Liquid discharge device

Abstract

To provide a liquid discharge device which reduces the possibility to break a meniscus.SOLUTION: A liquid discharge device 11 includes a discharge part 12 which has a nozzle surface 13 where a nozzle 14 is opened and discharges liquid from the nozzle, a storage part 15 for storing the liquid, and a supply part 26 for supplying the liquid to the discharge part from the storage part, wherein the supply part has a supply flow channel 27 having a first flow channel 28 connected to the storage part and the discharge part and a second flow channel 29 connected to the storage part and the discharge part, a supply valve 34 which is positioned on the first flow channel and closes the first flow channel when a power supply is turned off, and an adjustment valve 35 which is positioned on the second flow channel, and is configured to open the second flow channel when the pressure in the discharge part is equal to or less than a predetermined pressure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device. [Background technology]

[0002] Patent Document 1 describes a liquid ejection device that includes a ejection section that ejects liquid from a nozzle, a storage section that stores the liquid, and a supply section that supplies the liquid from the storage section to the ejection section. The liquid ejection device includes a supply valve between the storage section and the ejection section. Closing the supply valve reduces the risk of liquid leaking from the nozzle due to vibration, impact, or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-123202 Summary of the Invention [Problem to be solved by the invention]

[0004] In such a liquid ejection device, when the supply valve is closed, liquid is not supplied from the reservoir to the ejection portion. Therefore, if the supply valve remains closed for a long period of time, the liquid evaporates from the nozzle, causing a decrease in pressure within the ejection portion. If the pressure within the ejection portion decreases, there is a risk that the meniscus of the liquid formed in the nozzle will be destroyed. [Means for solving the problem]

[0005] A liquid ejection device that solves the above problem includes an ejection section having a nozzle surface where a nozzle opens and ejecting liquid from the nozzle, a storage section that stores liquid, and a supply section that supplies liquid from the storage section to the ejection section, wherein the supply section has a supply flow path having a first flow path connected to the storage section and the ejection section, and a second flow path connected to the storage section and the ejection section, a supply valve located in the first flow path that closes the first flow path when the power is off, and an adjustment valve located in the second flow path that is configured to open the second flow path when the pressure in the ejection section is below a predetermined pressure. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic diagram showing an embodiment of a liquid ejection device. [Figure 2] FIG. 2 is a cross-sectional view of the reservoir. [Figure 3] FIG. 3 is an exploded perspective view of the regulating valve. [Figure 4] FIG. 4 is an exploded perspective view seen from a different angle than FIG. [Figure 5] FIG. 5 is a plan view of the regulating valve. [Figure 6] FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. [Figure 8] FIG. 8 is a front view showing the positional relationship between the discharge portion and the adjusting valve. [Figure 9] FIG. 9 is a schematic diagram of the liquid discharger during idle suction and first filling. [Figure 10] FIG. 10 is a schematic diagram of the liquid discharger during circulation and second filling. [Figure 11] FIG. 11 is a schematic diagram of the liquid ejection device during cleaning and third filling. [Figure 12] FIG. 12 is a schematic diagram of the liquid ejection device in preparation for pressurization. [Figure 13] FIG. 13 is a schematic diagram of the liquid ejection device in a pressurized standby state. [Figure 14] FIG. 14 is a schematic diagram of the liquid discharger at the start of pressurization, during transportation, and during standby. [Figure 15] FIG. 15 is a schematic diagram of the liquid ejection device during wiping. [Figure 16] FIG. 16 is a schematic diagram of the liquid ejection device when liquid evaporates from the nozzles during transportation and standby. DETAILED DESCRIPTION OF THE INVENTION

[0007] An embodiment of a liquid ejection device will be described below with reference to the drawings. The liquid ejection device is, for example, an inkjet printer that records images such as characters and photographs by ejecting ink, which is an example of a liquid, onto a medium such as paper or fabric.

[0008] <Liquid discharge device> As shown in FIG. 1, the liquid ejection device 11 includes an ejection unit 12. The ejection unit 12 is configured to eject liquid. The ejection unit 12 prints an image on the medium by ejecting the liquid onto the medium. The ejection unit 12 has a nozzle surface 13. One or more nozzles 14 are opened in the nozzle surface 13. The ejection unit 12 ejects the liquid from the nozzles 14. In one example, the ejection unit 12 is a line head that can eject liquid simultaneously across the width of the medium. The ejection unit 12 may also be a serial head that scans across the medium.

[0009] The liquid ejection device 11 includes a storage unit 15. The storage unit 15 is configured to store liquid. The storage unit 15 stores the liquid to be supplied to the ejection unit 12. The storage unit 15 is, for example, a tank. The storage unit 15 may store the liquid supplied from the ejection unit 12. In other words, the storage unit 15 may store the liquid returned from the ejection unit 12.

[0010] The reservoir 15 has a reservoir body 16. The reservoir body 16 is a case that stores the liquid. The reservoir body 16 defines a reservoir chamber 17. The reservoir chamber 17 is a space in which the liquid is stored. The reservoir chamber 17 is open to the atmosphere.

[0011] 2, one or more outlets 18 open in reservoir 16. In one example, two outlets 18 open in reservoir 16. Outlet 18 is a hole through which liquid flows out of reservoir 16. Liquid is supplied from reservoir 15 to discharge portion 12 through outlet 18.

[0012] One or more inlets 19 may open in the reservoir 16. In one example, one inlet 19 opens in the reservoir 16. The inlet 19 is a hole through which liquid flows into the reservoir 16. Liquid is supplied from the discharge portion 12 to the reservoir 15 through the inlet 19. Liquid may also be supplied from the reservoir 15 to the discharge portion 12 through the inlet 19.

[0013] The reservoir 15 may have a partition member 20. The partition member 20 is a member that separates the reservoir chamber 17. The partition member 20 is attached to the reservoir body 16. The partition member 20 is positioned so as to separate the reservoir chamber 17 into an outflow chamber 21 and an inflow chamber 22. The partition member 20 divides the reservoir chamber 17 into the outflow chamber 21 and the inflow chamber 22. The partition member 20 separates the reservoir chamber 17 in a state in which liquid can move between the outflow chamber 21 and the inflow chamber 22.

[0014] The partition member 20 is located between the outlet 18 and the inlet 19. In one example, the partition member 20 is located on an imaginary line L1 that passes through the outlet 18 and the inlet 19. The partition member 20 is located so as to prevent the liquid that flows into the storage chamber 17 from the inlet 19 from immediately flowing out of the outlet 18. The partition member 20 separates the storage chamber 17 so that the liquid that flows in from the inlet 19 is temporarily stored in the storage section 15.

[0015] The storage section 15 removes air bubbles contained in the liquid by storing the liquid. The liquid returned to the storage section 15 from the discharge section 12 may contain air bubbles. This is because air bubbles may become mixed into the liquid as it flows between the storage section 15 and the discharge section 12. The air bubbles are removed from the liquid in the storage section 15 by floating up due to buoyancy. Therefore, the partition member 20 promotes the removal of air bubbles by preventing the liquid returned from the discharge section 12 from moving toward the outlet 18. If the liquid returned from the discharge section 12 immediately flows out of the outlet 18, the air bubbles may not be removed.

[0016] As shown in Fig. 1, the storage section 15 has an open pipe 23. The open pipe 23 extends from the storage body 16. The open pipe 23 communicates with the storage chamber 17. The open pipe 23 communicates with the outside of the storage body 16. The open pipe 23 opens the storage chamber 17 to the atmosphere.

[0017] The storage section 15 is configured so that a liquid container 100 can be attached thereto. The liquid container 100 is configured to contain liquid. The liquid container 100 contains liquid in a sealed space. The liquid container 100 is, for example, a cartridge. By attaching the liquid container 100 to the storage section 15, it becomes possible to supply liquid from the liquid container 100 to the storage section 15.

[0018] The storage section 15 has an introduction pipe 24. The introduction pipe 24 extends from the storage body 16. The introduction pipe 24 extends from the inside to the outside of the storage body 16. The introduction pipe 24 communicates with the storage chamber 17. The introduction pipe 24 communicates with the outside of the storage body 16. The introduction pipe 24 is a pipe that introduces liquid into the storage chamber 17. The introduction pipe 24 introduces liquid from the liquid container 100 into the storage body 16.

[0019] The inlet pipe 24 is attached to the liquid container 100. In one example, the inlet pipe 24 is inserted into the liquid container 100. As a result, liquid is introduced from the liquid container 100 to the reservoir 16 through the inlet pipe 24. At this time, the liquid flows from the liquid container 100 to the reservoir 16 due to a head difference between the liquid container 100 and the reservoir 16. More specifically, gas-liquid exchange occurs between the liquid container 100 and the reservoir 16 through the inlet pipe 24, causing the liquid to flow from the liquid container 100 to the reservoir 16. That is, air flows from the reservoir 16 to the liquid container 100 through the inlet pipe 24, causing the liquid to flow from the liquid container 100 to the reservoir 16 through the inlet pipe 24. Therefore, in the reservoir 15, the liquid is stored so that the position of the lower end of the inlet pipe 24 coincides with the position of the liquid level.

[0020] The storage unit 15 is configured to store the liquid so that the liquid level is located below the nozzle surface 13. In one example, the storage unit 15 is located so that the lower end of the introduction pipe 24 is located below the nozzle surface 13. By storing the liquid in the storage unit 15 so that the liquid level is located below the nozzle surface 13, a negative pressure is maintained inside the discharge unit 12. By maintaining a negative pressure inside the discharge unit 12, a meniscus is formed in the nozzle 14. By forming a meniscus in the nozzle 14, the discharge unit 12 can appropriately discharge the liquid.

[0021] The storage unit 15 may have a liquid level sensor 25. The liquid level sensor 25 is configured to detect the amount of liquid stored in the storage unit 15. The liquid level sensor 25 detects the liquid level, for example, by detecting the liquid level. In one example, the liquid level sensor 25 detects the position of the liquid level in multiple stages. When the liquid level sensor 25 detects that the liquid level in the storage unit 15 is dropping, the liquid ejection device 11 determines that the remaining amount of liquid in the liquid container 100 is small.

[0022] The liquid ejection device 11 includes a supply unit 26. The supply unit 26 is configured to supply liquid from the storage unit 15 to the ejection unit 12. The supply unit 26 may be configured to supply liquid from the ejection unit 12 to the storage unit 15. The supply unit 26 may be configured to circulate the liquid between the storage unit 15 and the ejection unit 12.

[0023] Supply unit 26 has supply flow path 27. Supply flow path 27 is a flow path through which liquid flows. Supply flow path 27 is connected to storage unit 15. Supply flow path 27 is connected to discharge unit 12. Liquid is supplied from storage unit 15 to discharge unit 12 through supply flow path 27.

[0024] The supply flow path 27 has a first flow path 28 and a second flow path 29. The first flow path 28 is connected to the storage portion 15 and the discharge portion 12. The second flow path 29 is connected to the storage portion 15 and the discharge portion 12. Liquid is supplied from the storage portion 15 to the discharge portion 12 through the first flow path 28, the second flow path 29, or both.

[0025] The first flow path 28 and the second flow path 29 may be flow paths independent of each other, or may be flow paths having a common portion. In one example, the first flow path 28 and the second flow path 29 have a common portion 30 that is a common portion. The common portion 30 constitutes the first flow path 28 and the second flow path 29. The first flow path 28 has the common portion 30. The second flow path 29 has the common portion 30. The common portion 30 simplifies the configuration of the first flow path 28 and the second flow path 29 compared to when the first flow path 28 and the second flow path 29 are flow paths independent of each other.

[0026] The first flow path 28 and the second flow path 29 each have an individual portion. The first flow path 28 has a first individual portion 31. The second flow path 29 has a second individual portion 32. Individual portions are portions that are not common to each other. The first flow path 28 has a first individual portion 31 and a common portion 30. The second flow path 29 has a second individual portion 32 and a common portion 30. The first individual portion 31 is connected to the common portion 30. The second individual portion 32 is connected to the common portion 30.

[0027] The first flow path 28 and the second flow path 29 extend from the storage section 15 toward the discharge section 12 so as to merge midway. The first individual portion 31 is located upstream of the common portion 30 in the first flow path 28. The second individual portion 32 is located upstream of the common portion 30 in the second flow path 29. The first individual portion 31 is connected to the storage body 16. The second individual portion 32 is connected to the storage body 16. The first individual portion 31 and the second individual portion 32 communicate with the storage chamber 17 via the outlet 18. The common portion 30 is connected to the discharge section 12.

[0028] The first flow path 28 and the second flow path 29 may extend from the storage section 15 toward the discharge section 12 so as to branch off midway. In this case, the first individual portion 31 is located downstream of the common portion 30 in the first flow path 28. The second individual portion 32 is located downstream of the common portion 30 in the second flow path 29. The first individual portion 31 is connected to the discharge section 12. The second individual portion 32 is connected to the discharge section 12. The common portion 30 is connected to the storage section 15.

[0029] The supply unit 26 may have a maintenance flow path 33. The maintenance flow path 33 is a flow path connected to the first flow path 28 and the second flow path 29. The maintenance flow path 33 is connected to the first flow path 28 upstream of the common portion 30. The maintenance flow path 33 is connected to the second flow path 29 upstream of the common portion 30. The maintenance flow path 33 is connected to the first individual portion 31. The maintenance flow path 33 is connected to the second individual portion 32.

[0030] The supply unit 26 may have a supply valve 34. The supply valve 34 is located in the first flow path 28. More specifically, the supply valve 34 is located in the first individual portion 31. In one example, the supply valve 34 is located upstream of the common portion 30 in the first flow path 28. The supply valve 34 is located downstream of the connection position with the maintenance flow path 33 in the first flow path 28. It can also be said that the maintenance flow path 33 is connected upstream of the supply valve 34 in the first flow path 28.

[0031] The supply valve 34 is configured to open and close the first flow path 28. When the supply valve 34 opens the first flow path 28, liquid can be supplied from the storage unit 15 to the discharge unit 12 via the first flow path 28. More specifically, when the supply valve 34 opens the first individual part 31, liquid can be supplied from the storage unit 15 to the discharge unit 12 via the first individual part 31 and the common part 30. At this time, liquid is supplied from the storage unit 15 to the discharge unit 12 through the first flow path 28 due to the suction force of the discharge unit 12. It can also be said that the storage unit 15 is positioned so that liquid can be supplied from the storage unit 15 to the discharge unit 12 due to negative pressure within the discharge unit 12. When the supply valve 34 closes the first flow path 28, the supply of liquid from the storage unit 15 to the discharge unit 12 via the first flow path 28 is blocked. Specifically, when the supply valve 34 closes the first individual part 31, the supply of liquid from the reservoir 15 to the discharge part 12 by the first individual part 31 and the common part 30 is cut off.

[0032] The supply valve 34 is a valve that prevents the liquid from continuing to leak from the ejection portion 12. When the liquid ejection device 11 is subjected to vibration, impact, or the like, the meniscus of the nozzle 14 may be destroyed. When the meniscus of the nozzle 14 is destroyed, the liquid may leak from the nozzle 14. In this case, if the liquid continues to be supplied from the storage portion 15 to the ejection portion 12 through the supply flow path 27, there is a risk that the liquid will continue to leak from the nozzle 14. Therefore, by the supply valve 34 closing the first flow path 28, the liquid is prevented from continuing to leak from the ejection portion 12.

[0033] The supply valve 34 is configured to close the first flow path 28 when the power of the liquid ejection device 11 is off. For example, the liquid ejection device 11 closes the supply valve 34 when the power is off. This prevents liquid from continuing to leak from the ejection portion 12, for example, when the liquid ejection device 11 is transported or inverted while the power of the liquid ejection device 11 is off. In one example, the supply valve 34 is configured as a normally closed valve. Therefore, when the power of the liquid ejection device 11 is off, the supply valve 34 automatically closes the first flow path 28.

[0034] The supply valve 34 may close the first flow path 28 at a predetermined timing, not just when the liquid ejection device 11 is powered off. For example, the supply valve 34 may close the first flow path 28 based on a user instruction. The user may instruct the supply valve 34 to close when, for example, moving the liquid ejection device 11.

[0035] The supply unit 26 may include an adjusting valve 35. The adjusting valve 35 is configured to adjust the pressure in the discharge unit 12. The adjusting valve 35 adjusts the pressure in the discharge unit 12 to a predetermined negative pressure. The adjusting valve 35 is located in the second flow path 29. In one example, the adjusting valve 35 is located in the second flow path 29 upstream of the common portion 30.

[0036] The adjustment valve 35 is configured to open and close the second flow path 29. When the adjustment valve 35 opens the second flow path 29, the supply of liquid from the storage portion 15 to the discharge portion 12 via the second flow path 29 becomes possible. When the adjustment valve 35 closes the second flow path 29, the supply of liquid from the storage portion 15 to the discharge portion 12 via the second flow path 29 is blocked. The adjustment valve 35 adjusts the pressure inside the discharge portion 12 by opening and closing the second flow path 29.

[0037] The adjustment valve 35 is configured to open the second flow path 29 when the pressure inside the discharge portion 12 is equal to or lower than a predetermined pressure. The adjustment valve 35 adjusts the pressure inside the discharge portion 12 so that it is equal to or lower than a predetermined pressure. The adjustment valve 35 adjusts the pressure inside the discharge portion 12 so that it is equal to or lower than a predetermined negative pressure. More specifically, the adjustment valve 35 opens when the pressure inside the discharge portion 12 is equal to or lower than the meniscus withstand pressure of the nozzle 14. In other words, the pressure inside the discharge portion 12 at which the adjustment valve 35 opens is equal to or lower than the meniscus withstand pressure of the nozzle 14. The adjustment valve 35 adjusts the pressure inside the discharge portion 12, thereby maintaining the meniscus of the nozzle 14.

[0038] In the discharge portion 12, liquid evaporates from the nozzle 14. When the liquid evaporates from the nozzle 14, the pressure inside the discharge portion 12 decreases. When the power of the liquid discharge device 11 is off, the supply valve 34 is closed, and therefore the pressure inside the discharge portion 12 is likely to decrease due to the evaporation of the liquid. When the pressure inside the discharge portion 12 decreases, there is a risk that the meniscus of the nozzle 14 will be destroyed. In this regard, when the pressure inside the discharge portion 12 decreases due to the evaporation of the liquid, the adjustment valve 35 opens before the meniscus of the nozzle 14 is destroyed. This allows liquid to be supplied to the discharge portion 12 through the second flow path 29. Therefore, even when the supply valve 34 is closed, the adjustment valve 35 reduces the risk that the meniscus will be destroyed due to the evaporation of the liquid.

[0039] The adjustment valve 35 has a main body member 36. The main body member 36 forms a pressure chamber 37, a supply chamber 38, and a through hole 39. The pressure chamber 37 is a space that communicates with the discharge portion 12. Therefore, the pressure in the pressure chamber 37 is approximately the same as the pressure in the discharge portion 12. The adjustment valve 35 adjusts the pressure in the discharge portion 12 by adjusting the pressure in the pressure chamber 37. The supply chamber 38 is a space that communicates with the storage portion 15. The supply chamber 38 is located upstream of the pressure chamber 37. More specifically, the supply chamber 38 is located upstream of the pressure chamber 37 in the direction in which the liquid is supplied. The through hole 39 is an opening that communicates with the pressure chamber 37 and the supply chamber 38. The through hole 39 connects the pressure chamber 37 and the supply chamber 38. Liquid is supplied from the supply chamber 38 to the pressure chamber 37 through the through hole 39.

[0040] The body member 36 is connected to the second flow paths 29. The body member 36 is connected to the second individual portions 32. The body member 36 is connected to the second flow paths 29 such that the second individual portions 32 communicate with the supply chambers 38. The body member 36 is connected to the common portion 30. The body member 36 is connected to the second flow paths 29 such that the common portion 30 communicates with the pressure chambers 37. Liquid flows from the second individual portions 32 to the common portion 30 in the second flow paths 29 by passing through the supply chambers 38 and the pressure chambers 37.

[0041] The body member 36 may be connected to the first flow path 28. The body member 36 may be connected to, for example, the first individual portion 31. In one example, the body member 36 is connected to the first flow path 28 such that the first individual portion 31 communicates with the pressure chamber 37. Liquid flows in the first flow path 28 from the first individual portion 31 to the common portion 30 by passing through the pressure chamber 37. In this case, the first flow path 28 is connected to the second flow path 29 through the regulating valve 35. The first flow path 28 may also be connected directly to the second flow path 29.

[0042] The body member 36 may be connected to the maintenance flow path 33. In one example, the body member 36 may be connected to the maintenance flow path 33 such that the maintenance flow path 33 communicates with the supply chamber 38. Liquid can flow from the first individual portion 31 to the second individual portion 32 in the supply flow path 27 by passing through the supply chamber 38. Liquid can flow from the second individual portion 32 to the first individual portion 31 in the supply flow path 27 by passing through the supply chamber 38. In this case, the maintenance flow path 33 is connected to the second flow path 29 through the regulating valve 35. The maintenance flow path 33 may also be connected directly to the second flow path 29.

[0043] As shown in Figures 3, 4, 5, 6, and 7, the body member 36 has a base member 40. The body member 36 has one or more cover members. In one example, the body member 36 has a first cover member 41 and a second cover member 42. The cover members are attached to the base member 40. The cover members are attached to the base member 40 by, for example, a plurality of screws. The first cover member 41 and the second cover member 42 are attached so as to sandwich the base member 40.

[0044] The base member 40 has a plurality of connecting pipes. In one example, the base member 40 has a first connecting pipe 43, a second connecting pipe 44, a third connecting pipe 45, and a fourth connecting pipe 46. The first connecting pipe 43 is a pipe connected to the second individual portion 32. The first connecting pipe 43 communicates with the supply chamber 38. The second connecting pipe 44 is a pipe connected to the first individual portion 31. The second connecting pipe 44 communicates with the pressure chamber 37. The third connecting pipe 45 is a pipe connected to the common portion 30. The third connecting pipe 45 communicates with the pressure chamber 37. The fourth connecting pipe 46 is a pipe connected to the maintenance flow path 33. The fourth connecting pipe 46 communicates with the supply chamber 38.

[0045] A plurality of recesses are formed in the base member 40. In one example, a first recess 47, a second recess 48, a third recess 49, and a fourth recess 50 are formed in the base member 40. The first recess 47, the second recess 48, and the third recess 49 are formed on the surface of the base member 40 facing the first cover member 41. The fourth recess 50 is formed on the surface of the base member 40 facing the second cover member 42.

[0046] The first recess 47 is a recess that defines the supply chamber 38. The first recess 47 communicates with the first connecting pipe 43 and the fourth connecting pipe 46. The first recess 47 communicates with the through-hole 39. The second recess 48 is a recess that defines the pressure chamber 37. The second recess 48 communicates with the second connecting pipe 44. The second recess 48 communicates with the fourth recess 50. The third recess 49 is a recess that defines the pressure chamber 37. The third recess 49 communicates with the third connecting pipe 45. The third recess 49 communicates with the fourth recess 50. The fourth recess 50 is a recess that defines the pressure chamber 37. The fourth recess 50 communicates with the through-hole 39.

[0047] The regulating valve 35 has a valve member 51. The valve member 51 is housed in the main body member 36. The valve member 51 is positioned to pass through the through hole 39. The valve member 51 is positioned across the pressure chamber 37 and the supply chamber 38. The valve member 51 is a valve that opens and closes the through hole 39. When the valve member 51 opens the through hole 39, liquid is supplied from the supply chamber 38 to the pressure chamber 37. When the valve member 51 closes the through hole 39, the second flow path 29 is closed. The valve member 51 opens the second flow path 29 by opening the through hole 39.

[0048] The valve member 51 is located downstream of the connection position of the second flow path 29 with the maintenance flow path 33. In other words, the maintenance flow path 33 is connected to the second flow path 29 upstream of the valve member 51.

[0049] The adjusting valve 35 has a pressing member 52. The pressing member 52 is a member that presses the valve member 51. More specifically, the pressing member 52 presses the valve member 51 so that the valve member 51 closes the through-hole 39. The pressing member 52 is, for example, a spring. The pressing member 52 is housed in the main body member 36. The pressing member 52 is located in the supply chamber 38. The pressing member 52 presses the valve member 51 from the supply chamber 38 toward the pressure chamber 37.

[0050] The adjustment valve 35 has a membrane member 53. The membrane member 53 is flexible. The membrane member 53 is attached to the main body member 36. The membrane member 53 is sandwiched between the base member 40 and the second cover member 42. The membrane member 53 forms part of the wall surface that defines the pressure chamber 37. The membrane member 53 faces the pressure chamber 37. The membrane member 53 deforms in response to the pressure in the pressure chamber 37. That is, the membrane member 53 deforms in response to the pressure inside the discharge portion 12. More specifically, the membrane member 53 deforms in response to the pressure difference between the pressure in the pressure chamber 37 and atmospheric pressure. When the pressure in the pressure chamber 37 decreases, the membrane member 53 deforms so that the volume of the pressure chamber 37 decreases.

[0051] The membrane member 53 deforms to reduce the volume of the pressure chamber 37, thereby pressing the valve member 51. More specifically, the membrane member 53 presses the valve member 51 so that the valve member 51 opens the through-hole 39. The membrane member 53 presses the valve member 51 from the pressure chamber 37 toward the supply chamber 38. When the force with which the membrane member 53 presses the valve member 51 becomes greater than the force with which the pressing member 52 presses the valve member 51, the valve member 51 opens the through-hole 39. In this way, the adjustment valve 35 adjusts the pressure inside the discharge portion 12.

[0052] As shown in FIG. 8 , the adjustment valve 35 may be located at the center of the discharge portion 12 in the longitudinal direction of the extension of the discharge portion 12. For example, the adjustment valve 35 may be located on an imaginary line L2 that bisects the discharge portion 12 in the longitudinal direction. In the liquid discharge device 11, the discharge portion 12 may be tilted so that it extends vertically. In this case, by positioning the adjustment valve 35 at the center of the longitudinal direction with respect to the discharge portion 12, the risk of an increase in the head difference between the adjustment valve 35 and the nozzle 14 can be reduced. More specifically, the risk of an increase in the head difference between the adjustment valve 35 and the nozzle 14 located at the lowest position among the multiple nozzles 14 can be reduced. If the head difference between the adjustment valve 35 and the nozzle 14 is large, the pressure in the pressure chamber 37 is likely to decrease. If the pressure in the pressure chamber 37 decreases, the adjustment valve 35 may open.

[0053] 1 , the supply unit 26 may have an on-off valve 54. The on-off valve 54 is located in the first flow path 28. The on-off valve 54 is located upstream of the supply valve 34 in the first flow path 28. The on-off valve 54 is located in the first individual part 31. The on-off valve 54 is located upstream of the connection position with the maintenance flow path 33 in the first flow path 28. The on-off valve 54 is configured to open and close the first flow path 28.

[0054] The supply unit 26 may include a pump 55. The pump 55 is configured to supply the liquid from the storage unit 15 to the discharge unit 12 through the supply flow path 27. The pump 55, for example, pressurizes the liquid in the supply flow path 27, thereby supplying the liquid from the storage unit 15 to the discharge unit 12 through the supply flow path 27. When performing maintenance on the discharge unit 12, the pump 55 pressurizes the liquid in the supply flow path 27, thereby supplying the liquid from the storage unit 15 to the discharge unit 12. In one example, the pump 55 is configured to circulate the liquid in the supply flow path 27 and a recovery flow path 56, which will be described later. The pump 55 pressurizes the liquid in the supply flow path 27, thereby circulating the liquid in the supply flow path 27 and the recovery flow path 56.

[0055] The pump 55 is located in the supply flow path 27. More specifically, the pump 55 is located in the second flow path 29. The pump 55 is located upstream of the common portion 30 in the second flow path 29. The pump 55 is located upstream of the adjustment valve 35 in the second flow path 29. The pump 55 is located in the second individual portion 32. The pump 55 is located upstream of the connection position with the maintenance flow path 33 in the second flow path 29. The pump 55 is, for example, a diaphragm pump. The pump 55 may be a tube pump or a syringe pump. The supply unit 26 causes the liquid to flow by driving the pump 55. The supply unit 26 supplies the liquid from the storage portion 15 to the discharge portion 12 through the second flow path 29 by the pump 55. The supply unit 26 supplies the liquid from the storage portion 15 to the discharge portion 12 through the second individual portion 32 by the pump 55. In one example, the supply unit 26 supplies liquid from the reservoir 15 to the discharge unit 12 through the second individual portion 32, the maintenance channel 33, the first individual portion 31, and the common portion 30.

[0056] The supply unit 26 may have a recovery channel 56. The recovery channel 56 is connected to the storage unit 15 and the discharge unit 12. The liquid is returned from the discharge unit 12 to the storage unit 15 through the recovery channel 56. The supply unit 26 circulates the liquid through the supply channel 27 and the recovery channel 56. Specifically, the supply unit 26 supplies the liquid from the storage unit 15 to the discharge unit 12 through the second channel 29 using the pump 55, thereby circulating the liquid through the second channel 29 and the recovery channel 56. The supply unit 26 may perform maintenance on the discharge unit 12 by circulating the liquid. The supply unit 26 may supply the liquid from the storage unit 15 to the discharge unit 12 through the recovery channel 56. For example, the supply unit 26 may supply the liquid from the storage unit 15 to the discharge unit 12 through the recovery channel 56 using the suction force of the discharge unit 12.

[0057] The supply unit 26 has a recovery valve 57. The recovery valve 57 is located in the recovery passage 56. The recovery valve 57 is configured to close and open the recovery passage 56. When the recovery valve 57 opens the recovery passage 56, liquid can be supplied through the recovery passage 56. When the recovery valve 57 is open, the supply unit 26 uses the pump 55 to supply liquid from the reservoir 15 to the discharge unit 12 through the second passage 29, thereby circulating the liquid through the second passage 29 and the recovery passage 56. When the recovery valve 57 closes the recovery passage 56, the supply of liquid through the recovery passage 56 is cut off. When the recovery valve 57 is closed, the supply unit 26 uses the pump 55 to supply liquid from the reservoir 15 to the discharge unit 12 through the second passage 29, thereby discharging the liquid from the discharge unit 12. This cleans the discharge unit 12.

[0058] The recovery valve 57 is a valve that prevents the liquid from continuing to leak from the discharge portion 12. When the liquid discharge device 11 is subjected to vibration, impact, or the like, the meniscus of the nozzle 14 may be destroyed. When the meniscus of the nozzle 14 is destroyed, the liquid may leak from the nozzle 14. In this case, if the liquid continues to be supplied from the storage portion 15 to the discharge portion 12 through the recovery flow path 56, there is a risk that the liquid will continue to leak from the nozzle 14. Therefore, by the recovery valve 57 closing the recovery flow path 56, the liquid is prevented from continuing to leak from the discharge portion 12.

[0059] The recovery valve 57 is configured to close the recovery passageway 56 when the power of the liquid ejection device 11 is off. For example, the liquid ejection device 11 closes the recovery valve 57 when it is powered off. This prevents the liquid from continuing to leak from the ejection section 12 when the liquid ejection device 11 is transported or inverted while it is powered off. In one example, the recovery valve 57 is configured as a normally closed valve. Therefore, when the power of the liquid ejection device 11 is off, the recovery valve 57 automatically closes the recovery passageway 56.

[0060] The recovery valve 57 may close the recovery passageway 56 at a predetermined timing, not just when the power of the liquid ejection device 11 is off. For example, the recovery valve 57 may close the recovery passageway 56 based on a user instruction. For example, the user may instruct the recovery valve 57 to close when moving the liquid ejection device 11.

[0061] The liquid ejection device 11 may include a maintenance unit 61. The maintenance unit 61 is configured to perform maintenance on the ejection unit 12. The maintenance unit 61 maintains or recovers the ejection performance of the ejection unit 12 by performing maintenance on the ejection unit 12.

[0062] The maintenance unit 61 receives the liquid used for cleaning to perform maintenance on the ejection unit 12. Cleaning is an operation for discharging the liquid from the nozzle 14. Viscous liquid, air bubbles, and the like are discharged from the ejection unit 12 by cleaning.

[0063] The maintenance unit 61 receives the liquid from flushing to perform maintenance on the discharge unit 12. Flushing is maintenance in which the discharge unit 12 appropriately discharges the liquid from the nozzles 14. Flushing prevents the nozzles 14 from clogging.

[0064] The maintenance unit 61 performs maintenance on the ejection unit 12 by wiping. Wiping is an operation of wiping off the nozzle surface 13. The maintenance unit 61 removes foreign matter such as liquid and dust adhering to the nozzle surface 13 by wiping.

[0065] The maintenance unit 61 maintains the discharge unit 12 by capping. Capping is an operation of covering the nozzle 14 to form a space that communicates with the nozzle 14. The maintenance unit 61 keeps the nozzle 14 moist by capping.

[0066] The maintenance unit 61 has a cap 62. The cap 62 is configured to cap the ejection unit 12. The cap 62 caps the ejection unit 12 by coming into contact with the nozzle surface 13. The cap 62 may receive liquid from cleaning and flushing. In this case, the liquid received by cleaning and flushing accumulates in the cap 62.

[0067] The maintenance unit 61 has a wiping unit 63. The wiping unit 63 is configured to wipe the discharge unit 12. The wiping unit 63 has a blade 64 and a holder 65. The blade 64 comes into contact with the nozzle surface 13 to scrape off foreign matter from the nozzle surface 13. The holder 65 supports the blade 64. The holder 65 receives the foreign matter removed by the blade 64.

[0068] The maintenance unit 61 has a pressurizing unit 66. The pressurizing unit 66 is located in the recovery passage 56. The pressurizing unit 66 is configured to pressurize the liquid in the recovery passage 56. The pressurizing unit 66 is, for example, a diaphragm pump. The pressurizing unit 66 pressurizes the inside of the discharge unit 12 through the recovery passage 56. This causes the liquid to be discharged from the nozzle 14. The pressurizing unit 66 pressurizes the inside of the discharge unit 12, thereby cleaning the discharge unit 12. The discharge unit 12 may be cleaned by pressurizing the inside of the discharge unit 12 using a pump 55, instead of the pressurizing unit 66.

[0069] The pressurizing section 66 has a deformable member 67. The deformable member 67 is flexible. The deformable member 67 divides the inside of the pressurizing section 66 into a pressurizing chamber 68 and an air chamber 69. The pressurizing chamber 68 contains a liquid. The air chamber 69 contains an elastic member 70, which will be described later. The deformable member 67 pressurizes the liquid in the recovery passageway 56 by deforming. The deformable member 67 pressurizes the liquid in the recovery passageway 56 by deforming so that the volume of the pressurizing chamber 68 becomes smaller.

[0070] The pressurizing unit 66 has an elastic member 70. The elastic member 70 is located in the air chamber 69. The elastic member 70 presses the deformable member 67. The elastic member 70 presses the deformable member 67 so that the volume of the pressurizing chamber 68 decreases. This pressurizes the liquid in the recovery passageway 56. The elastic member 70 is, for example, a spring.

[0071] The maintenance unit 61 has a waste liquid storage unit 71. The waste liquid storage unit 71 is configured to store waste liquid. The waste liquid is liquid discharged from the discharge unit 12 during maintenance. The waste liquid storage unit 71 stores liquid received by the cap 62, liquid removed by the wiping unit 63, etc. The waste liquid storage unit 71 is, for example, a tank.

[0072] The maintenance unit 61 has one or more suction flow paths. In one example, the maintenance unit 61 has three suction flow paths. More specifically, the maintenance unit 61 has a first suction flow path 72, a second suction flow path 73, and a third suction flow path 74. The suction flow paths are flow paths to which negative pressure is applied.

[0073] The first suction flow path 72 is connected to the cap 62. The first suction flow path 72 communicates with the inside of the cap 62. Negative pressure acts inside the cap 62 through the first suction flow path 72. The first suction flow path 72 is connected to the waste liquid storage section 71.

[0074] The second suction flow path 73 is connected to the wiping unit 63. The second suction flow path 73 communicates with the inside of the holder 65. Negative pressure acts on the inside of the holder 65 through the second suction flow path 73. The second suction flow path 73 is connected to the first suction flow path 72. The second suction flow path 73 is connected to the waste liquid storage unit 71 through the first suction flow path 72.

[0075] The third suction flow path 74 is connected to the pressurizing unit 66. The third suction flow path 74 communicates with the air chamber 69. Negative pressure acts on the air chamber 69 through the third suction flow path 74. The third suction flow path 74 is connected to the first suction flow path 72. More specifically, the third suction flow path 74 is connected to the first suction flow path 72, between the connection position with the second suction flow path 73 and the cap 62. The third suction flow path 74 is connected to the waste liquid storage unit 71 through the first suction flow path 72.

[0076] The maintenance unit 61 has one or more suction valves. In one example, the maintenance unit 61 has four suction valves. More specifically, the maintenance unit 61 has a first suction valve 75, a second suction valve 76, a third suction valve 77, and a fourth suction valve 78. The suction valves are valves that open and close the suction flow path.

[0077] The first suction valve 75 is located in the first suction flow path 72. More specifically, the first suction valve 75 is located in the first suction flow path 72, between the position where the first suction flow path 72 connects to the third suction flow path 74 and the cap 62. The first suction valve 75 opens and closes the first suction flow path 72. The second suction valve 76 is located in the second suction flow path 73. The second suction valve 76 opens and closes the second suction flow path 73. The third suction valve 77 is located in the third suction flow path 74. The third suction valve 77 opens and closes the third suction flow path 74. The fourth suction valve 78 is located in the first suction flow path 72. More specifically, the fourth suction valve 78 is located in the first suction flow path 72, between the position where the first suction flow path 72 connects to the second suction flow path 73 and the position where the first suction flow path 72 connects to the third suction flow path 74. The fourth suction valve 78 opens and closes the first suction flow path 72.

[0078] The maintenance unit 61 has a suction pump 79. The suction pump 79 is located in the suction flow path. Specifically, the suction pump 79 is located in the first suction flow path 72. More specifically, the suction pump 79 is located in the first suction flow path 72, between the connection position with the second suction flow path 73 and the waste liquid storage unit 71.

[0079] The suction pump 79 is configured to suck the connected destination of the suction flow path through the suction flow path. The suction pump 79 is, for example, a tube pump. The suction pump 79 sends the sucked liquid, air, etc. to the waste liquid storage unit 71 through the suction flow path.

[0080] The suction pump 79 sucks the inside of the cap 62 through the first suction flow path 72. When the suction pump 79 sucks the inside of the cap 62 while the cap 62 is in a capping state, liquid is discharged from the nozzle 14. In other words, the discharge part 12 is cleaned. When the suction pump 79 sucks the inside of the cap 62 while the inside of the cap 62 is open to the atmosphere, waste liquid is collected from the cap 62. The operation of collecting waste liquid from the cap 62 is called idle suction.

[0081] The suction pump 79 sucks the inside of the holder 65 through the second suction flow path 73. This causes waste liquid to be collected from the holder 65. The suction pump 79 sucks the air chamber 69 through the third suction flow path 74. This causes liquid to flow into the pressurizing chamber 68. In other words, the liquid is drawn into the pressurizing chamber 68.

[0082] The maintenance unit 61 has a first open flow path 80. The first open flow path 80 is connected to the cap 62. The first open flow path 80 communicates with the inside of the cap 62. The first open flow path 80 is a flow path that connects the inside of the cap 62 with the atmosphere. The first open flow path 80 reduces the risk of the pressure inside the cap 62 increasing during capping, for example. During capping, if the pressure inside the cap 62 increases due to a rise in temperature, for example, there is a risk that the meniscus of the nozzle 14 will be destroyed.

[0083] The maintenance unit 61 has a second open flow path 81. The second open flow path 81 is connected to the pressurizing unit 66. More specifically, the second open flow path 81 is connected to the pressurizing unit 66 so as to communicate with the air chamber 69. In one example, the second open flow path 81 is connected to the third suction flow path 74. The second open flow path 81 is connected to the pressurizing unit 66 through the third suction flow path 74. The second open flow path 81 is a flow path that connects the air chamber 69 to the atmosphere.

[0084] The maintenance unit 61 has a first open valve 82. The first open valve 82 is located in the first open flow path 80. The first open valve 82 opens and closes the first open flow path 80. When the first open valve 82 is open, the inside of the cap 62 communicates with the atmosphere through the first open flow path 80.

[0085] The maintenance unit 61 has a second open valve 83. The second open valve 83 is located in the second open flow path 81. The second open valve 83 opens and closes the second open flow path 81. When the second open valve 83 is open, the air chamber 69 communicates with the atmosphere through the second open flow path 81. When the depressurized air chamber 69 is opened to the atmosphere, the pressurizing unit 66 pressurizes the liquid in the pressurizing chamber 68. As a result, the pressurizing unit 66 pressurizes the inside of the discharge unit 12.

[0086] The maintenance unit 61 has a pressure sensor 84. The pressure sensor 84 is a sensor that measures the pressure inside the third suction flow path 74. The pressure sensor 84 is connected to the third suction flow path 74. In one example, the pressure sensor 84 is connected to the third suction flow path 74 at a position where the third suction flow path 74 connects to the second open flow path 81. The pressure sensor 84 can measure the pressure in the air chamber 69 through the third suction flow path 74.

[0087] The liquid ejection device 11 includes a control unit 90. The control unit 90 is configured to control the liquid ejection device 11. The control unit 90 is configured to control the ejection unit 12, the supply unit 26, the maintenance unit 61, and the like.

[0088] The control unit 90 may be configured with one or more processors that execute various processes according to a computer program. The control unit 90 may be configured with one or more dedicated hardware circuits, such as application specific integrated circuits, that execute at least some of the various processes. The control unit 90 may be configured with a circuit that includes a combination of a processor and a hardware circuit. The processor includes a CPU and memory, such as RAM and ROM. The memory stores program code or instructions that cause the CPU to execute processes. The memory, i.e., computer-readable medium, includes any readable medium that can be accessed by a general-purpose or special-purpose computer.

[0089] <Valve control by the control unit> Next, the control of the valves by the control unit 90 will be described. The control unit 90 controls the supply valve 34, the on-off valve 54, the recovery valve 57, the first suction valve 75, the second suction valve 76, the third suction valve 77, the fourth suction valve 78, the first open valve 82, and the second open valve 83 in accordance with the operation. The control unit 90 controls each valve according to the time, such as printing, flushing, dry suction, circulation, cleaning, wiping, pressurization preparation, pressurization standby, pressurization start, first filling, second filling, third filling, transportation, and standby. Pressurization preparation, pressurization standby, and pressurization start are a series of operations performed when the pressurization unit 66 pressurizes the inside of the discharge unit 12.

[0090] 1, during printing and flushing, the control unit 90 closes the second suction valve 76, the third suction valve 77, and the first open valve 82. During printing and flushing, the control unit 90 opens the supply valve 34, the on-off valve 54, the recovery valve 57, the first suction valve 75, the fourth suction valve 78, the first open valve 82, and the second open valve 83.

[0091] The control unit 90 causes the liquid to be ejected from the nozzles 14 during printing and flushing. This reduces the pressure inside the ejection unit 12. As the pressure inside the ejection unit 12 decreases, the liquid is supplied from the storage unit 15 to the ejection unit 12 through the supply flow path 27 and the recovery flow path 56. At this time, the liquid is supplied from the storage unit 15 to the ejection unit 12 by the suction force of the ejection unit 12.

[0092] 9, during dry suction and first filling, the control unit 90 closes the supply valve 34, the recovery valve 57, the second suction valve 76, and the third suction valve 77. During dry suction and first filling, the control unit 90 opens the on-off valve 54, the first suction valve 75, the fourth suction valve 78, the first open valve 82, and the second open valve 83.

[0093] During idle suction, the control unit 90 drives the suction pump 79 while the cap 62 is in the capped state, thereby recovering waste liquid from inside the cap 62. During the first filling, the control unit 90 drives the pump 55. This causes the liquid to flow from the storage unit 15 to the second individual portion 32, the supply chamber 38, the maintenance flow path 33, and the first individual portion 31 in that order. During the first filling, the control unit 90 fills the liquid into a portion of the first flow path 28, a portion of the second flow path 29, and the maintenance flow path 33.

[0094] 10, during circulation and second filling, the control unit 90 closes the on-off valve 54, the second suction valve 76, and the third suction valve 77. During circulation and second filling, the control unit 90 opens the supply valve 34, the recovery valve 57, the first suction valve 75, the fourth suction valve 78, the first open valve 82, and the second open valve 83.

[0095] During circulation, the control unit 90 drives the pump 55 with the cap 62 in the capped state. This causes the liquid to flow from the storage unit 15 to the supply flow path 27, the discharge unit 12, and the recovery flow path 56 in that order. That is, the liquid circulates between the storage unit 15 and the discharge unit 12. By circulating the liquid, the control unit 90 eliminates settling of the liquid and expels air bubbles from the liquid.

[0096] The control unit 90 executes the second filling after the first filling. During the second filling, the control unit 90 drives the pump 55 with the cap 62 in the capped state, as in the circulation. During the second filling, the control unit 90 fills the supply flow path 27, the adjustment valve 35, a part of the discharge unit 12, the pressurizing unit 66, and the recovery flow path 56 with liquid.

[0097] 11, during cleaning and third filling, the control unit 90 closes the on-off valve 54, the recovery valve 57, the second suction valve 76, and the third suction valve 77. During cleaning and third filling, the control unit 90 opens the supply valve 34, the first suction valve 75, the fourth suction valve 78, the first open valve 82, and the second open valve 83.

[0098] During cleaning, the control unit 90 drives the pump 55 with the cap 62 in place. This pressurizes the inside of the discharge unit 12. During cleaning, the control unit 90 drives the suction pump 79. This recovers waste liquid from inside the cap 62. The control unit 90 cleans the discharge unit 12 by performing idle suction while pressurizing the inside of the discharge unit 12 with the pump 55.

[0099] The control unit 90 performs the third filling after the second filling. During the third filling, the control unit 90 drives the pump 55 with the cap 62 in the capped state, as in the cleaning. This pressurizes the inside of the discharge unit 12. During the third filling, the control unit 90 drives the suction pump 79, as in the cleaning. This recovers the waste liquid inside the cap 62. The control unit 90 fills the nozzle 14 with liquid by performing idle suction while pressurizing the inside of the discharge unit 12 with the pump 55. That is, during the third filling, the control unit 90 fills the nozzle 14 with liquid.

[0100] 12, during pressurization preparation, the control unit 90 closes the first suction valve 75, the second suction valve 76, the first open valve 82, and the second open valve 83. During pressurization preparation, the control unit 90 opens the supply valve 34, the on-off valve 54, the recovery valve 57, the third suction valve 77, and the fourth suction valve 78. During pressurization preparation, the pressurization unit 66 prepares to pressurize the inside of the discharge unit 12.

[0101] When preparing to apply pressure, the control unit 90 drives the suction pump 79 with the cap 62 in the capped state, thereby drawing liquid into the pressurizing chamber 68. At this time, the liquid is drawn into the pressurizing chamber 68 from the reservoir 15 and the discharge unit 12 through the recovery flow path 56.

[0102] 13, during pressurization standby, the control unit 90 closes the supply valve 34, the on-off valve 54, the recovery valve 57, the first suction valve 75, the second suction valve 76, the third suction valve 77, the first open valve 82, and the second open valve 83. During pressurization standby, the control unit 90 opens the fourth suction valve 78. During pressurization standby, the control unit 90 waits for the pressurizing unit 66 to pressurize the inside of the discharge unit 12 after preparing to pressurize the inside of the discharge unit 12 by the pressurizing unit 66.

[0103] As shown in FIG. 14 , the control unit 90 closes the supply valve 34, the on-off valve 54, the recovery valve 57, the second suction valve 76, the third suction valve 77, and the first open valve 82 at the start of pressurization. The control unit 90 opens the first suction valve 75, the fourth suction valve 78, and the second open valve 83 at the start of pressurization. The start of pressurization refers to the time when the pressurizing unit 66 starts pressurizing the discharge portion 12 after preparations for pressurization of the discharge portion 12 by the pressurizing unit 66 have been made. At the start of pressurization, air flows into the air chamber 69 through the second open flow path 81. This pressurizes the discharge portion 12. As a result, the nozzle surface 13 is wetted with liquid. The pressurization by the pressurizing unit 66 is weaker than that by the pump 55. Therefore, the amount of liquid discharged from the nozzle 14 is small.

[0104] 15 , during wiping, the control unit 90 closes the supply valve 34, the on-off valve 54, the recovery valve 57, the third suction valve 77, the fourth suction valve 78, and the first open valve 82. During wiping, the control unit 90 opens the first suction valve 75, the second suction valve 76, and the second open valve 83. The control unit 90 starts wiping after pressurizing the inside of the discharge unit 12 with the pressurizing unit 66. By wiping while the inside of the discharge unit 12 is pressurized, the risk of the wiping unit 63 pushing foreign matter into the nozzle 14 is reduced.

[0105] During wiping, the control unit 90 moves the wiping unit 63 while separating the discharge unit 12 from the cap 62. As a result, the control unit 90 causes the wiping unit 63 to remove foreign matter along with the liquid adhering to the nozzle surface 13. Thereafter, the control unit 90 drives the suction pump 79. As a result, waste liquid is collected from the wiping unit 63.

[0106] 14, the control unit 90 closes the supply valve 34, the on-off valve 54, the recovery valve 57, the second suction valve 76, the third suction valve 77, and the first open valve 82 during transportation and standby. The control unit 90 opens the first suction valve 75, the fourth suction valve 78, and the second open valve 83 during transportation and standby. "During transportation" refers to when the liquid ejection device 11 is being transported. "During standby" refers to when the liquid ejection device 11 is waiting for a print instruction. Because the supply valve 34 is closed during transportation and standby, the risk of continuous leakage of liquid from the nozzles 14 is reduced.

[0107] 16, during transportation and standby, as the liquid evaporates from the nozzle 14, the pressure inside the discharge part 12 decreases. When the pressure inside the discharge part 12 decreases, the regulating valve 35 opens. By opening the regulating valve 35, liquid is supplied to the discharge part 12. In this way, during transportation and standby, the drop in pressure inside the discharge part 12 is automatically resolved.

[0108] <Actions and Effects of the Example> Next, the operation and effects of the above embodiment will be described. (1) The supply unit 26 has a supply valve 34 located in the first flow path 28 and configured to close the first flow path 28 when the power is off, and a regulation valve 35 located in the second flow path 29 and configured to open the second flow path 29 when the pressure in the discharge unit 12 is equal to or lower than a predetermined pressure. With the above configuration, the supply valve 34 closes the first flow path 28, thereby reducing the risk of liquid leaking from the nozzle 14. When the pressure in the discharge unit 12 falls below the predetermined pressure due to evaporation of liquid from the nozzle 14, the regulation valve 35 opens the second flow path 29. This allows liquid to be supplied from the storage unit 15 to the discharge unit 12 through the second flow path 29. Therefore, the risk of the meniscus of the nozzle 14 being destroyed is reduced.

[0109] (2) The first flow path 28 and the second flow path 29 have a common portion 30. According to the above configuration, the configuration of the liquid ejection device 11 is simpler than when the first flow path 28 and the second flow path 29 are configured independently.

[0110] (3) The common portion 30 is located downstream of the supply valve 34 in the first flow path 28, and is located downstream of the adjustment valve 35 in the second flow path 29. According to the above configuration, the supply valve 34 and the adjustment valve 35 can easily control the flow of liquid in the first flow path 28 and the second flow path 29.

[0111] (4) The reservoir 15 stores the liquid so that the liquid level is located below the nozzle surface 13. According to the above configuration, the inside of the discharge portion 12 is maintained at a negative pressure due to the head difference between the reservoir 15 and the discharge portion 12.

[0112] (5) The supply valve 34 is a normally closed valve. With the above configuration, when the liquid ejection device 11 is powered off, the supply valve 34 automatically closes the first flow path 28. This prevents the supply valve 34 from being left closed.

[0113] (6) The supply unit 26 is located in the recovery passage 56 and has a recovery valve 57 that closes the recovery passage 56 when the power is off. According to the above configuration, the recovery valve 57 closes the recovery passage 56, thereby reducing the risk of liquid leaking from the nozzle 14.

[0114] (7) The recovery valve 57 is a normally closed valve. With the above configuration, when the power of the liquid ejection device 11 is turned off, the recovery valve 57 automatically closes the recovery passageway 56. This prevents the recovery valve 57 from being left open.

[0115] (8) The pump 55 is located in the second flow path 29 upstream of the connection position with the maintenance flow path 33. With the above configuration, the pump 55 can easily cause the liquid to flow in the supply flow path 27 and the recovery flow path 56. For example, the pump 55 can supply the liquid from the storage portion 15 to the discharge portion 12 through the supply flow path 27, or circulate the liquid in the supply flow path 27 and the recovery flow path 56.

[0116] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0117] Pump 55 may be connected to storage unit 15. Pump 55 may be configured to pressurize the inside of storage unit 15. Pump 55 may be, for example, an air pump that supplies air to storage unit 15. When pump 55 pressurizes the inside of storage unit 15, liquid is supplied from storage unit 15 to discharge unit 12. When pump 55 pressurizes the inside of storage unit 15, liquid may be circulated between storage unit 15 and discharge unit 12.

[0118] The liquid ejected by the ejection unit 12 is not limited to ink, and may be, for example, a liquid in which particles of a functional material are dispersed or mixed in a liquid. For example, the ejection unit 12 may eject a liquid containing, in a dispersed or dissolved form, a material such as an electrode material or a pixel material used in the manufacture of liquid crystal displays, electroluminescent displays, and surface-emitting displays.

[0119] <Technical philosophy> The technical concepts and effects that can be understood from the above-described embodiment and modified examples will be described below.

[0120] (A) A liquid ejection device includes a nozzle surface on which a nozzle opens and an ejection section that ejects liquid from the nozzle, a storage section that stores liquid, and a supply section that supplies liquid from the storage section to the ejection section. The supply section includes a supply flow path having a first flow path connecting the storage section and the ejection section and a second flow path connecting the storage section and the ejection section, a supply valve located in the first flow path that closes the first flow path when the power is off, and an adjustment valve located in the second flow path that is configured to open the second flow path when the pressure in the ejection section is below a predetermined pressure. With the above configuration, the supply valve closes the first flow path, thereby reducing the risk of liquid leaking from the nozzle. When the pressure in the ejection section drops below a predetermined pressure due to evaporation of liquid from the nozzle, the adjustment valve opens the second flow path. This allows liquid to be supplied from the storage section to the ejection section through the second flow path. Therefore, the risk of the nozzle meniscus being destroyed is reduced.

[0121] (B) In the liquid ejection device, the first flow path and the second flow path may have a common portion that is a portion that is common to each other. This configuration simplifies the configuration of the liquid ejection device compared to when the first flow path and the second flow path are configured independently.

[0122] (C) In the liquid ejection device, the common portion may be located downstream of the supply valve in the first flow path and downstream of the adjustment valve in the second flow path. With this configuration, the flow of liquid in the first flow path and the second flow path can be easily controlled by the supply valve and the adjustment valve.

[0123] (D) In ​​the liquid ejection device, the storage section may store the liquid such that the liquid level is located below the nozzle surface. According to the above configuration, a negative pressure is maintained inside the ejection section due to a hydraulic head difference between the storage section and the ejection section.

[0124] (E) In the liquid ejection device, the supply valve may be a normally closed valve. With this configuration, when the power of the liquid ejection device is turned off, the supply valve automatically closes the first flow path. This prevents the supply valve from being left open.

[0125] (F) In the liquid ejection device, the supply unit may have a recovery passage connected to the ejection unit and the storage unit, a pump that circulates liquid through the supply passage and the recovery passage, and a recovery valve that is located in the recovery passage and closes the recovery passage when the power is off. According to the above configuration, the recovery valve closes the recovery passage, thereby reducing the risk of liquid leaking from the nozzle.

[0126] (G) In the liquid ejection device, the recovery valve may be a normally closed valve. With this configuration, when the power to the liquid ejection device is turned off, the recovery valve automatically closes the recovery passage. This prevents the recovery valve from being left open.

[0127] (H) In the above liquid discharge device, the adjustment valve may have a main body member connected to the second flow path and a valve member housed in the main body member, the main body member forming a supply chamber communicating with the storage portion, a pressure chamber communicating with the discharge portion, and a through-hole communicating with the supply chamber and the pressure chamber, the valve member opening the through-hole to open the second flow path, the supply portion connected to the first flow path upstream of the supply valve and a maintenance flow path connected to the second flow path upstream of the valve member, and the pump may be located upstream of the connection position with the maintenance flow path in the second flow path. This configuration makes it easier for the pump to flow liquid in the supply flow path and the recovery flow path. For example, the pump can supply liquid from the storage portion to the discharge portion through the supply flow path and circulate liquid through the supply flow path and the recovery flow path. [Explanation of symbols]

[0128] 11...liquid discharge device, 12...discharge portion, 13...nozzle surface, 14...nozzle, 15...storage portion, 16...storage body, 17...storage chamber, 18...outlet, 19...inlet, 20...partition member, 21...outlet chamber, 22...inlet chamber, 23...open pipe, 24...inlet pipe, 25...liquid level sensor, 26...supply portion, 27...supply flow path, 28...first flow path, 29...second flow path, 30...common portion , 31...first individual part, 32...second individual part, 33...maintenance flow path, 34...supply valve, 35...regulating valve, 36...main body member, 37...pressure chamber, 38...supply chamber, 39...through hole, 40...base member, 41...first cover member, 42...second cover member, 43...first connecting pipe, 44...second connecting pipe, 45...third connecting pipe, 46...fourth connecting pipe, 47...first recess, 48...second recess, 49...third recess, 50...fourth recess, 51...valve member, 52...pressure member, 53...membrane member, 54...opening / closing valve, 55...pump, 56...recovery flow path, 57...recovery valve, 61...maintenance part, 62...cap, 63...wiping part, 64...blade, 65...holder, 66...pressurizing part, 67...deformable member, 68...pressurizing chamber, 69...air chamber, 70...elastic Component, 71...waste liquid storage section, 72...first suction flow path, 73...second suction flow path, 74...third suction flow path, 75...first suction valve, 76...second suction valve, 77...third suction valve, 78...fourth suction valve, 79...suction pump, 80...first open flow path, 81...second open flow path, 82...first open valve, 83...second open valve, 84...pressure sensor, 90...control section, 100...liquid storage body.

Claims

1. a discharge unit having a nozzle surface on which nozzles are opened and configured to discharge liquid from the nozzles; a reservoir that stores a liquid; a supply unit that supplies liquid from the storage unit to the discharge unit, The supply unit includes: a supply flow path including a first flow path connected to the storage portion and the discharge portion, and a second flow path connected to the storage portion and the discharge portion; a supply valve located in the first flow path and configured to close the first flow path when power is off; a regulation valve located in the second flow path and configured to open the second flow path when the pressure in the discharge portion is equal to or lower than a predetermined pressure.

2. The liquid ejection device according to claim 1 , wherein the first flow path and the second flow path have a common portion that is a portion that is common to each other.

3. The liquid ejection device according to claim 2 , wherein the common portion is located downstream of the supply valve in the first flow path and downstream of the adjustment valve in the second flow path.

4. 2. The liquid ejection device according to claim 1, wherein the reservoir stores the liquid so that the liquid level is located below the nozzle surface.

5. 2. The liquid ejection device according to claim 1, wherein the supply valve is a normally closed valve.

6. The supply unit includes: a recovery flow path connected to the discharge portion and the storage portion; a pump that circulates liquid through the supply flow path and the recovery flow path; 6. The liquid ejection device according to claim 1, further comprising: a recovery valve positioned in the recovery passageway, the recovery valve closing the recovery passageway when the power is off.

7. 7. The liquid ejection device according to claim 6, wherein the recovery valve is a normally closed valve.

8. The adjusting valve is a body member connected to the second flow path; a valve member housed in the body member, The body member includes: a supply chamber communicating with the reservoir; a pressure chamber communicating with the discharge portion; a through-hole communicating with the supply chamber and the pressure chamber; the valve member opens the second flow path by opening the through-hole; the supply unit has a maintenance flow path connected to the first flow path upstream of the supply valve and connected to the second flow path upstream of the valve member, The liquid ejection device according to claim 6, wherein the pump is located upstream of a connection point between the second flow path and the maintenance flow path.

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