid L1a evaporates primarily in the humidifying chamber 55 within the unit cap 51a. Furthermore, for example, at the moment when the humidifying fluid L1a within the humidifying chamber 55 flows into the humidifying fluid storage section 61 and then flows into the humidifying chamber 55, the control unit 90 stops the flow of the humidifying fluid L1a and checks the amount of water evaporated from the humidifying fluid L1a. In other words, one of the purposes of the circulation operation in the cap device maintenance method is to check the amount of water evaporated from the humidifying fluid L1a.

[0138] like Figure 13 As shown, the control unit 90 manages time by using a timer or the like and periodically performs a cycle action. For example, when the power of the liquid ejection device 11 is turned on, the control unit 90 performs a cycle action once a day. At the end of the process of the cycle action described later, the control unit 90 obtains information on the liquid level in the humidifying fluid storage unit 61 from the detection unit 61a in order to confirm the amount of water evaporation from the humidifying fluid L1a. If the amount of water evaporation in the unit cover 51a is large, the liquid level in the humidifying fluid storage unit 61 becomes low. When the unit cover 51a is in the Figure 13 The time of the retreat position shown, that is, the unit cover 51a does not form an encirclement Figure 8 The amount of water evaporation increases during the time that the space SP of the opening 22a of the nozzle 22 shown is in the retracted position. Therefore, the control unit 90 may also perform a looping operation for each time that the temperature and humidity environment management unit cover 51a is in the retracted position. It should be noted that the control unit 90 may also perform a looping operation before the liquid ejection device 11 is installed and recording is first performed on the medium M, before the cover unit 51 is replaced with a new cover unit 51 and recording is first performed on the medium M, and before the water container 66a is replaced with a full water container 66a and recording is first performed on the medium M.

[0139] To reduce the frequency of the circulation operation, the humidification fluid storage section 61 preferably has a larger liquid surface area relative to its depth. This allows the water contained in the humidification fluid L1a to evaporate, thereby reducing changes in the liquid surface height when the amount of liquid in the humidification fluid storage section 61 changes. Furthermore, to ensure that the concentration of the humidification fluid L1a changes as gradually as possible as the water contained in the humidification fluid L1a evaporates from the humidification fluid L1a, the volume of the humidification fluid storage section 61 is preferably as large as possible within the dimensions of the liquid ejection device 11.

[0140] Next, refer to Figure 14 The flowchart shown in the figure sequentially explains the control performed by the control unit 90 in each step with respect to the flow of the cyclic operation in the maintenance method of the cap device.

[0141] In step S101, the control unit 90 determines whether the first on-off valve 66c is in the closed state. If the first on-off valve 66c is closed, the process proceeds to step S103. If the first on-off valve 66c is open, the process proceeds to step S102. Then, in step S102, the control unit 90 closes the first on-off valve 66c.

[0142] In step S103, the control unit 90 drives the first pump 63 for the first predetermined time T1 when the first on-off valve 66c is in the closed state. Figure 13 As shown, the humidification fluid L1a flows along the circulation path 62. Figure 13 Flow is shown in the direction of the solid arrow.

[0143] In step S104, the control unit 90 stops the first pump 63 for the second predetermined time T2 when the first on-off valve 66c is closed. This stabilizes the liquid level in the humidifying fluid storage section 61. It should be noted that to shorten the time required for the liquid level to stabilize, it is preferable to increase the area of ​​the liquid surface relative to the depth of the humidifying fluid storage section 61 to reduce the amount of change in the liquid level when the amount of liquid in the humidifying fluid storage section 61 changes.

[0144] In step S105, the control unit 90 obtains information about the liquid level in the humidifying fluid storage unit 61 from the detection unit 61a. Then, in step S106, the control unit 90 determines whether the liquid level is higher than the first predetermined height H1. If the liquid level is higher than the first predetermined height H1, the process ends.

[0145] If the liquid level is lower than the first predetermined height H1, the process proceeds to step S200. Then, in step S200, the control unit 90 executes a concentration adjustment subroutine described later. When the concentration adjustment subroutine is completed, the control unit 90 ends the process.

[0146] Concentration adjustment of humidification fluid

[0147] The concentration adjustment operation in the cap device maintenance method will be described.

[0148] like Figure 15 As shown, the cap device 50 performs the concentration adjustment operation. During the concentration adjustment operation, when the first opening and closing valve 66c is in the open state, the control unit 90 controls the humidification fluid circulation mechanism 60 to make the humidification fluid L1a flow in the circulation path 62 to the Figure 15 At this time, the first on-off valve 66c is in the open state, and the water L1b in the water supply unit 66 flows to the direction of the solid arrow shown. Figure 15The humidified fluid L1a flows in the direction of the dotted arrow and is supplied to the circulation path 62. That is, the concentration adjustment operation in the cap device maintenance method includes supplying the water L1b to the circulation path 62 through the water supply unit 66 and causing the humidification fluid L1a to flow in the circulation path 62.

[0149] The concentration adjustment operation is executed by the control unit 90 at the end of the aforementioned circulation process, when the control unit 90 acquires information on the liquid level in the humidifying fluid storage unit 61 and the detection unit 61a detects that the liquid level in the humidifying fluid storage unit 61 is below a first predetermined height H1, an example of a "predetermined height." Specifically, when the cap device 50 performs the concentration adjustment operation after the detection unit 61a detects that the liquid level in the humidifying fluid storage unit 61 is below the predetermined height, the cap device 50 supplies water L1b in the water storage unit 66a into the circulation path 62 until the liquid level is detected to be above the predetermined height. Subsequently, the humidifying fluid L1a is allowed to flow through the circulation path 62.

[0150] Inside the unit cap 51a, moisture evaporates from the humidifying fluid L1a, and through the aforementioned circulation action, this humidifying fluid L1a circulates within the circulation path 62. As a result, the moisture content within the humidifying fluid storage section 61 decreases, causing the liquid level within the humidifying fluid storage section 61 to decrease. As evaporation continues, the liquid level within the humidifying fluid storage section 61 falls below a first predetermined height H1. The first predetermined height H1 is set so that the concentration of the humidifying fluid L1a at this point is higher than a predetermined concentration. The control unit 90 executes a concentration adjustment operation, causing the moisture L1b within the moisture storage section 66a to be supplied to the circulation path 62 so that the liquid level is higher than the first predetermined height H1. This supplies approximately the same amount of moisture as evaporated within the unit cap 51a to the circulation path 62, reducing the concentration of the humidifying fluid L1a below the predetermined concentration. In other words, the concentration of the humidifying fluid L1a returns to the concentration it had before the moisture evaporated within the unit cap 51a.

[0151] During the concentration adjustment operation, the controller 90 opens the first on-off valve 66c to supply the water L1b in the water storage section 66a into the circulation path 62. Furthermore, when the controller 90 determines that the liquid level in the humidification fluid storage section 61 is higher than the first predetermined height H1, the controller 90 closes the first on-off valve 66c and performs the aforementioned circulation operation, allowing the humidification fluid L1a in the humidification fluid storage section 61 to flow through the circulation path 62. Specifically, the concentration adjustment operation in the cap device maintenance method includes opening the first on-off valve 66c, an example of an on-off valve, when supplying the water L1b in the water storage section 66a into the circulation path 62, and closing the first on-off valve 66c when allowing the humidification fluid L1a to flow through the circulation path 62.

[0152] At the first confluence 62c of the circulation path 62, the humidification fluid L1a flowing from the humidification fluid storage section 61 and the water L1b flowing from the water supply section 66 merge. If the volume of the water L1b flowing from the water supply section 66 is larger than the volume of the humidification fluid L1a flowing from the humidification fluid storage section 61, the liquid level in the humidification fluid storage section 61 changes more rapidly, increasing the error in liquid level detection and making it difficult to detect the liquid level in a timely manner. Therefore, in the first confluence 62c, the pressure loss in the flow path on the water supply section 66 side is preferably set to be equal to or greater than the pressure loss in the flow path on the humidification fluid storage section 61 side.

[0153] Next, refer to Figure 16 The flowchart shown in FIG. 1 sequentially describes the control performed by the control unit 90 in each step regarding the flow of the concentration adjustment operation in the method for maintaining the cap device.

[0154] In step S201, the control unit 90 determines whether the first on-off valve 66c is open. If the first on-off valve 66c is open, the process proceeds to step S203. If the first on-off valve 66c is closed, the process proceeds to step S202, in which the control unit 90 opens the first on-off valve 66c.

[0155] In step S203, the control unit 90 drives the first pump 63 for the third predetermined time T3 while the first on-off valve 66c is in the open state. Figure 15 As shown, the humidification fluid L1a flows in the circulation path 62 to Figure 15 Then, the water L1b flows in the direction of the solid arrow shown in FIG. Figure 15 The humidified fluid L1a flows in the direction of the dotted arrow shown in FIG. 6 and merges with the humidified fluid L1a at the first merging portion 62c. The humidified fluid L1a and the water L1b after the merging become the humidified fluid L1a with increased water content, and flows from the first merging portion 62c toward the unit cover 51a and flows in the circulation path 62. Figure 15 The liquid flows in the direction of the solid arrow shown, and flows into the humidification fluid storage section 61. In addition, the liquid level in the humidification fluid storage section 61 is higher than the first predetermined height H1.

[0156] In step S204, the control unit 90 obtains information about the liquid level in the humidifying fluid storage unit 61 from the detection unit 61a. Then, in step S205, the control unit 90 determines whether the liquid level is higher than the first predetermined height H1. If the liquid level is higher than the first predetermined height H1, the process proceeds to step S206. If the liquid level is lower than the first predetermined height H1, the process proceeds to step S207.

[0157] In step S206, the control unit 90 closes the first on-off valve 66c and moves to the subroutine of the aforementioned cyclic operation in step S100. When the subroutine of the cyclic operation is completed, the control unit 90 ends the process.

[0158] In step S207, the control unit 90 determines that the water L1b in the water storage unit 66a has been completely drained. In step S400, the control unit 90 executes the subroutine for the water storage unit pre-replacement operation, described below. Specifically, if the amount of water L1b in the water storage unit 66a reaches a level that indicates the need to replace the water storage unit 66a, the cap device 50 performs the pre-replacement operation. Upon completing the pre-replacement operation subroutine, the control unit 90 ends the process.

[0159] It should be noted that in steps S203 to S205, the control unit 90 may also drive the first pump 63 while obtaining information on the liquid level in the humidifying fluid storage section 61 from the detection unit 61a while the first on-off valve 66c is open, and stop the first pump 63 when the liquid level exceeds the first predetermined height H1. Alternatively, the control unit 90 may determine in step S207 that the water L1b in the water storage section 66a has been completely drained if the detection unit 61a detects that the liquid level has fallen below the first predetermined height H1 after a third predetermined time T3 has elapsed since the first pump 63 was driven.

[0160] About the cover replacement preparation action

[0161] The cap replacement preparation operation in the cap device maintenance method will be described.

[0162] The cap replacement preparation operation is an operation performed by the cap device 50 when the cap is replaced. Before the cap is replaced, the humidification fluid L1a in the cap is recovered. In the cap device 50 of this embodiment, when the cap is replaced, Figure 3 The cap unit 51 shown. It should be noted that the cap device 50 may also be configured so that the unit cap 51a is replaced when the cap is replaced.

[0163] like Figure 17 As shown, the cap device 50 performs the cap replacement preparation operation. During the cap replacement preparation operation, the first opening and closing valve 66c is in the closed state and the second opening and closing valve 67b is in the open state. The control unit 90 controls the pressurized air supply unit 67 of the humidification fluid circulation mechanism 60 to pressurize the pressurized air in the pressurized air supply path 67a. Figure 17 At this time, the humidification fluid L1a in the circulation path 62 flows in the direction of the dotted arrow shown. Figure 17 The pressurized air flows in the direction of the solid arrow shown, and is supplied into the circulation path 62 .

[0164] The pressurized air supply unit 67 continuously supplies pressurized air into the circulation path 62, whereby the humidified fluid L1a in the flow path from the second confluence portion 66e to the inflow portion 61f in the circulation path constituted by the circulation path 62 is pushed into the humidified fluid storage portion 61. In addition, air is filled in the flow path from the second confluence portion 66e to the inflow portion 61f. Thus, the humidified fluid L1a in the unit cover 51a is recovered by the humidified fluid storage portion 61. That is, the cover replacement preparation action in the maintenance method of the cover device refers to the action of supplying pressurized air from the pressurized air supply unit 67 to the unit cover 51a as an example of a cover, thereby discharging the humidified fluid L1a in the unit cover 51a to the humidified fluid storage portion 61 and supplying pressurized air into the unit cover 51a.

[0165] Since the moisture of the humidifying fluid L1a evaporates inside the unit cover 51a, the concentration of the humidifying fluid L1a inside the unit cover 51a is relatively high. Therefore, when the humidifying fluid L1a inside the unit cover 51a is recovered to the humidifying fluid storage section 61, the concentration of the humidifying fluid L1a inside the humidifying fluid storage section 61 becomes higher. In addition, when the humidifying fluid L1a inside the unit cover 51a is recovered to the humidifying fluid storage section 61, a small amount of the humidifying fluid L1a with a relatively high concentration remains inside the unit cover 51a. Therefore, when the moisture L1b is then supplied to the humidifying fluid L1a, the concentration of the humidifying fluid L1a inside the humidifying fluid storage section 61 becomes lower. In order to reduce the concentration change of the humidifying fluid L1a, it is preferable to increase the volume of the humidifying fluid storage section 61 as much as possible within the size of the liquid discharge device 11.

[0166] Next, refer to Figure 18 The flowchart shown in FIG. 1 sequentially describes the control performed by the control unit 90 in each step regarding the flow of the cap replacement preparation operation in the cap device maintenance method.

[0167] In step S301, the control unit 90 determines whether the first on-off valve 66c is in the closed state. If the first on-off valve 66c is closed, the process proceeds to step S303. If the first on-off valve 66c is open, the process proceeds to step S302. Then, in step S302, the control unit 90 closes the first on-off valve 66c.

[0168] In step S303, the control unit 90 opens the second on-off valve 67b. Then, in step S304, with the first on-off valve 66c closed and the second on-off valve 67b open, the control unit 90 drives the second pump 67c for the fourth predetermined time T4. This allows the humidification fluid L1a within the unit cover 51a to be recovered by the humidification fluid storage portion 61. Then, in step S305, the control unit 90 closes the second on-off valve 67b, terminating the process.

[0169] Regarding the action before replacing the moisture storage unit

[0170] The operation before replacing the moisture storage portion in the maintenance method of the cap device will be described.

[0171] like Figure 19 As shown, the cap device 50 performs a pre-water storage unit replacement operation. The pre-water storage unit replacement operation is an operation executed by the control unit 90 when the amount of water L1b within the water storage unit 66a reaches a level that determines that the water storage unit 66a needs to be replaced. In this embodiment, during the aforementioned concentration adjustment operation, when the first pump 63 is driven for the third predetermined time T3 and the detection unit 61a detects that the liquid level within the humidification fluid storage unit 61 is below the first predetermined height H1, the control unit 90 determines that the water within the water storage unit 66a has been completely drained. In other words, if the concentration of the humidification fluid L1a within the circulation path 62 cannot be returned to the concentration before the water evaporated within the unit cap 51a, the control unit 90 determines that the water storage unit 66a needs to be replaced.

[0172] When it is determined that the moisture storage section 66a needs to be replaced, the control section 90 performs the same operations as the cap replacement preparation operation described above. Furthermore, after the humidification fluid L1a in the unit cap 51a is recovered and until the moisture storage section 66a is replaced, the first parameter table for flushing is switched to the second parameter table for when the moisture L1b in the moisture storage section 66a is completely drained.

[0173] The parameter table lists flushing conditions, frequency, and other parameters, and flushing is performed based on this table. If the humidification fluid L1a in the unit cap 51a is recovered, the space SP in the unit cap 51a is not humidified by the humidification fluid L1a. Therefore, the control unit 90 performs a dry discharge, i.e., a liquid not related to printing, into the space SP in the unit cap 51a to humidify the nozzles 22. Therefore, the flushing conditions, frequency, and other parameters are changed to parameters suitable for humidifying the nozzles 22.

[0174] In summary, the actions before replacing the moisture containing section include the above-mentioned cap replacement preparation actions and the cap device 50 performing an empty ejection of liquid not related to printing from the liquid ejection head 21 to the space SP within the unit cap 51a as an example of a cap to humidify the nozzle 22 until the moisture containing section 66a is replaced.

[0175] It should be noted that the previously periodic cycle is not performed until the moisture storage unit 66a is replaced. After the moisture storage unit 66a is replaced, the control unit 90 returns the second parameter table to the first parameter table used before the parameter table was switched, and then begins the concentration adjustment process described above. The cycle is then performed periodically thereafter.

[0176] Next, refer to Figure 20The flowchart shown in the figure sequentially describes the control performed by the control unit 90 in each step regarding the flow of the operation before the moisture storage unit is replaced in the maintenance method of the cap device.

[0177] In step S300, the control unit 90 executes the above-mentioned subroutine of the cap replacement preparation operation. When the subroutine of the cap replacement preparation operation ends, in step S401, the control unit 90 switches the parameter table and ends the process.

[0178] About humidification fluid filling operation

[0179] The humidification fluid filling operation in the cap device maintenance method will be described.

[0180] The humidification fluid filling action means that during assembly Figure 1 The process of storing the humidifying fluid L1a in the humidifying fluid storage section 61 before the liquid ejection device 11 shown in the figure is shipped from the factory. After the humidifying fluid L1a is stored in the humidifying fluid storage section 61, the liquid ejection device 11 is shipped from the factory in a state where the humidifying fluid L1a in the unit cover 51a is recovered in the humidifying fluid storage section 61. The humidifying fluid filling operation is performed before the moisture storage section 66a is installed in the moisture supply flow path 66b. It should be noted that when the moisture storage section 66a has been installed in the moisture supply flow path 66b, the process of the humidifying fluid filling operation is performed after the moisture storage section 66a is removed from the moisture supply flow path 66b. It should be noted that in the process of the humidifying fluid filling operation, a part of the process is performed by manual operation of the operator.

[0181] like Figure 21 As shown, a humidifying fluid bag 68 is attached to the water supply passage 66b. The humidifying fluid bag 68 contains the humidifying fluid L1a intended to be contained in the humidifying fluid container 61. Furthermore, the humidifying fluid bag 68 communicates with the water supply passage 66b at the outflow portion 68a of the humidifying fluid bag 68. Thus, when the first on-off valve 66c is open, the humidifying fluid bag 68 and the first confluence portion 62c are connected via the water supply passage 66b.

[0182] The circulation path 62 has a flow regulator section 62d upstream of the first confluence section 62c. Preferably, the distance between the flow regulator section 62d and the first confluence section 62c is as short as possible. If the flow regulator section 62d is closed by the flow regulator 69, the flow path becomes closed at the flow regulator section 62d. That is, the humidification fluid storage section 61 and the first confluence section 62c become disconnected by the flow regulator 69. It should be noted that the flow regulator is an instrument that is arranged midway in the flow path and regulates the flow rate of the flow path by clamping the flow path.

[0183] In this state, when the first on-off valve 66c is in the open state, the control unit 90 controls the humidification fluid circulation mechanism 60 by driving the first pump 63, so that the humidification fluid L1a flows in the circulation path 62. Figure 21 At this time, the humidifying fluid L1a in the humidifying fluid bag 68 flows in the direction of the solid arrow shown. Figure 21 Flowing in the direction of the solid arrow shown. Furthermore, with the first on-off valve 66c in the open state, the humidifying fluid L1a is supplied to the circulation path 62. Furthermore, at this time, the flow regulator 69 is in the closed state of the flow regulator 62d. Therefore, the humidifying fluid L1a in the humidifying fluid storage section 61 is not supplied to the circulation path 62. As a result, a predetermined amount of the humidifying fluid L1a in the humidifying fluid bag 68 flows into the humidifying fluid storage section 61. Furthermore, the liquid level in the humidifying fluid storage section 61 becomes higher than the first predetermined height H1.

[0184] The control unit 90 closes the first on-off valve 66c, and the operator removes the flow regulator 69. The humidifying fluid L1a circulates within the circulation path 62, stabilizing the liquid level within the humidifying fluid storage unit 61. The control unit 90 then executes a cap replacement preparation operation, recovering the humidifying fluid L1a within the unit cap 51a back into the humidifying fluid storage unit 61. The liquid ejection device 11 is shipped from the factory in this state.

[0185] Next, refer to Figure 22 The flowchart shown in FIG. 1 sequentially describes the process of each step of the humidification fluid filling operation.

[0186] In step S501, the operator attaches the humidification fluid bag 68. Then, in step S502, the operator attaches the flow regulator 69 to the flow regulator portion 62d and closes the flow regulator 69.

[0187] In step S503, the control unit 90 determines whether the first on-off valve 66c is open. If the first on-off valve 66c is open, the process proceeds to step S505. If the first on-off valve 66c is closed, the process proceeds to step S504. Then, in step S504, the control unit 90 opens the first on-off valve 66c.

[0188] In step S505, the control unit 90 starts driving the first pump 63. Figure 21 As shown, the humidification fluid L1a flows in the moisture supply flow path 66b. Figure 21 Then, the humidification fluid L1a flows from the first merging portion 62c toward the unit cover 51a and flows in the circulation path 62. Figure 21 Flow is shown in the direction of the solid arrow.

[0189] In step S506, the control unit 90 obtains information about the liquid level in the humidifying fluid storage unit 61 from the detection unit 61a. Then, in step S507, it determines whether the liquid level in the humidifying fluid storage unit 61 is higher than the first predetermined height H1. If the liquid level is higher than the first predetermined height H1, the process proceeds to step S508. Then, in step S508, the control unit 90 stops driving the first pump 63. If the liquid level is lower than the first predetermined height H1, the process continues driving the first pump 63 and the process proceeds to step S506.

[0190] In step S509, the control unit 90 closes the first on-off valve 66c. Then, in step S510, the operator removes the flow regulator 69.

[0191] In step S511, the control unit 90 drives the first pump 63 for the first predetermined time T1 when the first on-off valve 66c is in the closed state. Figure 13 As shown, the humidification fluid L1a flows in the circulation path 62 to Figure 13 Flow is shown in the direction of the solid arrow.

[0192] In step S512, the control unit 90 stops the first pump 63 for the second predetermined time T2 when the first on-off valve 66c is in the closed state.

[0193] In step S513, the control unit 90 obtains information on the liquid level in the humidifying fluid storage section 61 from the detection unit 61a. Then, in step S514, it is determined whether the liquid level in the humidifying fluid storage section 61 is higher than the first predetermined height H1. When the liquid level is higher than the first predetermined height H1, the process moves to step S300. Then, in step S300, the control unit 90 executes a subroutine for the cap replacement preparation operation. As a result, the humidifying fluid L1a in the unit cap 51a is recovered into the humidifying fluid storage section 61. It should be noted that if the cap replacement preparation operation is executed, there is a possibility that the liquid level will further increase due to the humidifying fluid L1a in the unit cap 51a. Therefore, in the cap replacement preparation operation, before the humidifying fluid L1a in the unit cap 51a is completely recovered into the humidifying fluid storage section 61, the first predetermined height H1 is set to a height at which the humidifying fluid storage section 61 will not be completely filled with the humidifying fluid L1a.

[0194] If the liquid level falls below the first predetermined height H1 in step S514, the control unit 90 proceeds to step S502. This causes the humidifying fluid L1a in the humidifying fluid bag 68 to be supplied back into the circulation path 62. In other words, the liquid level in the humidifying fluid storage unit 61 is finely adjusted.

[0195] When the subroutine of the cap replacement preparation operation is completed, in step S515 , the operator removes the humidifying fluid bag 68 and installs the moisture storage portion 66 a .

[0196] About the liquid ejected from the liquid ejection head

[0197] Ink, which is an example of liquid ejected by the liquid ejecting device 11 , will be described in detail below.

[0198] The ink used in the liquid ejection device 11 contains resin and is substantially free of glycerin, which has a boiling point of 290°C at 1 atmosphere. If the ink contains substantial amounts of glycerin, the ink's drying properties are significantly impaired. As a result, image shading unevenness is noticeable on various media, particularly those with low or no ink absorption, and the ink's fixability is impaired. Furthermore, the ink is preferably free of alkyl polyols (excluding the aforementioned glycerin) with a boiling point of 280°C or higher at 1 atmosphere.

[0199] As used herein, "substantially free" means not containing an amount greater than that sufficient to fully demonstrate the significance of addition. Quantitatively speaking, glycerin preferably does not contain 1.0% or more by mass, more preferably 0.5% or more by mass, even more preferably 0.1% or more by mass, even more preferably 0.05% or more by mass, and particularly preferably 0.01% or more by mass, relative to the total mass of the ink (100% by mass). Furthermore, it is most preferred that glycerin not be contained in an amount greater than 0.001% by mass.

[0200] Next, the additives (components) contained or capable of being contained in the above-mentioned ink will be described.

[0201] 1. Pigment

[0202] The ink may also contain a colorant selected from pigments and dyes.

[0203] 1-1. Pigments

[0204] By using a pigment as a colorant, the light resistance of the ink can be improved. The pigment can be either an inorganic pigment or an organic pigment. Inorganic pigments are not particularly limited, and examples thereof include carbon black, iron oxide, titanium oxide, and silicon oxide.

[0205] The organic pigment is not particularly limited, and examples thereof include quinacridone pigments, quinacridonequinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, anthraquinone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinacridone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments, and azo pigments. Specific examples of the organic pigment include the following pigments.

[0206] Examples of pigments used for cyan ink include CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 15:34, 16, 18, 22, 60, 65, 66, and CI Vat Blue 4 and 60. Among them, CI Pigment Blue 15:3 and 15:4 are preferred.

[0207] Examples of pigments used in magenta ink include CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48 (Ca), 48 (Mn), 57 (Ca), 57:1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168, 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, 245, 254, 264, CI Pigment Violet 19, 23, 32, 33, 36, 38, 43, 50. Among them, one or more selected from the group consisting of CI Pigment Red 122, CI Pigment Red 202 and CI Pigment Violet 19 are preferred.

[0208] Examples of pigments used in yellow ink include CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 155, 167, 172, 180, 185, and 213. Among these, one or more selected from the group consisting of CI Pigment Yellow 74, 155, and 213 are preferred.

[0209] In addition, examples of pigments used for inks of colors other than those mentioned above, such as green ink and orange ink, include conventionally known pigments.

[0210] The average particle size of pigment can suppress the clogging of nozzle 22, and ejection stability is better, therefore is preferably below 250nm.It should be noted that, the average particle size in this manual is volume reference.As measuring method, for example, can be measured by the particle size distribution measuring device that takes laser diffraction scattering method as measuring principle.As particle size distribution measuring device, for example, can enumerate the particle size distribution meter (for example Microtrack UPA of Japanese machine equipment company (Nikkiso Co., Ltd.) that takes dynamic light scattering method as measuring principle).

[0211] 1-2. Dye

[0212] As the colorant, a dye can be used. The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used. The colorant content is preferably 0.4 to 12% by mass relative to the total mass of the ink (100% by mass), more preferably 2% to 5% by mass.

[0213] 2. Resin

[0214] The ink contains a resin. The inclusion of a resin in the ink forms a resin film on the medium, effectively fixing the ink to the medium and significantly improving the abrasion resistance of the image. Therefore, the resin emulsion is preferably a thermoplastic resin. The heat deformation temperature of the resin is preferably 40°C or higher, more preferably 60°C or higher, as this temperature is less likely to clog the nozzle 22 and improves the abrasion resistance of the medium.

[0215] In this specification, "heat deformation temperature" refers to a temperature value expressed as either the glass transition temperature (Tg) or the minimum film forming temperature (MFT). Specifically, "a heat deformation temperature of 40°C or higher" simply means that either the Tg or the MFT is 40°C or higher. It should be noted that the MFT is more easily used to assess the redispersibility of a resin than the Tg, so the heat deformation temperature is preferably expressed as the MFT. Inks with excellent resin redispersibility prevent ink adhesion, making nozzle 22 less likely to clog.

[0216] Specific examples of the thermoplastic resin include, but are not particularly limited to, poly(meth)acrylates or copolymers thereof, polyacrylonitrile or copolymers thereof, (meth)acrylic acid polymers such as polycyanoacrylate, polyacrylamide, and poly(meth)acrylic acid, polyethylene, polypropylene, polybutene, polyisobutylene, and polystyrene, and copolymers thereof, polyolefin polymers such as petroleum resins, coumarone-indene resins, and terpene resins, polyvinyl acetate or copolymers thereof, vinyl acetate-based or vinyl alcohol-based polymers such as polyvinyl alcohol, polyvinyl acetal, and polyvinyl ether, polyvinyl chloride or copolymers thereof, halogen-containing polymers such as polyvinylidene chloride, fluororesins, and fluororubbers, nitrogen-containing vinyl polymers such as polyvinylcarbazole, polyvinylpyrrolidone, and copolymers thereof, polyvinylpyridine, and polyvinylimidazole, polybutadiene or copolymers thereof, diene polymers such as polychloroprene and polyisoprene (butyl rubber), and other ring-opening polymerization resins, polycondensation resins, and natural polymer resins.

[0217] The resin content is preferably 1 to 30% by mass, more preferably 1 to 5% by mass, relative to the total mass of the ink (100% by mass). Within this range, the gloss and abrasion resistance of the resulting overcoat image can be further improved. Examples of resins that may be included in the ink include resin dispersants, resin emulsions, and waxes.

[0218] 2-1. Resin emulsion

[0219] The ink may contain a resin emulsion. When the medium is heated, the resin emulsion preferably forms a resin film together with the wax (emulsion), thereby effectively fixing the ink to the medium and improving the image's abrasion resistance. This effect allows the ink containing a resin emulsion to be printed on a medium, particularly on non-absorbent or low-absorbent media.

[0220] In addition, the resin emulsion that functions as a binder is contained in the ink in an emulsion state. By containing the resin that functions as a binder in the ink in an emulsion state, the viscosity of the ink can be easily adjusted to an appropriate range in the inkjet recording method, and the storage stability and ejection stability of the ink can be improved.

[0221] The resin emulsion is not limited to the following substances, and examples thereof include: homopolymers or copolymers of (meth)acrylic acid, (meth)acrylate, acrylonitrile, cyanoacrylate, acrylamide, olefins, styrene, vinyl acetate, vinyl chloride, vinyl alcohol, vinyl ether, vinyl pyrrolidone, vinyl pyridine, vinyl carbazole, vinyl imidazole, and vinylidene chloride, fluororesins, and natural resins. Among them, any one of methacrylic acid-based resins and styrene-methacrylic acid copolymer-based resins is preferred, any one of acrylic acid-based resins and styrene-acrylic acid copolymer-based resins is more preferred, and styrene-acrylic acid copolymer-based resins is further preferred. It should be noted that the above-mentioned copolymers may be in the form of random copolymers, block copolymers, alternating copolymers, and graft copolymers.

[0222] To improve the ink's storage stability and ejection stability, the average particle size of the resin emulsion is preferably between 5 nm and 400 nm, more preferably between 20 nm and 300 nm. The resin emulsion content in the resin is preferably between 0.5 and 7% by mass relative to the total mass of the ink (100% by mass). A content within this range can reduce the solids concentration, thereby improving ejection stability.

[0223] 2-2. Wax

[0224] The ink may contain wax. By including wax in the ink, the ink's fixability on non-absorbent and low-absorbent media is further improved. The wax is preferably an emulsion wax. Examples of such waxes include, but are not limited to, polyethylene wax, paraffin wax, and polyolefin wax, with polyethylene wax, described below, being preferred. It should be noted that, in this specification, "wax" primarily refers to wax obtained by dispersing solid wax particles in water using a surfactant, described below.

[0225] The inclusion of polyethylene wax in the ink can improve the ink's abrasion resistance. To further improve the ink's storage stability and ejection stability, the average particle size of the polyethylene wax is preferably in the range of 5 nm to 400 nm, more preferably in the range of 50 nm to 200 nm.

[0226] The polyethylene wax content (based on solids content) is preferably 0.1-3% by mass, more preferably 0.3-3% by mass, and even more preferably 0.3-1.5% by mass, relative to the total mass of the ink (100% by mass), independently of each other. A content within this range allows for good ink curing and fixing even on non-absorbent or low-absorbent media, and further improves the ink's storage stability and ejection stability.

[0227] 3. Surfactants

[0228] The ink may contain a surfactant. Examples of surfactants include, but are not limited to, nonionic surfactants. Nonionic surfactants have the effect of uniformly spreading the ink on the medium. Therefore, when printing with ink containing a nonionic surfactant, a high-definition image with almost no bleeding can be obtained. Examples of such nonionic surfactants include, but are not limited to, silicone-based, polyoxyethylene alkyl ether-based, polyoxypropylene alkyl ether-based, polycyclic phenyl ether-based, sorbitan derivatives, and fluorine-based surfactants. Silicon-based surfactants are preferred.

[0229] The content of the surfactant is preferably in the range of 0.1% by mass or more and 3% by mass or less relative to the total mass of the ink (100% by mass) because the storage stability and ejection stability of the ink are better.

[0230] 4. Organic solvents

[0231] The ink may contain a known volatile water-soluble organic solvent. However, as described above, the ink preferably contains substantially no glycerin (boiling point 290°C at 1 atmosphere) as one type of organic solvent, and substantially no alkyl polyols (excluding glycerin) with a boiling point of 280°C or higher at 1 atmosphere.

[0232] 5. Aprotic polar solvents

[0233] The ink may contain an aprotic polar solvent. The inclusion of an aprotic polar solvent in the ink dissolves the resin particles contained therein, effectively preventing nozzle 22 from clogging during printing. Furthermore, the ink's ability to dissolve media such as vinyl chloride improves image adhesion.

[0234] The aprotic polar solvent is not particularly limited, but preferably contains one or more selected from pyrrolidones, lactones, sulfoxides, imidazolinones, sulfolanes, urea derivatives, dialkylamides, cyclic ethers, and amide ethers. Representative examples of pyrrolidones include 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone; representative examples of lactones include γ-butyrolactone, γ-valerolactone, and ε-caprolactone; and representative examples of sulfoxides include dimethyl sulfoxide and tetramethylene sulfoxide.

[0235] Representative examples of imidazolinones include 1,3-dimethyl-2-imidazolidinone, representative examples of sulfolanes include sulfolane and dimethylsulfolane, and representative examples of urea derivatives include dimethylurea and 1,1,3,3-tetramethylurea. Representative examples of dialkylamides include dimethylformamide and dimethylacetamide, and representative examples of cyclic ethers include 1,4-dioxane and tetrahydrofuran.

[0236] Among them, pyrrolidones, lactones, sulfoxides, and amide ethers are particularly preferred from the perspective of the above-mentioned effects, with 2-pyrrolidone being most preferred. The content of the aprotic polar solvent is preferably in the range of 3 to 30 mass %, more preferably in the range of 8 to 20 mass %, relative to the total mass of the ink (100 mass %).

[0237] 6. Other ingredients

[0238] In addition to the above-mentioned components, the ink may further contain a mildew preventer, a rust preventer, a chelating agent, and the like.

[0239] About humidification fluid

[0240] The components of the surfactant mixed with the humidification fluid L1a will be described.

[0241] As surfactants, cationic surfactants such as alkylamine salts and quaternary ammonium salts; anionic surfactants such as dialkyl sulfosuccinates, alkylnaphthalene sulfonates and fatty acid salts; zwitterionic surfactants such as alkyldimethylamine oxide and alkylcarboxybetaine; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, and polyoxyethylene-polyoxypropylene block copolymers can be used. Among them, anionic surfactants or nonionic surfactants are particularly preferred.

[0242] The content of the surfactant is preferably 0.1 to 5.0 mass % relative to the total mass of the humidifying fluid L1a. In addition, from the perspective of bubble properties and defoaming properties after bubbling, the content of the surfactant is preferably 0.5 to 1.5 mass % relative to the total mass of the humidifying fluid L1a. It should be noted that the surfactant can be only one type or two or more types. In addition, the surfactant contained in the humidifying fluid L1a is preferably the same as the surfactant contained in the ink (liquid). For example, when the surfactant contained in the ink (liquid) is a nonionic surfactant, the nonionic surfactant is not limited to the following, for example, silicon-based, polyoxyethylene alkyl ether-based, polyoxypropylene alkyl ether-based, polycyclic phenyl ether-based, sorbitan derivatives, and fluorine-based surfactants can be mentioned, among which silicon-based surfactants are preferred.

[0243] In particular, to achieve bubble heights within the aforementioned ranges (bubble height of 50 mm or greater immediately after foaming and 5 mm or less after foaming) as determined by the Rosemyers method, it is preferred to use an adduct of ethylene oxide (EO) added to acetylene glycol at a molar ratio of 4 to 30, with the content of the adduct being 0.1 to 3.0% by weight relative to the total weight of the cleaning solution. Furthermore, to achieve bubble heights within the aforementioned preferred ranges (bubble height of 100 mm or greater immediately after foaming and 5 mm or less after foaming) as determined by the Rosemyers method, it is preferred to use an adduct of ethylene oxide (EO) added to acetylene glycol at a molar ratio of 10 to 20, with the content of the adduct being 0.5 to 1.5% by weight relative to the total weight of the cleaning solution. However, if the content of the ethylene oxide adduct of acetylene glycol is too high, the critical micelle concentration may be reached, resulting in an emulsion.

[0244] Surfactants facilitate the wetting and spreading of aqueous ink on the recording medium. Surfactants that can be used in the present invention are not particularly limited, and include anionic surfactants such as dialkyl sulfosuccinates, alkylnaphthalene sulfonates, and fatty acid salts; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylenic diols, and polyoxyethylene-polyoxypropylene block copolymers; cationic surfactants such as alkylamine salts and quaternary ammonium salts; silicone surfactants; and fluorine-based surfactants.

[0245] It should be noted that the surfactant has the effect of breaking up the aggregates and dispersing them through the surface activity between the humidifying fluid L1a and the aggregates. Furthermore, since it reduces the surface tension of the cleaning liquid, the cleaning liquid easily penetrates between the aggregates and the nozzle surface 23, making it easier to peel the aggregates from the nozzle surface 23.

[0246] As long as the surfactant is a compound having a hydrophilic portion and a hydrophobic portion in the same molecule, it can be suitably used. As a specific example, compounds represented by the following formulas (I) to (IV) are preferred. That is, polyoxyethylene alkylphenyl ether surfactants of the following formula (I), acetylene glycol surfactants of the following formula (II), polyoxyethylene alkyl ether surfactants of the following formula (III), and polyoxyethylene polyoxypropylene alkyl ether surfactants of the following formula (IV) can be mentioned.

[0247] [Chemical Formula 1]

[0248]

[0249] (R is a branched hydrocarbon chain with 6 to 14 carbon atoms, k: 5 to 20)

[0250] [Chemical Formula 2]

[0251]

[0252] (m, n≤20,0 <m+n≤40)

[0253] [Chemical Formula 3]

[0254] R-(OCH2CH2)nH…(III)

[0255] (R is a branched hydrocarbon chain with 6 to 14 carbon atoms, and n is 5 to 20)

[0256] [Chemical Formula 4]

[0257]

[0258] (R is a hydrocarbon chain having 6 to 14 carbon atoms, and m and n are numbers not greater than 20)

[0259] In addition to the compounds of formulae (I) to (IV), alkyl and aryl ethers of polyols such as diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, and tetraethylene glycol chlorophenyl ether, nonionic surfactants such as polyoxyethylene-polyoxypropylene block copolymers, fluorine-based surfactants, and lower alcohols such as ethanol and 2-propanol can be used, with diethylene glycol monobutyl ether being particularly preferred.

[0260] The operation of this embodiment will be described.

[0261] Before the liquid ejection device 11 is assembled and shipped from the factory, Figure 22 The flow of the humidification fluid filling action is shown.

[0262] like Figure 21 As shown, in the humidification fluid filling operation, the humidification fluid L1a in the humidification fluid receiving portion 61 is not supplied to the circulation path 62 by the flow regulator 69, and the first opening and closing valve 66c is in the open valve state, the control unit 90 drives the first pump 63 to flow the humidification fluid L1a into the circulation path 62. Figure 21 The liquid flows in the direction of the solid arrow shown. By driving the first pump 63 until the detection unit 61a detects that the liquid level in the humidification fluid storage unit 61 is higher than the first predetermined height H1, a predetermined amount of the humidification fluid L1a in the humidification fluid bag 68 can be stored in the humidification fluid storage unit 61. Therefore, the liquid ejecting device 11 can be shipped from the factory with the predetermined amount of the humidification fluid L1a stored in the humidification fluid storage unit 61.

[0263] The cap replacement preparation operation executed by the controller 90 at the end of the humidification fluid filling operation drains most of the humidification fluid L1a within the unit cap 51a to the outside of the unit cap 51a. Therefore, the liquid ejecting device 11 can be shipped from the factory with almost no humidification fluid L1a remaining within the unit cap 51a.

[0264] The liquid ejection device 11 shipped from the factory is set up by the user and starts to be used. Before the liquid ejection device 11 is set up and recording is performed on the medium M for the first time, the control unit 90 executes Figure 14 The flow of the cycle action is shown.

[0265] like Figure 13 As shown, in the circulation operation, when the first on-off valve 66c is in the closed state, the control unit 90 drives the first pump 63 to move the humidification fluid L1a to the circulation path 62. Figure 13 The humidification fluid L1a flows in the direction of the solid arrow shown. This allows the humidification fluid L1a to flow through the unit cap 51a, which is almost empty of the humidification fluid L1a at the time of shipment. In addition, the humidification chamber 55 of the unit cap 51a can be filled with the humidification fluid L1a.

[0266] In more detail, Figure 7 As shown, the humidifying fluid L1a can flow through the humidifying chamber 55, which has a flow path formed as a single passage connecting the inlet 55a and the outlet 55b by the grooves 55c and the first moisture-permeable membrane 54 covering the grooves 55c. That is, during shipment, the grooves 55c of the humidifying chamber 55, which are substantially free of the humidifying fluid L1a, can be filled with the humidifying fluid L1a.

[0267] By forming the humidification chamber 55 into such a single-channel flow path, the humidification fluid L1a can be easily filled into the humidification chamber 55 by the circulation action. In addition, since the humidification chamber 55 is formed into a curved flow path, the humidification fluid L1a filled in the humidification chamber 55 by the circulation action can be prevented from flowing out of the humidification chamber 55 through the inlet 55a or the outlet 55b.

[0268] like Figure 3 As shown, the cover device 50 is formed by arranging a plurality of unit covers 51a. In addition, as described above, the outlet 55b of one unit cover 51a among the plurality of unit covers 51a is connected to the inlet 55a of another unit cover 51a adjacent to the unit cover 51a. Figure 11 As shown, the inlet 55a located most upstream is connected to the supply flow path 62a, and the outlet 55b located most downstream is connected to the recovery flow path 62b. Thus, the plurality of unit caps 51a can be filled with the humidification fluid L1a using only one supply flow path 62a and recovery flow path 62b.

[0269] like Figure 8 As shown, the humidification chamber 55 is arranged in an inclined position relative to the horizontal. In addition, the inlet 55a and the outlet 55b are arranged above the vertical center of the humidification chamber 55. Therefore, the humidification fluid L1a filled in the humidification chamber 55 due to the circulation operation can be prevented from flowing out of the humidification chamber 55 through the inlet 55a or the outlet 55b due to water pressure.

[0270] like Figure 2 As shown, in the liquid ejection device 11, when the liquid ejection head 21 records on the medium M, Figure 1 The medium M is fed from the medium storage unit 16 shown, and the medium M passes through the transport path 19 toward the recording unit 20. Furthermore, in the recording unit 20, the liquid ejection head 21 ejects liquid toward the medium M being transported in the first transport direction Z1. Furthermore, the liquid ejection device 11 records text, images, etc. on the medium M by alternately repeating a transport operation of transporting the medium M to the next recording position and a recording operation of ejecting liquid from the liquid ejection head 21.

[0271] like Figure 8 As shown, when the liquid ejection head 21 is not ejecting liquid, the liquid ejection device 11 performs a capping operation, i.e., capping, such that the cap unit 51 surrounds the nozzle 22 and contacts the nozzle surface 23 of the liquid ejection head 21. That is, when the liquid ejection head 21 is not ejecting liquid, the unit cap 51a surrounds the nozzle 22 and maintains contact with the nozzle surface 23 of the liquid ejection head 21.

[0272] like Figure 2 As shown, during capping, after the cap unit 51 moves from the retracted position in the third direction D3 to the maintenance position, the head unit 24 moves from the recording position in the first direction D1 to the maintenance position. Thus, the cap unit 51 caps the head unit 24. That is, the capping device 50 contacts the liquid ejecting head 21. Consequently, the contact surface 56f of the unit cap 51a contacts the nozzle surface 23 of the liquid ejecting head 21, allowing the sealing portion 56e to seal the nozzle surface 23.

[0273] like Figure 10 As shown, the humidification chamber 55 is filled with the humidification fluid L1a. Moisture evaporated from the humidification fluid L1a, along with the moist air containing it, passes through the first moisture-permeable membrane 54 and the absorber 53 and reaches the recess 57. Furthermore, this moisture humidifies the interior of the recess 57. Consequently, the space SP surrounding the opening of the nozzle 22 when the unit cap 51a is in contact with the liquid ejection head 21 is humidified, thereby humidifying the opening of the nozzle 22. Furthermore, since the thickening of the liquid within the nozzle 22 is suppressed, the occurrence of ejection defects can be prevented.

[0274] like Figure 8 As shown, in the humidifying chamber 55, since the flow path is routed along the entire bottom surface of the unit cover 51a, the entire recess 57 can be humidified. This allows the openings of the plurality of nozzles 22 included in the liquid ejecting head 21 to be humidified more uniformly.

[0275] like Figure 8 As shown, the liquid ejection device 11 periodically performs a flushing operation to discharge droplets not related to printing from the nozzles 22 into the space SP within the unit cap 51a. During flushing, the unit cap 51a is kept in contact with the nozzle surface 23 of the liquid ejection head 21 in a manner surrounding the nozzles 22.

[0276] like Figure 2 As shown, during flushing or cleaning, after the cap unit 51 moves from the retracted position in the third direction D3 to the maintenance position, the head unit 24 moves from the recording position in the first direction D1 to the maintenance position. This brings the cap device 50 into contact with the liquid ejecting head 21. Consequently, the contact surface 56f of the unit cap 51a comes into close contact with the nozzle surface 23 of the liquid ejecting head 21, and the sealing portion 56e seals the nozzle surface 23.

[0277] like Figure 9 As shown, the waste liquid L2 discharged from the nozzle 22 into the recess 57 by flushing or cleaning passes through the restricting member 52 and the absorber 53. The waste liquid L2 is absorbed by the absorber 53. Furthermore, the waste liquid L2 absorbed by the absorber 53 spreads throughout the entire absorber 53. Furthermore, when the absorber 53 reaches a point where it can no longer absorb the waste liquid L2, the waste liquid L2 flows vertically within the absorber 53 due to gravity. Because the first moisture-permeable membrane 54 is not liquid-permeable, the waste liquid L2 does not flow into the humidification chamber 55. Since the recess 57 has a drain hole 56b, any waste liquid L2 that cannot be absorbed by the absorber 53 within the recess 57 can be drained out of the unit cover 51a through the drain hole 56b.

[0278] The drain hole 56b may be provided in the recess 57 at a position lower than the first moisture-permeable membrane 54. The waste liquid L2 can be discharged from the drain hole 56b to the outside of the unit cover 51a by gravity. Furthermore, the surface of the first moisture-permeable membrane 54 is clogged with the waste liquid L2, thereby preventing gas from passing through.

[0279] The discharge hole 56b may be provided at the bottom of the recess 57. The waste liquid L2 can be discharged from the discharge hole 56b to the outside of the unit cover 51a by gravity. In addition, the waste liquid L2 can be prevented from remaining in the recess 57.

[0280] like Figure 11As shown, recessed portion 57 includes an atmosphere communication hole 56a for communicating space SP with the atmosphere. As described above, in this embodiment, third on-off valve 58b for communicating space SP with the atmosphere is opened and closed by movement of cover unit 51. This allows third on-off valve 58b to be opened and closed, allowing space SP to communicate with the atmosphere, without using a dedicated actuator for the third on-off valve.

[0281] When the third on-off valve 58b is opened or closed, the space SP communicates with the atmosphere. Thus, even when the space SP surrounding the opening of the nozzle 22 is formed, the atmosphere flows into the space SP, thereby making it easier for the waste liquid L2 in the recess 57 to be discharged from the discharge hole 56b to the outside of the unit cover 51a.

[0282] During flushing or cleaning, the liquid ejection head 21 discharges liquid into the unit cap 51a while the first atmosphere communication passage 58a is open. Furthermore, the first atmosphere communication passage 58a is also open when the liquid ejection head 21 is not capping the unit cap to eject liquid. In other words, since the first atmosphere communication passage 58a is open most of the time, the waste liquid L2 can be prevented from remaining in the recess 57.

[0283] like Figure 10 As shown, the air communication hole 56a may be provided above the vertical center of the recess 57. The air communication hole 56a is blocked by the waste liquid L2, thereby preventing the waste liquid L2 from being unable to be discharged from the recess 57.

[0284] The atmosphere communication hole 56a may be provided in the recess 57 at a position higher than the first moisture permeable membrane 54. The waste liquid L2 flowing on the surface of the first moisture permeable membrane 54 blocks the atmosphere communication hole 56a, thereby preventing the waste liquid L2 from being unable to be discharged from the recess 57.

[0285] like Figure 9 As shown in FIG. 1 , the waste liquid L2 discharged from the nozzle 22 to the recess 57 by flushing or cleaning is absorbed by the absorber 53. Figure 10 As shown, water evaporated from the humidifying fluid L1a and passed through the first moisture-permeable membrane 54 humidifies the waste liquid L2 absorbed by the absorber 53. Thus, when the viscosity of the waste liquid L2 absorbed by the absorber 53 is high, the viscosity of the waste liquid L2 is adjusted by the water evaporated from the humidifying fluid L1a. The space SP can be humidified more efficiently by the water evaporated from the humidifying fluid L1a and the waste liquid L2 with adjusted viscosity.

[0286] In this embodiment, the moisturizing power of the humidifying fluid L1a is the same as the moisturizing power of fresh ink. Therefore, when the ink absorbed by the absorbent body 53 is thickened, the ink absorbed by the absorbent body 53 is moisturized, so that the moisturizing power of the ink absorbed by the absorbent body 53 can be maintained at the same moisturizing power as the fresh ink.

[0287] The waste liquid L2 absorbed by the absorber 53 spreads across the entire absorber 53. This allows the waste liquid L2 absorbed by the absorber 53 to be distributed more evenly, thereby more evenly humidifying the entire space SP. Furthermore, the openings of the plurality of nozzles 22 included in the liquid ejection head 21 can be more evenly humidified.

[0288] When flushing or cleaning is performed, the liquid discharged from the nozzles 22 of the liquid ejection head 21 adheres to the nozzle surface 23. Therefore, after flushing or cleaning is performed, the liquid ejection device 11 is wiped.

[0289] like Figure 4 As shown, after the head unit 24 moves from the recording position in the first direction D1 to the maintenance position, the wiper carriage 41 moves from the retracted position in the fifth direction D5 to the retracted position. This allows the wiper member 42 of the wiper carriage 41 to wipe the nozzle surface 23 of the head unit 24. Furthermore, liquid adhering to the nozzle surface 23 can be recovered as waste liquid L2 within the wiper carriage 41. This removes liquid and contaminants such as dust adhering to the nozzle surface 23 of the liquid ejecting head 21.

[0290] like Figure 11 As shown, the waste liquid recovery mechanism 80 causes the waste liquid L2 recovered by flushing or cleaning and the waste liquid L2 recovered by wiping to flow out to the waste liquid storage portion 86 through the waste liquid recovery path 81 by means of the third pump 82. Thus, the waste liquid L2 recovered by flushing or cleaning and the waste liquid L2 recovered by wiping can be stored together in the waste liquid storage portion 86.

[0291] The fourth pump 84 is a pressure-reducing pump. Therefore, in the first waste liquid recovery path 81a, the fourth pump 84 discharges the air in the buffer chamber 83 to the outside of the buffer chamber 83, thereby reducing the air pressure in the buffer chamber 83. This facilitates the flow of waste liquid L2 recovered by flushing or cleaning into the buffer chamber 83. Furthermore, it facilitates the flow of waste liquid L2 recovered by flushing or cleaning into the waste liquid storage portion 86. In other words, it is possible to prevent waste liquid L2 from remaining in the recess 57.

[0292] like Figure 10As shown, during capping, the water contained in the humidifying fluid L1a filling the humidifying chamber 55 humidifies the space SP surrounding the opening of the nozzle 22 when the unit cap 51a is in contact with the liquid ejection head 21. As a result, the amount of water contained in the humidifying fluid L1a filling the humidifying chamber 55 decreases. In other words, the concentration of the humidifying fluid L1a filling the humidifying chamber 55 is greater than the concentration of the humidifying fluid L1a contained in the humidifying fluid storage portion 61.

[0293] like Figure 13 As shown, in the cap device 50, which includes a humidifying fluid storage portion 61, a supply flow path 62a, a recovery flow path 62b, and a first pump 63, a circulation operation is performed to circulate the humidifying fluid L1a within the circulation path 62. This agitates the humidifying fluid L1a within the circulation path 62. By agitating the humidifying fluid L1a within the circulation path 62, the concentration of the humidifying fluid L1a throughout the circulation path 62 can be made uniform. Specifically, the circulation operation can restore the amount of water contained in the humidifying fluid L1a filling the humidifying chamber 55 to a level close to the amount at the time of shipment.

[0294] The control unit 90 manages time using a timer or the like, and regularly executes the circulation operation. This allows the concentration of the humidifying fluid L1a throughout the circulation path 62 to be uniform at the appropriate time. In other words, the concentration of the humidifying fluid L1a filled in the humidifying chamber 55 can be prevented from being greater than the concentration of the humidifying fluid L1a contained in the humidifying fluid storage portion 61. More specifically, even if the amount of water contained in the humidifying fluid L1a filled in the humidifying chamber 55 decreases, the amount of water can be returned to a level close to that at the time of shipment at the appropriate time. This prevents the occurrence of poor discharge due to insufficient humidification of the nozzle 22 opening.

[0295] As described above, the outlet 55b of one of the multiple unit caps 51a is connected to the inlet 55a of another adjacent unit cap 51a. The inlet 55a located farthest upstream is connected to the supply flow path 62a, and the outlet 55b located farthest downstream is connected to the recovery flow path 62b. This allows the humidifying fluid L1a within the circulation path 62 within the humidifying chamber 55 containing the multiple unit caps 51a to be stirred using only the single supply flow path 62a and the recovery flow path 62b. Furthermore, using only the single supply flow path 62a and the recovery flow path 62b allows the concentration of the humidifying fluid L1a within the circulation path 62 within the humidifying chamber 55 containing the multiple unit caps 51a to be uniform.

[0296] The cap device 50 humidifies the space SP with the moisture contained in the humidifying fluid L1a filling the humidifying chamber 55 and periodically circulates the space SP, thereby reducing the volume of the humidifying fluid L1a contained in the humidifying fluid section 61 by the amount of evaporated moisture. The humidifying fluid section 61 includes a detector 61a for detecting the liquid level within the humidifying fluid section 61, thereby determining whether the concentration of the humidifying fluid L1a has exceeded a predetermined concentration.

[0297] During the circulation operation, when the detection unit 61a detects that the liquid level in the humidification fluid storage unit 61 is lower than the first predetermined height H1, it is determined that the concentration of the humidification fluid L1a in the circulation path 62 is higher than the predetermined concentration, and the operation is executed. Figure 16 The concentration adjustment action flow is shown.

[0298] like Figure 15 As shown, by further including a moisture supply unit 66 capable of supplying moisture into the circulation path 62, when moisture evaporates from the humidification fluid L1a, moisture L1b can be replenished to the humidification fluid L1a, thereby optimizing the concentration of the humidification fluid L1a. In other words, the amount of moisture contained in the humidification fluid L1a can be returned to the amount of moisture at the time of shipment.

[0299] The pressure loss in the flow path on the water supply unit 66 side is set to be equal to or greater than the pressure loss in the flow path on the side of the humidification fluid storage unit 61. As a result, the rate of change of the liquid level in the humidification fluid storage unit 61 is slowed down, and the deviation in liquid level detection is reduced, so that the liquid level can be detected promptly.

[0300] When the detection unit 61a detects that the liquid level in the humidification fluid storage unit 61 is below the first predetermined height H1 and concentration adjustment is performed, the cap device 50 supplies water from the water storage unit 66a to the circulation path 62 until the liquid level is detected to be above the first predetermined height H1. The cap device 50 then allows the humidification fluid L1a to flow within the circulation path 62. This replenishes the humidification fluid L1a with water in an amount corresponding to evaporation, and then circulates the humidification fluid L1a within the circulation path 62, thereby optimizing the concentration of the humidification fluid L1a.

[0301] During the concentration adjustment operation, when the detection unit 61a detects that the liquid level in the humidification fluid storage unit 61 exceeds the first predetermined height H1, the cap device 50 closes the first on-off valve 66c, and the aforementioned circulation operation is performed. Specifically, during the concentration adjustment operation, the circulation operation is performed before the concentration adjustment operation is completed. This agitates the humidification fluid L1a in the circulation path 62, thereby maintaining a uniform concentration of the humidification fluid L1a throughout the circulation path 62 even during the concentration adjustment operation.

[0302] The cap device 50 replenishes the humidifying fluid L1a in the circulation path 62 by replenishing the amount of water evaporated. This increases the volume of the humidifying fluid L1a in the circulation path 62. Furthermore, the second moisture-permeable membrane 61e, located at the junction of the humidifying fluid storage section 61 and the second atmosphere communication passage 61d, allows the passage of gas between the humidifying fluid storage section 61 and the second atmosphere communication passage 61d. This allows the same volume of air as the increased volume of the humidifying fluid L1a to flow out of the humidifying fluid storage section 61 into the second atmosphere communication passage 61d as the volume of the humidifying fluid L1a increases. This facilitates the replenishment of moisture in the humidifying fluid L1a in the circulation path 62. Furthermore, by making the area of ​​the second moisture-permeable membrane 61e larger than the volume of the humidifying fluid storage section 61, the amount of air flowing out of the second atmosphere communication passage 61d into the atmosphere can be increased. Consequently, the humidifying fluid L1a can be efficiently replenished by replenishing the amount of water evaporated.

[0303] like Figure 15 As shown, the cap device 50 performs a concentration adjustment operation, including supplying water L1b into the circulation path 62 via the water supply unit 66 and causing the humidification fluid L1a to flow within the circulation path 62. Furthermore, the cap device 50 performs a concentration adjustment operation, including opening the first on-off valve 66c when supplying water L1b from the water storage unit 66a into the circulation path 62 and closing the first on-off valve 66c when causing the humidification fluid L1a to flow within the circulation path 62. The state of the first on-off valve 66c allows the supply of evaporated water into the circulation path 62 and the flow of the humidification fluid L1a within the circulation path 62 as needed. Thus, after the humidification fluid L1a is replenished with the evaporated amount of water, it is allowed to circulate within the circulation path 62, thereby optimizing the concentration of the humidification fluid L1a.

[0304] In the liquid ejection device 11, when the liquid ejection head 21 repeatedly records on the medium M, the seal portion 56e of the unit cap 51a may deteriorate or fatigue due to long-term repeated stress, causing the seal portion 56e to lose contact with the nozzle surface 23. Furthermore, there are cases where a component constituting the cap unit 51 fails. In this case, the previously used cap unit 51 is replaced with a new cap unit 51. It should be noted that the cap unit 51 may also be configured so that only one unit cap 51a is replaced at a time.

[0305] like Figure 17As shown, when the cover unit 51 is replaced, a cover replacement preparation action is performed. By supplying pressurized air from the pressurized air supply unit 67 to the unit cover 51a, the pressurized air is supplied to the unit cover 51a, and the humidification fluid L1a in the unit cover 51a is discharged to the humidification fluid storage unit 61. In this way, the humidification fluid L1a in the unit cover 51a can be discharged to the outside of the unit cover 51a. In addition, the humidification fluid L1a in the unit cover 51a can be recovered to the humidification fluid storage unit 61. That is, the humidification fluid L1a in the cover unit 51 used previously can be used as the humidification fluid L1a in the cover unit 51 used later.

[0306] The cap device 50 may also include an air supply unit for supplying air to the circulation path 62, between the first merging portion 62c where the moisture supply unit 66 merges with the circulation path 62, and the inlet 55a of the unit cap 51a. Furthermore, the cap device 50 may include a pump for delivering this air to the circulation path 62. This allows the humidifying fluid L1a within the unit cap 51a to be discharged outside the unit cap 51a. Furthermore, the humidifying fluid L1a within the unit cap 51a can be recovered in the humidifying fluid storage unit 61.

[0307] like Figure 7 As shown, the humidification chamber 55 is formed into a single-channel flow path, with the inlet 55a and the outlet 55b connected via the groove 55c and the first moisture-permeable membrane 54 covering the groove 55c. Therefore, during the cap replacement preparation operation, by supplying pressurized air from the inlet 55a of the single-channel flow path within the humidification chamber 55, the humidification fluid L1a can be easily discharged from the outlet 55b within the humidification chamber 55.

[0308] As described above, the outlet 55b of one of the multiple unit caps 51a is connected to the inlet 55a of another adjacent unit cap 51a. The inlet 55a located most upstream is connected to the supply flow path 62a, and the outlet 55b located most downstream is connected to the recovery flow path 62b. Thus, the humidified fluid L1a within the humidification chambers 55 of the multiple unit caps 51a can be discharged through the one supply flow path 62a, one recovery flow path 62b, and one pressurized air supply unit 67 during the cap replacement preparation operation.

[0309] like Figure 17As shown, the humidifying fluid storage section 61 has a second atmosphere communication passage 61d. The second atmosphere communication passage 61d connects the humidifying fluid storage section 61 to the atmosphere via a labyrinthine structure of narrow tubes. During the cap replacement preparation operation, when pressurized air is supplied to the humidifying fluid storage section 61, the labyrinthine structure of the second atmosphere communication passage 61d also prevents the humidifying fluid L1a from flowing out of the humidifying fluid storage section 61 through the second atmosphere communication passage 61d.

[0310] like Figure 17 As shown, the humidifying fluid storage section 61 includes a second moisture-permeable membrane 61e. The second moisture-permeable membrane 61e allows the passage of gas while restricting the passage of liquid. During the cap replacement preparation operation, while pressurized air is being supplied to the humidifying fluid storage section 61, the outflow of the humidifying fluid L1a from the humidifying fluid storage section 61 through the second atmosphere communication passage 61d to the outside of the humidifying fluid storage section 61 can also be suppressed.

[0311] The previously used cap unit 51 is replaced with a new cap unit 51. Before the initial recording on the medium M, the aforementioned circulation operation is performed, and the humidification chamber 55 of the unit cap 51a of the new cap unit 51 is filled with the humidification fluid L1a. Thus, in the replaced cap unit 51, the space SP surrounding the opening of the nozzle 22 when the unit cap 51a is in contact with the liquid ejection head 21 is also humidified, so that the opening of the nozzle 22 can be humidified.

[0312] In the liquid ejection device 11, in a replaced cap unit 51, the space SP surrounding the opening of the nozzle 22 when the unit cap 51a is in contact with the liquid ejection head 21 is humidified, thereby utilizing the moisture within the humidification fluid L1a. This moisture is replenished from the moisture storage portion 66a into the humidification fluid L1a during concentration adjustment. In other words, even in a replaced cap unit 51, the opening of the nozzle 22 of the liquid ejection head 21 can be humidified without replenishing the humidification fluid L1a into the circulation path 62.

[0313] like Figure 15 As shown, during the concentration adjustment operation, when the first pump 63 is driven for the third predetermined time T3, and the detection unit 61a detects that the liquid level in the humidifying fluid storage unit 61 is lower than the first predetermined height H1, the control unit 90 determines that the water in the water storage unit 66a has been completely drained. The humidifying fluid storage unit 61 includes the detection unit 61a for detecting the liquid level in the humidifying fluid storage unit 61. This can detect when the amount of water in the water storage unit 66a has reached a level that determines that the water storage unit 66a needs to be replaced.

[0314] When the amount of water in the water container 66a used to humidify the nozzle 22 opening reaches a level that necessitates replacement of the water container 66a, the previously used water container 66a is replaced with a fully filled water container 66a. However, if the user does not have a replacement water container 66a at hand, the nozzle 22 opening cannot be humidified with the humidifying fluid L1a until the replacement water container 66a arrives. Furthermore, if the water container 66a is not user-replaceable, the nozzle 22 opening cannot be humidified with the humidifying fluid L1a until maintenance personnel replace it.

[0315] Before the moisture storage section 66a is replaced, the first parameter table for flushing is switched to the second parameter table for when the moisture L1b in the moisture storage section 66a is completely drained. This allows the nozzle 22 opening to be humidified by flushing. Specifically, before replacing the moisture storage section 66a, the space SP can be humidified by performing a dry discharge from the liquid ejection head 21 into the unit cap 51a. Therefore, the user can continue printing.

[0316] like Figure 19 As shown, when the moisture storage section 66a is replaced, the cover replacement preparation operation is performed. Pressurized air is supplied from the pressurized air supply section 67 into the unit cover 51a, discharging the humidified fluid L1a within the unit cover 51a into the humidified fluid storage section 61. Furthermore, pressurized air is supplied into the unit cover 51a. This allows the humidified fluid L1a within the unit cover 51a to be discharged.

[0317] like Figure 9 As shown, the recess 57 includes an absorber 53 capable of absorbing liquid at a position in contact with the first moisture-permeable membrane 54. Since the amount of waste liquid L2 ejected into the unit cap 51a increases during flushing or cleaning, the absorber 53 absorbs a larger amount of waste liquid L2 than usual. Furthermore, the waste liquid L2 absorbed by the absorber 53 spreads throughout the entire absorber 53. The large amount of waste liquid L2 absorbed by the absorber 53 allows the space SP to be more effectively humidified until the moisture storage portion 66a is replaced. Furthermore, the openings of the nozzles 22 of the liquid ejection head 21 can be more effectively humidified.

[0318] When the humidification chamber 55 is tilted relative to the horizontal, as in this embodiment, the waste liquid L2 absorbed by the absorber 53 also spreads throughout the absorber 53. In other words, the absorption of the waste liquid L2 by the absorber 53 can suppress the influence of gravity on the distribution of the waste liquid L2 within the recess 57. Thus, even when the humidification chamber 55 is tilted relative to the horizontal, the entire space SP can be humidified more evenly. Furthermore, the openings of the multiple nozzles 22 of the liquid ejection head 21 can be humidified more evenly.

[0319] The absorber 53 is located in contact with the first moisture-permeable film 54. Therefore, by restricting only the surface of the absorber 53 that is not in contact with the first moisture-permeable film 54 by the restriction member 52, the position of the absorber 53 can be restricted.

[0320] The sealing portion 56e uses a material that repels the liquid ejected from the liquid ejection head 21, thereby preventing the liquid in the unit cover 51a from dripping from the sealing portion 56e to the outside of the unit cover 51a even when the amount of waste liquid L2 discharged into the unit cover 51a by flushing or cleaning increases.

[0321] When the water container 66a is replaced, the second parameter table for flushing returns to the normal first parameter table, and the concentration adjustment operation is performed. Since the amount of waste liquid L2 discharged into the unit cover 51a increases only until the water container 66a is replaced, the amount of liquid used for flushing can be reduced.

[0322] As described above, the cap device 50 includes a unit cap 51a having a recess 57 forming the space SP, a humidification chamber 55, and a first moisture-permeable membrane 54. Furthermore, the recess 57 has a discharge hole 56b. Therefore, a single unit cap 51a can be used to accommodate and discharge the liquid discharged from the nozzle 22, as well as humidify the nozzle 22, as needed. Furthermore, by circulating the humidification fluid L1a within the circulation path 62 while replenishing the evaporating amount of water, the humidification fluid L1a is stirred and its concentration is adjusted to an appropriate level. In other words, the entire humidification fluid L1a within the circulation path 62 can be maintained in a state suitable for humidifying the nozzle 22 of the liquid ejection head 21.

[0323] The effects of this embodiment will be described.

[0324] (1) The cap device 50 includes a unit cap 51a having a recess 57 that forms a space SP when the unit cap 51a contacts the liquid ejection head 21; a humidification chamber 55 through which the humidification fluid L1a flows; and a first moisture-permeable membrane 54 that divides the recess 57 and the humidification chamber 55 and is air-permeable. Furthermore, the recess 57 has a discharge hole 56b that allows the waste liquid L2 discharged from the nozzle 22 of the liquid ejection head 21 into the unit cap 51a to be discharged. Water evaporated from the humidification fluid L1a in the humidification chamber 55 passes through the first moisture-permeable membrane 54 and reaches the recess 57, thereby humidifying the space SP formed by the recess 57 and the opening of the nozzle 22. Furthermore, the waste liquid L2 discharged into the unit cap 51a does not flow into the humidification chamber 55 through the first moisture-permeable membrane 54 and is discharged out of the unit cap 51a through the discharge hole 56b in the recess 57. Thus, a single unit cap 51a can be used to accommodate and discharge the waste liquid L2 discharged from the nozzle 22, as well as to humidify the nozzle 22. Specifically, in the liquid ejection device 11, the space required to accommodate both the capping mechanism for preventing clogging of the nozzle 22 and the capping mechanism for suppressing drying of the nozzle 22 is sufficient. This prevents the liquid ejection device 11 from becoming larger.

[0325] (2) The discharge hole 56b is provided in the recess 57 at a position lower than the first moisture-permeable membrane 54. By utilizing gravity, the waste liquid L2 within the recess 57 can be discharged from the discharge hole 56b to the outside of the unit cover 51a. Furthermore, the amount of waste liquid L2 remaining within the recess 57 can be reduced. Furthermore, by clogging the surface of the first moisture-permeable membrane 54 with the waste liquid L2, it is possible to prevent water evaporating from the humidifying fluid L1a within the humidifying chamber 55 from passing through the first moisture-permeable membrane 54. In other words, it is possible to prevent the opening of the nozzle 22 of the liquid ejection head 21 from being humidified.

[0326] (3) The drain hole 56b is provided at the bottom of the recess 57. The waste liquid L2 in the recess 57 can be drained from the drain hole 56b to the outside of the unit cover 51a by gravity. In addition, the waste liquid L2 can be prevented from remaining in the recess 57.

[0327] (4) The recess 57 includes an absorber 53 capable of absorbing liquid at a position in contact with the first moisture-permeable membrane 54. The waste liquid L2 discharged into the recess 57 is absorbed by the absorber 53. Furthermore, the water evaporated from the humidifying fluid L1a and passed through the first moisture-permeable membrane 54 humidifies the waste liquid L2 absorbed by the absorber 53. The waste liquid L2 absorbed by the absorber 53 spreads throughout the absorber 53. This allows the waste liquid L2 absorbed by the absorber 53 to be distributed nearly uniformly. In other words, the entire space SP can be humidified more uniformly. Furthermore, the openings of the plurality of nozzles 22 included in the liquid ejection head 21 can be humidified more uniformly.

[0328] (5) The humidifying chamber 55 has a groove 55c for circulating the humidifying fluid L1a. Furthermore, the humidifying chamber 55 is formed into a flow path, with the inlet 55a and the outlet 55b connected via the groove 55c and the first moisture-permeable membrane 54 covering the groove 55c. By flowing the humidifying fluid L1a through the humidifying chamber 55, which is formed into a single channel connecting the inlet 55a and the outlet 55b, the humidifying fluid L1a can be filled into or discharged from the humidifying chamber 55 as needed. Furthermore, since the humidifying chamber 55 is formed into such a flow path, it is possible to prevent the humidifying fluid L1a filled in the humidifying chamber 55 from unnecessarily flowing out of the humidifying chamber 55. Furthermore, since the flow path is routed throughout the entire bottom surface of the unit cover 51a, the entire interior of the recess 57 can be humidified. This allows the openings of the multiple nozzles 22 of the liquid ejection head 21 to be humidified more evenly.

[0329] (6) The humidification chamber 55 is arranged in an inclined position relative to the horizontal, and the inlet 55a and the outlet 55b are arranged above the vertical center of the humidification chamber 55. This can prevent the humidification fluid L1a filled in the humidification chamber 55 from flowing out of the humidification chamber 55 through the inlet 55a or the outlet 55b due to water level pressure.

[0330] (7) The recess 57 includes an atmospheric communication hole 56a for communicating the space SP with the atmosphere. The atmospheric communication hole 56a is provided above the vertical center of the recess 57. This prevents the atmospheric communication hole 56a from being clogged with the waste liquid L2 and preventing the waste liquid L2 from being discharged from the recess 57.

[0331] (8) The cap device 50 further includes a humidifying fluid storage portion 61, a supply flow path 62a, a recovery flow path 62b, and a first pump 63 capable of causing the humidifying fluid L1a to flow within the circulation path 62. This allows the humidifying fluid L1a within the circulation path 62 to be stirred. In order to humidify the space SP, a large amount of water evaporates from the humidifying fluid L1a filled in the humidifying chamber 55. Therefore, by stirring the humidifying fluid L1a within the circulation path 62, the concentration of the humidifying fluid L1a throughout the circulation path 62 can be made uniform. In other words, the amount of water contained in the humidifying fluid L1a filled in the humidifying chamber 55 can be returned to a level close to the amount at the time of shipment of the liquid ejection device 11.

[0332] (9) The cap device 50 further includes a moisture supply unit 66 capable of supplying moisture into the circulation path 62. This allows the humidification fluid L1a to be replenished with moisture L1b when moisture evaporates from the humidification fluid L1a, thereby optimizing the concentration of the humidification fluid L1a. In other words, the amount of moisture contained in the humidification fluid L1a can be returned to the amount at the time of shipment of the liquid ejection device.

[0333] (10) The cap device 50 is constructed by arranging a plurality of unit caps 51a. Furthermore, the outlet 55b of one of the plurality of unit caps 51a is connected to the inlet 55a of another unit cap 51a adjacent to the unit cap 51a. Furthermore, the inlet 55a located most upstream is connected to the supply flow path 62a, and the outlet 55b located most downstream is connected to the recovery flow path 62b. Thus, the humidification fluid L1a can be filled, stirred, and discharged from the plurality of unit caps 51a using only one supply flow path 62a and one recovery flow path 62b.

[0334] (11) The maintenance method for the cap device 50 includes supplying water to the circulation path 62 via the water supply unit 66 and adjusting the concentration of the humidification fluid L1a by causing it to flow within the circulation path 62. Thus, after the humidification fluid L1a is replenished with water in an amount corresponding to evaporation, the humidification fluid L1a is circulated within the circulation path 62, thereby optimizing the concentration of the humidification fluid L1a. In other words, the humidification fluid L1a throughout the circulation path 62 can be maintained in a state suitable for humidifying the nozzles 22 of the liquid ejection head 21.

[0335] (12) The maintenance method of the cap device 50 includes performing a concentration adjustment operation by opening the first on-off valve 66c when supplying water from the water storage portion 66a into the circulation path 62, and closing the first on-off valve 66c when allowing the humidification fluid L1a to flow within the circulation path 62. The state of the first on-off valve 66c allows the supply of evaporated water to the circulation path 62 and the flow of the humidification fluid L1a within the circulation path 62 as needed. Thus, after the humidification fluid L1a is replenished with the evaporated water, the humidification fluid L1a is circulated within the circulation path 62, thereby optimizing the concentration of the humidification fluid L1a. That is, the entire humidification fluid L1a within the circulation path 62 can be maintained in a state suitable for humidifying the nozzles 22 of the liquid ejection head 21.

[0336] (13) The maintenance method of the cap device 50 is as follows: when replacing the unit cap 51a, pressurized air is supplied from the pressurized air supply unit 67 into the unit cap 51a, and the cap replacement preparation action is performed to discharge the humidification fluid L1a in the unit cap 51a to the humidification fluid storage unit 61 and to supply pressurized air into the unit cap 51a. In this way, the humidification fluid L1a in the unit cap 51a can be discharged to the outside of the unit cap 51a. In addition, the humidification fluid L1a in the unit cap 51a can be recovered to the humidification fluid storage unit 61. That is, the humidification fluid L1a in the cap unit 51 used previously can be used as the humidification fluid L1a in the cap unit 51 used thereafter. In addition, in the cap unit 51 after replacement, the opening of the nozzle 22 of the liquid ejection head 21 can also be humidified.

[0337] (14) The maintenance method for the cap device 50 is to perform a pre-water storage unit replacement operation. The pre-water storage unit replacement operation includes: the cap replacement preparatory operation described above; and performing a dry discharge of liquid unrelated to printing from the liquid ejection head 21 into the space SP within the unit cap 51a to humidify the nozzle 22 until the water storage unit 66a is replaced. This allows the humidification fluid L1a within the unit cap 51a to be discharged. Furthermore, while the humidification fluid L1a within the unit cap 51a is discharged, a dry discharge can be performed from the liquid ejection head 21 into the space SP within the unit cap 51a to humidify the space SP. This allows the user to continue the printing operation.

[0338] (15) The maintenance method of the cap device 50 is as follows: when the liquid level in the humidifying fluid storage section 61 is detected to be below the first predetermined height H1 and the concentration adjustment operation is performed, water in the water storage section 66a is supplied to the circulation path 62 until the liquid level is detected to be above the first predetermined height H1. Thereafter, the humidifying fluid L1a is allowed to flow within the circulation path 62. In this manner, after the humidifying fluid L1a is replenished with water in an amount corresponding to evaporation, the humidifying fluid L1a is allowed to circulate within the circulation path 62, thereby optimizing the concentration of the humidifying fluid L1a. In other words, the humidifying fluid L1a throughout the circulation path 62 can be maintained in a state suitable for humidifying the nozzles 22 of the liquid ejection head 21.

[0339] This embodiment can be implemented by modifying as follows: This embodiment and the following modifications can be implemented in combination with each other within a range that does not technically conflict.

[0340] The cap device 50 may also include a liquid ejection device that ejects liquid vertically from the liquid ejection head 21 toward the medium M. Furthermore, the contact surface 56f, which is in close contact with the nozzle surface 23 of the liquid ejection head 21 when the unit cap 51a is capped, the absorbent body 53, the first moisture-permeable membrane 54, and the humidification chamber 55 may also be arranged in a horizontal position. That is, the unit cap 51a of this embodiment may also be arranged in a horizontal position on the liquid ejection device that ejects liquid vertically from the liquid ejection head 21 toward the medium M. Furthermore, as in this embodiment, the absorbent body 53, the first moisture-permeable membrane 54, and the humidification chamber 55 may be arranged in a tilted position relative to the horizontal, with only the contact surface 56f arranged in a horizontal position.

[0341] The angle at which the humidifying chamber 55 is inclined relative to the horizontal may not be the same as the angle at which the nozzle surface 23 of the liquid ejecting head 21 is inclined relative to the horizontal, on which the nozzles 22 are arranged. The angle at which the humidifying chamber 55 is inclined relative to the horizontal may be greater than or less than the angle at which the nozzle surface 23 is inclined relative to the horizontal.

[0342] The capping device 50 can also be provided in a liquid ejection device, such as a serial inkjet printer, which performs printing by ejecting liquid toward a medium M using a liquid ejection head supported by a carriage that reciprocates in the width direction X. For maintenance purposes, when the reciprocating carriage moves in the width direction X from a jetting area for printing on the medium M to a maintenance area outside the jetting area, the cap of the capping device 50, which is positioned in the maintenance area, can cap the nozzle surface of the liquid ejection head. In this case, the capping device 50 can also be configured so that when the carriage moves to the maintenance area and the liquid ejection head is in the maintenance position, the cap moves toward the nozzle surface of the liquid ejection head, bringing the cap into close contact with the nozzle surface, thereby performing capping. Thus, even in a serial liquid ejection device, a single cap can be used to accommodate and discharge waste liquid discharged from the nozzles and to humidify the nozzles. Furthermore, in a serial liquid ejecting device, the space for both the cap of the capping mechanism for preventing nozzle clogging and the capping device for suppressing nozzle drying may be space for only one cap. This can prevent the serial liquid ejecting device 11 from becoming larger.

[0343] The cap device 50 may include a plurality of unit caps 51a or only one unit cap 51a. When the cap device 50 includes only one unit cap 51a, the unit cap 51a may include one restriction member 52, one absorber 53, one first moisture-permeable film 54, one humidifying chamber 55, and one housing 56.

[0344] As in the above embodiment, when using a line inkjet printer having a liquid ejection head 21 composed of five unit ejection heads 21a, the capping device 50 may have only one unit cap 51a. In addition, in the above-mentioned serial type liquid ejection device, the capping device 50 may also have only one unit cap 51a.

[0345] The cap device 50 may include different numbers of the restricting member 52, absorbent body 53, first moisture-permeable membrane 54, and humidifying chambers 55. For example, the cap device 50 may include only one unit cap 51a, which includes one restricting member 52, one absorbent body 53, one first moisture-permeable membrane 54, and multiple humidifying chambers 55. Alternatively, the cap device 50 may include multiple unit caps 51a, each of which includes one restricting member 52, one absorbent body 53, one first moisture-permeable membrane 54, and multiple humidifying chambers 55.

[0346] The unit cover 51 a may include a plurality of recessed portions 57 .

[0347] The recessed portion 57 may have a plurality of discharge holes 56b.

[0348] The recessed portion 57 may have a plurality of atmosphere communication holes 56 a .

[0349] When the cover device 50 includes multiple unit covers 51a, the recesses 57 of the unit covers 51a may be configured so that the spaces SP formed by the recesses are connected to each other without passing through the discharge holes 56b. For example, the unit covers 51a may be configured so that the bottom of one unit cover 51a is connected to the bottom of another unit cover 51a adjacent to it within the cover unit 51. In this case, the number of discharge holes 56b in the cover unit 51 may be one.

[0350] The absorber 53 does not need to be in contact with the first moisture-permeable film 54. For example, a configuration may be adopted in which the position of the surface of the absorber 53 on the −Y1 direction side is restricted by a restriction member different from the restriction member 52 that restricts the position of the surface of the absorber 53 on the +Y1 direction side, thereby providing a space between the first moisture-permeable film 54 and the absorber 53.

[0351] In the above embodiment, the flow path of the humidification chamber 55 is formed in a labyrinthine shape with one channel from the inlet 55a to the outlet 55b, but it may be two channels or three channels.

[0352] The arrangement of the unit ejection heads 21a constituting the liquid ejection head 21 can be modified as appropriate. The arrangement is not limited to the configuration in which the unit ejection heads 21a are arranged obliquely as in the above-described embodiment. For example, a staggered arrangement may be employed in which the unit ejection heads 21a are arranged in two rows at a predetermined interval in the width direction X, with the rows being staggered in the width direction by half the interval.

[0353] In the above embodiment, the supply flow path 62a in the circulation path 62 includes the moisture supply unit 66 capable of supplying moisture. However, the recovery flow path 62b in the circulation path 62 may also include the moisture supply unit 66. In this case, the cap device 50 may further include a pump for supplying moisture to the recovery flow path 62b.

[0354] In the above embodiment, the third on-off valve 58b that connects the space SP to the atmosphere is opened and closed by movement of the cover unit 51. Alternatively, an actuator-type on-off valve that can be opened and closed by the controller 90 may be provided in the first atmosphere communication passage 58a regardless of the position of the cover unit 51.

[0355] The cap device 50 may also include a second detector for detecting the amount of water L1b in the water storage portion 66a. Based on the detection result of the second detector, the control portion 90 may also determine whether the amount of water L1b in the water storage portion 66a has reached a level requiring replacement of the water storage portion.

[0356] The cap device 50 may be configured to be able to replenish the moisture in the moisture storage portion 66a. In addition, the cap device 50 may be configured to be able to replace the humidification fluid storage portion 61.

[0357] The time at which the cyclic action is executed can be changed by an administrator or a user.

[0358] The first predetermined time T1, the second predetermined time T2, the third predetermined time T3, and the fourth predetermined time T4 do not always have to be fixed. The values ​​may be changed according to the temperature and humidity environment. In addition, the administrator or user may also change the values.

[0359] The liquid ejection device 11 may also include a third parameter table for a greater amount of liquid ejected as a parameter table for flushing. Furthermore, when the interval between concentration adjustment operations is short, the control unit 90 may switch to the third parameter table during the flushing table switchover during the operation before the water storage unit is replaced. In other words, the liquid ejection device 11 may include multiple parameter tables for different amounts of liquid ejected as parameter tables for flushing. Furthermore, when switching between the flushing tables during the operation before the water storage unit is replaced, the control unit 90 may switch from one of the multiple parameter tables to an appropriate parameter table based on the interval between concentration adjustment operations.

[0360] The liquid ejection device 11 may also be a liquid ejection device that ejects or sprays other liquids besides ink. The state of the liquid ejected from the liquid ejection device as a tiny amount of droplets also includes the state of being granular, tear-shaped, or having a filamentous tail. The liquid mentioned here can be any material that can be ejected from the liquid ejection device. For example, the liquid can be any material in the state when the substance is in the liquid phase, including high-viscosity or low-viscosity liquids, sols, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals, molten metals and other fluids. The liquid not only includes liquids as a state of matter, but also includes liquids in which particles of functional materials composed of solids such as pigments or metal particles are dissolved, dispersed or mixed in a solvent. Representative examples of liquids include inks and liquid crystals described in the above embodiments.

[0361] Hereinafter, second to fourth embodiments of the liquid ejection device 111 and a control method for the liquid ejection device 111 will be described with reference to the drawings. The liquid ejection device 111 is, for example, an inkjet printer that ejects ink, an example of liquid, onto a medium M such as paper to perform recording.

[0362] Second embodiment

[0363] Regarding the structure of the liquid ejection device

[0364] like Figure 23As shown, the liquid ejecting device 111 includes a substantially rectangular parallelepiped main body 1102, an image reading unit 1103, and an automatic feeder 1104. The image reading unit 1103 is mounted above the main body 1102. The automatic feeder 1104 is mounted above the image reading unit 1103.

[0365] The image reading unit 1103 is configured to read images recorded on a document, such as text and photographs. The automatic feeder 1104 is configured to feed the document to the image reading unit 1103. The image reading unit 1103 includes an operation unit 1105. The operation unit 1105 includes, for example, a touch-panel liquid crystal display and operation buttons. A user operates the operation unit 1105 to instruct the liquid ejection device 111.

[0366] The main body 1102 includes one or more media storage sections 1106 capable of storing multiple media, such as multiple sheets of paper. In one example, the main body 1102 includes four media storage sections 1106. The media storage sections 1106 are stored so as to be pulled out from the main body 1102. The main body 1102 includes a loading section 1107 on its upper portion. The loading section 1107 has a loading surface 1107a on which recorded media are loaded.

[0367] The medium stored in the medium storage section 1106 is transported to the loading section 1107 by a feed roller (not shown). More specifically, the feed roller rotates while being in contact with the uppermost medium among the plurality of media stored in the medium storage section 1106. As a result, the uppermost medium is fed from the medium storage section 1106 to the upper side of the medium storage section 1106. The liquid ejection head 113a (see Figure 24 ) toward the medium being transported. The ejected liquid adheres to the medium, thereby performing recording. The recorded medium is discharged toward the loading portion 1107 by one or more discharge rollers (not shown).

[0368] like Figure 24As shown, the liquid ejection device 111 includes a liquid ejection portion 113, a liquid container 120, a reservoir 125, a supply mechanism 140, a pressure regulating portion 150, a supply limiting portion 160, a liquid pressurizing portion 170, a maintenance portion 180, and a control portion 1100. The liquid container 120 contains liquid to be supplied to the liquid ejection portion 113. The reservoir 125 temporarily stores the liquid supplied from the liquid container 120 to the liquid ejection portion 113. The supply mechanism 140 is configured to send air to the liquid container 120, the supply limiting portion 160, and the liquid pressurizing portion 170. The pressure regulating portion 150 is configured to regulate the pressure of the liquid supplied from the liquid container 120 to the liquid ejection portion 113. The supply limiting portion 160 is configured to limit the supply of liquid from the liquid container 120 to the liquid ejection portion 113. The liquid pressurizing portion 170 is configured to pressurize the liquid supplied to the liquid ejection portion 113. The maintenance unit 180 is configured to perform maintenance on the liquid ejection unit 113. The control unit 1100 is configured to control various components of the liquid ejection device 111.

[0369] The liquid ejection device 111 includes a plurality of supply channels 190 for circulating liquid. The plurality of supply channels 190 include a first supply channel 191, a second supply channel 192, a third supply channel 193, a fourth supply channel 194, and a fifth supply channel 195. The first supply channel 191 connects the liquid storage section 120 with the reservoir 125. The second supply channel 192 connects the reservoir 125 with the pressure regulating section 150. The third supply channel 193 connects the pressure regulating section 150 with the supply limiting section 160. The fourth supply channel 194 connects the supply limiting section 160 with the liquid pressurizing section 170. The fifth supply channel 195 connects the liquid pressurizing section 170 with the liquid ejection section 113. The liquid contained in the liquid storage section 120 is supplied to the liquid ejection section 113 via these supply channels 191 to 195. In the following description, among these supply flow paths, the side where the first supply flow path 191 is located is referred to as upstream, and the side where the fifth supply flow path 195 is located is referred to as downstream.

[0370] The liquid ejection unit 113 includes one or more liquid ejection heads 113a capable of ejecting liquid. Each liquid ejection head 113a includes a nozzle surface 112a where one or more nozzles 112 are opened. The fifth supply flow path 195 is connected to each liquid ejection head 113a in a branched manner.

[0371] The liquid ejection head 113a ejects liquid from multiple nozzles 112 onto the medium M. For example, the liquid ejection unit 113 includes a cavity for storing liquid for each nozzle 112 of the liquid ejection head 113a, a vibration plate forming a portion of the cavity, and a piezoelectric element attached to the vibration plate. By driving these piezoelectric elements, the vibration plate vibrates, changing the volume of the cavity, thereby ejecting liquid from the nozzles 112. By ejecting liquid onto the medium M, text and images are recorded on the medium M.

[0372] The liquid containing section 120 includes a liquid containing body 114 that is compressed and deformed by an external force. The liquid containing body 114 is, for example, a bag formed of a flexible film member. The liquid containing body 114 has a supply port connected to the upstream end of the first supply flow path 191. The liquid containing section 120 includes a storage container 121 that stores the liquid containing body 114. The storage container 121 is a sealed container connected to the upstream end of the first supply flow path 191. When gas flows into the storage container 121 through the first delivery flow path 141, the pressure in the storage container 121 increases. Thus, when the storage container 121 is pressurized, the liquid containing body 114 is compressed and deformed. As a result, the liquid contained in the liquid containing body 114 is pressurized and supplied toward the downstream. It should be noted that the details of the structure around the liquid containing section 120, including the storage section 125 that temporarily stores the liquid supplied from the liquid containing section 120 to the liquid ejection section 113, will be described later.

[0373] The supply mechanism 140 includes a supply pump 144 and a delivery channel 147. The delivery channel 147 may also include a plurality of branch channels, such as a first delivery channel 141, a second delivery channel 142, and a third delivery channel 143. The supply pump 144 is, for example, a compression pump that pressurizes air. The first delivery channel 141 connects the supply mechanism 140 to the liquid storage portion 120. The second delivery channel 142 connects the first delivery channel 141 to the supply restriction portion 160. The third delivery channel 143 connects the second delivery channel 142 to the liquid pressurizing portion 170. The delivery channel 147, the first delivery channel 141, the second delivery channel 142, and the third delivery channel 143 are channels through which gas can flow. It should be noted that the gas flows from the supply pump 144 toward the liquid containing part 120, the supply limiting part 160 and the liquid pressurizing part 170. Therefore, in the subsequent description, the side where the supply pump 144 is located is referred to as the upstream side, and the side where the liquid containing part 120, the supply limiting part 160 and the liquid pressurizing part 170 are located is referred to as the downstream side.

[0374] The supply mechanism 140 includes a third delivery valve 145 and a fourth delivery valve 146. The third delivery valve 145 allows gas to flow from the supply pump 144 to the supply restriction unit 160 via the second delivery channel 142 when the valve is open, while restricting gas flow from the supply pump 144 to the supply restriction unit 160 when the valve is closed. Furthermore, the fourth delivery valve 146 allows gas to flow from the supply pump 144 to the liquid pressurizing unit 170 via the third delivery channel 143 when the valve is open, while restricting gas flow from the supply pump 144 to the liquid pressurizing unit 170 when the valve is closed. The supply mechanism 140 delivers gas to the supply restriction unit 160 and the liquid pressurizing unit 170 via the second delivery channel 142 and the third delivery channel 143, depending on the open and closed states of the third delivery valve 145 and the fourth delivery valve 146. It should be noted that opening a valve is referred to as "valve opening," and closing a valve is referred to as "valve closing."

[0375] When the pressure of the liquid in the third supply flow path 193, which is connected to the liquid ejection head 113a due to liquid ejection from the liquid ejection head 113a, becomes lower than a predetermined pressure lower than atmospheric pressure, the pressure regulating unit 150 connects the second supply flow path 192 with the third supply flow path 193. On the other hand, when the pressure of the liquid in the third supply flow path 193 becomes higher than a predetermined pressure by connecting the second supply flow path 192 with the third supply flow path 193, the pressure regulating unit 150 disconnects the second supply flow path 192 from the third supply flow path 193.

[0376] The pressure regulating unit 150 regulates the pressure of the liquid supplied to the liquid ejecting head 113a to a pressure below a predetermined pressure. In one example, the pressure regulating unit 150 regulates the pressure of the liquid upstream of the pressure regulating unit 150 to a pressure above atmospheric pressure, for example, approximately 20 Pa, and regulates the pressure of the liquid downstream of the pressure regulating unit 150 to a pressure below atmospheric pressure, for example, approximately -1 kPa.

[0377] Each liquid ejection head 113a includes a plurality of pressure regulators 150 provided for each type of liquid. For example, when four types of liquid are supplied to each liquid ejection head 113a, four pressure regulators 150 are provided for each type of liquid.

[0378] like Figure 24As shown, the supply limiting section 160 includes a gas chamber 161 capable of storing gas, a liquid chamber 162 capable of storing liquid, and a protrusion 163 formed within the liquid chamber 162 and extending from the liquid chamber 162 toward the gas chamber 161. The supply limiting section 160 includes a film member 164, a biasing member 165, and a first opening valve 166. The film member 164 divides the gas chamber 161 and the liquid chamber 162. The biasing member 165 biases the film member 164 within the liquid chamber 162 in a direction that increases the volume of the liquid chamber 162. The first opening valve 166 opens to open the liquid chamber 162 to the atmosphere.

[0379] The gas chamber 161 is connected to the downstream end of the second delivery flow path 142, and the liquid chamber 162 is connected to the downstream end of the third supply flow path 193 and the upstream end of the fourth supply flow path 194. The upstream end of the fourth supply flow path 194 is connected to the liquid chamber 162 via the opening 167 of the protrusion 163. The film component 164 is flexible and displaces in the direction of increasing or decreasing the volume of the gas chamber 161 and the liquid chamber 162 according to the pressure difference between the gas chamber 161 and the liquid chamber 162. In addition, the film component 164 is configured to be able to block the opening 167 of the protrusion 163. The first open valve 166 connects the gas chamber 161 to the atmosphere when the valve is open, and on the other hand, blocks the gas chamber 161 from the atmosphere when the valve is closed. That is, when the film component 164 is configured as Figure 24 In the illustrated arrangement, the opening 167 of the protrusion 163 is opened by the biasing force of the biasing member 165 , thereby allowing the liquid to be supplied from the third supply flow path 193 to the fourth supply flow path 194 .

[0380] like Figure 24 As shown, the liquid pressurizing unit 170 includes a gas chamber 171 capable of storing gas and a liquid chamber 172 capable of storing liquid. The liquid pressurizing unit 170 includes a film member 173, a biasing member 174, and a second opening valve 175. The film member 173 divides the gas chamber 171 and the liquid chamber 172. The biasing member 174 biases the film member 173 within the liquid chamber 172 in a direction that increases the volume of the liquid chamber 172. The second opening valve 175 opens to expose the liquid chamber 172 to the atmosphere.

[0381] The gas chamber 171 is connected to the downstream end of the third delivery channel 143, and the liquid chamber 172 is connected to the downstream end of the fourth supply channel 194 and the upstream end of the fifth supply channel 195. The film member 173 is flexible and displaces in a direction that increases or decreases the volume of the gas chamber 171 and the liquid chamber 172 according to the pressure difference between the gas chamber 171 and the liquid chamber 172. Furthermore, the second opening valve 175 allows the gas chamber 171 to communicate with the atmosphere when open, and blocks the gas chamber 171 from the atmosphere when closed.

[0382] Regarding the structure around the liquid container

[0383] like Figure 24 As shown, in the liquid container 114 in the liquid container portion 120 , liquid is contained in the liquid container. This liquid is supplied to the liquid ejection head 113 a. A plurality of containers 121 are detachably mounted on the liquid ejection device 111 . Each container 121 contains a corresponding liquid container 114 .

[0384] The liquid ejection device 111 is provided with, for example, two removable storage containers 121. These two storage containers 121 contain the same type of liquid. Furthermore, storage containers 121 corresponding to other types of liquids may be installed in the liquid ejection device 111. Furthermore, a configuration may be provided in which multiple storage containers 121 can be installed for all liquids used. Furthermore, the storage containers 121 may be mounted in a non-removable manner relative to the liquid ejection device 111, with only the liquid container 114 being removable and replaceable.

[0385] The first liquid container 114f and the second liquid container 114s contain the same type of liquid. The supply mechanism 140 sends gas to at least one of the first liquid container 114f and the second liquid container 114s and pressurizes it, thereby causing the liquid contained in the pressurized liquid container to flow out to the first supply flow path 191 and supply the liquid to the downstream pressure regulating unit 150. In other words, the supply mechanism 140 can selectively pressurize the first liquid container 114f and the second liquid container 114s. The liquid container 114 selected for pressurization is referred to as the liquid container 114 of the pressurization destination. It should be noted that, of the two liquid containers 114, the liquid container 114 that is used first is referred to as the first liquid container 114f, and the liquid container 114 that is used after the first liquid container 114f is referred to as the second liquid container 114s. Therefore, when the liquid in the first liquid container 114f is exhausted and the first liquid container 114f is replaced with a new liquid container 114, the second liquid container 114s that is used next becomes the first liquid container 114f, and the new liquid container 114 after the replacement becomes the second liquid container 114s. In other words, the first liquid container 114f is replaced by the second liquid container 114s, and the second liquid container 114s is replaced by the first liquid container 114f.

[0386] The first supply flow path 191 includes two outlet flow paths 122, each connected to two liquid containers 114 containing the same type of liquid, and a merging flow path 123, which connects the two outlet flow paths 122 to the liquid ejection head 113a via a pressure regulator 150. A valve is provided on each of the two outlet flow paths 122. The valve provided on the outlet flow path 122 connected to the first liquid container 114f is referred to as the first valve 124f, and the valve provided on the outlet flow path 122 connecting the liquid container 114 to the second liquid container 114s is referred to as the second valve 124s.

[0387] The outlet flow path 122 connected to the first liquid container 114f and the outlet flow path 122 connected to the second liquid container 114s merge at a point where they merge with the merging flow path 123. Thus, the two outlet flow paths 122 form a connecting flow path 126 that connects the first liquid container 114f and the second liquid container 114s. That is, the first supply flow path 191 includes the connecting flow path 126 and the merging flow path 123 that connects the connecting flow path 126 to the liquid ejection head 113a.

[0388] The first valve 124f is provided in the portion of the connecting channel 126 between the first liquid container 114f and the merging channel 123. The connecting channel 126 is opened when the liquid in the first liquid container 114f is supplied. Furthermore, the second valve 124s is provided in the portion of the connecting channel 126 between the second liquid container 114s and the merging channel 123. The connecting channel 126 is opened when the liquid in the second liquid container 114s is supplied. Thus, the connecting channel 126 is configured to selectively connect the first liquid container 114f and the second liquid container 114s to the merging channel 123.

[0389] like Figure 24 As shown, the supply mechanism 140 delivers gas to the liquid container 120 via the first delivery channel 141. The supply mechanism 140 includes a first delivery channel 141, a delivery valve 129, and a supply pump 144. The first delivery channel 141 has two gas delivery channels 128. In the first delivery channel 141, the two gas delivery channels 128 respectively connect the supply mechanism 140 and the internal spaces of the two storage containers 121. Thus, the supply pump 144 delivers gas to the internal spaces of each storage container 121 through the corresponding gas delivery channel 128. A corresponding delivery valve 129 is provided in each gas delivery channel 128. The delivery valve 129 is referred to as a first delivery valve 129f, and the delivery valve 129 is provided in the gas delivery channel 128 connected to the storage container 121 that stores the first liquid container 114f. The delivery valve 129 is referred to as a second delivery valve 129 s , and is provided in the gas delivery path 128 that communicates with the storage container 121 that stores the second liquid storage body 114 s .

[0390] The supply pump 144 may be provided separately for each storage container 121. Furthermore, as described above, the supply mechanism 140 also delivers gas to the supply restriction portion 160 and the liquid pressurizing portion 170. Separate from the supply pump 144 that delivers gas to the supply restriction portion 160 and the liquid pressurizing portion 170, a supply pump that delivers gas to the storage container 121 may be provided. In other words, a separate supply pump may be provided for each delivery destination.

[0391] The first delivery valve 129f and the first valve 124f corresponding to the first liquid container 114f are opened, while the second delivery valve 129s and the second valve 124s corresponding to the second liquid container 114s to be used next are closed. Furthermore, when gas is delivered through the gas delivery path 128 by driving the supply pump 144, the gas enters the storage container 121 and pressurizes the storage container 121 containing the first liquid container 114f. In this way, the liquid in the first liquid container 114f is selectively delivered to the liquid ejection head 113a.

[0392] Both the first valve 124f and the second valve 124s can be one-way valves that allow liquid to flow from upstream to downstream and restrict liquid flow from downstream to upstream. In this case, the first delivery valve 129f corresponding to the first liquid container 114f is opened, and the second delivery valve 129s corresponding to the second liquid container 114s is closed. When the supply pump 144 is driven, the liquid in the first liquid container 114f, whose pressure has increased within the container 121, is delivered to the liquid ejection head 113a. It should be noted that the first valve 124f and the second valve 124s can also be on-off valves that are opened and closed by the control unit 1100.

[0393] like Figure 24 As shown, the storage unit 125 includes a detection unit 131, a movable wall 132, a movable body 133, a first force applying member 134, a rod 135, and a second force applying member 136. The movable body 133 moves in response to the displacement of the movable wall 132. The first force applying member 134 applies a force to the movable body 133 toward the movable wall 132. The rod 135 moves in response to the movement of the movable body 133. The second force applying member 136 applies a force to the rod 135 toward the movable body 133. The detection unit 131 detects the displacement of the rod 135.

[0394] When the pressure of the liquid in the first supply flow path 191 decreases, the movable wall 132 is displaced toward the inside of the reservoir 125, and the movable body 133 is moved toward the movable wall 132 by the force of the first force-applying member 134. As a result, the rod 135 pressed by the movable body 133 is displaced by the force of the second force-applying member 136, and the detection unit 131 detects the displacement of the rod 135.

[0395] The reservoir 125 is capable of temporarily storing liquid and is provided in the merging flow path 123. When the remaining amount of liquid in the liquid container 114 being used by the liquid ejection head 113a falls below a first threshold value QL1, the liquid supply pressure in the first supply flow path 191 reaches a pressurization threshold value PL, and the detection unit 131 detects the displacement of the rod 135. By setting the value of the first threshold value QL1 in this manner, the detection unit 131 can detect whether the remaining amount of liquid in the liquid container 114 has fallen below the first threshold value QL1. Specifically, the reservoir 125 includes the detection unit 131, which can detect the remaining amount of liquid in the liquid container 114 being used by the liquid ejection head 113a by detecting the amount of liquid in the reservoir 125. Furthermore, the detection unit 131 is configured to detect the remaining amount of liquid in the liquid container 114 being used by the liquid ejection head 113a by detecting the amount of liquid stored in the reservoir 125. More specifically, when the liquid ejection head 113 a is discharging liquid from one of the liquid containers 114 , the detection unit 131 detects the amount of liquid stored in the storage unit 125 to thereby detect the remaining amount of liquid in the liquid container 114 .

[0396] The detection unit 131 is, for example, an optical sensor having a light-emitting portion and a light-receiving portion. When the light-receiving portion changes from receiving light from the light-emitting portion to blocking light from the light-emitting portion, the detection unit 131 detects whether the remaining amount of liquid in the liquid container 114 being used by the liquid ejection head 113a is below a first threshold value QL1. Alternatively, an optical or magnetic linear encoder capable of detecting continuous displacement may be used, allowing the detection unit 131 to continuously measure the displacement of the rod 135.

[0397] The storage portion 125 may also be a tank having a hole open to the atmosphere. In this case, the detection portion 131 may detect the amount of liquid in the storage portion 125 by detecting the liquid level in the storage portion 125. Furthermore, the detection portion 131 may be provided at a location other than the storage portion 125. For example, each liquid container 114 may also include a detection portion 131 capable of detecting the remaining amount of liquid in the liquid container 114.

[0398] About the structure of the maintenance department

[0399] like Figure 24 As shown, the maintenance unit 180 includes a cleaning mechanism 181 and a wiping mechanism 182. In order to prevent or eliminate poor discharge caused by clogging of the nozzle 112 or adhesion of foreign matter, the liquid discharge head 113a performs maintenance operations such as flushing, capping, suction cleaning, or wiping under the control of the control unit 1100.

[0400] The cleaning mechanism 181 includes a box-shaped cover 183 having an opening and a lifting mechanism (not shown) for lifting and lowering the cover 183. The cover 183 is lifted and lowered to move relatively between a covered position in which the space opening of the nozzle 112 is enclosed and formed as a closed space, and an open position in which the space opening of the nozzle 112 is open and formed as an open space.

[0401] Flushing is the process of ejecting liquid droplets not involved in recording from the nozzles 112. Flushing removes thickened liquid, bubbles, or foreign matter that could cause poor ejection from the nozzles 112, thereby preventing clogging of the nozzles 112. Flushing is performed by ejecting liquid droplets from the nozzles 112 toward the interior of the cap 183 via the liquid ejection head 113a.

[0402] Capping refers to the action of placing the cap 183 in the capping position when the liquid ejection head 113a is not ejecting liquid, so that the cap 183 abuts against the liquid ejection head 113a, surrounding the opening of the nozzle 112. This creates a closed space between the nozzle surface 112a and the opening of the nozzle 112 of the liquid ejection head 113a. Capping suppresses the thickening of the liquid within the nozzle 112, thereby preventing ejection defects.

[0403] Cleaning mechanism 181 includes a discharge flow path 185 and multiple suction valves 186 disposed in discharge flow path 185. Discharge flow path 185 has a downstream end connected to suction mechanism 184 and multiple upstream ends, each of which is connected to a corresponding cap 183. A corresponding suction valve 186 is disposed midway along each branched discharge flow path 185. Suction valve 186 is configured to open and close discharge flow path 185.

[0404] Suction cleaning is the action of applying suction force to the nozzle 112 of the liquid ejection head 113a to forcibly discharge the liquid from the nozzle 112. By placing the cap 183 in the capping position, the cap 183 defines a closed space CS between the cap 183 and the lower surface side of the opening of the nozzle 112 of the liquid ejection head 113a (see Figure 25 ). The suction mechanism 184 causes negative pressure to act on the closed space CS (refer to Figure 25 ). In addition, the liquid is sucked and discharged from the nozzle 112 by the negative pressure, thereby performing suction cleaning.

[0405] The wiping mechanism 182 includes an elastic wiper 188, a wiper support portion 189 that supports the wiper 188, and a moving mechanism (not shown) configured to move the wiper support portion 189 in the arrangement direction of the liquid ejection heads 113a.

[0406] Wiping is an operation of wiping the nozzle surface 112a by the wiper 188. By wiping, liquid and dirt such as dust adhering to the nozzle surface 112a of the liquid ejecting head 113a are removed.

[0407] After the suction cleaning, the liquid inside the liquid ejection head 113a may be pressurized and then wiped. Since the liquid inside the liquid ejection head 113a is pressurized, this cleaning is called pressure cleaning.

[0408] After suction cleaning, pressure cleaning is performed by pressurizing the liquid inside the liquid ejection head 113a. After pressure cleaning, wiping is performed. The operations of the supply mechanism 140, supply control unit 160, liquid pressurizing unit 170, and maintenance unit 180 during pressure cleaning will be described.

[0409] like Figure 25 As shown, when there are at least one liquid ejection head 113a requiring suction cleaning, the control unit 1100 selectively moves the caps 183 corresponding to the liquid ejection heads 113a requiring suction cleaning to the capping position. The control unit 1100 then selectively performs suction cleaning on the liquid ejection heads 113a requiring suction cleaning by driving the suction mechanism 184 for a predetermined period.

[0410] The suction mechanism 184 sucks the air in the closed space CS through the exhaust flow path 185, so that the closed space CS becomes negative pressure. The nozzle 112 opened in the closed space CS is connected to the third supply flow path 193 via the fifth supply flow path 195, the liquid chamber 172 of the liquid pressurizing part 170, the fourth supply flow path 194, and the liquid chamber 162 of the supply limiting part 160. As a result, the pressure of the third supply flow path 193 is lower than the specified pressure. The pressure regulating part 150 connects the second supply flow path 192 with the third supply flow path 193. Thus, liquid is continuously supplied from the liquid containing part 120 to the liquid ejecting part 113, as shown in FIG. Figure 25 As shown in FIG. 1 , the liquid is discharged from the liquid discharge head 113 a to be cleaned by suction. The liquid discharged from the liquid discharge head 113 a is discharged through the cap 183 and the discharge flow path 185 .

[0411] The control unit 1100 moves all caps 183 to the open position. Specifically, since the caps 183 corresponding to the liquid ejection heads 113a not being vacuum-cleaned are already in the open position, the control unit 1100 moves the caps 183 in the capping position to the open position. It should be noted that the caps 183 can be moved to the open position after the suction mechanism 184 is stopped and the pressure in the closed space CS is negative, or the pressure in the closed space CS can be approximately equal to atmospheric pressure.

[0412] The control unit 1100 opens the third delivery valve 145 while the first opening valve 166 is closed. As a result, the gas is supplied from the supply pump 144 to the gas chamber 161 of the supply limiting unit 160 via the second delivery flow path 142. Figure 25 The gas flows in the direction of the solid arrow shown, and as the amount of gas flowing into the gas chamber 161 increases, the pressure in the gas chamber 161 gradually increases.

[0413] like Figure 26 As shown, when the pressure of the gas chamber 161 is greater than the pressure of the liquid chamber 162, the film member 164 overcomes the force of the force member 165 and reduces the volume of the liquid chamber 162. Figure 26 The position indicated by the solid line is displaced, blocking the opening 167 of the protrusion 163 located within the liquid chamber 162. As a result, the third supply channel 193 and the fourth supply channel 194 are disconnected, and the pressure regulator 150 and the liquid pressurizing unit 170 are disconnected. In other words, the supply restrictor 160 restricts the supply of liquid from the liquid storage unit 120 to the liquid ejection unit 113.

[0414] The controller 1100 opens the fourth delivery valve 146 while the second opening valve 175 is closed. As a result, the gas is delivered from the supply pump 144 to the gas chamber 171 of the liquid pressurizing unit 170 via the third delivery passage 143. Figure 26 The gas flows in the direction of the solid arrow shown, and as the amount of gas flowing into the gas chamber 171 increases, the pressure in the gas chamber 171 gradually increases.

[0415] like Figure 26 As shown, when the pressure of the gas chamber 171 is greater than the pressure of the liquid chamber 172, the film member 173 overcomes the force of the force member 174 and moves to a position where the volume of the liquid chamber 172 is reduced. Figure 26 As a result, the liquid in the liquid chamber 172 of the liquid pressurizing unit 170, the fourth supply flow path 194, the fifth supply flow path 195, the interior of the liquid ejection head 113a, and the interior of the nozzle 112 is pressurized.

[0416] In all the nozzles 112 of the liquid ejecting heads 113a, the hydraulic pressure within the nozzles 112 is higher than the atmospheric pressure, causing liquid to leak from the nozzles 112 of all the liquid ejecting heads 113a. It should be noted that liquid leakage from the nozzles 112 refers to a state in which the concave meniscus formed toward the interior of the nozzles 112 is broken, and the liquid overflowing from the nozzles 112 diffuses toward the nozzle surface 112a. In this state, the control unit 1100 drives a moving mechanism (not shown) to execute wiping of the nozzle surfaces 112a of all the liquid ejecting heads 113a using the wiper 188. After the liquid leaks from the nozzles 112 by applying pressure, the liquid is wiped by the wiper 188, and therefore this action is also referred to as pressurized wiping.

[0417] The controller 1100 closes the third delivery valve 145 and opens the first opening valve 166. While the flow of gas from the supply pump 144 into the gas chamber 161 of the supply restrictor 160 is restricted, the gas chamber 161 of the supply restrictor 160 is opened to the atmosphere, thereby reducing the pressure in the gas chamber 161 to atmospheric pressure. Consequently, the film member 164 is displaced by the force of the biasing member 165 in a direction that increases the volume of the liquid chamber 162, thereby opening the opening 167 of the protrusion 163 of the liquid chamber 162. Furthermore, the third supply channel 193 is connected to the fourth supply channel 194, and the pressure regulator 150 is connected to the liquid pressurizing unit 170. In other words, liquid is allowed to flow from the liquid storage section 120, which is restricted by the supply restrictor 160, to the liquid ejection section 113. It should be noted that as the volume of the liquid chamber 162 increases, the liquid flowing into the liquid chamber 162 is supplied from the third supply channel 193.

[0418] The control unit 1100 closes the fourth delivery valve 146 and opens the second opening valve 175. While the flow of gas from the supply pump 144 into the gas chamber 171 of the liquid pressurizing unit 170 is restricted, the gas chamber 171 of the liquid pressurizing unit 170 is opened to the atmosphere, thereby reducing the pressure in the gas chamber 171 to atmospheric pressure. As a result, the film member 173 is displaced in a direction that increases the volume of the liquid chamber 172 due to the force of the force-applying member 174. Then, as the volume of the liquid chamber 172 increases, the liquid flowing into the liquid chamber 172 is supplied from the fourth supply flow path 194. In other words, the supply from the fifth supply flow path 195 can be suppressed. The control unit 1100 then terminates the pressurized cleaning operation.

[0419] The pressure regulating unit 150, the supply limiting unit 160 and the liquid pressurizing unit 170 may also be Figure 27 The hydraulic pressure adjustment mechanism 1280 and the valve opening mechanism 1290 are shown. The hydraulic pressure adjustment mechanism 1280 and the valve opening mechanism 1290 are provided between the reservoir 125 and the liquid ejection head 113a.

[0420] like Figure 27As shown, the hydraulic adjustment mechanism 1280 is integrally provided with the filter portion 1220 at a position downstream of the storage portion 125. The hydraulic adjustment mechanism 1280 includes an upstream filter chamber 1222, a downstream filter chamber 1223, a liquid chamber 1282, a valve core 1283, and a pressure-receiving component 1284. The upstream filter chamber 1222 is connected to the storage portion 125. The downstream filter chamber 1223 is connected to the upstream filter chamber 1222 via a filter 1221 that captures foreign matter. The liquid chamber 1282 is connected to the downstream filter chamber 1223 via a connecting hole 1281, and is connected to the liquid ejection head 113a. The valve core 1283 is configured to be able to open and close the connecting hole 1281. The base end side of the pressure-receiving component 1284 is accommodated in the downstream filter chamber 1223, and the front end side is accommodated in the liquid chamber 1282.

[0421] Liquid chamber 1282 is configured to store liquid. A portion of the wall of liquid chamber 1282 is formed by a flexibly displaceable flexible wall 1285. Valve element 1283 may be, for example, an elastic body such as rubber or resin attached to the base end of pressure-receiving member 1284 located within downstream filter chamber 1223.

[0422] The hydraulic adjustment mechanism 1280 includes a first pressing member 1286 housed in the downstream filter chamber 1223 and a second pressing member 1287 housed in the liquid chamber 1282. The first pressing member 1286 presses the valve element 1283 in a direction to close the communication hole 1281 via the pressure-receiving member 1284. The second pressing member 1287 pushes the pressure-receiving member 1284 back toward the flexible wall 1285 when the flexible wall 1285 deflects and displaces in a direction to reduce the volume of the liquid chamber 1282, causing the flexible wall 1285 to press the pressure-receiving member 1284.

[0423] When the internal pressure of liquid chamber 1282 decreases and the force exerted by flexible wall 1285 on pressure-receiving member 1284 exceeds the pressing force of first pressing member 1286 and second pressing member 1287, valve element 1283 opens communication hole 1281. As liquid flows from downstream filter chamber 1223 into liquid chamber 1282 due to the opening of communication hole 1281, the internal pressure of liquid chamber 1282 rises. As a result, before the internal pressure of liquid chamber 1282 reaches positive pressure, valve element 1283 blocks communication hole 1281 due to the pressing force of first pressing member 1286 and second pressing member 1287. This maintains the internal pressure of liquid chamber 1282 within a negative pressure range corresponding to the pressing force of first pressing member 1286 and second pressing member 1287.

[0424] The internal pressure of liquid chamber 1282 decreases as liquid is discharged from liquid ejection portion 113. Valve element 1283 autonomously opens and closes communication hole 1281 according to the differential pressure between atmospheric pressure (external pressure) and the internal pressure of liquid chamber 1282. Therefore, hydraulic pressure adjustment mechanism 1280 is a differential pressure valve.

[0425] like Figure 27 As shown, the valve opening mechanism 1290 forcibly opens the connecting hole 1281 and the liquid is directed to the Figure 24 The liquid ejection head 113a shown is supplied. The valve opening mechanism 1290 includes a pressurizing bag 1292 and a ventilation flow path 1293. The pressurizing bag 1292 is accommodated in a receiving chamber 1291, and the receiving chamber 1291 and the liquid chamber 1282 are divided by a flexible wall 1285. The ventilation flow path 1293 allows the liquid to be discharged from the liquid chamber 1282. Figure 24 The gas delivered by the supply pump 144 of the supply mechanism 140 shown flows into the pressurized bag 1292.

[0426] The valve opening mechanism 1290 uses the gas flowing in through the ventilation flow path 1293 to expand the pressurized bag 1292, causing the flexible wall 1285 to bend and displace in the direction of reducing the volume of the liquid chamber 1282, thereby forcibly opening the communication hole 1281. The liquid ejection device 111 is constructed so that the liquid ejection device 111 can eject the liquid from the communication hole 1281 when the communication hole 1281 is open. Figure 24 The liquid container 120 shown supplies liquid under pressure to the liquid ejecting head 113 a , thereby enabling pressure cleaning to cause the liquid to leak from the nozzles 112 of the liquid ejecting head 113 a .

[0427] How to calculate the remaining amount of liquid

[0428] The liquid contained in the liquid container 114 is pressurized and supplied to the liquid ejection head 113a. Therefore, the control unit 1100 calculates the remaining amount of liquid in the first liquid container 114f based on the amount of liquid discharged from the liquid ejection head 113a when the first liquid container 114f is pressurized. More specifically, the control unit 1100 calculates the remaining amount Q3 of liquid in the liquid container 114 based on the storage capacity Q1, which represents the amount of liquid contained in the liquid container 114, and the total discharge amount Q2, which represents the amount of liquid discharged from the liquid ejection head 113a when the liquid container 114 is pressurized. In other words, the remaining amount Q3 of liquid in the liquid container 114 is calculated for each liquid container 114. The control unit 1100 calculates the remaining amount Q3 each time liquid is discharged from the liquid ejection head 113a, from the start of use of the liquid container 114 until the liquid in the liquid container 114 is exhausted.

[0429] The storage capacity Q1 refers to the liquid storage capacity of the unused liquid container 114. When the storage container 121 containing the liquid container 114 or the liquid container 114 is shipped, if the liquid storage capacity of the liquid container 114 is managed as a fixed value, this value is the storage capacity Q1. Specifically, the storage capacity Q1 is the amount of liquid contained in the liquid container 114 when the storage container 121 containing the unused liquid container 114 is installed.

[0430] When the storage container 121 is attached to the liquid ejection device 111, the storage container 121 and the liquid ejection device 111 may be electrically connected. In this case, the control unit 1100 may also read various information related to the storage container 121 from the IC chip of the storage container 121. When the storage container 121 is shipped, if the storage capacity of the liquid container 114 contained in the storage container 121 is stored in the IC chip, the storage capacity value may also be read from the IC chip as the storage capacity Q1. In this case, the control unit 1100 manages the storage capacity Q1 as a separate value for each storage container 121.

[0431] The total discharge volume Q2 can also be calculated based on the amount of liquid discharged from the liquid discharge head 113a. For example, the total discharge volume Q2 can be calculated by multiplying the discharge volume Q2p by the number of injections np. That is, the control unit 1100 calculates the total discharge volume Q2 using the formula Q2 = Q2p × np.

[0432] The ejection volume Q2p refers to the amount of liquid ejected from the liquid ejection head 113a. More specifically, the ejection volume Q2p refers to the amount of liquid discharged from one nozzle 112 in one injection. It should be noted that one ejection from one nozzle 112 is referred to as one injection. The control unit 1100 manages the ejection volume Q2p so that each liquid has a separate value. The number of injections np is the total number of times the liquid in the liquid container 114 is ejected from one nozzle 112 across all nozzles 112 after the liquid container 114 is installed in the liquid ejection device 111. That is, the number of injections np in the first liquid container 114f refers to the total number of times the liquid in the liquid container 114 is ejected from one nozzle 112 across all nozzles 112 when the first liquid container 114f is pressurized. The number of injections np includes not only the number of times liquid is ejected onto the medium M by recording but also the number of times liquid is ejected by flushing. The number of injections np is counted for each liquid container 114. That is, the total discharge volume Q2 is calculated for each liquid container 114. If the discharge volume Q2p varies depending on the driving conditions of the actuator of the liquid discharge head 113a or environmental conditions such as temperature and humidity, the discharge volume Q2p may also be a value that varies based on these conditions. Furthermore, if the discharge volume Q2p is affected by the recording density, the discharge volume Q2p may also be a value that varies based on the recording density.

[0433] The total discharge volume Q2 can also be calculated by adding the amount of liquid sucked from the liquid ejection head 113a during suction cleaning. For example, the total discharge volume Q2 can be calculated by adding the value obtained by multiplying the suction volume Q2s during one suction cleaning operation by the number of suction cleaning operations ns. In other words, the control unit 1100 can calculate the total discharge volume Q2 using the formula Q2 = (Q2p × np) + (Q2s × ns).

[0434] The suction volume Q2s of the first liquid container 114f is the amount of liquid sucked from the entire liquid ejection head 113a during a single suction cleaning operation when the first liquid container 114f is pressurized. The suction cleaning frequency ns is the number of suction cleaning operations performed on the liquid ejection head 113a after the liquid container 114f is attached to the liquid ejection device 111. During suction cleaning, when adjusting the suction intensity, the suction volume Q2s may also vary depending on the suction intensity.

[0435] The total discharge volume Q2 can also be calculated by adding the amount of liquid wiped from the nozzles 112 of the liquid ejection head 113a during pressure wiping. For example, the total discharge volume Q2 can be calculated by adding the amount of liquid leaked during a single pressure wiping operation, Q2w, multiplied by the number of pressure wiping operations, nw. Specifically, the control unit 1100 can calculate the total discharge volume Q2 using the formula Q2 = (Q2p × np) + (Q2s × ns) + (Q2w × nw).

[0436] The leakage amount Q2w from the first liquid container 114f is the amount of liquid that leaks from the entire liquid ejection head 113a during a single pressurized wipe when the first liquid container 114f is pressurized. The number of pressurized wipes nw is the number of pressurized wipes performed on the liquid ejection head 113a after the liquid container 114f is attached to the liquid ejection device 111. During pressurized wiping, when adjusting the intensity of liquid leakage, the leakage amount Q2w can be set to a value that varies depending on the intensity of the liquid leakage.

[0437] The control unit 1100 calculates the remaining amount Q3 by subtracting the total discharge amount Q2 from the storage volume Q1. That is, the control unit 1100 calculates the remaining amount Q3 using the equation Q3 = Q1 - Q2. The control unit 1100 then calculates the remaining amount Q3 for each liquid container 114. Thus, the control unit 1100 can detect that the remaining amount of liquid in the liquid container 114 is below the first threshold value QL1, even without referring to the detection results of the detection unit 131. In other words, the control unit 1100 can detect that the remaining amount of liquid in the liquid container 114 is below the first threshold value QL1 by using both the detection results of the detection unit 131 and the calculation result of the remaining amount Q3.

[0438] Regarding the structure of the suction mechanism

[0439] like Figure 28 As shown, suction mechanism 184 includes a discharge flow path 185, a pressure chamber 1111, and a discharge valve 1112. Pressure chamber 1111 is located midway along discharge flow path 185, downstream of suction valve 186. Discharge valve 1112 is located downstream of pressure chamber 1111 midway along discharge flow path 185. Discharge valve 1112 is configured to open and close discharge flow path 185.

[0440] When the waste liquid in the cover 183 is discharged through the discharge flow path 185, it is temporarily stored in the pressure chamber 1111. The suction mechanism 184 may also include a pressure sensor 1113 and a release valve 1114 connected to the pressure chamber 1111. The pressure sensor 1113 detects the pressure in the pressure chamber 1111. When the release valve 1114 is opened, the pressure chamber 1111 is connected to the atmosphere. The discharge valve 1112 may also be a one-way valve that allows liquid to flow from upstream to downstream and restricts liquid from flowing from downstream to upstream. In more detail, the discharge valve 1112 is not electrically or mechanically controlled, and opens the discharge flow path 185 when a certain pressure is applied from upstream, but autonomously closes the discharge flow path 185 under normal circumstances (under atmospheric pressure) and when pressure is applied from downstream.

[0441] The suction mechanism 184 may also include a waste liquid tank 1115 connected downstream of the discharge valve 1112 of the discharge flow path 185. When the pressure chamber 1111 is pressurized, the waste liquid in the pressure chamber 1111 flows through the discharge flow path 185 into the waste liquid tank 1115. At this time, the one-way valve, or discharge valve 1112, opens due to the pressure of the pressurized waste liquid. If the discharge valve 1112 is controlled to open and close, it can be opened when the pressure chamber 1111 is pressurized. The waste liquid tank 1115 may also be mounted on the liquid ejection device 111 in a replaceable manner.

[0442] Suction mechanism 184 includes a cleaning pump 1116, a pressure-reducing flow path 1117, and a pressure-reducing valve 1118. Cleaning pump 1116 is configured to reduce the pressure in pressure chamber 1111 to a negative pressure. Cleaning pump 1116 is connected to pressure chamber 1111 via pressure-reducing flow path 1117. Pressure-reducing valve 1118 is disposed midway along pressure-reducing flow path 1117 between pressure chamber 1111 and cleaning pump 1116.

[0443] The pressure reducing valve 1118 opens and closes the pressure reducing flow path 1117. When the pressure reducing valve 1118 is open, the cleaning pump 1116 communicates with the pressure chamber 1111. When the pressure reducing valve 1118 is closed, the suction force of the cleaning pump 1116 does not reach the pressure chamber 1111.

[0444] The suction mechanism 184 includes a pressurizing flow path 1127 communicating with the supply pump 144 and the pressure chamber 1111, and a pressurizing valve 1128 configured to open and close the pressurizing flow path 1127. The pressurizing flow path 1127 may be a flow path branching from the delivery flow path 147.

[0445] When the pressurizing valve 1128 is open, the supply pump 144 communicates with the pressure chamber 1111. When the pressurizing valve 1128 is closed, the pressurizing pressure of the supply pump 144 does not reach the pressure chamber 1111. The supply pump 144 can pressurize the interior of the pressure chamber 1111 via the pressurizing flow path 1127. When supplying liquid to the liquid ejection head 113a (during liquid ejection and pressure cleaning), the pressurizing valve 1128 closes the pressurizing flow path 1127.

[0446] Regarding the electrical structure of the liquid ejection device 111

[0447] like Figure 29 As shown, the liquid ejection device 111 includes a control unit 1100. The control unit 1100 includes a CPU 1142 and a storage unit 1143. The CPU 1142 is a central processing unit that centrally controls the liquid ejection device 111. The storage unit 1143 is a non-volatile memory that stores programs executed by the CPU 1142 and related information, including various maintenance operations. In addition to the pressure sensor 1113, the control unit 1100 is also connected to an operation unit 1105 and a poor ejection detection unit 1146.

[0448] The pressure sensor 1113 periodically detects the pressure within the pressure chamber 1111 and transmits a detection signal indicating the detection result to the control unit 1100. The ejection failure detection unit 1146 is, for example, a detection circuit that detects residual vibration in the cavity within the liquid ejection unit 113. Specifically, the piezoelectric element is used to detect the residual vibration in the cavity after the piezoelectric element is driven to vibrate, thereby detecting nozzles 112 with ejection failure.

[0449] For example, when the viscosity of the liquid in the cavity becomes higher, the residual vibration is easy to attenuate, and the period of the residual vibration becomes shorter. On the other hand, when bubbles are mixed into the cavity, the residual vibration is difficult to attenuate, and the period of the residual vibration becomes longer. When the period of the residual vibration in the cavity detected by the piezoelectric element is shorter than the specified lower limit period, or longer than the specified upper limit period, the poor ejection detection unit 1146 detects the nozzle 112 corresponding to the cavity and the piezoelectric element as a poor ejection nozzle 112. In addition, the poor ejection detection unit 1146 sends a detection signal indicating the detection result to the control unit 1100. The control unit 1100 can also perform maintenance actions such as suction cleaning or pressurized cleaning based on the detection result of the poor ejection detection unit 1146.

[0450] like Figure 29As shown, various drive circuits are connected to the output-side interface (not shown) of the control unit 1100. The piezoelectric element drive circuit 1147 drives the piezoelectric element, causing liquid to be ejected from the nozzle 112 corresponding to the piezoelectric element. The piezoelectric element drive circuit 1147 also drives the piezoelectric element when detecting residual vibration to detect nozzles 112 with poor ejection. The cover drive circuit 1148 drives the lifting mechanism that raises and lowers the cover 183. The cleaning pump drive circuit 1149 drives the cleaning pump 1116.

[0451] The supply pump drive circuit 1150 drives the supply pump 144. The suction valve drive circuit 1151 drives the suction valve 186 to open or close. The pressurizing valve drive circuit 1152 drives the pressurizing valve 1128 to open or close. The pressure reducing valve drive circuit 1153 drives the pressure reducing valve 1118 to open or close. The release valve drive circuit 1154 drives the release valve 1114 to open or close. The discharge valve drive circuit 1155 drives the discharge valve 1112 to open or close. Each of the above drive circuits drives its corresponding drive target based on a control signal appropriately sent from the control unit 1100. If the discharge valve 1112 is a one-way valve that opens and closes autonomously, the liquid discharge device 111 may not include the discharge valve drive circuit 1155. That is, in the following description, when “the control unit 1100 opens (or closes) the discharge valve 1112 ,” the discharge valve 1112 is not controlled but autonomously opens (or closes).

[0452] The operation of the second embodiment will be described.

[0453] When recording onto the medium M using the liquid ejection device 111, the first delivery valve 129f and the first valve 124f are opened, and the supply pump 144 is driven. The operation of the supply pump 144 causes gas to flow into the storage container 121 containing the first liquid container 114f, pressurizing the interior of the storage container 121. When the interior of the storage container 121 is pressurized, the first liquid container 114f is compressed, and the liquid in the first liquid container 114f is delivered to the liquid ejection head 113a. It should be noted that at this time, the second delivery valve 129s and the second valve 124s are closed.

[0454] Liquid delivered from liquid container 114 is temporarily stored in reservoir 125 via first supply channel 191. When the pressure of the liquid in first supply channel 191 decreases, movable wall 132 displaces toward the inside of reservoir 125, which in turn displaces movable body 133 and rod 135. Detection unit 131 detects the displacement of rod 135, thereby detecting the remaining amount of liquid in liquid container 114.

[0455] The liquid temporarily stored in the reservoir 125 has its pressure adjusted by the pressure regulator 150 and is supplied to the liquid ejection head 113a through the supply regulator 160 and the liquid pressurizing unit 170. The liquid supplied to the liquid ejection head 113a is ejected toward the medium M from the plurality of nozzles 112.

[0456] The liquid ejection device 111 performs various maintenance operations. To remove thickened liquid, bubbles, and foreign matter that could cause poor ejection from the nozzle 112, the liquid ejection head 113a performs flushing, ejecting droplets from the nozzle 112 into the cap 183. Furthermore, to prevent thickening of the liquid within the nozzle 112, the cap 183 is placed in contact with the liquid ejection head 113a, surrounding the opening of the nozzle 112, when the liquid ejection head 113a is not ejecting liquid.

[0457] The liquid ejection device 111 also performs suction cleaning. First, the control unit 1100 moves the cap 183 corresponding to the liquid ejection head 113a requiring suction cleaning to the capping position. Then, the control unit 1100 opens the pressure reducing valve 1118 and, with the suction valve 186, release valve 1114, discharge valve 1112, and pressurizing valve 1128 closed, drives the cleaning pump 1116. This exhausts the gas within the pressure chamber 1111 through the pressure reducing flow path 1117, reducing the pressure within the pressure chamber 1111 to a negative pressure.

[0458] Then, when the controller 1100 closes the pressure-reducing valve 1118 and opens the suction valve 186, the negative pressure accumulated in the pressure chamber 1111 acts on the closed space CS. The nozzle 112, which opens into the closed space CS, communicates with the third supply channel 193 via the fifth supply channel 195, the liquid chamber 172 of the liquid pressurizing unit 170, the fourth supply channel 194, and the liquid chamber 162 of the supply restricting unit 160. As a result, the pressure in the third supply channel 193 falls below a predetermined pressure, causing the pressure regulator 150 to connect the second supply channel 192 with the third supply channel 193. Consequently, liquid is continuously supplied from the liquid storage unit 120 to the liquid ejection unit 113, and the liquid is discharged from the nozzle 112 through the discharge channel 185.

[0459] When the discharge valve 1112 is a one-way valve, the discharge valve 1112 is not opened or closed by the control unit 1100, allowing the liquid to flow from upstream to downstream of the discharge flow path 185. After the suction cleaning is performed, the release valve 1114 may be temporarily opened to release the pressure chamber 1111 to the atmosphere.

[0460] Furthermore, the liquid ejection device 111 performs pressure cleaning, for example, after suction cleaning. Specifically, after suction cleaning, the control unit 1100 moves the cover 183 to the open position. The control unit 1100 then closes the pressurizing valve 1128 and the first opening valve 166, and drives the supply pump 144 while opening the third delivery valve 145. This causes gas to flow into the gas chamber 161 of the supply restrictor 160 via the second delivery channel 142, pressurizing the gas chamber 161.

[0461] When the pressure in gas chamber 161 becomes greater than the pressure in liquid chamber 162, film member 164 overcomes the force of biasing member 165, reducing the volume of liquid chamber 162. Film member 164 then blocks opening 167 of protrusion 163 of liquid chamber 162. This restricts the supply of liquid from liquid storage section 120 to liquid ejection section 113.

[0462] The controller 1100 closes the second opening valve 175 and drives the supply pump 144 while keeping the fourth delivery valve 146 open. This causes gas to flow into the gas chamber 171 of the liquid pressurizing unit 170 via the third delivery channel 143, pressurizing the gas chamber 171. When the pressure in the gas chamber 171 exceeds the pressure in the liquid chamber 172, the film member 173 overcomes the force of the force-applying member 174, reducing the volume of the liquid chamber 172. This pressurizes the liquid inside the liquid ejection head 113a and the nozzle 112.

[0463] Since the hydraulic pressure in the nozzles 112 of all liquid ejecting heads 113a is higher than the atmospheric pressure, liquid leaks from the nozzles 112 of all liquid ejecting heads 113a. The controller 1100 drives the moving mechanism to execute wiping operation by the wiper 188 to wipe the nozzle surfaces 112a of all liquid ejecting heads 113a.

[0464] After suction cleaning or pressure cleaning, the inside of cover 183 can also be suctioned while cover 183 is in the open position or while the inside of cover 183 is open to the atmosphere. This is an action that allows the waste liquid remaining in cover 183 to be discharged through discharge flow path 185, also known as air (or vacuum) suction. When performing vacuum suction, the cleaning pump 1116 is driven in the same manner as during suction cleaning to reduce the pressure in pressure chamber 1111 to a negative pressure, and then the suction valve 186 is opened.

[0465] Waste liquid contained in the lid 183 is temporarily stored in a pressure chamber 1111 located midway along the discharge flow path 185. When the waste liquid in the pressure chamber 1111 reaches a certain level, the controller 1100 discharges the waste liquid stored in the pressure chamber 1111 into the waste liquid tank 1115. More specifically, the controller 1100 drives the supply pump 144 while opening the pressurizing valve 1128 and the discharge valve 1112, and closing the suction valve 186, the release valve 1114, and the pressure reducing valve 1118. This causes gas to flow into the pressure chamber 1111 through the pressurizing flow path 1127, pressurizing the interior of the pressure chamber 1111. The waste liquid in the pressure chamber 1111 is then discharged into the waste liquid tank 1115 through the discharge flow path 185. Alternatively, after pressurizing the pressure chamber 1111, the release valve 1114 may be opened to release the pressure chamber 1111 to the atmosphere.

[0466] When pressurizing or depressurizing the pressure chamber 1111, the pressurization or depressurization time can be changed based on the detection results of the pressure sensor 1113. This can increase the negative pressure by extending the depressurization time, for example, and thus enable more powerful suction cleaning. Furthermore, if the pressure chamber 1111 is pressurized during wiping or other actions, waste liquid in the pressure chamber 1111 can be discharged more quickly.

[0467] According to the second embodiment, the following effects can be achieved.

[0468] (1-1) The pressure chamber 1111 is pressurized by the supply pump 144, and waste liquid in the pressure chamber 1111 can be discharged through the discharge flow path 185. Since the liquid ejection device 111 uses the supply pump 144 for supplying liquid and discharges the waste liquid, there is no need for a dedicated pump for discharging the waste liquid. Therefore, the structure of the liquid ejection device 111 can be simplified.

[0469] (1-2) Pressure cleaning can be performed using the supply pump 144 for supplying liquid. The liquid ejection device 111 does not need to include a dedicated pressure pump for pressure cleaning. Therefore, the structure of the liquid ejection device 111 can be simplified.

[0470] (1-3) When the cleaning pump 1116 is driven with the suction valve 186, pressurizing valve 1128, and discharge valve 1112 closed, the pressure in the pressure chamber 1111 is reduced to a negative pressure. Subsequently, when the suction valve 186 is opened, the negative pressure in the pressure chamber 1111 acts on the inside of the cover 183. This allows suction cleaning to be performed, discharging the liquid in the liquid ejection head 113a through the nozzle 112.

[0471] (1-4) When the discharge valve 1112 is a one-way valve that opens and closes autonomously, there is no need to provide a mechanism for opening and closing the discharge valve 1112. Therefore, the structure of the liquid ejection device 111 can be simplified.

[0472] Third embodiment

[0473] Hereinafter, a third embodiment of the liquid ejection device 111 will be described with reference to the drawings. The same components as those in the second embodiment are denoted by the same reference numerals, and redundant descriptions will be omitted.

[0474] like Figure 30 As shown, the suction mechanism 184 includes a decompression flow path 1117, a pressurization flow path opening valve 1129, and a decompression flow path opening valve 1119. The suction mechanism 184 of the third embodiment does not include the cleaning pump 1116.

[0475] The supply pump 144 has a suction port and a discharge port. The decompression channel 1117 has an upstream end communicating with the pressure chamber 1111 and a downstream end communicating with the suction port of the supply pump 144. The discharge port of the supply pump 144 is connected to the upstream end of the delivery channel 147.

[0476] Pressurizing channel opening valve 1129 is connected to pressurizing channel 1127 between supply pump 144 and pressurizing valve 1128. When pressurizing channel opening valve 1129 is open, pressurizing channel 1127 is connected to the atmosphere. Decompression channel opening valve 1119 is connected to decompression channel 1117 between supply pump 144 and decompression valve 1118. When decompression channel opening valve 1119 is open, decompression channel 1117 is connected to the atmosphere.

[0477] When the storage container 121 , the gas chamber 161 , the gas chamber 171 , or the pressure chamber 1111 is pressurized by driving the supply pump 144 , the pressurization flow path opening valve 1129 is closed and the decompression flow path opening valve 1119 is opened.

[0478] Regarding the operation of the third embodiment, the differences from the second embodiment will be described.

[0479] When performing suction cleaning, the controller 1100 first moves the cap 183 corresponding to the liquid ejection head 113a requiring suction cleaning to the capping position. The controller 1100 then opens the pressure reducing valve 1118 and the pressurized flow path release valve 1129, closes the suction valve 186, the discharge valve 1112, the pressurized valve 1128, and the pressure reducing flow path release valve 1119, and activates the supply pump 144. This causes the gas within the pressure chamber 1111 to be discharged through the pressure reducing flow path 1117, reducing the pressure within the pressure chamber 1111 to a negative pressure. The controller 1100 then closes the pressure reducing valve 1118 and the pressurized flow path release valve 1129 and opens the suction valve 186. This causes the negative pressure accumulated in the pressure chamber 1111 to act on the closed space CS, causing the liquid within the liquid ejection head 113a to be discharged into the closed space CS through the nozzle 112.

[0480] When pressure cleaning is performed, the control unit 1100 performs the same control as in the second embodiment, and applies the pressure of the supply pump 144 to the nozzle 112 .

[0481] When performing air suction, the inside of the cover 183 is suctioned while the cover 183 is in the open position or while the inside of the cover 183 is open to the atmosphere. More specifically, similar to suction cleaning, the supply pump 144 is driven to reduce the pressure in the pressure chamber 1111 to a negative pressure, and then the suction valve 186 is opened.

[0482] To discharge the waste liquid in pressure chamber 1111 into waste liquid tank 1115, control unit 1100 drives supply pump 144 to pressurize pressure chamber 1111. More specifically, control unit 1100 closes suction valve 186, pressurization flow path release valve 1129, and pressure reducing valve 1118, and opens pressurization valve 1128 and pressure reducing flow path release valve 1119. In this state, when control unit 1100 drives supply pump 144, pressure in pressure chamber 1111 is pressurized via pressurization flow path 1127. Consequently, waste liquid in pressure chamber 1111 is discharged into waste liquid tank 1115 via discharge flow path 185.

[0483] According to the third embodiment, the following effects can be achieved.

[0484] (2-1) The pressure chamber 1111 is pressurized by the supply pump 144, and waste liquid in the pressure chamber 1111 can be discharged through the discharge flow path 185. Since the liquid ejection device 111 uses the supply pump 144 for supplying liquid and discharges the waste liquid, there is no need for a dedicated pump for discharging the waste liquid. Therefore, the structure of the liquid ejection device 111 can be simplified.

[0485] (2-2) Pressure cleaning can be performed using the supply pump 144 for supplying liquid. The liquid ejection device 111 does not need to include a dedicated pump for pressure cleaning. Therefore, the structure of the liquid ejection device 111 can be simplified.

[0486] (2-3) Suction cleaning can be performed using the supply pump 144 for supplying liquid. The liquid ejection device 111 does not need to include a dedicated pump for suction cleaning. Therefore, the structure of the liquid ejection device 111 can be simplified.

[0487] (Fourth embodiment)

[0488] Hereinafter, a fourth embodiment of the liquid ejection device 111 will be described with reference to the drawings. The same components as those in the second embodiment are denoted by the same reference numerals, and redundant descriptions will be omitted.

[0489] like Figure 31As shown, the suction mechanism 184 includes a cleaning pump 1116, a decompression flow path 1117, a pressurizing flow path 1127, a decompression flow path opening valve 1119, and a pressurizing flow path opening valve 1129. The cleaning pump 1116 has a suction port and a discharge port. The decompression flow path 1117 has an upstream end connected to the pressure chamber 1111 and a downstream end connected to the suction port of the cleaning pump 1116. The pressurizing flow path 1127 has an upstream end connected to the suction port of the cleaning pump 1116 and a downstream end connected to the pressure chamber 1111. The cleaning pump 1116 is configured to decompress the pressure chamber 1111 via the decompression flow path 1117.

[0490] A pressure-reducing valve 1118, which opens and closes pressure-reducing flow path 1117, is disposed midway along pressure-reducing flow path 1117. Pressure-reducing valve 1118 is configured to open and close pressure-reducing flow path 1117. A pressure-reducing flow path release valve 1119 is connected to pressure-reducing flow path 1117 between pressure-reducing valve 1118 and cleaning pump 1116. When pressure-reducing flow path release valve 1119 is opened, pressure-reducing flow path 1117 is connected to the atmosphere.

[0491] A pressurizing valve 1128 is disposed midway along the pressurizing passage 1127 to open and close the pressurizing passage 1127. A pressurizing passage opening valve 1129 is connected to the pressurizing passage 1127 between the pressure chamber 1111 and the cleaning pump 1116. When the pressurizing passage opening valve 1129 is opened, the pressurizing passage 1127 is connected to the atmosphere.

[0492] When the suction valve 186, pressurizing valve 1128, discharge valve 1112, and pressure-reducing flow path opening valve 1119 are closed, opening pressure-reducing valve 1118 and pressurizing flow path opening valve 1129 and driving cleaning pump 1116 reduces the pressure in pressure chamber 1111 to a negative pressure. Subsequently, when suction valve 186 is opened, the negative pressure in pressure chamber 1111 acts on the closed space CS defined by cover 183. This negative pressure draws liquid from nozzle 112 of liquid ejection head 113a and discharges it through discharge flow path 185.

[0493] When cleaning pump 1116 is driven with suction valve 186, pressure reducing valve 1118, and pressurizing flow path release valve 1129 closed and pressurizing valve 1128, discharge valve 1112, and pressure reducing flow path release valve 1119 open, the pressure chamber 1111 is pressurized. Consequently, waste liquid is discharged from pressure chamber 1111 through discharge flow path 185.

[0494] Regarding the operation of the fourth embodiment, the differences from the first and third embodiments will be described.

[0495] When performing suction cleaning, the controller 1100 first moves the cap 183 corresponding to the liquid ejection head 113a requiring suction cleaning to the capping position. The controller 1100 then closes the suction valve 186, the discharge valve 1112, the pressurizing valve 1128, and the pressure relief valve 1119. It then opens the pressurizing valve 1129 and the pressure relief valve 1118, driving the cleaning pump 1116. This causes the gas within the pressure chamber 1111 to be discharged through the pressure relief valve 1117, reducing the pressure within the pressure chamber 1111 to a negative pressure. The controller 1100 then closes the pressure relief valve 1118 and the pressure relief valve 1129, and opens the suction valve 186. The negative pressure accumulated in the pressure chamber 1111 acts on the closed space CS, causing the liquid within the liquid ejection head 113a to be discharged into the closed space CS through the nozzle 112.

[0496] When pressure cleaning is performed, the control unit 1100 performs the same control as in the second embodiment, and applies the pressure of the supply pump 144 to the nozzle 112 .

[0497] When performing air suction, the cover 183 is placed in the open position, or the inside of the cover 183 is connected to the atmosphere, and suction is performed on the inside of the cover 183. More specifically, as in the case of suction cleaning, the cleaning pump 1116 is driven to reduce the pressure in the pressure chamber 1111 to a negative pressure, and then the suction valve 186 is opened.

[0498] To discharge the waste liquid in pressure chamber 1111 into waste liquid tank 1115, control unit 1100 drives cleaning pump 1116 to pressurize pressure chamber 1111. Specifically, control unit 1100 closes suction valve 186, pressurization flow path opening valve 1129, and pressure reducing valve 1118, and opens pressurization valve 1128, discharge valve 1112, and pressure reducing flow path opening valve 1119. In this state, when control unit 1100 drives cleaning pump 1116, pressure in pressure chamber 1111 is increased via pressurization flow path 1127. Consequently, waste liquid in pressure chamber 1111 is discharged into waste liquid tank 1115 via discharge flow path 185.

[0499] According to the fourth embodiment, the following effects can be achieved.

[0500] (3-1) The pressure chamber 1111 is pressurized by the cleaning pump 1116, and waste liquid in the pressure chamber 1111 can be discharged through the discharge flow path 185. Since the liquid ejection device 111 uses the cleaning pump 1116 to depressurize the pressure chamber 1111 and discharge the waste liquid, there is no need for a dedicated pump for discharging the waste liquid. Therefore, the structure of the liquid ejection device 111 can be simplified.

[0501] (3-2) When the cleaning pump 1116 is driven with the suction valve 186, the pressurizing valve 1128, and the discharge valve 1112 closed, the pressure in the pressure chamber 1111 is reduced to a negative pressure. Thereafter, when the suction valve 186 is opened, the negative pressure in the pressure chamber 1111 acts on the inside of the cover 183. This enables suction cleaning, where the liquid in the liquid ejection head 113a is discharged through the nozzle 112.

[0502] (3-3) When suction valve 186 is closed and pressurizing valve 1128 and discharge valve 1112 are opened to drive cleaning pump 1116, pressure in pressure chamber 1111 is increased. This allows waste liquid in pressure chamber 1111 to be discharged. Since liquid ejection device 111 uses cleaning pump 1116 to depressurize pressure in pressure chamber 1111 to discharge waste liquid, a dedicated pump for waste liquid discharge is unnecessary. Consequently, the structure of liquid ejection device 111 can be simplified.

[0503] The above-mentioned embodiments may also be modified as shown in the following modified examples. In addition, the structures included in these embodiments and the structures included in the following modified examples may be arbitrarily combined, and the structures included in the following modified examples may be arbitrarily combined with each other.

[0504] After the suction valve 186 is opened and the negative pressure in the pressure chamber 1111 is applied to the closed space CS, the cleaning pump 1116 or the supply pump 144 may be continuously driven.

[0505] The pressurizing valve 1128 may also be used as a switching valve, and a pressurizing flow path branching from the switching valve may be provided. Each branched pressurizing flow path may also have a blow-out port, which is configured to blow pressurized air toward at least one of the nozzle surface 112a, the wiper 188 in the standby position, or the opening (cover lip) of the cover 183 in the standby position. In this way, foreign matter such as liquid, dust, or paper powder adhering to the nozzle surface 112a, the wiper 188, or the cover lip can be removed by pressurized air. Alternatively, the blow-out port of the branched pressurized flow path may be arranged in the medium storage portion 1106. In this way, paper powder adhering to the medium M before recording can be removed by pressurized air.

[0506] like Figure 32 As in the modified example described above, the liquid ejecting device 111 of the second embodiment may be configured to supply liquid using the water head difference between the liquid container 114 and the liquid ejecting head 113 a .

[0507] The liquid ejection device 111 according to this modification includes a liquid ejection head 113 a , a supply mechanism 140 that supplies liquid contained in a liquid container 114 to the liquid ejection head 113 a , and a drive mechanism 1130 that drives the supply mechanism 140 .

[0508] The supply mechanism 140 includes a first storage container 1131, a communication passage 1334, and a second storage container 1134. The communication passage 1334 has an upstream end connected to the first storage container 1131 and a downstream end connected to the second storage container 1134. The first storage container 1131 and the second storage container 1134 store the liquid supplied from the liquid container 114.

[0509] The supply mechanism 140 includes a first valve 1336 capable of closing the communication path 1334 and a supply channel 1337 for supplying liquid from the second reservoir 1134 to the liquid ejecting head 113a. The supply mechanism 140 may also include a second valve 1338, a recovery channel 1339 for recovering liquid from the liquid ejecting head 113a to the first reservoir 1131, a third valve 1340 capable of opening and closing the recovery channel 1339, and a liquid chamber 1341 disposed midway along the recovery channel 1339. The second valve 1338 can close the supply channel 1337 between the second reservoir 1134 and the liquid ejecting head 113a.

[0510] The liquid chamber 1341 is disposed between the liquid ejection head 113a and the third valve 1340. A portion of the liquid chamber 1341 is defined by a flexible member 1342. The volume of the liquid chamber 1341 changes as the flexible member 1342 deforms.

[0511] The liquid ejection head 113a may also include a first connection portion 1344 and a second connection portion 1345. The recovery flow path 1339 has an upstream end connected to the first connection portion 1344 and a downstream end connected to the first storage container 1131. The supply flow path 1337 has an upstream end connected to the second storage container 1134 and a downstream end connected to the second connection portion 1345.

[0512] The drive mechanism 1130 includes a supply pump 144 that pressurizes the interior of the second storage container 1134. In other words, the supply pump 144 is configured to pressurize the supply channel for supplying the liquid in the liquid container 114 to the liquid ejection head 113a. The drive mechanism 1130 may also include a switching mechanism 1348 connected to the supply pump 144 and a pressure sensor 1349 for detecting pressure. The drive mechanism 1130 may also include an atmosphere-release channel 1350 connected to the first storage container 1131, a pressurization channel 1351 connected to the second storage container 1134, and a connecting channel 1352 connecting the atmosphere-release channel 1350 and the pressurization channel 1351 to the supply pump 144. The drive mechanism 1130 may also include an air chamber 1353 separated from the liquid chamber 1341 by a flexible member 1342, a spring 1354 disposed within the air chamber 1353, and an air channel 1355 connected to the air chamber 1353. The spring 1354 reduces pressure fluctuations of the liquid in the recovery flow path 1339 and the liquid ejection head 113 a by pressing the flexible member 1342 .

[0513] Supply pump 144 has a suction port and a discharge port. The suction port is connected to air flow path 1355, and the discharge port is connected to connecting flow path 1352. Supply pump 144 is driven in the forward direction to deliver air drawn in from air flow path 1355 to connecting flow path 1352. Supply pump 144 is driven in the reverse direction to deliver air drawn in from connecting flow path 1352 to air flow path 1355.

[0514] The pressurizing mechanism 1357 includes the supply pump 144, the air chamber 1353, an air flow path 1355 connecting the supply pump 144 and the air chamber 1353, and a pressurizing flow path 1127 connecting the supply pump 144 and the pressure chamber 1111. The micro-pressurizing unit 1358 includes the pressurizing mechanism 1357 and the liquid chamber 1341. The micro-pressurizing unit 1358 includes the liquid chamber 1341 and the pressurizing mechanism 1357 capable of pressurizing the flexible member 1342 from outside the liquid chamber 1341. The micro-pressurizing unit 1358 is arranged in the recovery flow path 1339 between the liquid ejection head 113a and the third valve 1340. The micro-pressurizing unit 1358 is configured to pressurize the liquid in the recovery flow path 1339.

[0515] The liquid container 114 has a storage chamber 1329 for storing liquid. The first storage container 1131 has an inlet portion 1360 for introducing the liquid stored in the liquid container 114 mounted on the mounting portion 1328. The first storage container 1131 may also include: a device-side valve 1361 provided on the inlet portion 1360; a first storage chamber 1362 for storing liquid; a liquid level sensor 1363 for detecting the amount of liquid stored in the first storage chamber 1362; and a first gas-liquid separation membrane 1364 for separating the first storage chamber 1362 from the atmosphere release path 1350. The first gas-liquid separation membrane 1364 is a membrane that allows gas to pass but not liquid.

[0516] The valves 1331 and 1361 are opened by attaching the liquid container 114 to the attachment portion 1328 , and are maintained in the open state while the liquid container 114 is attached to the attachment portion 1328 .

[0517] Introduction portion 1360 is disposed above first storage container 1131. In this modified example, introduction portion 1360 extends through top portion 1365 of first storage chamber 1362. The lower end of introduction portion 1360 is located within first storage chamber 1362, below top portion 1365. The upper end of introduction portion 1360 is located outside first storage chamber 1362, above top portion 1365. Introduction portion 1360 is connected to discharge portion 1330 of liquid storage chamber 114 by attaching liquid storage chamber 114 to attachment portion 1328.

[0518] The second storage container 1134 may also include a second storage chamber 1368 for storing liquid and a second gas-liquid separation membrane 1369 separating the second storage chamber 1368 from the pressurization flow path 1351. The second gas-liquid separation membrane 1369, like the first gas-liquid separation membrane 1364, is a membrane having the property of allowing gas to pass but not allowing liquid to pass.

[0519] First valve 1336 closes communication path 1334 when the pressure in second storage container 1134 is greater than the pressure in first storage container 1131. Therefore, first valve 1336 blocks communication path 1334 when the supply pump 144 pressurizes the interior of second storage container 1134. First valve 1336 may also include a check valve that allows liquid to flow from first storage container 1131 to second storage container 1134 while restricting liquid flow from second storage container 1134 to first storage container 1131.

[0520] The controller 1100 controls the opening and closing of the second valve 1338 and the third valve 1340. The second valve 1338 can open and close the supply flow path 1337 when pressurized by the supply pump 144. The third valve 1340 can open and close the recovery flow path 1339.

[0521] Switching mechanism 1348 includes a capillary portion 1372 provided in connecting flow path 1352, first through eleventh selector valves 1373a through 1373k capable of opening and closing the flow path, and a pressurizing valve 1128. Pressurizing valve 1128 opens and closes pressurizing flow path 1127. Capillary portion 1372 is a thin, winding tube that significantly restricts the flow of liquid relative to the flow of air.

[0522] When first selector valve 1373a is opened, air flow path 1355 communicates with the atmosphere. When second selector valve 1373b is opened, air flow path 1355 communicates with pressure sensor 1349. When third selector valve 1373c is opened, air flow path 1355 is opened, and supply pump 144 communicates with air chamber 1353. When pressurizing valve 1128 is opened, pressurizing flow path 1127 is opened, and supply pump 144 communicates with pressure chamber 1111.

[0523] When the fourth selector valve 1373d is opened, the connecting flow path 1352 between the supply pump 144 and the eighth selector valve 1373h is connected to the atmosphere. When the fifth selector valve 1373e is opened, the connecting flow path 1352 is connected to the pressure sensor 1349. When the sixth and seventh selector valves 1373f and 1373g are opened, the connecting flow path 1352 is connected to the atmosphere. When the eighth selector valve 1373h is opened, the connecting flow path 1352 is opened. When the ninth selector valve 1373i is opened, the capillary portion 1372 is connected to the atmosphere. When the tenth selector valve 1373j is opened, the atmosphere release path 1350 is opened, connecting the first storage tank 1131 to the connecting flow path 1352. When the eleventh selector valve 1373k is opened, the pressurizing path 1351 is opened, connecting the second storage tank 1134 to the connecting flow path 1352.

[0524] The liquid in the liquid container 114 flows into the first storage container 1131 through the outlet 1330 and the inlet 1360 due to the water head difference. The liquid in the first storage container 1131 flows into the second storage container 1134 due to the water head difference.

[0525] The lower end of the introduction portion 1360 is located below the nozzle surface 112a. Consequently, a first liquid level 1366 of the liquid stored in the first storage container 1131 fluctuates within a range below the nozzle surface 112a. When atmospheric pressure is applied to the first storage chamber 1362 and the second storage chamber 1368, a second liquid level 1370 of the liquid in the second storage chamber 1368 reaches the same height as the first liquid level 1366. In other words, the second liquid level 1370 is maintained at a standard position approximately at the same height as the lower end of the introduction portion 1360, fluctuating within a range below the nozzle surface 112a.

[0526] The liquid in the liquid ejection head 113a is maintained at a negative pressure by the water level difference with the liquid in the first storage tank 1131 and the second storage tank 1134. When the liquid is consumed in the liquid ejection head 113a, the liquid stored in the second storage tank 1134 is supplied to the liquid ejection head 113a.

[0527] In this modification, when performing various cleaning operations, the control unit 1100 controls the pressurizing valve 1128 in the same manner as in the second embodiment. Furthermore, when discharging waste liquid from the pressure chamber 1111, the pressure chamber 1111 can be pressurized by opening the pressurizing valve 1128 and driving the supply pump 144.

[0528] The supply mechanism 140 may not include a mechanism for selectively pressurizing the plurality of liquid containers 114f and 114s.

[0529] The liquid ejection device 111 is not limited to a device having a line head with a recording area covering the entire width of the medium M. It may also be a serial type device, in which the carriage holding the liquid ejection head 113a alternately ejects liquid while moving in the width direction of the medium M and transports the liquid in a transport direction intersecting the width direction of the medium M. In this case, the wiper support portion 189 may be fixed, and the wiper 188 may wipe the nozzle surface 112a of the liquid ejection head 113a as the carriage holding the liquid ejection head 113a moves.

[0530] The control unit 1100 is not limited to being equipped with a CPU 1142 and a storage unit 1143 to execute software processing. For example, it may also include a dedicated hardware circuit (e.g., an ASIC) that processes at least a portion of the software processing executed in the above-described embodiments. In other words, the control unit 1100 may have any of the following configurations (a) to (c).

[0531] (a) A processing device that executes all the above-mentioned processing according to a program and a program storage device such as a ROM that stores the program.

[0532] (b) A processing device and a program storage device are provided for executing part of the above-mentioned processing according to a program, and a dedicated hardware circuit for executing the remaining processing.

[0533] (c) It has dedicated hardware circuitry to perform all the above-mentioned processing.

[0534] Here, there may be multiple software processing circuits or dedicated hardware circuits including a processing device and a program storage device. In other words, the above-mentioned processing can be executed by a processing circuit (processing circuitry) including at least one of one or more software processing circuits and one or more dedicated hardware circuits.

[0535] The liquid ejection device 111 may also be a liquid ejection device 111 that ejects liquids other than ink. The state of the liquid ejected from the liquid ejection device 111 in the form of tiny droplets also includes the state of being in the form of particles, tears, or silk-like trailing. The liquid mentioned here can be any material that can be ejected from the liquid ejection device 111. For example, the liquid can be any material in the form of a substance in a liquid phase, including high-viscosity or low-viscosity liquids, sols, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals, molten metals and other fluids. Liquids include not only liquids as a state of matter, but also liquids in which particles of functional materials composed of solids such as pigments or metal particles are dissolved, dispersed or mixed in a solvent. Representative examples of liquids include the inks and liquid crystals described in the above embodiments. Here, inks include various liquid compositions such as general aqueous inks, oil-based inks, gel inks, and hot melt inks. Specific examples of the liquid ejection device 111 include devices that eject liquids containing materials such as electrode materials or pigments in dispersed or dissolved form, such as those used in the manufacture of liquid crystal displays, electroluminescent displays, surface-emitting displays, color filters, and the like. The liquid ejection device 111 may also be a device that ejects bioorganic matter used in the manufacture of biochips, a device that ejects liquids used as samples for precision pipettes, a printing and dyeing device, or a micro-dispenser. The liquid ejection device 111 may also be a device that uses precise positioning to eject lubricating oil onto precision machinery such as clocks or cameras, or a device that ejects transparent resin liquids such as ultraviolet-curing resins onto substrates to form tiny hemispherical lenses, optical lenses, and the like used in optical communication components. The liquid ejection device 111 may also be a device that ejects etching liquids such as acids or alkalis used to etch substrates.

[0536] The following describes the technical ideas and effects grasped from the above-described embodiments and modifications.

[0537] (A) A cover device is a cover device that is capable of forming a space surrounding an opening of a liquid ejecting head having a nozzle for ejecting liquid when in contact with the liquid ejecting head, the cover device comprising a cover having: a recess that forms the space; a humidifying chamber that has an inlet for a humidifying fluid for humidifying the space and an outlet for the humidifying fluid; and a partition wall that divides the recess and the humidifying chamber and is air-permeable, the recess having a hole that can discharge liquid discharged from the liquid ejecting head into the cover.

[0538] According to this structure, since the water evaporated from the humidification fluid in the humidification chamber reaches the recess through the partition wall, the space formed by the recess is humidified, and the opening of the nozzle of the liquid ejection head is humidified. In addition, the liquid discharged into the cover does not flow into the humidification chamber due to the partition wall, and is therefore discharged from the hole in the recess to the outside of the cover. Thus, it is possible to use a single cover to accommodate and discharge the liquid discharged from the nozzle and to humidify the nozzle. That is, in the liquid ejection device, the space for the cover of both the cover with the cover mechanism for preventing nozzle clogging and the cover with the cover device for suppressing nozzle drying can be the space for only the cover of one side. Thus, the liquid ejection device can be prevented from becoming larger.

[0539] (B) In the above-described lid device, the hole may be provided in the recessed portion at a position lower than the partition wall.

[0540] With this structure, gravity can be used to drain the liquid in the recess through the hole to the outside of the lid. Furthermore, the amount of liquid remaining in the recess can be reduced. Furthermore, the surface of the partition wall is blocked by liquid, thereby preventing water evaporating from the humidifying fluid in the humidifying chamber from passing through the partition wall. In other words, this prevents the nozzle opening of the liquid ejection head from being humidified.

[0541] (C) In the above-described lid device, the hole may be provided at a lowermost portion of the recess.

[0542] According to this structure, the liquid in the recessed portion can be discharged from the hole to the outside of the cover by gravity. In addition, the liquid can be suppressed from remaining in the recessed portion.

[0543] (D) In ​​the above-described cap device, the recess may include an absorber capable of absorbing liquid at a position in contact with the partition wall.

[0544] With this structure, the liquid discharged into the recessed portion is absorbed by the absorber. Furthermore, the water that evaporates from the humidifying fluid and passes through the partition wall humidifies the liquid absorbed by the absorber. The liquid absorbed by the absorber diffuses throughout the absorber. This allows for a nearly uniform distribution of the liquid absorbed by the absorber. In other words, the entire space can be humidified more evenly. Furthermore, the openings of the multiple nozzles in the liquid ejection head can be humidified more evenly.

[0545] (E) In the cap device described above, the humidification chamber may include a groove through which the humidification fluid flows, and the humidification chamber may be formed into a flow path communicating between the inlet and the outlet by the groove and the partition wall covering the groove.

[0546] According to this structure, by flowing the humidifying fluid through the humidifying chamber, which is formed into a flow path connecting the inlet and outlet, the humidifying fluid can be filled into the humidifying chamber or discharged from the humidifying chamber as needed. Furthermore, since the humidifying chamber is formed into a flow path, it is possible to prevent the humidifying fluid filled in the humidifying chamber from unnecessarily flowing out of the humidifying chamber. Furthermore, since the flow path is formed around the entire bottom surface of the cover, the entire recess can be humidified. This allows for more uniform humidification of the multiple nozzle openings of the liquid ejection head.

[0547] (F) In the cap device described above, the humidification chamber may be provided in an inclined posture relative to the horizontal, and the inlet and the outlet may be provided above the center of the humidification chamber in the vertical direction.

[0548] According to this configuration, it is possible to suppress the humidification fluid filled in the humidification chamber from flowing out of the humidification chamber from the inlet or the outlet due to the water level pressure.

[0549] (G) In the above-described lid device, the recess may include an atmosphere communication hole for communicating the space with the atmosphere, and the atmosphere communication hole may be provided above a vertical center of the recess.

[0550] According to this structure, it is possible to prevent the atmosphere communication hole from being clogged with liquid and from being unable to discharge the liquid from the recessed portion.

[0551] (H) Alternatively, the above-mentioned cover device further comprises: a humidifying fluid storage portion that stores the humidifying fluid; a supply flow path that connects the humidifying fluid storage portion with the inlet; a recovery flow path that connects the outlet with the humidifying fluid storage portion; and a pump that enables the humidifying fluid to flow in a circulation path including the humidifying fluid storage portion, the supply flow path, and the recovery flow path.

[0552] This structure allows the humidification fluid within the circulation path to be stirred. To humidify the space, a significant amount of water evaporates from the humidification fluid within the humidification chamber. Therefore, by stirring the humidification fluid within the circulation path, the concentration of the humidification fluid throughout the circulation path can be made uniform. In other words, the amount of water contained in the humidification fluid within the humidification chamber can be returned to a level close to that at the time of shipment of the liquid ejection device.

[0553] (I) The cap device may further include a moisture supply unit capable of supplying moisture into the circulation path.

[0554] According to this configuration, when water evaporates from the humidification fluid, water can be replenished to optimize the concentration of the humidification fluid. In other words, the amount of water contained in the humidification fluid can be returned to the amount at the time of shipment of the liquid ejection device.

[0555] (J) It may also be that in the above-mentioned cover device, the cover device is constructed by arranging a plurality of the covers, the outflow port of the first cover among the plurality of covers is connected to the inflow port of the second cover adjacent to the first cover, the inflow port located at the far upstream is connected to the supply flow path, and the outflow port located at the far downstream is connected to the recovery flow path.

[0556] According to this configuration, the humidification fluid can be filled, stirred, and discharged from the plurality of caps using only one supply flow path and one recovery flow path.

Claims

1. A cover device, characterized in that: A cap device that, when in contact with a liquid ejection head having a nozzle for ejecting liquid, can form a space surrounding the opening of the nozzle. The cover device includes a cover having: a recessed portion forming the space; a humidifying chamber having an inlet for inflow of a humidifying fluid for humidifying the space and an outlet for outflow of the humidifying fluid; as well as The partition wall restricts the passage of liquid and has air permeability, and divides the recess and the humidification chamber. The recess has a hole capable of discharging the liquid discharged from the liquid ejection head into the cap, When the space is formed, the partition wall faces the opening of the nozzle.

2. The cover device according to claim 1, wherein: The hole is provided in the recessed portion at a position lower than the partition wall.

3. The cover device according to claim 2, characterized in that The hole is provided at the lowermost portion of the recess.

4. The cover device according to any one of claims 1 to 3, characterized in that The recessed portion includes an absorber capable of absorbing liquid at a position in contact with the partition wall.

5. The cover device according to any one of claims 1 to 3, characterized in that: The humidification chamber has a groove for allowing the humidification fluid to flow. The humidification chamber is formed into a flow path shape communicating between the inlet and the outlet by the groove and the partition wall covering the groove.

6. The cover device according to any one of claims 1 to 3, characterized in that: The humidification chamber is arranged in an inclined posture relative to the horizontal, The inlet and the outlet are provided above the vertical center of the humidification chamber.

7. The cover device according to any one of claims 1 to 3, characterized in that: The recess has an atmosphere communication hole for communicating the space with the atmosphere. The atmosphere communication hole is provided above the vertical center of the recess.

8. The cover device according to claim 1, wherein: The cover device further comprises: a humidifying fluid receiving portion for receiving the humidifying fluid; a supply flow path connecting the humidification fluid receiving portion with the inlet; a recovery flow path connecting the outflow port and the humidification fluid receiving portion; and The pump can cause the humidification fluid to flow through a circulation path including the humidification fluid storage portion, the supply flow path, and the recovery flow path.

9. The cover device according to claim 8, characterized in that The cap device further includes a moisture supply unit capable of supplying moisture into the circulation path.

10. The cover device according to claim 8 or 9, characterized in that The cover device is formed by arranging a plurality of the covers, The outflow port of a first cover among the plurality of covers is connected to the inflow port of a second cover adjacent to the first cover, The inlet located most upstream is connected to the supply flow path, and the outlet located most downstream is connected to the recovery flow path.

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