Liquid ejecting apparatus and stirring method for liquid ejecting apparatus

Abstract

The present application provides a liquid ejection device and a stirring method for the liquid ejection device, the liquid ejection device including: a liquid ejection head; a cover having a closed space forming portion that forms a closed space, an inflow port through which a humidification fluid for humidifying the closed space flows in, and an outflow port through which the humidification fluid flows out; a humidification fluid storage portion that stores the humidification fluid; a supply flow path that communicates the humidification fluid storage portion and the inflow port; a recovery flow path that communicates the humidification fluid storage portion and the outflow port; a second pump; a water supply portion; and a control portion. One end of the recovery flow path opens in the humidification fluid storage portion at a position lower than a liquid surface of the humidification fluid. As a first stirring cycle, the control portion supplies water into the circulation path through the water supply portion and drives the second pump to flow the humidification fluid in the circulation path.

Description

Technical Field

[0001] This invention relates to a liquid ejection device, such as an inkjet printer, and a stirring method for the liquid ejection device. Background Technology

[0002] As an example of the liquid ejection device described in Patent Document 1, the liquid ejection device includes a cover device. After the cover device contacts the liquid ejection head to form a space surrounding the nozzle, moisturizing liquid is supplied to the space from the moisturizing liquid storage section through a connecting flow channel, thereby humidifying the nozzle.

[0003] In the aforementioned liquid spraying device, for example, if the water in the moisturizing liquid in the moisturizing liquid storage section evaporates, water needs to be supplied to the moisturizing liquid storage section in order to maintain the concentration of the moisturizing liquid. However, when water is supplied to the moisturizing liquid, there is a problem that the moisturizing liquid and the supplied water are difficult to mix together.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2019-38159 Summary of the Invention

[0005] A liquid ejection device for solving the above-mentioned problems includes: a liquid ejection head capable of ejecting liquid from a nozzle; a cover having a closed space forming portion, an inlet, and an outlet, wherein the closed space forming portion is capable of forming a closed space through contact with the liquid ejection head to open the nozzle, the inlet is for receiving humidifying fluid for humidifying the closed space, and the outlet is for receiving the humidifying fluid; a humidifying fluid receiving portion for receiving the humidifying fluid; a supply channel connecting the humidifying fluid receiving portion and the inlet; and a recovery channel for receiving the humidifying fluid. The humidified fluid receiving section is connected to the outlet; a pump is capable of flowing the humidified fluid within a circulation path including the humidified fluid receiving section, the supply channel, and the recovery channel; a water supply section is capable of supplying water into the circulation path; a control section is provided, wherein one end of the recovery channel opens within the humidified fluid receiving section at a position lower than the liquid level of the humidified fluid, and as a first stirring cycle, the control section supplies water into the circulation path via the water supply section and drives the pump to flow the humidified fluid within the circulation path.

[0006] A stirring method for a liquid ejection device that solves the above-mentioned problems, the liquid ejection device comprising: a liquid ejection head capable of ejecting liquid from a nozzle; a cover having a closed space forming portion, an inlet, and an outlet, wherein the closed space forming portion is capable of forming a closed space through contact with the liquid ejection head to open the nozzle, the inlet is for receiving humidifying fluid for humidifying the closed space, and the outlet is for receiving the humidifying fluid; a humidifying fluid receiving portion for receiving the humidifying fluid; a supply channel connecting the humidifying fluid receiving portion and the inlet; and a recovery channel for receiving... The humidifying fluid receiving section is connected to the outlet; a pump is capable of flowing the humidifying fluid within a circulation path including the humidifying fluid receiving section, the supply channel, and the recovery channel; a water supply section is capable of supplying water into the circulation path; one end of the recovery channel opens within the humidifying fluid receiving section at a position lower than the liquid level of the humidifying fluid; in the stirring method of the liquid ejection device, a first stirring cycle is implemented in which water is supplied into the circulation path through the water supply section and the pump is driven to flow the humidifying fluid within the circulation path. Attached Figure Description

[0007] Figure 1 This is a perspective view of a liquid ejection device in one embodiment.

[0008] Figure 2 A schematic diagram showing the arrangement of structural elements around a liquid ejector head.

[0009] Figure 3 A schematic diagram illustrating the structure of the maintenance device.

[0010] Figure 4 A block diagram illustrating the electrical structure of a liquid ejection device.

[0011] Figure 5 This is a flowchart illustrating the mixing process during setup.

[0012] Figure 6 This is a flowchart illustrating the post-setting stirring process.

[0013] Figure 7 This is a flowchart illustrating the post-printing stirring process. Detailed Implementation

[0014] Hereinafter, an embodiment of the liquid ejection device and its stirring method will be described based on the accompanying drawings.

[0015] Liquid ejection devices include, for example, inkjet printers that print by ejecting ink, an example of a liquid, onto media such as paper.

[0016] In the accompanying drawings, the liquid ejection device 11 is positioned on a plane. The width and depth directions are substantially horizontal. The vertical direction is represented by the Z-axis, and the directions along the planes intersecting the Z-axis are represented by the X-axis and Y-axis. The X-axis, Y-axis, and Z-axis are preferably orthogonal to each other. In the following description, the X-axis direction is referred to as the width direction X, the Y-axis direction as the depth direction Y, and the Z-axis direction as the vertical direction Z.

[0017] Liquid ejection device 11

[0018] like Figure 1 as well as Figure 2 As shown, the liquid dispensing device 11 includes a main body 12 in the shape of a cuboid, an image reading unit 13 mounted on the main body 12, and an automatic feeding unit 14 mounted on the image reading unit 13. That is, the liquid dispensing device 11 has a structure in which the main body 12, the image reading unit 13, and the automatic feeding unit 14 are stacked sequentially from the bottom side in the vertical direction Z.

[0019] The image reading unit 13 is configured to read images such as text and photographs recorded on the original document. The automatic feeding unit 14 is configured to feed the placed original document toward the image reading unit 13. The image reading unit 13 has an operation unit 15 for operating the liquid dispensing device 11. The operation unit 15 has, for example, a touch panel-type liquid crystal display and operation buttons.

[0020] The main body 12 has multiple media storage sections 16 capable of storing media M such as paper. The main body 12 has one or more media storage sections 16. The number of media storage sections 16 in the main body 12 can be arbitrarily varied. The media storage section 16 is configured to be able to be pulled out relative to the main body 12.

[0021] The main body 12 has a printing section 17 for printing on a medium M within the main body 12. The printing section 17 includes a head unit 19, which has a liquid ejection head 18 capable of ejecting liquid. The main body 12 has a mounting section 20 at its upper part for mounting the printed medium M. The mounting section 20 has a mounting surface 20a for mounting the medium M.

[0022] The media M stored in the media storage section 16 is conveyed from the media storage section 16 to the printing section 17 along the conveying path 21 to the mounting section 20. By rotating a feed roller (not shown) in contact with the uppermost media among the plurality of media M stored in the media storage section 16, the uppermost media M is fed from the media storage section 16 to the printing section 17 located above the media storage section 16.

[0023] As the medium M passes through the printing section 17, the liquid ejector head 18 ejects ink, as an example of a liquid, toward the medium M. Printing is performed by causing the ink ejected from the liquid ejector head 18 to adhere to the medium M. The printed medium M is then discharged to the mounting section 20 via a discharge roller pair (not shown).

[0024] Printing Department 17

[0025] like Figure 2 As shown, a cover 22 is disposed around the liquid nozzle 18 of the printing section 17, and on the opposite side of the head unit 19 relative to the transport path 21. The head unit 19 includes the liquid nozzle 18 and a support portion 23 for holding the liquid nozzle 18.

[0026] The liquid nozzle 18 is configured to spray liquid from multiple nozzles 24 constituting multiple nozzle groups onto the medium M while extending along the width direction X. In the following description, when the liquid nozzle 18 sprays liquid onto the medium M, the direction in which the liquid is sprayed is referred to as the spray direction Y1. When the liquid nozzle 18 sprays liquid onto the medium M, the direction in which the medium M is conveyed is referred to as the conveying direction Z1.

[0027] The opening surface of the nozzle 24 in the liquid ejector head 18 is designated as the nozzle surface 25. The nozzle surface 25 may not be horizontal, for example. That is, the liquid ejector head 18 may be configured such that the nozzle surface 25 is at a predetermined angle θ1 relative to the horizontal plane. The liquid ejector head 18 ejects liquid from the nozzle 24 into the medium M, for example, with the nozzle surface 25 at a predetermined angle θ1 relative to the horizontal plane. The liquid ejector head 18 may also be configured with the nozzle surface 25 in a horizontal position.

[0028] The liquid ejection head 18 is, for example, a line head having a number of nozzles 24 in the width direction X, which intersects the transport direction Z1 and the ejection direction Y1, capable of simultaneously ejecting liquid across the entire width of the medium M. The liquid ejection device 11 performs line printing by ejecting liquid towards the medium M, which is being transported at a fixed speed, from multiple nozzles 24 located opposite to the entire width of the medium M.

[0029] In the liquid dispensing device 11, maintenance operations such as capping, cleaning, and rinsing are performed to prevent or eliminate poor liquid dispensing caused by clogging of the nozzle 24 or adhesion of foreign objects to the nozzle 24. The liquid dispensing device 11 is equipped with a maintenance device 26 (see reference 11) for performing the above-mentioned maintenance operations. Figure 3 ).

[0030] Maintenance actions

[0031] like Figure 2As shown, the capping refers to the action of the cap 22 contacting the nozzle surface 25 of the liquid nozzle 18 in a manner that surrounds the nozzle 24 when the liquid nozzle 18 is not dispensing liquid. Since the capping can suppress the thickening of the liquid in the nozzle 24, it can prevent the occurrence of poor liquid dispensing from the nozzle 24.

[0032] Cleaning refers to the action of forcibly discharging liquid from nozzle 24 by pressurizing the upstream side of liquid nozzle 18, or by forcibly discharging liquid from nozzle 24 by applying suction force to nozzle 24 of liquid nozzle 18.

[0033] Rinsing refers to the action of ejecting droplets from nozzle 24 unrelated to printing. Because rinsing removes thickened ink, air bubbles, foreign matter, etc., that could cause poor ejection, which are then expelled from nozzle 24, clogging of nozzle 24 can be prevented. Liquid discharged from liquid ejection head 18 that is not used in printing is called waste liquid.

[0034] The liquid discharged through rinsing is waste liquid since it will not be used in printing. The waste liquid L3 discharged through rinsing is received and contained, for example, by a cover 22. That is, rinsing is performed by spraying droplets from a nozzle 24 through a liquid nozzle 18, for example, toward the inside of the cover 22.

[0035] The position of the head unit 19 when printing on the medium M by spraying liquid from the liquid nozzle 18 is called the printing position. The position of the cover 22 when printing on the medium M by spraying liquid from the liquid nozzle 18 is called the retraction position. The position of the head unit 19 when performing maintenance operations on the liquid spraying device 11 is called the maintenance position. The position of the cover 22 when performing maintenance operations on the liquid spraying device 11 is also called the maintenance position.

[0036] Head unit 19 is moved by head unit moving mechanism 27 (see reference). Figure 4 ), thus in Figure 2 The printing position is shown in solid lines in the middle and Figure 2 The head unit 19 is moved between the maintenance positions indicated by the double-dotted lines. The direction in which the head unit 19 is moved from the printing position to the maintenance position is called the first direction D1. The direction in which the head unit 19 is moved from the maintenance position to the printing position is called the second direction D2.

[0037] Cover 22 is moved by cover moving mechanism 28 (see reference) Figure 4 ), thus in Figure 2 The retreat position is shown in solid line in the middle and Figure 2 The cover 22 is moved between the maintenance positions indicated by the double-dotted lines. The direction in which the cover 22 is moved from the retracted position to the maintenance position is called the third direction D3. The direction in which the cover 22 is moved from the maintenance position to the retracted position is called the fourth direction D4.

[0038] like Figure 2 As shown, make the cover 22 from Figure 2 The retreat position, indicated by the solid line, is moved towards a third party, D3, and configured accordingly. Figure 2 The maintenance location is indicated by a double-dotted line. Then, the head unit 19 is moved from... Figure 2 The printing position, indicated by the solid line, is moved in the first direction D1 and configured in Figure 2 The maintenance position is indicated by a double-dotted line. Thus, the head unit 19 is covered by the cover 22.

[0039] In this state, rinsing is performed by spraying liquid droplets from the nozzle 24 of the liquid nozzle 18 toward the inside of the cover 22. Alternatively, in this state, cleaning is performed by pressurizing the liquid in the nozzle 24 of the liquid nozzle 18, thereby forcibly expelling liquid droplets from the nozzle 24 of the liquid nozzle 18 toward the inside of the cover 22. That is, in the liquid spraying device 11 of this embodiment, capping, rinsing, and cleaning are performed at the maintenance position. Rinsing can also be performed with the liquid nozzle 18 removed from the cover 22.

[0040] When maintenance actions such as rinsing or cleaning are completed, the head unit 19 is moved from... Figure 2 The maintenance position, indicated by the double-dotted line, is moved in the second direction D2 and configured in... Figure 2 The printed position is shown in solid line. Then, make the cover 22 from... Figure 2 The maintenance position, indicated by the double-dotted line, is moved in the fourth direction (D4) and configured in... Figure 2 The retreat position is indicated by a solid line in the middle.

[0041] Maintenance device 26

[0042] like Figure 2 as well as Figure 3 As shown, the maintenance device 26 includes a cover 22, a cover moving mechanism 28, a humidifying fluid circulation mechanism 29, and a waste liquid recovery mechanism 30.

[0043] Cover 22

[0044] like Figure 2 as well as Figure 3 As shown, the cover 22 has a bottomed, box-shaped enclosed space forming portion 31 with an opening at one end. The enclosed space forming portion 31 forms an enclosed space through which the nozzle 24 opens by contacting the end with its opening side with the nozzle surface 25 of the liquid spray head 18. A humidification chamber 32 is formed in the center of the bottom of the enclosed space forming portion 31. The space within the enclosed space forming portion 31 includes the humidification chamber 32 and a waste liquid storage area 33.

[0045] The waste liquid storage area 33 is the area within the enclosed space forming section 31, excluding the humidification chamber 32, and is the area for storing waste liquid L3. An absorber (not shown) capable of absorbing and retaining waste liquid L3 may also be disposed within the waste liquid storage area 33. The humidification chamber 32 is separated from the waste liquid storage area 33 by a partition 34 that prevents liquid from passing through. A portion of the partition 34 is constructed through a first permeable membrane 35 that is gas-permeable. The first permeable membrane 35 allows gas to pass through while impeding the passage of liquid.

[0046] An atmospheric communication hole 36, an inlet 37, and an outlet 38 are formed on the enclosed space forming section 31 to enable communication between the inside and outside of the enclosed space forming section 31. The atmospheric communication hole 36 is located at the upper part of the enclosed space forming section 31 and communicates with the waste liquid storage area 33. The inlet 37 and the outlet 38 are respectively communicated with the humidification chamber 32. Humidifying fluid L1 flows into the humidification chamber 32 from the inlet 37. The humidifying fluid L1 humidifies the enclosed space formed by the enclosed space forming section 31. The humidifying fluid L1 contains, for example, glycerin as a humectant and water. The concentration of the humidifier in the humidifying fluid L1 is set to, for example, 22.5 ± 5%. The humidifying fluid L1 is conductive. The humidifying fluid L1 that flows into the humidification chamber 32 from the inlet 37 flows out from the outlet 38.

[0047] Humidifying fluid circulation mechanism 29

[0048] like Figure 3 As shown, the humidifying fluid circulation mechanism 29 includes a humidifying fluid receiving section 39, a supply channel 40, and a return channel 41. The supply channel 40 connects the humidifying fluid receiving section 39 and the inlet 37. That is, the humidifying fluid receiving section 39 is connected to the humidifying chamber 32 via the supply channel 40 and the inlet 37.

[0049] The recovery channel 41 connects the humidifying fluid receiving section 39 and the outlet 38. That is, the humidifying fluid receiving section 39 is connected to the humidifying chamber 32 via the recovery channel 41 and the outlet 38. The humidifying fluid circulation mechanism 29 has a circulation path 42, which includes the humidifying fluid receiving section 39, the supply channel 40, and the recovery channel 41.

[0050] The humidifying fluid receiving section 39 has an upper wall 43, a peripheral wall 44, and a bottom wall 45. The humidifying fluid receiving section 39 internally receives the humidifying fluid L1. A recovery channel 41 penetrates the upper wall 43 and extends to the lower end of the humidifying fluid receiving section 39. One end 41a of the recovery channel 41 opens within the humidifying fluid receiving section 39 at a position lower than the liquid level of the humidifying fluid L1. Alternatively, the recovery channel 41 may penetrate the peripheral wall 44 and have one end 41a open within the humidifying fluid receiving section 39 at a position lower than the liquid level of the humidifying fluid L1.

[0051] The liquid level of the humidifying fluid L1 within the humidifying fluid receiving section 39 includes the liquid level that has dropped due to the evaporation of water in the humidifying fluid L1. One end 40a of the supply channel 40 is connected to the lower end of the peripheral wall 44. One end 40a of the supply channel 40 communicates with the interior of the humidifying fluid receiving section 39. The humidifying fluid receiving section 39 includes a detection section 46 for detecting the height of the liquid level of the humidifying fluid L1 within the humidifying fluid receiving section 39. The detection section 46 has a first electrode 47 and a second electrode 48.

[0052] The first electrode 47 and the second electrode 48 are arranged vertically downwards from the upper surface (lower surface of the upper wall 43) inside the humidifying fluid receiving section 39. The length of the first electrode 47 is shorter than the length of the second electrode 48. The height of the lower end of the first electrode 47 from the bottom surface inside the humidifying fluid receiving section 39 is set as a first height H. The detection unit 46 detects the liquid level of the humidifying fluid L1 inside the humidifying fluid receiving section 39 based on whether the first electrode 47 and the second electrode 48 are conductive.

[0053] When the height of the humidifying fluid L1 contained in the humidifying fluid receiving section 39 is above the first height H, the first electrode 47 and the second electrode 48 will be connected. When the height of the humidifying fluid L1 contained in the humidifying fluid receiving section 39 is less than the first height H, the first electrode 47 and the second electrode 48 will not be connected.

[0054] Therefore, by confirming whether the first electrode 47 and the second electrode 48 are conductive, it is possible to determine whether the height of the humidifying fluid L1 contained in the humidifying fluid receiving section 39 is above or below the first height H. The method for determining whether the height of the humidifying fluid L1 contained in the humidifying fluid receiving section 39 is above or below the first height H is not limited to the electrode method described above; it can also be an optical method or an electrostatic capacitance method.

[0055] When the height of the liquid level of the humidifying fluid L1 contained in the humidifying fluid receiving section 39 is above the first height H, the concentration of the humidifier in the humidifying fluid L1 can be determined based on the current value flowing between the first electrode 47 and the second electrode 48 when a constant voltage is applied between the first electrode 47 and the second electrode 48.

[0056] The position of one end 41a of the recovery channel 41 within the humidifying fluid receiving section 39 can also be below the height corresponding to the concentration of the humidifier in the humidifying fluid L1 (22.5 ± 5% in this example) when the height of the liquid surface of the humidifying fluid L1 is the first height H. The position of one end 41a of the recovery channel 41 within the humidifying fluid receiving section 39 can also be below the height of the lower end of the second electrode 48 of the detection section 46.

[0057] The position of one end 41a of the recovery channel 41 within the humidifying fluid receiving section 39 can also be below the height of the connection between one end 40a of the supply channel 40 and the peripheral wall 44 of the humidifying fluid receiving section 39. The position of one end 41a of the recovery channel 41 within the humidifying fluid receiving section 39 can also be below half the height of the humidifying fluid L1 at its highest point within the humidifying fluid receiving section 39.

[0058] The humidifying fluid receiving section 39 has a first atmospheric communication channel 49 and a second permeable membrane 50. The first atmospheric communication channel 49 communicates the interior of the humidifying fluid receiving section 39 with the atmosphere. One end of the first atmospheric communication channel 49 is connected to the upper wall 43 of the humidifying fluid receiving section 39, and the other end is open to the atmosphere. One end of the first atmospheric communication channel 49 communicates with the interior of the humidifying fluid receiving section 39. A first on / off valve 51 and a first pump 52, as an example of a pressure reducing unit, are provided in the first atmospheric communication channel 49. The first pump 52 is, for example, a pressure reducing pump.

[0059] The first on / off valve 51 is positioned closer to the humidifying fluid receiving section 39 than the first pump 52. The first pump 52 draws fluid from the humidifying fluid receiving section 39 by operating the first on / off valve 51 with the first on / off valve 51 open. In other words, the first pump 52 depressurizes the space within the humidifying fluid receiving section 39 by operating the first on / off valve 51 with the first on / off valve open.

[0060] In the first atmospheric communication channel 49, a labyrinthine capillary structure is formed instead of the first on / off valve 51, or a labyrinthine capillary structure is formed in addition to the first on / off valve 51. A labyrinthine capillary structure refers to a pipe structure that is narrow and has a tortuous, complex path, allowing air to enter and exit but significantly restricting the entry and exit of liquids. This labyrinthine capillary structure suppresses the evaporation of liquid (e.g., water in the humidifying fluid L1) within the humidifying fluid receiving section 39.

[0061] A second permeable membrane 50 is disposed at the connection between the humidifying fluid receiving section 39 and the first atmospheric communication channel 49. The second permeable membrane 50 is disposed within the humidifying fluid receiving section 39 such that it covers one end of the first atmospheric communication channel 49. The second permeable membrane 50 allows gas to pass through while impeding the passage of liquid.

[0062] like Figure 3 As shown, the humidifying fluid circulation mechanism 29 includes: a second pump 53, which is an example of a pump capable of flowing humidifying fluid L1 within the circulation path 42; a first check valve 54; and a pressure regulating valve 55. The second pump 53 flows the humidifying fluid L1 within the circulation path 42. Driven by the second pump 53, the humidifying fluid L1 flowing in the supply channel 40 is transported to the humidifying chamber 32 within the enclosed space forming portion 31 of the cover 22.

[0063] The first check valve 54 allows the humidifying fluid L1 to flow from the humidifying fluid receiving section 39 to the cover 22 side, and prevents the backflow of humidifying fluid L1 from the cover 22 side to the humidifying fluid receiving section 39 side due to water level difference. An on / off valve may also be used instead of the first check valve 54. Furthermore, it may be configured such that the second pump 53 is driven when the on / off valve is opened, thereby allowing the humidifying fluid L1 to flow from the humidifying fluid receiving section 39 side to the cover 22 side.

[0064] When the pressure regulating valve 55 reaches a predetermined negative pressure on the humidifying fluid receiving section 39 side, it allows the humidifying fluid L1 to flow from the cover 22 side to the humidifying fluid receiving section 39 side, and always prevents the backflow of the humidifying fluid L1 from the humidifying fluid receiving section 39 side to the cover 22 side. The pressure difference of the water level difference is adjusted by the pressure regulating valve 55 so that the humidifying fluid L1 will not flow from the cover 22 side to the humidifying fluid receiving section 39 side due to the water level pressure.

[0065] like Figure 3 As shown, the humidifying fluid circulation mechanism 29 includes a water supply section 56, which supplies water L2 into the circulation path 42. The water supply section 56 includes a water collection section 57, a water supply channel 58, a second on / off valve 59, and a second check valve 60. The water collection section 57 collects the water L2 that can be supplied into the circulation path 42. The water supply channel 58 is connected to the circulation path 42. The second on / off valve 59 opens and closes the water supply channel 58.

[0066] The moisture collection section 57 has an outlet section 61. The moisture collection section 57 communicates with the moisture supply channel 58 at the outlet section 61. The moisture supply channel 58 communicates with the circulation path 42 at the first confluence section 62 of the circulation path 42. That is, the moisture collection section 57 and the circulation path 42 are connected. Preferably, the moisture collection section 57 is configured to be replaceable. The moisture L2 supplied from the moisture collection section 57 to the circulation path 42 is moisture used to replenish the moisture evaporated from the humidifying fluid L1. The moisture L2 is, for example, composed of pure water and a small amount of preservative.

[0067] When the second on / off valve 59 is opened, the water collection section 57 and the circulation path 42 are connected via the water supply channel 58. The second one-way valve 60 allows the flow of water L2 from the water collection section 57 side to the circulation path 42 side, and prevents the backflow of humidifying fluid L1 from the circulation path 42 side to the water collection section 57 side due to the water level difference. The second one-way valve 60 may also be omitted. If the second one-way valve 60 is omitted, the second pump 53 may be driven at the moment the second on / off valve 59 is opened, thereby causing water L2 to flow from the water collection section 57 side to the cover 22 side.

[0068] like Figure 3 As shown, the humidifying fluid circulation mechanism 29 includes a pressurized air supply unit 63. The pressurized air supply unit 63 is configured to supply pressurized air into the circulation path 42. The pressurized air supply unit 63 includes a pressurized air supply passage 64 communicating with the circulation path 42, a third on / off valve 65, and a third pump 66. By opening the third on / off valve 65, the third pump 66 and the circulation path 42 are connected via the pressurized air supply passage 64. The third pump 66 is, for example, a pressure pump. The third pump 66 applies atmospheric pressure to provide pressurized air and supplies this pressurized air to the pressurized air supply passage 64.

[0069] In the circulation path 42, instead of providing the pressurized air supply unit 63 downstream of the second pump 53, an atmospheric supply unit may be provided upstream of the second pump 53 and downstream of the first confluence 62. This atmospheric supply unit may also include an atmospheric communication channel communicating with the atmosphere and an on / off valve. Furthermore, it may be configured such that the second pump 53 is driven by opening the on / off valve, thus connecting the circulation path 42 to the atmosphere via the atmospheric communication channel, thereby supplying atmosphere to the circulation path 42.

[0070] Waste liquid recycling facility 30

[0071] like Figure 3 As shown, the waste liquid recovery mechanism 30 includes a waste liquid recovery channel 67, a fourth pump 68, a buffer chamber 69, a fifth pump 70, a second atmospheric communication channel 71, and a waste liquid collection section 72.

[0072] The waste liquid recovery channel 67 communicates with the waste liquid storage area 33 within the enclosed space forming section 31 at the discharge hole 73 formed at the lower end of the enclosed space forming section 31 of the cover 22. The waste liquid recovery channel 67 connects the waste liquid storage area 33 and the waste liquid collection section 72 via a buffer chamber 69. The buffer chamber 69 is, for example, located at a midway point in the waste liquid recovery channel 67.

[0073] During rinsing and cleaning, ink, as an example of a liquid, is discharged as waste liquid L3 from the nozzle 24 of the liquid ejector head 18 into the enclosed space forming section 31 of the cover 22. This waste liquid L3 is recovered from the enclosed space forming section 31 and flows into the waste liquid recovery channel 67. The waste liquid L3 recovered through rinsing or cleaning is transported to the waste liquid collection section 72 by the fourth pump 68. Then, the waste liquid L3 is collected in the waste liquid collection section 72.

[0074] The fifth pump 70 is, for example, a pressure reducing pump. The fifth pump 70 expels air from the buffer chamber 69 to the outside of the buffer chamber 69 via the second atmospheric communication channel 71, thereby reducing the air pressure inside the buffer chamber 69. As a result, waste liquid L3 discharged from the nozzle 24 of the liquid spray head 18 into the enclosed space forming portion 31 of the cover 22 during rinsing or cleaning becomes easier to flow back into the buffer chamber 69 via the waste liquid recovery channel 67. The buffer chamber 69, the fifth pump 70, and the second atmospheric communication channel 71 may also be omitted.

[0075] like Figure 3 As shown, cover 22 has an atmospheric opening mechanism 74. The atmospheric opening mechanism 74 has a third atmospheric communication channel 75 and a fourth on / off valve 76. The third atmospheric communication channel 75 connects the atmospheric communication hole 36 to the atmosphere at cover 22. The fourth on / off valve 76 opens and closes the third atmospheric communication channel 75.

[0076] Electrical structure of liquid ejection device 11

[0077] like Figure 4 As shown, the liquid dispensing device 11 includes a control unit 77 that controls the head unit 19, the head unit moving mechanism 27, the cover moving mechanism 28, and the maintenance device 26. The maintenance device 26 includes a detector group 78 that outputs a detection signal to the control unit 77. The detector group 78 includes a detection unit 46 that detects the liquid level of the humidifying fluid L1 in the humidifying fluid receiving section 39. The detection unit 46 outputs a detection signal to the control unit 77.

[0078] The control unit 77 includes an interface unit 79, a CPU 80, a memory 81, a timer 82 (an example of a measurement unit), a control circuit 83, and a drive circuit 84. The interface unit 79 transmits and receives various data between a computer 85 (an example of an external device) and the liquid ejection device 11. The drive circuit 84 generates drive signals to drive the actuator of the liquid ejection head 18.

[0079] CPU 80 is a central processing unit. Memory 81 is a storage device that stores various programs executed by CPU 80, or a work area, and includes storage elements such as RAM and EEPROM. Memory 81 includes... Figures 5 to 7 The flowchart shows various programs and information, including the stirring process during setup, the stirring process after setup, and the stirring process after printing. The CPU 80 controls the head unit 19, the head unit moving mechanism 27, the cover moving mechanism 28, the maintenance device 26, etc., according to the program stored in the memory 81 and via the control circuit 83.

[0080] The timer 82 measures various periods of time, including unused time, which is the time during which the liquid dispensing device 11 is not used. This unused time is, for example, the time from when the power supply to the liquid dispensing device 11 is turned off until the power supply to the liquid dispensing device 11 is turned on.

[0081] The stirring action of the humidifying fluid L1 in the humidifying fluid receiving section 39

[0082] like Figure 3 As shown, as the first stirring cycle, the control unit 77 supplies water L2 into the circulation path 42 via the water supply unit 56, and drives the second pump 53 to make the humidifying fluid L1 flow within the circulation path 42. The supply of water L2 into the circulation path 42 by the water supply unit 56 is implemented by the control unit 77 opening the second on / off valve 59.

[0083] In the first stirring cycle, the supply of water L2 to the circulation path 42 and the driving of the second pump 53 can be carried out at any time. That is, in the first stirring cycle, the supply of water L2 to the circulation path 42 and the driving of the second pump 53 can be carried out simultaneously, one can be carried out before the other, or one can be carried out alternately more than once.

[0084] As part of the first stirring cycle, for example, when the second pump 53 is driven with the second on / off valve 59 open, the humidifying fluid L1 in the humidifying fluid receiving section 39 is transported to the humidifying chamber 32 through the supply channel 40. At this time, the water L2 in the water receiving section 57 flows into the circulation path 42 through the water supply channel 58 and the first confluence section 62, and together with the humidifying fluid L1 from the humidifying fluid receiving section 39, is transported to the humidifying chamber 32 through the supply channel 40.

[0085] The humidifying fluid L1, supplied to the humidifying chamber 32 via the supply channel 40, and the water L2 from the water collection section 57, are supplied to the humidifying fluid collection section 39 via the recovery channel 41. At this time, one end 41a of the recovery channel 41 opens within the humidifying fluid collection section 39 at a position lower than the liquid level of the humidifying fluid L1. Therefore, the humidifying fluid L1 supplied from the humidifying chamber 32 to the humidifying fluid collection section 39 via the recovery channel 41, and the water L2 from the water collection section 57, are discharged from one end 41a of the recovery channel 41 into the humidifying fluid L1 within the humidifying fluid collection section 39.

[0086] As a result, the humidifying fluid L1 within the humidifying fluid receiving section 39 generates flow in all directions, including flow from bottom to top, thereby efficiently agitating the humidifying fluid L1 within the humidifying fluid receiving section 39. Therefore, the humidifying fluid L1 output from one end 41a of the recovery channel 41 to the humidifying fluid receiving section 39, along with the water L2 from the water receiving section 57, can be thoroughly mixed with the humidifying fluid L1 within the humidifying fluid receiving section 39.

[0087] The first stirring cycle can also be performed when the closed space forming part 31 of the cover 22 contacts the nozzle surface 25 of the liquid ejector head 18 to form a closed space through which the nozzle 24 opens, and the fourth on / off valve 76 is closed, that is, when the closed space forming part 31 is sealed. The first stirring cycle can also be performed when the closed space forming part 31 of the cover 22 is in communication with the atmosphere.

[0088] The enclosed space forming section 31 is separated from the nozzle surface 25 of the liquid ejector head 18, thereby becoming a state in which the enclosed space forming section 31 is connected to the atmosphere. Even if the enclosed space forming section 31 contacts the nozzle surface 25 of the liquid ejector head 18 to form an enclosed space with the nozzle 24 opening, it will become a state in which the enclosed space forming section 31 is connected to the atmosphere by opening the fourth on / off valve 76.

[0089] The first mixing cycle includes a short-duration first mixing cycle and a long-duration first mixing cycle. The short-duration first mixing cycle is, for example, performing the first mixing cycle for a predetermined first time (short time). The long-duration first mixing cycle is, for example, performing the first mixing cycle for a longer time (long time) compared to the predetermined first time.

[0090] like Figure 3 As shown, in the second stirring cycle, the control unit 77 supplies water L2 into the circulation path 42 via the water supply unit 56, and drives the first pump 52 and the second pump 53 to cause the humidifying fluid L1 to flow within the circulation path 42. The second stirring cycle adds the operation of driving the first pump 52 to the operation of the first stirring cycle described above. That is, the second stirring cycle is performed while driving the first pump 52 to reduce the pressure within the humidifying fluid receiving unit 39 with the first on / off valve 51 open. The second stirring cycle provides a stronger stirring action compared to the first stirring cycle described above.

[0091] In the second stirring cycle, the supply of water L2 to the circulation path 42, the depressurization of the humidifying fluid collection section 39 driven by the first pump 52, and the driving of the second pump 53 can be performed at any time. That is, in the second stirring cycle, the three actions of supplying water L2 to the circulation path 42, depressurizing the humidifying fluid collection section 39 driven by the first pump 52, and driving the second pump 53 can also be performed at the following times. In other words, the above three actions can be performed simultaneously, or any two actions can be performed simultaneously followed by the remaining action, or any one action can be performed followed by the remaining two actions, or they can be performed one by one in sequence.

[0092] As a second stirring cycle, for example, the second pump 53 is driven with the second on / off valve 59 open, and the first pump 52 is driven with the first on / off valve 51 open. Thus, while the pressure in the humidifying fluid receiving section 39 is reduced, the humidifying fluid L1 in the humidifying fluid receiving section 39 is transported to the humidifying chamber 32 through the supply channel 40. At this time, the water L2 in the water receiving section 57, after flowing into the circulation path 42 via the water supply channel 58 and the first confluence section 62, is transported to the humidifying chamber 32 together with the humidifying fluid L1 from the humidifying fluid receiving section 39 through the supply channel 40.

[0093] The humidifying fluid L1, supplied to the humidifying chamber 32 via the supply channel 40, and the water L2 from the water collection section 57, are then transported to the humidifying fluid collection section 39 via the recovery channel 41. At this time, because the pressure in the humidifying fluid collection section 39 is reduced by the first pump 52, the pressure in the humidifying fluid collection section 39 becomes lower than the pressure in the humidifying chamber 32. Therefore, due to the pressure difference between the humidifying fluid collection section 39 and the humidifying chamber 32, the humidifying fluid L1 from the humidifying chamber 32 and the water L2 from the water collection section 57 are rapidly and smoothly transported to the humidifying fluid collection section 39 via the recovery channel 41.

[0094] Furthermore, at this time, one end 41a of the recovery channel 41 opens at a position lower than the liquid level of the humidifying fluid L1 within the humidifying fluid receiving section 39. Therefore, the humidifying fluid L1, which is transported from the humidifying chamber 32 to the humidifying fluid receiving section 39 through the recovery channel 41, and the water L2 from the water receiving section 57, are forcefully ejected from one end 41a of the recovery channel 41 into the humidifying fluid L1 within the humidifying fluid receiving section 39.

[0095] Therefore, since a strong flow in all directions, including flow from bottom to top, is generated in the humidifying fluid L1 within the humidifying fluid receiving section 39, the humidifying fluid L1 within the humidifying fluid receiving section 39 can be stirred more efficiently by this flow. Thus, the humidifying fluid L1 that is fed into the humidifying fluid L1 within the humidifying fluid receiving section 39 from one end 41a of the recovery channel 41, the water L2 from the water receiving section 57, and the humidifying fluid L1 within the humidifying fluid receiving section 39 can be mixed together in a shorter time.

[0096] The second stirring cycle can also be performed when the enclosed space forming part 31 of the cover 22 contacts the nozzle surface 25 of the liquid ejector head 18 to form a closed space through which the nozzle 24 opens, and the fourth on / off valve 76 is closed, that is, when the enclosed space forming part 31 is sealed. The second stirring cycle can also be performed when the enclosed space forming part 31 of the cover 22 is connected to the atmosphere.

[0097] The enclosed space forming section 31 is separated from the nozzle surface 25 of the liquid ejector head 18, thereby becoming a state in which the enclosed space forming section 31 is connected to the atmosphere. Even if the enclosed space forming section 31 contacts the nozzle surface 25 of the liquid ejector head 18 to form an enclosed space with the nozzle 24 opening, it will become a state in which the enclosed space forming section 31 is connected to the atmosphere by opening the fourth on / off valve 76.

[0098] When the second stirring cycle is performed in a state where the enclosed space forming part 31 of the cover 22 is in communication with the atmosphere, not only is humidifying fluid L1 and water L2 from the moisture collection part 57 transported from the humidifying chamber 32 to the humidifying fluid collection part 39 through the recovery channel 41, but air is also transported through the first permeable membrane 35. That is, in addition to the humidifying fluid L1 and the water L2 from the moisture collection part 57, air is also supplied to the humidifying fluid L1 flowing from one end 41a of the recovery channel 41 into the humidifying fluid collection part 39.

[0099] Furthermore, the air in the humidifying fluid L1, which is sent from one end 41a of the recovery channel 41 into the humidifying fluid receiving section 39, rises towards the liquid surface as bubbles. Thus, the humidifying fluid L1 in the humidifying fluid receiving section 39 can be efficiently and effectively agitated. That is, the humidifying fluid L1 in the humidifying fluid receiving section 39 is effectively agitated by air. Specifically, as a second agitation cycle, the control unit 77 performs agitation of the humidifying fluid L1 in the humidifying fluid receiving section 39 by opening the first on / off valve 51 while the enclosed space forming section 31 is connected to the atmosphere, thereby driving the first pump 52. The second agitation cycle is performed, for example, only for a pre-set second predetermined time.

[0100] Compared to discharging humidifying fluid L1 and water L2 from water collection section 57 into humidifying fluid collection section 39 and stirring, discharging air into humidifying fluid L1 in humidifying fluid collection section 39 to generate bubbles and stir, a greater stirring effect can be obtained. Therefore, it is preferable that the second stirring cycle is performed in a state where the enclosed space forming section 31 is in communication with the atmosphere. By setting it in this way, the humidifying fluid L1 in humidifying fluid collection section 39, which is discharged from one end 41a of recovery channel 41 into humidifying fluid collection section 39, and the water L2 from water collection section 57, and the humidifying fluid L1 in humidifying fluid collection section 39 can be mixed more effectively using air bubbles.

[0101] Set up the stirring process

[0102] Next, based on Figure 5 The flowchart shown illustrates the setup stirring process performed by the control unit 77. The setup stirring process is performed after the initial filling of the liquid into the liquid nozzle 18 is completed when the liquid dispensing device 11 is set up by a user or service personnel after being shipped from the factory, with the power on. In the liquid dispensing device 11, the initial filling of the liquid into the liquid nozzle 18 is performed when the power is on during setup.

[0103] In the liquid dispensing device 11, a marker is activated when the initial filling of liquid into the liquid nozzle 18 is completed. The control unit 77 checks the activation status of the marker indicating that the initial filling of liquid into the liquid nozzle 18 is complete, thereby understanding the setup status of the liquid dispensing device 11. The marker indicating that the initial filling of liquid into the liquid nozzle 18 is activated is deactivated because the power supply is turned off after the stirring process is executed during setup.

[0104] like Figure 5 As shown, when the setup stirring process is executed, firstly, the control unit 77 determines whether the height of the humidifying fluid L1 stored in the humidifying fluid storage unit 39 is above the first height H (step S1). If the determination result in step S1 is positive, the control unit 77 terminates the setup stirring process after executing the first stirring cycle (step S2).

[0105] In step S2, although either a short-duration first stirring cycle or a long-duration first stirring cycle can be performed, it is preferable to perform the long-duration first stirring cycle. If the determination result in step S1 is negative, the control unit 77 terminates the stirring process at the setting time after performing the second stirring cycle (step S3).

[0106] Post-set stirring process

[0107] Next, based on Figure 6 The flowchart shown illustrates the post-setting stirring process performed by the control unit 77. The post-setting stirring process is executed after the liquid ejection device 11 has been set by the user (after the power was set to off during setting), and when the power is turned on. The control unit 77 monitors the status of the liquid ejection device 11 after setting by confirming that the indicator that was on when the initial filling of liquid into the liquid ejection head 18 is completed has turned off.

[0108] like Figure 6 As shown, when the set-up stirring process is executed, firstly, the control unit 77 determines whether the unused time, which is the time during which the liquid ejection device 11 is not used, is longer than a first time (step S11). The first time is, for example, set to six months. If the determination result in step S11 is affirmative, the control unit 77 terminates the set-up stirring process after executing the second stirring cycle (step S12).

[0109] If the judgment result in step S11 is negative, the control unit 77 determines whether the unused time is greater than the second time but less than the first time (step S13). The second time is a shorter time compared to the first time. For example, the second time is set to one month. If the judgment result in step S13 is positive, the control unit 77 terminates the set-up stirring process after executing the long-duration first stirring cycle (step S14).

[0110] If the judgment result in step S13 is negative, that is, if the unused time is less than the second time, the control unit 77 terminates the set-up stirring process after executing the short-term first stirring cycle (step S15).

[0111] Post-printing stirring process

[0112] Next, based on Figure 7 The flowchart shown illustrates the post-printing stirring process performed by the control unit 77. The post-printing stirring process is performed after the printing (printing operation) performed by the liquid ejection device 11 has ended.

[0113] like Figure 7 As shown, when performing the post-printing stirring process, firstly, the control unit 77 determines whether the height of the humidifying fluid L1 stored in the humidifying fluid storage unit 39 is above the first height H (step S21). If the determination result of step S21 is affirmative, the control unit 77 terminates the post-printing stirring process. If the determination result of step S21 is negative, the control unit 77 terminates the post-printing stirring process after performing a short first stirring cycle (step S22).

[0114] Function of liquid ejection device 11

[0115] When installing the liquid dispensing device 11 after it has been shipped from the factory, there is sometimes a long time before installation. Therefore, sometimes moisture L2 evaporates from the humidifying fluid L1 in the humidifying fluid receiving section 39, resulting in a higher concentration of humidifier in the humidifying fluid L1. In particular, when the liquid level of the humidifying fluid L1 in the humidifying fluid receiving section 39 is less than the first height H when the liquid dispensing device 11 is installed, a large amount of moisture L2 may evaporate from the humidifying fluid L1 in the humidifying fluid receiving section 39.

[0116] This is because the humidifying fluid receiving section 39 of the liquid spraying device 11 manufactured in the factory contains not only the amount of humidifying fluid L1 contained in the humidifying fluid receiving section 39, but also the amount of humidifying fluid L1 supplied to the circulation path 42 and the humidification chamber 32. When a large amount of water L2 evaporates from the humidifying fluid L1 in the humidifying fluid receiving section 39, causing the concentration of humidifier in the humidifying fluid L1 to increase, even if water L2 is supplied, the supplied water L2 and humidifier will become difficult to mix together.

[0117] Regarding this, in the liquid ejection device 11 of this embodiment, one end 41a of the recovery channel 41 in the circulation path 42 is structured to open within the humidifying fluid receiving section 39 at a position lower than the liquid level of the humidifying fluid L1. Based on this, when the liquid ejection device 11 is installed, if the height of the liquid level of the humidifying fluid L1 within the humidifying fluid receiving section 39 is a first height H or higher, a first stirring cycle (either a long-duration first stirring cycle or a short-duration first stirring cycle) is performed. On the other hand, when the liquid ejection device 11 is installed, if the height of the liquid level of the humidifying fluid L1 within the humidifying fluid receiving section 39 is less than the first height H, a second stirring cycle is performed, which is a stronger stirring action than the first stirring cycle.

[0118] Furthermore, after the liquid ejection device 11 is installed, under normal circumstances, the longer the liquid ejection device 11 is not used, the more water L2 from the humidifying fluid L1 in the humidifying fluid collection section 39 evaporates. Therefore, after the liquid ejection device 11 is installed, a second stirring cycle is performed when the liquid ejection device 11 is not used for a first time or longer.

[0119] After the liquid ejection device 11 is installed, if the time during which the liquid ejection device 11 is not used is greater than a second time but less than a first time, a long-duration first stirring cycle is implemented, which is a weaker stirring action compared to the second stirring cycle. After the liquid ejection device 11 is installed, if the time during which the liquid ejection device 11 is not used is less than the second time, a short-duration first stirring cycle is implemented, which is a weaker stirring action compared to the long-duration first stirring cycle.

[0120] Furthermore, after the liquid ejection device 11 is installed, if the height of the humidifying fluid L1 in the humidifying fluid collection section 39 is less than the first height H after the printing (printing operation) is completed, a short-term first stirring cycle is performed.

[0121] Thus, in the liquid ejection device 11 of this embodiment, an appropriate stirring action is performed in accordance with the degree of drop in the liquid level of the humidifying fluid L1 in the humidifying fluid collection section 39 caused by the evaporation of water L2. At this time, regardless of whether any stirring action is performed in the first stirring cycle (long-duration first stirring cycle and short-duration first stirring cycle) and the second stirring cycle, the humidifying fluid L1 flowing through the recovery channel 41, the water L2 from the water collection section 57, and the air are all sent from one end 41a of the recovery channel 41 into the humidifying fluid L1 in the humidifying fluid collection section 39.

[0122] Therefore, regardless of the evaporation rate of water L2 in the humidifying fluid L1 within the humidifying fluid receiving section 39, the humidifying fluid receiving section 39 is efficiently agitated while water L2 is supplied to the humidifying fluid L1. Thus, the humidifying fluid L1 within the humidifying fluid receiving section 39 and the water L2 supplied to it can be thoroughly and effectively mixed together.

[0123] Effects of this implementation method

[0124] The following effects can be achieved according to the implementation methods described in detail above.

[0125] (1) In the liquid ejection device 11, one end 41a of the recovery channel 41 opens at a position lower than the liquid level of the humidifying fluid L1 within the humidifying fluid receiving section 39. As a first stirring cycle, the control section 77 supplies water L2 into the circulation path 42 via the water supply section 56 and drives the second pump 53 to make the humidifying fluid L1 flow within the circulation path 42.

[0126] According to this structure, by implementing the first stirring cycle, even if the water L2 in the humidifying fluid L1 evaporates, the humidifying fluid L1 and the water L2 supplied from the water supply unit 56 can be stirred efficiently. Therefore, the humidifying fluid L1 and the water L2 supplied from the water supply unit 56 can be thoroughly mixed together.

[0127] (2) The liquid ejection device 11 is equipped with a first pump 52 that can depressurize the space within the humidifying fluid receiving section 39. As a second stirring cycle, the control unit 77 supplies water L2 into the circulation path 42 through the water supply unit 56 and drives the second pump 53 and the first pump 52 to make the humidifying fluid L1 flow in the circulation path 42.

[0128] According to this structure, by implementing a second stirring cycle, the humidifying fluid L1 and the water L2 supplied from the water supply unit 56 can be stirred in a short time. That is, the stirring time required to mix the humidifying fluid L1 and the water L2 supplied from the water supply unit 56 can be shortened.

[0129] (3) In the liquid ejection device 11, as a second stirring cycle, the control unit 77 drives the first pump 52 in a state in which the enclosed space forming unit 31 is connected to the atmosphere, thereby performing stirring in the humidified fluid receiving unit 39 using air.

[0130] According to this structure, stirring within the humidifying fluid receiving section 39 can be carried out efficiently through air bubbles.

[0131] (4) The liquid ejection device 11 is equipped with a detection unit 46 capable of detecting the height of the liquid level in the humidifying fluid collection section 39. When the liquid ejection device 11 is installed, the control unit 77 performs a first stirring cycle when the height of the liquid level is above the first height H, and performs a second stirring cycle when the height of the liquid level is below the first height H.

[0132] According to this structure, appropriate stirring can be performed in accordance with the degree of drop in the liquid level in the humidifying fluid receiving section 39 caused by the evaporation of water L2.

[0133] (5) The liquid ejection device 11 is equipped with a timer 82 that measures the unused time, which is the time during which the liquid ejection device 11 is not used. After the liquid ejection device 11 is installed, the control unit 77 performs a second stirring cycle when the unused time is more than a first time, performs a long first stirring cycle with a longer stirring time when the unused time is more than a second time but less than a first time, and performs a short first stirring cycle with a shorter stirring time when the unused time is less than a second time.

[0134] According to this structure, appropriate stirring action can be performed in accordance with the length of the unused time of the liquid spraying device 11, which is related to the evaporation rate of water L2.

[0135] Change Example

[0136] The above embodiments can be implemented by modifications as follows. The above embodiments and the following modifications can be implemented in combination with each other within the scope of technical inconsistency.

[0137] • Timer 82 can also be omitted.

[0138] • The testing section 46 can also be omitted.

[0139] • The maintenance device 26 can also be installed on a liquid ejection device that ejects liquid in the vertical direction from the liquid ejection head 18 toward the medium M.

[0140] • The maintenance device 26 may also be provided on a liquid ejection device, which is a serial inkjet printer that performs printing by ejecting liquid toward the medium M by having a liquid ejection head supported on a carriage that reciprocates in the width direction X.

[0141] • In the maintenance device 26, the water supply unit 56 may also be configured on the recovery channel 41. In this case, the second pump 53 may also be configured on the recovery channel 41.

[0142] • The maintenance device 26 may also be configured to replenish the water L2 in the water collection section 57.

[0143] • The maintenance device 26 can also be configured to replace the humidifying fluid receiving section 39.

[0144] • In the liquid ejection device 11, the short-term first stirring cycle can be performed regularly, for example, once a day or once every two days, regardless of the height of the liquid level in the humidifying fluid receiving section 39 or the unused time of the liquid ejection device 11, or it can be performed irregularly.

[0145] • The liquid ejection device 11 can also be a liquid ejection device that sprays or ejects liquids other than ink. The state of the liquid ejected from the liquid ejection device as tiny droplets can also include states where it is drawn out as granular, tear-like, or filamentous tail-like objects. The liquid referred to here simply needs to be a material that can be ejected from the liquid ejection device. For example, the liquid can be any material in a liquid phase state, including liquids with high or low viscosity, sols, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals, molten metals, and other fluids. The liquid is not only a liquid as a state of matter, but also includes particles of functional materials composed of solids such as pigments and metal particles dissolved, dispersed, or mixed in a solvent. Representative examples of liquids include inks or liquid crystals as described in the above embodiments. Here, ink is defined as a substance including general water-based inks and oil-based inks, as well as various liquid compositions such as gel inks and hot melt adhesive inks. Specific examples of liquid ejection devices include those that eject liquids, in dispersed or dissolved form, containing materials such as electrode materials or color materials used in the manufacture of liquid crystal displays, electroluminescent displays, field emission displays, and color filters. Liquid ejection devices can also be devices for ejecting biological organic matter used in biochip manufacturing, devices used as precision pipettes to eject liquids as samples, dyeing devices, or microdispensers. Liquid ejection devices can also be devices for ejecting lubricating oil into precision machinery such as watches or cameras using a needle, or devices for ejecting transparent resins such as UV-curable resins onto a substrate to form micro-hemispherical lenses or optical lenses used in optical communication components. Liquid ejection devices can also be devices for ejecting etching solutions such as acidic or alkaline solutions to etch substrates.

[0146] The following describes the technical ideas and effects that can be grasped from the above-described implementation methods and variations.

[0147] (A) A liquid ejection device comprising: a liquid ejection head capable of ejecting liquid from a nozzle; a cover having a closed space forming portion, an inlet, and an outlet, wherein the closed space forming portion is capable of forming a closed space through contact with the liquid ejection head to open the nozzle, the inlet is for receiving the humidifying fluid for humidifying the closed space, and the outlet is for receiving the humidifying fluid; a humidifying fluid receiving portion for receiving the humidifying fluid; a supply channel connecting the humidifying fluid receiving portion and the inlet; and a recovery channel for receiving the humidifying fluid. The fluid receiving section is connected to the outlet; a pump is capable of flowing the humidifying fluid within a circulation path including the humidifying fluid receiving section, the supply channel, and the recovery channel; a water supply section is capable of supplying water into the circulation path; a control section is provided, wherein one end of the recovery channel opens within the humidifying fluid receiving section at a position lower than the liquid level of the humidifying fluid, and as a first stirring cycle, the control section supplies water into the circulation path via the water supply section and drives the pump to flow the humidifying fluid within the circulation path.

[0148] According to this structure, by implementing a first stirring cycle, the humidifying fluid and the water supplied from the water supply unit can be efficiently stirred even if the water in the humidifying fluid evaporates. Therefore, the humidifying fluid and the water supplied from the water supply unit can be thoroughly mixed together.

[0149] (B) Alternatively, the liquid ejection device may be equipped with a pressure reducing unit, which can reduce the pressure of the space within the humidifying fluid receiving unit. As a second stirring cycle, the control unit supplies water to the circulation path through the water supply unit and drives the pump and the pressure reducing unit to make the humidifying fluid flow within the circulation path.

[0150] According to this structure, by implementing a second stirring cycle, the humidifying fluid and the water supplied from the water supply unit can be stirred in a short time. That is, the stirring time required to mix the humidifying fluid and the water supplied from the water supply unit can be shortened.

[0151] (C) Alternatively, in the liquid ejection device, as the second stirring cycle, the control unit drives the decompression unit in a state where the enclosed space forming part is connected to the atmosphere, thereby performing stirring in the humidifying fluid receiving part using air.

[0152] According to this structure, air bubbles can be used to efficiently agitate the fluid within the humidification reservoir.

[0153] (D) Alternatively, the liquid ejection device may be equipped with a detection unit that can detect the height of the liquid level in the humidifying fluid receiving unit. When the liquid ejection device is installed, the control unit performs the first stirring cycle when the height of the liquid level is above the first height, and performs the second stirring cycle when the height of the liquid level is below the first height.

[0154] According to this structure, appropriate stirring can be performed in accordance with the degree of drop in the liquid level in the humidifying fluid receiving section caused by evaporation.

[0155] (E) Alternatively, the liquid ejection device may be equipped with a measuring unit that measures the unused time, which is the time during which the liquid ejection device is not used. After the liquid ejection device is installed, the control unit implements the second stirring cycle when the unused time is more than a first time, implements the first stirring cycle with a longer stirring time when the unused time is more than a second time but less than the first time, and implements the first stirring cycle with a shorter stirring time when the unused time is less than the second time.

[0156] According to this structure, appropriate stirring actions can be performed in accordance with the length of the unused time of the liquid ejection device related to evaporation.

[0157] (F) A stirring method for a liquid ejection device, the liquid ejection device comprising: a liquid ejection head capable of ejecting liquid from a nozzle; a cover having a closed space forming portion, an inlet, and an outlet, wherein the closed space forming portion is capable of forming a closed space through contact with the liquid ejection head to open the nozzle, the inlet is for receiving a humidifying fluid for humidifying the closed space, and the outlet is for receiving the humidifying fluid; a humidifying fluid receiving portion for receiving the humidifying fluid; a supply channel connecting the humidifying fluid receiving portion and the inlet; and a recovery channel for receiving the humidifying fluid. The humidifying fluid receiving section is connected to the outlet; a pump is capable of flowing the humidifying fluid within a circulation path including the humidifying fluid receiving section, the supply channel, and the recovery channel; a water supply section is capable of supplying water into the circulation path; one end of the recovery channel opens within the humidifying fluid receiving section at a position lower than the liquid level of the humidifying fluid; in the stirring method of the liquid ejection device, a first stirring cycle is implemented in which water is supplied into the circulation path through the water supply section and the pump is driven to flow the humidifying fluid within the circulation path.

[0158] According to this structure, by implementing a first stirring cycle, the humidifying fluid and the water supplied from the water supply unit can be efficiently stirred even if the water in the humidifying fluid evaporates. Therefore, the humidifying fluid and the water supplied from the water supply unit can be thoroughly mixed together.

[0159] (G) In the stirring method of the liquid ejection device, it may also be configured to include a pressure reducing unit that can reduce the pressure of the space within the humidifying fluid receiving unit and implement a second stirring cycle in which water is supplied to the circulation path through the water supply unit and the pump and the pressure reducing unit are driven to make the humidifying fluid flow in the circulation path.

[0160] According to this structure, by implementing a second stirring cycle, the humidifying fluid and the water supplied from the water supply unit can be stirred in a short time. That is, the stirring time required to mix the humidifying fluid and the water supplied from the water supply unit can be shortened.

[0161] (H) In the stirring method of the liquid ejection device, the second stirring cycle may also be configured to include a stirring operation in the humidifying fluid receiving section using air by driving the decompression section in a state in which the enclosed space forming section is connected to the atmosphere.

[0162] According to this structure, air bubbles can be used to efficiently agitate the fluid within the humidification reservoir.

[0163] (I) In the stirring method of the liquid ejection device, it can also be configured to include a detection unit that can detect the height of the liquid level in the humidifying fluid receiving unit. When the liquid ejection device is installed, the first stirring cycle is performed when the height of the liquid level is above the first height, and the second stirring cycle is performed when the height of the liquid level is below the first height.

[0164] According to this structure, appropriate stirring can be performed in accordance with the degree of drop in the liquid level in the humidifying fluid receiving section caused by evaporation.

[0165] (J) In the stirring method of the liquid ejection device, it may also be configured to include a measuring unit that measures the unused time, which is the time during which the liquid ejection device is not used. After the liquid ejection device is installed, a second stirring cycle is performed when the unused time is more than a first time, a first stirring cycle with a longer stirring time is performed when the unused time is more than a second time and less than the first time, and a first stirring cycle with a shorter stirring time is performed when the unused time is less than the second time.

[0166] According to this structure, appropriate stirring actions can be performed in accordance with the length of the unused time of the liquid ejection device related to evaporation.

[0167] Symbol explanation:

[0168] 11…Liquid ejection device; 12…Main body; 13…Image reading unit; 14…Automatic feeding unit; 15…Operation unit; 16…Media collection unit; 17…Printing unit; 18…Liquid ejection head; 19…Head unit; 20…Placement unit; 20a…Placement surface; 21…Conveying path; 22…Cover; 23…Support unit; 24…Nozzle; 25…Nozzle surface; 26…Maintenance device; 27…Head unit moving mechanism; 28…Cover moving mechanism; 29…Humidifying fluid circulation mechanism; 30…Waste liquid recovery mechanism; 31…Enclosed space forming unit; 32…Humidification chamber; 33…Waste… Liquid storage area; 34…partition wall; 35…first permeable membrane; 36…atmospheric communication hole; 37…inlet; 38…outlet; 39…humidifying fluid collection section; 40…supply channel; 40a…one end; 41…recovery channel; 41a…one end; 42…circulation path; 43…upper wall; 44…peripheral wall; 45…bottom wall; 46…detection section; 47…first electrode; 48…second electrode; 49…first atmospheric communication channel; 50…second permeable membrane; 51…first on / off valve; 52…first pump (pressure reducing section); 53…second pump; 54…first check valve ; 55… Pressure regulating valve; 56… Water supply section; 57… Water collection section; 58… Water supply channel; 59… Second on / off valve; 60… Second check valve; 61… Outlet section; 62… First confluence section; 63… Pressurized air supply section; 64… Pressurized air supply channel; 65… Third on / off valve; 66… Third pump; 67… Waste liquid recovery channel; 68… Fourth pump; 69… Buffer chamber; 70… Fifth pump; 71… Second atmospheric connection channel; 72… Waste liquid collection section; 73… Discharge port; 74… Atmospheric opening mechanism; 75… Third atmospheric connection 76…Fourth on / off valve; 77…Control unit; 78…Detector group; 79…Interface unit; 80…CPU; 81…Memory; 82…Timer (measuring unit); 83…Control circuit; 84…Drive circuit; 85…Computer; θ1…Angle; D1…First direction; D2…Second direction; D3…Third direction; D4…Fourth direction; H…First height; L1…Humidifying fluid; L2…Moisture (water); L3…Waste liquid; M…Media; X…Width direction; Y…Depth direction; Y1…Ejection direction; Z…Vertical direction; Z1…Conveying direction.

Claims

1. A liquid ejection device, characterized in that, have: A liquid ejector head that can eject liquid from a nozzle; The cover has a closed space forming part, an inlet and an outlet, wherein the closed space forming part can form a closed space by contacting a nozzle surface in the liquid spray head that is configured as a nozzle opening, the inlet is for humidifying fluid to flow into the closed space, and the outlet is for the humidifying fluid to flow out. A humidifying fluid receiving section for receiving the humidifying fluid; A supply channel connects the humidifying fluid receiving section and the inlet. A recovery channel connects the humidifying fluid receiving section and the outlet. A pump that enables the humidifying fluid to flow within a circulation path including the humidifying fluid receiving section, the supply channel, and the recovery channel; A water supply unit, which is capable of supplying water into the circulation path; Control Department One end of the recovery channel forms an opening inside the humidifying fluid receiving section, and the position of the opening is lower than the liquid level of the humidifying fluid inside the humidifying fluid receiving section. As a first stirring cycle, the control unit supplies water into the circulation path through the water supply unit and drives the pump to make the humidifying fluid flow in the circulation path.

2. The liquid ejection device as described in claim 1, characterized in that, It includes a pressure-reducing unit, which can reduce the pressure in the space within the humidifying fluid receiving section. As a second stirring cycle, the control unit supplies water into the circulation path through the water supply unit and drives the pump and the pressure reducing unit to make the humidifying fluid flow in the circulation path.

3. The liquid ejection device as described in claim 2, characterized in that, As the second stirring cycle, the control unit drives the decompression unit in a state where the enclosed space forming part is connected to the atmosphere, thereby performing stirring in the humidifying fluid receiving part using air.

4. The liquid ejection device as described in claim 3, characterized in that, It includes a detection unit capable of detecting the liquid level height within the humidifying fluid receiving section. When the liquid ejection device is installed, The control unit performs the first stirring cycle when the liquid level is above the first height, and performs the second stirring cycle when the liquid level is below the first height.

5. The liquid ejection device as described in claim 3, characterized in that, It includes a measuring unit that measures the unused time, which is the time during which the liquid dispensing device is not used. After the liquid ejection device is installed, The control unit implements the second stirring cycle when the unused time is more than a first time, implements the first stirring cycle with a longer stirring time when the unused time is more than a second time but less than the first time, and implements the first stirring cycle with a shorter stirring time when the unused time is less than the second time.

6. A stirring method for a liquid ejection device, characterized in that, The liquid ejection device includes: A liquid ejector head that can eject liquid from a nozzle; The cover has a closed space forming part, an inlet and an outlet, wherein the closed space forming part can form a closed space by contacting a nozzle surface in the liquid spray head that is configured as a nozzle opening, the inlet is for humidifying fluid to flow into the closed space, and the outlet is for the humidifying fluid to flow out. A humidifying fluid receiving section for receiving the humidifying fluid; A supply channel connects the humidifying fluid receiving section and the inlet. A recovery channel connects the humidifying fluid receiving section and the outlet. A pump that enables the humidifying fluid to flow within a circulation path including the humidifying fluid receiving section, the supply channel, and the recovery channel; A water supply unit, which is capable of supplying water into the circulation path; One end of the recovery channel forms an opening inside the humidifying fluid receiving section, and the position of the opening is lower than the liquid level of the humidifying fluid inside the humidifying fluid receiving section. In the stirring method of the liquid ejection device, A first stirring cycle is implemented in which water is supplied into the circulation path through the water supply unit and the pump is driven to make the humidifying fluid flow in the circulation path.

7. The stirring method of the liquid ejection device as described in claim 6, characterized in that, It includes a pressure-reducing unit, which can reduce the pressure in the space within the humidifying fluid receiving section. A second stirring cycle is implemented, in which water is supplied into the circulation path through the water supply unit and the pump and the pressure reducing unit are driven to make the humidifying fluid flow in the circulation path.

8. The stirring method of the liquid ejection device as described in claim 7, characterized in that, The second stirring cycle includes performing a stirring operation within the humidifying fluid receiving section using air by driving the decompression section while the enclosed space forming section is in communication with the atmosphere.

9. The stirring method of the liquid ejection device as described in claim 8, characterized in that, It includes a detection unit capable of detecting the liquid level height within the humidifying fluid receiving section. When the liquid ejection device is installed, The first stirring cycle is performed when the liquid level is above a first height. The second stirring cycle is performed when the height of the liquid level is less than the first height.

10. The stirring method of the liquid ejection device as described in claim 8, characterized in that, It includes a measuring unit that measures the unused time, which is the time during which the liquid dispensing device is not used. After the liquid ejection device is installed, The second stirring cycle is performed when the unused time exceeds the first time. When the unused time is greater than the second time but less than the first time, a first stirring cycle with a longer stirring time is performed. When the unused time is less than the second time, the first stirring cycle with a shorter stirring time is performed.

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