Liquid dispensing device

Abstract

The present invention provides a liquid dispensing device that simplifies the control required to pressurize the liquid dispensing head. [Solution] The liquid dispensing device comprises a liquid dispensing head for dispensing liquid, a liquid supply channel for supplying liquid to the liquid dispensing head, a first liquid chamber provided in the liquid supply channel, a second liquid chamber provided in the liquid supply channel, an air chamber to which air is supplied, and a pressure adjustment unit for adjusting the air pressure in the air chamber. The first liquid chamber is located upstream of the liquid dispensing head. The second liquid chamber is located upstream of the liquid dispensing head and downstream of the first liquid chamber. The air chamber has a first air chamber to which the pressure adjustment unit is connected, a second air chamber, and a first resistance channel connected to the first air chamber and the second air chamber. The first liquid chamber has a first flexible member that can open and close the liquid supply channel by deforming in accordance with the pressure in the first air chamber. The second liquid chamber has a second flexible member that deforms in accordance with the pressure in the second air chamber.

Description

[[Technical Field]]

[0001] The present invention relates to a liquid ejecting apparatus. [[Background Art]]

[0002] For example, as disclosed in Patent Document 1, there is disclosed a liquid ejecting apparatus including a liquid ejecting head having a nozzle surface in which nozzles for ejecting liquid are open. In such a liquid ejecting apparatus, cleaning is performed by wiping the nozzle surface while pressurizing the liquid ejecting head. In such a case, a flexible member is provided in a flow path that supplies liquid to the liquid ejecting head, and the liquid ejecting head is pressurized by switching a valve to adjust the air pressure applied to the flexible member, which is controlled accordingly. [[Prior Art Literature]] [[Patent Literature]]

[0003] [[Patent Document 1]] Japanese Patent Application Laid-Open No. 2016-68299 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] However, in such a liquid ejecting apparatus, control for pressurizing the liquid ejecting head has been complicated. [[Means for Solving the Problem]]

[0005] A liquid dispensing device that solves the above problems comprises a liquid dispensing head for dispensing liquid, a liquid supply channel for supplying liquid to the liquid dispensing head, a first liquid chamber provided in the liquid supply channel, a second liquid chamber provided in the liquid supply channel, an air chamber for which air is supplied, and a pressure adjustment unit for adjusting the air pressure in the air chamber, wherein the first liquid chamber is located upstream of the liquid dispensing head in the supply direction for supplying liquid to the liquid dispensing head, the second liquid chamber is located upstream of the liquid dispensing head in the supply direction and downstream of the first liquid chamber in the supply direction, the air chamber has a first air chamber to which the pressure adjustment unit is connected, a second air chamber, and a first resistance channel connected to the first air chamber and the second air chamber, the first liquid chamber has a first flexible member that can open and close the liquid supply channel by deforming in accordance with the pressure in the first air chamber, and the second liquid chamber has a second flexible member that deforms in accordance with the pressure in the second air chamber. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 is a schematic diagram showing a liquid dispensing device according to the first embodiment. [Figure 2] Figure 2 is a top view showing the head unit of the first embodiment. [Figure 3] Figure 3 is a top view showing the head unit of the first embodiment. [Figure 4] Figure 4 is a top view showing the head unit of the first embodiment. [Figure 5] Figure 5 is a rear view showing the head unit of the first embodiment. [Figure 6] Figure 6 is a schematic diagram showing the negative pressure release section of the first embodiment. [Figure 7] Figure 7 is a flowchart showing the cleaning control process of the first embodiment. [Figure 8] Figure 8 is a schematic diagram showing the negative pressure release section of the second embodiment. [Modes for carrying out the invention]

[0007] [First Embodiment] The following describes one embodiment of a liquid dispensing device. In the following description, the direction intersecting the vertical direction Z is referred to as the width direction X, and the direction intersecting both the vertical direction Z and the width direction X is referred to as the front-rear direction Y. The vertical direction Z corresponds to an example of the first direction. One direction along the width direction X is referred to as the first width direction X1, and the other direction along the width direction X is referred to as the second width direction X2. One direction along the front-rear direction Y is referred to as the front Y1, and the other direction along the front-rear direction Y is referred to as the rear Y2. The upper part of the vertical direction Z is referred to as the upper Z1, and the lower part of the vertical direction Z is referred to as the lower Z2. A top view seen from the upper Z1 is simply referred to as a top view.

[0008] <Configuration of liquid dispensing device 11> As shown in Figure 1, the liquid ejection device 11 prints on the medium 99 by ejecting liquid onto the medium 99. The liquid ejection device 11 may also be an inkjet printer that ejects ink, which is an example of a liquid, onto the medium 99.

[0009] The liquid dispensing device 11 includes a head unit 12. The head unit 12 is a unit for dispensing liquid. The head unit 12 includes a liquid dispensing head 13 and a supply unit 14. In other words, the liquid dispensing device 11 includes a liquid dispensing head 13 and a supply unit 14.

[0010] The liquid dispensing head 13 is configured to dispense liquid. The liquid dispensing head 13 is capable of dispensing liquid into a medium 99 that is transported by a transport unit (not shown). The liquid dispensing head 13 comprises at least one nozzle 15 and a nozzle surface 16. The nozzle 15 opens onto the nozzle surface 16. The liquid dispensing head 13 dispenses liquid from the nozzle 15. The nozzle surface 16 is the surface facing the medium 99. The nozzle surface 16 is the surface facing the dispensing direction E. The dispensing direction E is the direction in which the liquid dispensing head 13 dispenses liquid. The dispensing direction E is downward Z2, but may be inclined with respect to the vertical direction Z. Thus, the liquid dispensing head 13 is configured to dispense liquid in the dispensing direction E.

[0011] The liquid discharge head 13 is a line head, but it may also be a serial head. A line head is a head that extends in the width direction of the medium 99. The width direction of the medium 99 corresponds to the longitudinal direction of the liquid discharge head 13. The width direction of the medium 99 may also be the width direction X. The width direction of the medium 99 is the direction that intersects the discharge direction E. A line head is a head that discharges liquid simultaneously across the width direction of the medium 99. A serial head is a head that scans the width direction of the medium 99 and discharges liquid at the same time.

[0012] The supply unit 14 is configured to supply liquid to the liquid discharge head 13. The supply unit 14 may be located above the liquid discharge head 13 at Z1. The supply unit 14 may be detachable from the liquid discharge head 13.

[0013] The supply unit 14 includes a liquid supply channel 17, a hydraulic pressure regulating valve 18, and a negative pressure release unit 19. The liquid supply channel 17 is a channel that supplies liquid from the liquid storage unit 21 (described later) to the liquid discharge head 13.

[0014] The hydraulic pressure regulating valve 18 is located upstream of the negative pressure release section 19 in the supply direction D. The supply direction D is the direction in which liquid is supplied from the liquid storage section 21 (described later) to the liquid discharge head 13. The hydraulic pressure regulating valve 18 adjusts the pressure of the liquid supplied to the liquid discharge head 13 to a regulated pressure that can be discharged from the nozzle 15. The hydraulic pressure regulating valve 18 is a valve mechanism for maintaining negative pressure in the nozzle 15. The hydraulic pressure regulating valve 18 is a differential pressure valve. The hydraulic pressure regulating valve 18 is also called a pressure reducing valve or a self-sealing valve.

[0015] The negative pressure release unit 19 is located upstream of the liquid discharge head 13 in the supply direction D. The negative pressure release unit 19 is located downstream of the hydraulic pressure regulating valve 18 in the supply direction D. The negative pressure release unit 19 may also be provided to release the negative pressure in the nozzle 15 and discharge a predetermined amount of liquid from the liquid discharge head 13 when cleaning the liquid discharge head 13.

[0016] The supply unit 14 includes a gas supply channel 20. The gas supply channel 20 is a channel to which gas is supplied. When gas is supplied from the gas supply channel 20 to the negative pressure release unit 19, liquid is supplied from the negative pressure release unit 19 to the liquid ejection head 13. In other words, the gas supply channel 20 is an example of a channel for supplying liquid to the liquid ejection head 13.

[0017] The liquid ejection apparatus 11 may include a liquid storage unit 21, a first supply channel 22, and a supply pump 23. The liquid storage unit 21 can store liquid to be supplied to the liquid ejection head 13. The liquid storage unit 21 may be an ink tank attached to the liquid ejection apparatus 11, or may be an ink cartridge detachably mountable to the liquid ejection apparatus 11.

[0018] The first supply channel 22 has an upstream end in the supply direction D connected to the liquid storage unit 21. The first supply channel 22 allows liquid to flow out from the liquid storage unit 21. The first supply channel 22 has a downstream end in the supply direction D connected to the head unit 12.

[0019] More specifically, the first supply channel 22 has a downstream end in the supply direction D connected to the supply unit 14. The first supply channel 22 has a downstream end in the supply direction D connected to the liquid supply channel 17. The first supply channel 22 supplies the liquid stored in the liquid storage unit 21 to the liquid ejection head 13. In other words, the first supply channel 22 is an example of a supply channel for supplying liquid to the liquid ejection head 13.

[0020] The supply pump 23 is provided in the first supply channel 22. The supply pump 23 supplies liquid from the liquid storage unit 21 to the liquid ejection head 13. The supply pump 23 may be, for example, any one of a diaphragm pump, a tube pump, a gear pump, and a piston pump.

[0021] The liquid ejection apparatus 11 includes an air pressure adjustment unit 24 and a second supply channel 25. The air pressure adjustment unit 24 is configured to adjust the air pressure in the negative pressure release unit 19. The air pressure adjustment unit 24 can pressurize the negative pressure release unit 19.

[0022] The upstream end of the second supply channel 25 is connected to the pressure adjustment unit 24. The second supply channel 25 allows gas to flow out from the pressure adjustment unit 24. The downstream end of the second supply channel 25 is connected to the head unit 12.

[0023] More specifically, the downstream end of the second supply channel 25 is connected to the supply unit 14. The downstream end of the second supply channel 25 is connected to the upstream end of the gas supply channel 20. The second supply channel 25 supplies gas from the pressure adjustment unit 24 to the negative pressure release unit 19. Thus, the second supply channel 25 is a channel that supplies gas for supplying liquid to the liquid discharge head 13. In other words, the second supply channel 25 is an example of a supply channel for supplying liquid to the liquid discharge head 13.

[0024] The liquid dispensing device 11 includes a wiping section 26. The wiping section 26 is configured to wipe the nozzle surface 16. The wiping section 26 may also be configured to wipe the nozzle surface 16 after liquid has been dispensed during cleaning of the liquid dispensing head 13.

[0025] The wiping unit 26 comprises a main body 27 and a wiping member 28. The wiping member 28 is provided on the main body 27 so as to face in the opposite direction to the discharge direction E. The main body 27 may be movable in the width direction X. The wiping member 28 wipes the nozzle surface 16 by moving the main body 27 in the width direction X while in contact with the nozzle surface 16.

[0026] The liquid dispensing device 11 includes a control unit 29. The control unit 29 controls the liquid dispensing device 11. In particular, the control unit 29 controls the head unit 12. More specifically, the control unit 29 controls the liquid dispensing head 13. The control unit 29 controls the supply pump 23. The control unit 29 controls the pressure adjustment unit 24.

[0027] The control unit 29 may consist of one or more processors that perform various processes according to a computer program. The control unit 29 may consist of one or more dedicated hardware circuits. The control unit 29 may consist of an application-specific integrated circuit that performs at least some of the various processes. The control unit 29 may consist of a circuit that includes a combination of processors and hardware circuits. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to perform processes. Memory, i.e., computer-readable media, includes any readable media that can be accessed by a general-purpose or dedicated computer.

[0028] <Configuration of head unit 12> As shown in Figure 2, the liquid dispensing device 11 includes a relay substrate unit 30. The relay substrate unit 30 is configured such that its length is in the width direction X relative to the front-to-back direction Y. The relay substrate unit 30 is configured to extend in the longitudinal direction of the liquid dispensing head 13.

[0029] The relay board unit 30 is detachable from the head unit 12. The relay board unit 30 is detachable from the head unit 12 with multiple wiring sections 33, which will be described later, connected to it. The relay board unit 30 can be mounted on the rear Y2 side of the liquid discharge head 13. The supply section 14 is provided on the front Y1 side of the liquid discharge head 13.

[0030] The relay board unit 30 is a unit for supplying electrical signals from the control unit 29 to the liquid discharge head 13. The relay board unit 30 may also be a unit for supplying electrical signals from the liquid discharge head 13 to the control unit 29.

[0031] The relay board unit 30 comprises a relay board 31 and a relay board case 32, as shown in Figure 3, which will be described later. In other words, the liquid dispensing device 11 comprises a relay board 31 and a relay board case 32.

[0032] The relay board case 32 is a component that houses the relay board 31. The relay board case 32 may be made of resin. The relay board case 32 may cover the relay board 31 from at least the upper Z1 side. Therefore, the relay board 31 can be attached to and detached from the head unit 12 while covered by the relay board case 32 and with the multiple wiring sections 33 described later attached.

[0033] In other words, the relay board unit 30 can be handled together with the multiple wiring sections 33, which will be described later, attached. In particular, the relay board unit 30 can be temporarily placed together with the multiple wiring sections 33, which will be described later, attached.

[0034] The liquid dispensing device 11 includes a plurality of wiring sections 33. The plurality of wiring sections 33 may be provided in the width direction X, on the second width direction X2 side of the center of the relay board unit 30. The plurality of wiring sections 33 are components for supplying electrical signals from the control unit 29 to the liquid dispensing head 13. The plurality of wiring sections 33 may also be components for supplying electrical signals from the liquid dispensing head 13 to the control unit 29. The plurality of wiring sections 33 may also be flexible flat cables.

[0035] Multiple wiring sections 33 may be detachable from the relay board unit 30. Multiple wiring sections 33 may be detachable from the head unit 12 via the relay board unit 30. In other words, multiple wiring sections 33 may be detachable from the head unit 12.

[0036] As shown in Figure 3, the relay substrate 31 is configured such that its length is in the width direction X relative to the front-to-back direction Y. The relay substrate 31 is configured to extend in the longitudinal direction of the liquid discharge head 13. The relay substrate 31 is located rearward Y2 from the supply unit 14.

[0037] The relay board 31 is detachable from the head unit 12. The relay board 31 can be mounted on the rear Y2 side of the liquid discharge head 13. In a top view, the relay board 31 can be mounted on the rear Y2 side of the liquid discharge head 13, which is opposite to the area where the supply unit 14 is provided.

[0038] The relay board 31 is a board for supplying electrical signals from the control unit 29 to the liquid discharge head 13. The relay board 31 may also be a board for supplying electrical signals from the liquid discharge head 13 to the control unit 29.

[0039] The relay board unit 30 includes a wiring connector 34. The relay board unit 30 may include multiple wiring connectors 34. The wiring connector 34 is provided on the upper surface of the relay board 31. The wiring connector 34 is provided on the rear Y2 side of the relay board 31. Multiple wiring connectors 34 may be provided on the second width direction X2 side of the center of the relay board 31 in the width direction X. Multiple wiring sections 33 can be connected to each of the multiple wiring connectors 34. In this way, multiple wiring sections 33 can be attached to and detached from the relay board 31 via the multiple wiring connectors 34. The wiring connector 34 is a connector for driving the liquid discharge head 13.

[0040] The relay board unit 30 includes a relay board connector 35. The relay board unit 30 may include multiple relay board connectors 35. The relay board connector 35 is provided on the bottom surface of the relay board 31. The relay board connector 35 is provided on the front Y1 side of the relay board 31. The relay board connector 35 is connectable to the head board connector 37 of the head board 36. In other words, the relay board 31 is detachable from the head unit 12 via the relay board connector 35 and the head board connector 37. Multiple relay board connectors 35 may be arranged in a line in the width direction X. The relay board connector 35 is a connector for driving the liquid discharge head 13.

[0041] As shown in Figure 4, the head unit 12 includes a head substrate 36. The head substrate 36 is located above the liquid discharge head 13 at a position Z1. The head substrate 36 is configured such that its length is in the width direction X relative to the front-to-back direction Y. The head substrate 36 is configured to extend in the longitudinal direction of the liquid discharge head 13. The head substrate 36 is a substrate for controlling the liquid discharge head 13.

[0042] The head unit 12 includes a head board connector 37. The head unit 12 may have multiple head board connectors 37. The head board connector 37 is provided on the upper surface of the head board 36.

[0043] The head board connector 37 is connectable to the relay board connector 35. The head board connector 37 is a connector for driving the liquid discharge head 13. The head board connector 37 transmits electrical signals from the control unit 29 to the head board 36 via the relay board connector 35.

[0044] The supply unit 14 includes a flow path joint 40. In other words, the head unit 12 includes a flow path joint 40. The flow path joint 40 is provided at the end of the supply unit 14 in the first width direction X1, but may also be provided at the end in the second width direction X2.

[0045] The flow path joint 40 is configured to open downward Z2, but may be configured to open in any direction. The flow path joint 40 is a joint for supplying liquid and gas to the supply unit 14. The flow path joint 40 can connect to the downstream end of the supply flow path.

[0046] The flow path fitting 40 may include a liquid flow path fitting 41. In other words, the head unit 12 may include a liquid flow path fitting 41. The liquid flow path fitting 41 is a fitting for connecting the liquid supply flow path 17 and the first supply flow path 22. The liquid flow path fitting 41 can connect to the downstream end of the first supply flow path 22. The liquid flow path fitting 41 may be detachable from the tube that constitutes the lower end of the first supply flow path 22.

[0047] When the first supply channel 22 is connected to the liquid channel fitting 41, it is positioned along the longitudinal direction Y. When the first supply channel 22 is connected to the liquid channel fitting 41, it may also be positioned to extend forward Y1.

[0048] Therefore, when the first supply channel 22 is connected to the liquid channel fitting 41, it is positioned in a location that does not overlap with the liquid discharge head 13 when viewed from above. When the first supply channel 22 is connected to the liquid channel fitting 41, it is positioned in a location that does not overlap with the relay board 31 and the multiple wiring sections 33 when viewed from above.

[0049] In other words, when viewed from above, the multiple wiring sections 33 do not overlap with the first supply channel 22 connected to the liquid flow path fitting 41 at the position where they overlap with the liquid discharge head 13 when mounted on the head unit 12. The multiple wiring sections 33 do not intersect with the first supply channel 22 connected to the liquid flow path fitting 41 when mounted on the head unit 12.

[0050] When viewed from above, the relay board 31, when mounted on the head unit 12, does not overlap with the first supply channel 22 connected to the liquid flow path connector 41 at a position where it overlaps with the liquid discharge head 13. The relay board 31 does not intersect with the first supply channel 22 connected to the liquid flow path connector 41 when mounted on the head unit 12.

[0051] The flow path joint 40 may include a gas flow path joint 42. In other words, the head unit 12 may include a gas flow path joint 42. The gas flow path joint 42 is a joint for connecting the gas supply flow path 20 and the second supply flow path 25. The gas flow path joint 42 can connect to the downstream end of the second supply flow path 25. The gas flow path joint 42 may be detachable from the tube that constitutes the lower end of the second supply flow path 25.

[0052] When the second supply channel 25 is connected to the gas flow joint 42, it is positioned along the longitudinal direction Y. When the second supply channel 25 is connected to the gas flow joint 42, it may also be positioned to extend forward Y1.

[0053] Therefore, when the second supply channel 25 is connected to the gas flow path joint 42, it is positioned in a location that does not overlap with the liquid discharge head 13 when viewed from above. When the second supply channel 25 is connected to the gas flow path joint 42, it is positioned in a location that does not overlap with the relay substrate 31 and the multiple wiring sections 33 when viewed from above.

[0054] In other words, when viewed from above, the multiple wiring sections 33 do not overlap with the second supply channel 25 connected to the gas flow path coupling 42 at the position where they overlap with the liquid discharge head 13 when mounted on the head unit 12. The multiple wiring sections 33 do not intersect with the second supply channel 25 connected to the gas flow path coupling 42 when mounted on the head unit 12.

[0055] When viewed from above, the relay board 31, when mounted on the head unit 12, does not overlap with the second supply channel 25 connected to the gas flow path coupling 42 at the position where it overlaps with the liquid discharge head 13. The relay board 31 does not intersect with the second supply channel 25 connected to the gas flow path coupling 42 when mounted on the head unit 12.

[0056] The supply unit 14 includes an introduction section 43. In other words, the head unit 12 includes an introduction section 43. The introduction section 43 is the part for introducing liquid and gas from the flow path coupling 40 into the supply unit 14. More specifically, the introduction section 43 is the part for introducing liquid from the liquid flow path coupling 41 into the supply unit 14. The introduction section 43 is the part for introducing gas from the gas flow path coupling 42 into the supply unit 14. The introduction section 43 includes the upstream part of the liquid supply flow path 17 and the upstream part of the gas supply flow path 20.

[0057] As shown in Figure 3, the supply unit 14 is positioned so as to overlap a portion of the liquid discharge head 13 when viewed from above. The relay substrate 31 is positioned so as to overlap a portion of the liquid discharge head 13 when viewed from above.

[0058] When the relay board 31 is mounted on the head unit 12, it is positioned in a region that overlaps with a portion of the liquid discharge head 13 when viewed from above, but does not overlap with the supply unit 14. In addition, when the multiple wiring sections 33 are mounted on the head unit 12, they are positioned in a region that overlaps with the liquid discharge head 13 when viewed from above, but do not overlap with the supply unit 14.

[0059] In particular, the supply unit 14 and the relay board 31 are arranged so as to straddle the first virtual line VL1 when viewed from above. The first virtual line VL1 is a virtual line that runs along the width direction X. In other words, the first virtual line VL1 is a virtual line that extends in the longitudinal direction of the liquid discharge head 13.

[0060] The relay board connector 35 and the supply unit 14 are positioned to straddle the first virtual line VL1 when viewed from above. In other words, as shown in Figure 4, the head board connector 37 and the supply unit 14 are positioned to straddle the first virtual line VL1 when viewed from above. This makes it possible to miniaturize the head unit 12.

[0061] In particular, the air chamber 53 of the negative pressure release section 19, which will be described in detail later, and the head board connector 37 are positioned to straddle the first virtual line VL1 when viewed from above. In other words, the air chamber 53 and the relay board connector 35 are positioned to straddle the first virtual line VL1 when viewed from above.

[0062] The supply unit 14 and the head board connector 37 are positioned so as to straddle the second virtual line VL2 when viewed from above. The second virtual line VL2 is a virtual line that runs along the front-rear direction Y. In other words, the second virtual line VL2 is a virtual line that extends in a direction intersecting the longitudinal direction of the liquid discharge head 13.

[0063] As shown in Figure 5, the hydraulic pressure regulating valve 18 is located in front of the head board connector 37 at Y1. In other words, as shown in Figure 4, the relay board connector 35, the head board connector 37, and the hydraulic pressure regulating valve 18 are arranged so as to straddle the second virtual line VL2 in a top view. This makes it possible to miniaturize the head unit 12.

[0064] As shown in Figure 5, in the supply unit 14, the hydraulic pressure regulating valve 18 and the negative pressure release unit 19 are arranged side by side in the width direction X. In particular, in the supply unit 14, the air chamber 53 of the negative pressure release unit 19 is positioned so as to overlap with at least a portion of the hydraulic pressure regulating valve 18 when viewed from the longitudinal direction. The hydraulic pressure regulating valve 18 is located inside the negative pressure release unit 19 in the width direction X.

[0065] The negative pressure release section 19 is provided so as to be higher by a height H than the hydraulic pressure regulating valve 18 in the vertical direction Z. The hydraulic pressure regulating valve 18 may be provided so as to be higher than the negative pressure release section 19 in the vertical direction Z. The hydraulic pressure regulating valve 18 and the negative pressure release section 19 may be provided so as to be at the same height in the vertical direction Z.

[0066] The gas flow passage coupling 42 opens downward Z2. The gas flow passage coupling 42 is positioned higher than the inlet 43. The lower end of the second supply passage 25 is connected to the gas flow passage coupling 42 from the downward Z2 side. When connected to the gas flow passage coupling 42, the second supply passage 25 is routed forward Y1 so as to curve downward Z2.

[0067] The liquid flow passage joint 41 opens downward Z2. The liquid flow passage joint 41 is positioned higher than the inlet 43. This prevents liquid from dripping from the liquid flow passage joint 41 when the lower end of the first supply passage 22 is removed from the liquid flow passage joint 41.

[0068] The lower end of the first supply channel 22 is connected to the liquid channel fitting 41 from the downward Z2 side. When connected to the liquid channel fitting 41, the first supply channel 22 is routed forward Y1 so as to curve downward Z2.

[0069] As a result, the first supply channel 22 can be removed from the liquid channel fitting 41 with its lower end facing upward Z1. Therefore, when removing the lower end of the first supply channel 22 from the liquid channel fitting 41, it is possible to prevent liquid from dripping from the lower end of the first supply channel 22.

[0070] In addition, the intermediate board 31 and the multiple wiring sections 33 are not located below Z2 of the liquid flow path joint 41. In particular, the multiple wiring connectors 34, intermediate board connector 35, and head board connector 37 are not located below Z2 of the liquid flow path joint 41, thereby improving safety.

[0071] <Configuration of the negative pressure release unit 19> As shown in Figure 6, the negative pressure release unit 19 comprises a first liquid chamber 51, a second liquid chamber 52, and an air chamber 53. The first liquid chamber 51 is provided in the liquid supply channel 17. The first liquid chamber 51 is provided upstream of the liquid discharge head 13 in the liquid supply channel 17. The first liquid chamber 51 is provided downstream of the hydraulic pressure regulating valve 18 in the liquid supply channel 17. In other words, the hydraulic pressure regulating valve 18 is provided upstream of the first liquid chamber 51.

[0072] The first liquid chamber 51 includes a first flexible member 61. The first flexible member 61 is elastic. The first flexible member 61 is an elastic resin member, but it can be made of any material, and may be an elastic film.

[0073] The first flexible member 61 deforms in response to the pressure in the first air chamber 71, which will be described later. The first flexible member 61 deforms in conjunction with the deformation of the third flexible member 63, which will be described later. The first flexible member 61 is pressed and deformed by the pressing member 65, which will be described later, in conjunction with the deformation of the third flexible member 63.

[0074] The first flexible member 61 comprises a first surface 61A and a second surface 61B. The first surface 61A and the second surface 61B are surfaces that intersect with the vertical direction Z. The first surface 61A is the surface facing the first liquid chamber 51. The first surface 61A is the surface that receives the liquid pressure from the first liquid chamber 51. The second surface 61B is the surface facing the first air chamber 71, which will be described later.

[0075] The first flexible member 61 can open and close the liquid supply channel 17 by deforming. In response to the pressurization of the first air chamber 71, the first flexible member 61 bends toward the first liquid chamber 51 against the biasing force from the biasing member 64 (described later), thereby closing the first liquid chamber 51. In response to the cessation of pressurization of the first air chamber 71, the first flexible member 61 returns to a non-bending position, thereby opening the first liquid chamber 51.

[0076] The first liquid chamber 51 is equipped with a biasing member 64. The biasing member 64 may be provided between the first surface 61A of the first flexible member 61 and the inner wall surface 51A of the first liquid chamber 51. The biasing member 64 biases the first flexible member 61 toward the first air chamber 71. In this way, the biasing member 64 can speed up the opening response of the first liquid chamber 51.

[0077] The second liquid chamber 52 is provided in the liquid supply channel 17. The second liquid chamber 52 is provided upstream of the liquid discharge head 13 in the liquid supply channel 17. The second liquid chamber 52 is provided downstream of the first liquid chamber 51 in the liquid supply channel 17. The capacity of the second liquid chamber 52 may be corresponding to the amount of liquid used for cleaning.

[0078] The second liquid chamber 52 includes a second flexible member 62. The second flexible member 62 is elastic. The second flexible member 62 is an elastic resin member, but it can be made of any material, and may be an elastic film.

[0079] The second flexible member 62 deforms in response to the pressure in the second air chamber 72, which will be described later. The second flexible member 62 pressurizes the second liquid chamber 52 by bending toward the second liquid chamber 52 in response to the pressurization of the second air chamber 72. The second flexible member 62 depressurizes the second liquid chamber 52 by returning to a non-bending position when the pressurization of the second air chamber 72 stops.

[0080] The second flexible member 62 comprises a first surface 62A and a second surface 62B. The first surface 62A and the second surface 62B are surfaces that intersect with the vertical direction Z. The first surface 62A is the surface facing the second liquid chamber 52. The first surface 62A is the surface that receives the liquid pressure from the second liquid chamber 52. The second surface 62B is the surface facing the second air chamber 72, which will be described later. The second surface 62B is the surface that receives the atmospheric pressure from the second air chamber 72.

[0081] The hardness of the second flexible member 62 is greater than the hardness of the first flexible member 61. In other words, the hardness of the first flexible member 61 is less than or equal to the hardness of the second flexible member 62. The hardness of the second flexible member 62 may be less than the hardness of the first flexible member 61, or it may be the same as the hardness of the first flexible member 61.

[0082] The air chamber 53 is connected to the pressure adjustment unit 24. More specifically, the air chamber 53 is connected to the downstream end of the first air passage 81, which will be described later. Air is supplied to the air chamber 53 from the pressure adjustment unit 24. The supply of air from the pressure adjustment unit 24 to the air chamber 53 enables the negative pressure release unit 19 to be driven.

[0083] The air chamber 53 comprises a first air chamber 71, a second air chamber 72, and a communication channel 73. The pressure adjustment unit 24 is connected to the first air chamber 71. More specifically, the downstream end of the first air channel 81, which will be described later, is connected to the first air chamber 71. The first air chamber 71 is a region for deforming the first flexible member 61. The first air chamber 71 may be provided in a position that overlaps with the first liquid chamber 51 in the vertical direction Z. The first air chamber 71 may be provided coaxially with the first liquid chamber 51 in the vertical direction Z.

[0084] The first air chamber 71 includes a third flexible member 63. The first air chamber 71 may also include a pressing member 65. The third flexible member 63 is elastic. The third flexible member 63 may be an elastic resin member. The third flexible member 63 deforms in response to the pressure in the first air chamber 71. The third flexible member 63 is a member for deforming the first flexible member 61.

[0085] The third flexible member 63 comprises a first surface 63A and a second surface 63B. The first surface 63A and the second surface 63B are surfaces that intersect with the vertical direction Z. The first surface 63A is the surface on the first flexible member 61 side. The first surface 63A may also be the surface facing the first surface 61A of the first flexible member 61. The second surface 63B is the surface on the pressure adjustment section 24 side. The second surface 63B is the surface that receives pressure from the first air chamber 71.

[0086] The diameter of the third flexible member 63 is larger than the diameter of the first flexible member 61. In other words, the diameter of the first flexible member 61 is smaller than the diameter of the third flexible member 63, but it may be larger than the diameter of the third flexible member 63, or it may be the same as the diameter of the third flexible member 63. The pressure-receiving area of ​​the first flexible member 61 is smaller than that of the third flexible member 63.

[0087] The third flexible member 63 may be provided so as to be centered on the same axis as the first flexible member 61 in the vertical direction Z. In other words, the first flexible member 61 and the third flexible member 63 may be provided so as to be centered on the same axis in the vertical direction Z. To put it another way, at least a part of the first flexible member 61 may be provided so as to overlap with the third flexible member 63 when viewed from above.

[0088] The third flexible member 63 may include a retaining portion 63C. The retaining portion 63C may be configured to protrude downward Z2 from the first surface 63A. The retaining portion 63C is configured to hold the pressing member 65. The retaining portion 63C may have a recess for holding the pressing member 65.

[0089] The pressing member 65 is provided between the first flexible member 61 and the third flexible member 63. The pressing member 65 has a pressing surface 65A. The pressing surface 65A is the surface facing downward Z2. The pressing surface 65A is the surface facing the first flexible member 61. The pressing surface 65A is in contact with the second surface 61B of the first flexible member 61.

[0090] The pressing member 65 is provided with a protruding portion 65B. The protruding portion 65B may be configured to protrude upward Z1. The protruding portion 65B may be configured to protrude toward the third flexible member 63. The protruding portion 65B may be configured to protrude toward the holding portion 63C. The protruding portion 65B is held by the holding portion 63C of the third flexible member 63.

[0091] As a result, the pressing member 65 moves in the vertical direction Z as the third flexible member 63 deforms. The pressing member 65 moves downward Z2 as the third flexible member 63 bends downward Z2. In this case, the pressing member 65 presses the first flexible member 61 downward Z2, causing the first flexible member 61 to bend downward Z2.

[0092] The pressing member 65 moves upward Z1 as the third flexible member 63 returns to a position where it does not bend. In this case, the pressing member 65 returns to a position where the first flexible member 61 does not bend as the downward Z2 pressing on the first flexible member 61 is released.

[0093] The second air chamber 72 is configured to communicate with the first air chamber 71 via a communication channel 73. The second air chamber 72 is a region for deforming the second flexible member 62. The volume of the second air chamber 72 is larger than the volume of the first air chamber 71, but may be smaller than the volume of the first air chamber 71, or it may be the same as the volume of the first air chamber 71.

[0094] The communication channel 73 is connected to the first air chamber 71 and the second air chamber 72. The communication channel 73 includes a first resistance channel 74. That is, the first resistance channel 74 is connected to the first air chamber 71 and the second air chamber 72. The first resistance channel 74 is a channel that provides resistance to the gas flow in the communication channel 73. The first resistance channel 74 slows down the gas flow between the first air chamber 71 and the second air chamber 72.

[0095] The pressure adjustment unit 24 is configured to adjust the pressure in the air chamber 53. The pressure adjustment unit 24 includes a pump 80, a first air passage 81, a second air passage 82, a regulator 83, an atmospheric release passage 84, and an atmospheric release valve 85.

[0096] Pump 80 is a pressurizing pump that pressurizes the air chamber 53. Pump 80 is located at the upstream end of the first air passage 81. The downstream end of the first air passage 81 is connected to the air chamber 53. The first air passage 81 is a passage that connects pump 80 and the air chamber 53.

[0097] The second air passage 82 is a passage for adjusting the pressure in the air chamber 53. A regulator 83 is connected to the upstream end of the second air passage 82. The downstream end of the second air passage 82 is connected to the first air passage 81. The downstream end of the second air passage 82 is connected between the pump 80 and the air chamber 53 in the first air passage 81. The regulator 83 adjusts the pressure in the air chamber 53. The regulator 83 is controlled by the control unit 29 to adjust the pressure in the air chamber 53.

[0098] The atmospheric venting channel 84 is a channel for opening the first air channel 81 to the atmosphere. The downstream end of the atmospheric venting channel 84 is connected to the first air channel 81. The downstream end of the atmospheric venting channel 84 is connected between the pump 80 and the air chamber 53.

[0099] The atmospheric release passage 84 includes an atmospheric release valve 85. The atmospheric release valve 85 is provided in the atmospheric release passage 84. The atmospheric release valve 85 is controlled to open and close by the control unit 29. The atmospheric release passage 84 includes a second resistance passage 86. The second resistance passage 86 is provided upstream of the atmospheric release valve 85 in the atmospheric release passage 84. The resistance of the second resistance passage 86 is less than the resistance of the first resistance passage 74. In other words, the resistance of the first resistance passage 74 is greater than the resistance of the second resistance passage 86.

[0100] <Cleaning process> The cleaning process will now be explained with reference to Figure 7. The cleaning process is executed by the control unit 29 when the cleaning conditions are met. The cleaning conditions are met when the liquid discharge head 13 is to be cleaned.

[0101] The cleaning condition may be met when a nozzle failure of the liquid ejection head 13 is detected. The cleaning condition may be met based on the number of printed pages. The cleaning condition may be met when a predetermined time has elapsed. The cleaning condition may be met at predetermined intervals. The cleaning condition may be met in response to user instructions.

[0102] As shown in Figure 7, in step S11, the control unit 29 performs the process of closing the atmospheric release valve. In this process, the control unit 29 closes the atmospheric release valve 85. As a result, the air chamber 53 is not opened to the atmosphere.

[0103] In step S12, the control unit 29 performs a pump drive process. In this process, the control unit 29 drives the pump 80. As a result, the air chamber 53 is pressurized while the air chamber 53 is not open to the atmosphere.

[0104] In this manner, the first air chamber 71 is pressurized in the negative pressure release section 19 by the drive of the pump 80. When the first air chamber 71 is pressurized, the third flexible member 63 bends toward the first flexible member 61, and the pressing member 65 moves toward the first flexible member 61. As a result, the first flexible member 61 bends toward the first liquid chamber 51, closing the liquid supply passage 17.

[0105] In particular, the first flexible member 61 has a smaller pressure-receiving area than the third flexible member 63. Therefore, the third flexible member 63 is more flexible than the first flexible member 61, which can speed up the closing response of the first liquid chamber 51.

[0106] When the first air chamber 71 is pressurized by the operation of the pump 80, the second air chamber 72 is also pressurized via the communication channel 73. When the second air chamber 72 is pressurized, the second flexible member 62 bends toward the second liquid chamber 52, pressurizing the liquid supply channel 17.

[0107] In particular, the second air chamber 72 is pressurized later than the first air chamber 71 by the first resistance channel 74 provided in the communication channel 73. The second air chamber 72 has a larger volume than the first air chamber 71. The hardness of the second flexible member 62 is greater than that of the first flexible member 61.

[0108] Therefore, the second flexible member 62 is less flexible than the first flexible member 61. As a result, the second liquid chamber 52 is pressurized after the liquid supply channel 17 is closed by the first flexible member 61. Therefore, by properly pressurizing the second liquid chamber 52, an appropriate amount of liquid is supplied to the liquid discharge head 13.

[0109] In step S13, the control unit 29 performs a wiping process. In this process, the control unit 29 adjusts to maintain the air pressure in the air chamber 53. More specifically, the control unit 29 may control the pump 80 to maintain the air pressure in the air chamber 53 using a check valve built into the pump 80. This maintains the air pressure in the air chamber 53 when the air chamber 53 is not open to the atmosphere.

[0110] Subsequently, the control unit 29 controls the wiping unit 26 to wipe the nozzle surface 16. This ensures that any liquid remaining on the nozzle surface 16 after cleaning is wiped away by the wiping unit 26.

[0111] In step S14, the control unit 29 executes a pump stop process. In this process, the control unit 29 stops the drive of the pump 80. In step S15, the control unit 29 performs an atmospheric release valve opening process. In this process, the control unit 29 opens the atmospheric release valve 85. As a result, the air chamber 53 is opened to the atmosphere.

[0112] In this way, when the pump 80 is stopped and the first air chamber 71 is opened to the atmosphere in the negative pressure release section 19, the pressure in the first air chamber 71 is reduced. When the pressure in the first air chamber 71 is reduced, the third flexible member 63 returns to a position where it does not bend, and the pressing member 65 moves in the opposite direction to the first flexible member 61. As a result, the first flexible member 61 receives the liquid pressure from the first liquid chamber 51, returns to a position where it does not bend, and opens the liquid supply passage 17.

[0113] In particular, the first flexible member 61 has a smaller pressure-receiving area than the third flexible member 63. Therefore, self-choking of the liquid supply channel 17 can be suppressed. In addition, the first flexible member 61 returns to a position where it does not bend even when biased by the biasing member 64. Therefore, the opening response of the first liquid chamber 51 can be accelerated.

[0114] When the pressure in the first air chamber 71 is reduced, the pressure in the second air chamber 72 is also reduced via the communication channel 73. When the pressure in the second air chamber 72 is reduced, the second flexible member 62 returns to its non-flexible position, reducing the pressure in the liquid supply channel 17.

[0115] In particular, the second air chamber 72 is depressurized later than the first air chamber 71 by the first resistance channel 74 provided in the communication channel 73. The second air chamber 72 has a larger volume than the first air chamber 71. The hardness of the second flexible member 62 is greater than that of the first flexible member 61.

[0116] Therefore, the second flexible member 62 is less likely to return to a position that is less flexible than the first flexible member 61. As a result, the second liquid chamber 52 is depressurized after the liquid supply channel 17 is opened by the first flexible member 61. Therefore, by appropriately depressurizing the second liquid chamber 52, the meniscus of the nozzle 15 can be brought to an appropriate state.

[0117] <Operation and Effects of the First Embodiment> The operation and effects of the first embodiment will now be described. (1-1) Conventionally, the control for pressurizing the liquid discharge head 13 has become complicated. Therefore, in this embodiment, the air chamber 53 includes a first air chamber 71 to which the pressure adjustment unit 24 is connected, a second air chamber 72, and a first resistance flow path 74 connected to the first air chamber 71 and the second air chamber 72. The first liquid chamber 51 includes a first flexible member 61 that can open and close the liquid supply flow path 17 by deforming in accordance with the pressure of the first air chamber 71. The second liquid chamber 52 includes a second flexible member 62 that deforms in accordance with the pressure of the second air chamber 72.

[0118] With this configuration, the first resistance channel 74 can improve the reliability of deforming the first flexible member 61 in response to the pressure in the first air chamber 71 before deforming the second flexible member 62 in response to the pressure in the second air chamber 72. Therefore, the control for pressurizing the liquid discharge head 13 can be simplified.

[0119] In addition, the deformation timing of the first flexible member 61 and the deformation timing of the second flexible member 62 can be adjusted without the need for a configuration that controls the pressure in the first air chamber 71 and the second air chamber 72, respectively. Therefore, space can be saved. In particular, by simplifying the configuration of the pressure adjustment unit 24, such as the number of valves, the number of parts can be reduced, and space and weight can be reduced.

[0120] It is possible to control both the air pressure in the first air chamber 71 and the air pressure in the second air chamber 72. Therefore, the number of second supply channels 25 connected to the head unit 12 can also be reduced.

[0121] (1-2) The liquid dispensing device 11 includes a biasing member 64 that biases the first flexible member 61 toward the first air chamber 71. This configuration improves the reliability of the deformation of the first flexible member 61 from a position where it is bent toward the first liquid chamber 51 to a position where it is not bent, and also speeds up the response of the deformation of the first flexible member 61 to the position where it is not bent.

[0122] (1-3) The first air chamber 71 includes a third flexible member 63 that deforms in accordance with the pressure in the first air chamber 71. The first flexible member 61 deforms in accordance with the deformation of the third flexible member 63. The diameter of the first flexible member 61 is smaller than the diameter of the third flexible member 63. With this configuration, the first flexible member 61 can be deformed in accordance with the deformation of the third flexible member 63, which has a larger diameter than the first flexible member 61. Therefore, by using a third flexible member 63 with a large pressure-receiving area from the first air chamber 71, the certainty of deformation of the first flexible member 61 can be improved, and the response of deformation of the first flexible member 61 can be accelerated.

[0123] (1-4) In a top view, at least a portion of the first flexible member 61 overlaps with the third flexible member 63. With this configuration, the first flexible member 61 can be efficiently deformed in conjunction with the deformation of the third flexible member 63, and space can be saved.

[0124] (1-5) The first flexible member 61 and the third flexible member 63 are arranged so as to be centered on the same axis when viewed from above. With this configuration, the first flexible member 61 can be deformed more efficiently in conjunction with the deformation of the third flexible member 63, and space can be saved.

[0125] (1-6) The hardness of the first flexible member 61 is less than or equal to the hardness of the second flexible member 62. With this configuration, the response of deformation of the first flexible member 61 can be made faster than that of the second flexible member 62. Therefore, the certainty of deformation of the first flexible member 61 before deformation of the second flexible member 62 can be improved.

[0126] (1-7) The volume of the second air chamber 72 is larger than the volume of the first air chamber 71. With this configuration, the response of the first flexible member 61 to deform faster than that of the second flexible member 62 can be increased. Therefore, the certainty of deforming the first flexible member 61 before deforming the second flexible member 62 can be improved.

[0127] (1-8) The pressure adjustment unit 24 includes a pump 80, a first air passage 81 connecting the pump 80 and the first air chamber 71, and an atmospheric release passage 84 for opening the first air passage 81 to the atmosphere. The atmospheric release passage 84 includes an atmospheric release valve 85 and a second resistance passage 86 upstream of the atmospheric release valve 85. With this configuration, the speed at which the first air chamber 71 is opened to the atmosphere can be reduced. This makes it possible to reduce the speed at which the first flexible member 61 returns to a non-flexible position and the second flexible member 62 returns to a non-flexible position. Therefore, the meniscus of the nozzle 15 can be brought to an appropriate state.

[0128] (1-9) The resistance of the first resistive channel 74 is greater than the resistance of the second resistive channel 86. With this configuration, the response of the first flexible member 61 to deform faster than that of the second flexible member 62 can be increased. Therefore, the certainty of deforming the first flexible member 61 before deforming the second flexible member 62 can be improved.

[0129] (1-10) In the supply direction D, a hydraulic pressure regulating valve 18 is provided upstream of the first liquid chamber 51. With this configuration, pressurization can be applied to the liquid discharge head 13 between the hydraulic pressure regulating valve 18 and the liquid discharge head 13.

[0130] (1-11) The air chamber 53 is positioned so as to overlap with at least a portion of the hydraulic pressure regulating valve 18 when viewed from the longitudinal direction. This configuration allows for efficient arrangement of the air chamber 53 and the hydraulic pressure regulating valve 18. Therefore, space can be saved.

[0131] (1-12) The air chamber 53 and the relay board connector 35 and head board connector 37 for driving the liquid discharge head 13 are positioned to straddle the first virtual line VL1 extending in the longitudinal direction when viewed from above. This configuration allows for efficient arrangement of the air chamber 53, the relay board connector 35 and the head board connector 37. Therefore, space can be saved.

[0132] (2-1) Conventionally, when performing maintenance on the liquid discharge head 13, it has been desirable to improve the workability of removing the multiple wiring sections 33. Therefore, when the multiple wiring sections 33 are attached to the head unit 12, they do not overlap with the supply flow path connected to the flow path fitting 40 at the position where they overlap with the liquid discharge head 13. With this configuration, when performing maintenance on the liquid discharge head 13, the removal of the multiple wiring sections 33 from the head unit 12 and the removal of the supply flow path from the flow path fitting 40 can be performed independently. Thus, workability can be improved.

[0133] (2-2) The relay board 31 is detachable from the head unit 12. Multiple wiring sections 33 are detachable from the relay board 31. In a top view, when the relay board 31 is mounted on the head unit 12, it does not overlap with the supply channel connected to the flow path fitting 40 at the position where it overlaps with the liquid discharge head 13. With this configuration, when performing maintenance on the liquid discharge head 13, the relay board 31 can be removed from the head unit 12 and the supply channel can be removed from the flow path fitting 40 independently. Therefore, work efficiency can be improved.

[0134] In addition, by removing the relay board 31 from the head unit 12, multiple wiring sections 33 can be removed from the head unit 12. Therefore, workability can be improved.

[0135] (2-3) In a top view, the relay board 31 does not overlap with the supply unit 14 for supplying liquid to the liquid discharge head 13 at the position where it overlaps with the liquid discharge head 13. With this configuration, the relay board 31, on which multiple wiring units 33 are attached, can be handled so as not to overlap with the supply unit 14. As a result, when attaching or detaching the relay board 31 from the head unit 12, the relay board 31 can be handled without colliding with the supply unit 14. Therefore, workability can be improved.

[0136] (2-4) The relay board 31 and the supply unit 14 are positioned to straddle the first virtual line VL1, which extends in the longitudinal direction, when viewed from above. This configuration allows for efficient arrangement of the relay board 31 and the supply unit 14. Therefore, space can be saved.

[0137] (2-5) The head unit 12 includes a flow path coupling 40, which includes a liquid flow path coupling 41 that can be attached to the downstream end of the first supply flow path 22, and a gas flow path coupling 42 that can be attached to the downstream end of the second supply flow path 25. With this configuration, even when the first supply flow path 22 is connected to the liquid flow path coupling 41 and the second supply flow path 25 is connected to the gas flow path coupling 42, workability can be improved.

[0138] [Second Embodiment] Next, a second embodiment will be described. In the following description, redundant explanations of the same configuration as in the previously described embodiment will be omitted or simplified, and configurations that differ from those in the previously described embodiment will be described.

[0139] As shown in Figure 8, in the second embodiment, the communication passage 73 may have different flow resistances in the passage from the first air chamber 71 to the second air chamber 72 and in the passage from the second air chamber 72 to the first air chamber 71. The communication passage 73 may have a one-way valve 75 provided in a passage parallel to the first resistance passage 74. The one-way valve 75 is configured to allow gas to flow out from the first air chamber 71 to the second air chamber 72. In other words, gas may flow from the first air chamber 71 to the second air chamber 72 without passing through the first resistance passage 74, while gas may flow from the second air chamber 72 to the first air chamber 71 via the first resistance passage 74. This allows for appropriate adjustment of the gas flow between the first air chamber 71 and the second air chamber 72. The one-way valve 75 may be configured on the same plane as the first resistance passage 74.

[0140] [Example of changes] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0141] In the second embodiment, the one-way valve 75 may be configured to discharge gas from the second air chamber 72 to the first air chamber 71. That is, the gas may be configured to flow from the second air chamber 72 to the first air chamber 71 without passing through the first resistive passage 74, while the gas may flow from the first air chamber 71 to the second air chamber 72 via the first resistive passage 74.

[0142] The control unit 29 may control the regulator 83 to adjust the pressure in the air chamber 53. For example, in step S13, the control unit 29 may stop the pump 80 from running and control the regulator 83 to maintain the air pressure in the air chamber 53. The regulator 83 may be the same valve as the atmospheric release valve 85. In other words, the regulator 83 may be equipped with a mechanism for releasing to the atmosphere.

[0143] The negative pressure release unit 19 is configured to be driven by pressurization from the pump 80, but is not limited to this configuration. For example, the negative pressure release unit 19 may be configured to be driven by depressurization from the pump 80.

[0144] The negative pressure release unit 19 may be configured to pressurize the hydraulic pressure regulating valve 18. In the liquid dispensing device 11, the hydraulic pressure regulating valve 18 does not have to be located upstream of the negative pressure release unit 19. The liquid dispensing device 11 does not have to include the hydraulic pressure regulating valve 18.

[0145] The diameter of the first flexible member 61 may be smaller than the diameter of the second flexible member 62. The diameter of the first flexible member 61 may be larger than the diameter of the second flexible member 62. The diameter of the first flexible member 61 may be the same as the diameter of the second flexible member 62.

[0146] The multiple wiring sections 33 may be made of any wiring material other than a flexible flat cable. The multiple wiring sections 33 may also be USB (Universal Serial Bus) cables. The flow path fitting 40 may include either a liquid flow path fitting 41 or a gas flow path fitting 42. The liquid flow path fitting 41 only needs to be able to connect to at least one first supply flow path 22. The gas flow path fitting 42 only needs to be able to connect to at least one second supply flow path 25.

[0147] A lateral printer may be used as the liquid ejection device 11. A lateral printer is a printer in which the carriage on which the liquid ejection head 13 is mounted is movable in two directions: the width direction X and the front-to-back direction Y. The liquid ejection head 13 may be configured to eject liquid at an angle with respect to the up-and-down direction Z.

[0148] The medium 99 may be any material, such as paper, rolls, resin films or sheets, resin-metal composite films, laminate films, textiles, nonwoven fabrics, metal foils, metal films, ceramic sheets, and clothing.

[0149] The liquid can be any liquid that can be applied to the medium 99 and used for printing on the medium 99. The liquid may be a dye ink, such as a disperse dye ink or a reactive dye ink. For example, the ink may include a mixture of functional material particles consisting of solids such as pigments or metal particles dissolved, dispersed, or mixed in a solvent, and shall encompass various compositions such as water-based inks, oil-based inks, gel inks, and hot-melt inks.

[0150] As used herein, the expression "at least one of" means one or more of the desired options. For example, as used herein, if there are two options, the expression "at least one of" means either one option or both of the two options. As another example, as used herein, if there are three or more options, the expression "at least one of" means either one option or any combination of two or more options.

[0151] [Note] The technical concepts and their effects, as understood from the embodiments and modifications described above, are outlined below. These technical concepts and their effects can be combined with each other to the extent that they do not contradict each other.

[0152] [1-1] The liquid dispensing device comprises a liquid dispensing head for dispensing liquid, a liquid supply channel for supplying liquid to the liquid dispensing head, a first liquid chamber provided in the liquid supply channel, a second liquid chamber provided in the liquid supply channel, an air chamber for which air is supplied, and a pressure adjustment unit for adjusting the pressure of the air chamber, wherein the first liquid chamber is located upstream of the liquid dispensing head in the supply direction for supplying liquid to the liquid dispensing head, the second liquid chamber is located upstream of the liquid dispensing head in the supply direction and downstream of the first liquid chamber in the supply direction, the air chamber has a first air chamber to which the pressure adjustment unit is connected, a second air chamber, and a first resistance channel connected to the first air chamber and the second air chamber, the first liquid chamber has a first flexible member that can open and close the liquid supply channel by deforming in accordance with the pressure of the first air chamber, and the second liquid chamber has a second flexible member that deforms in accordance with the pressure of the second air chamber.

[0153] This configuration improves the reliability of deforming the first flexible member in response to the pressure in the first air chamber before deforming the second flexible member in response to the pressure in the second air chamber, thanks to the first resistance flow path. Therefore, the control for pressurizing the liquid discharge head can be simplified.

[0154] In addition, the deformation timing of the first flexible member and the deformation timing of the second flexible member can be adjusted without the need for a configuration that controls the pressure in the first air chamber and the second air chamber separately. Therefore, space can be saved.

[0155] [1-2] The liquid dispensing device described above may include a biasing member that biases the first flexible member toward the first air chamber. This configuration improves the reliability of the deformation of the first flexible member from a position where it is bent toward the first liquid chamber to a position where it is not bent, and also speeds up the response time for the deformation of the first flexible member to the position where it is not bent.

[0156] [1-3] The liquid dispensing device described above, wherein the first air chamber has a third flexible member that deforms in accordance with the pressure of the first air chamber, the first flexible member deforms in accordance with the deformation of the third flexible member, and the diameter of the first flexible member may be smaller than the diameter of the third flexible member.

[0157] With this configuration, the first flexible member can be deformed in conjunction with the deformation of the third flexible member, which has a larger diameter than the first flexible member. Therefore, by using a third flexible member with a larger pressure-receiving area from the first air chamber, the certainty of deformation of the first flexible member can be improved, and the response of deformation of the first flexible member can be accelerated.

[0158] [1-4] In the liquid dispensing device described above, at least a portion of the first flexible member may overlap with the third flexible member when viewed from a first direction intersecting the first surface of the first flexible member.

[0159] This configuration allows for efficient deformation of the first flexible member in conjunction with the deformation of the third flexible member, while also saving space. [1-5] In the above liquid dispensing device, the first flexible member and the third flexible member may be provided so as to be centered on the same axis in the first direction.

[0160] With this configuration, the deformation of the third flexible member allows for more efficient deformation of the first flexible member, while also saving space. [1-6] In the above liquid dispensing device, the hardness of the first flexible member may be less than or equal to the hardness of the second flexible member.

[0161] This configuration allows for a faster response time for the deformation of the first flexible member compared to the second flexible member. Therefore, it is possible to improve the certainty of deforming the first flexible member before deforming the second flexible member.

[0162] [1-7] In the above-mentioned liquid dispensing device, the volume of the second air chamber may be greater than the volume of the first air chamber. This configuration allows for a faster response time for the deformation of the first flexible member compared to the second flexible member. Therefore, it is possible to improve the certainty of deforming the first flexible member before deforming the second flexible member.

[0163] [1-8] The liquid discharge device described above, wherein the pressure adjustment unit includes a pump, a first air passage connecting the pump and the first air chamber, and an atmospheric release passage for opening the first air passage to the atmosphere, and the atmospheric release passage may include an atmospheric release valve and a second resistance passage upstream of the atmospheric release valve.

[0164] This configuration allows the speed at which the first air chamber is released to the atmosphere to be reduced. This reduces the speed at which the first flexible member returns to its non-flexible position, and also reduces the speed at which the second flexible member returns to its non-flexible position. Therefore, the nozzle meniscus can be kept in an appropriate state.

[0165] [1-9] In the above-described liquid dispensing device, the resistance of the first resistive channel may be greater than the resistance of the second resistive channel. This configuration allows for a faster response time for the deformation of the first flexible member compared to the second flexible member. Therefore, it is possible to improve the certainty of deforming the first flexible member before deforming the second flexible member.

[0166] [1-10] The above liquid dispensing device may include a liquid pressure regulating valve provided upstream of the first liquid chamber in the supply direction. With this configuration, pressurization can be applied to the liquid discharge head between the hydraulic pressure regulating valve and the liquid discharge head.

[0167] [1-11] In the above-described liquid discharge device, the liquid discharge head is a line head extending in the longitudinal direction, and the air chamber may be provided in a position that overlaps with at least a part of the hydraulic pressure regulating valve when viewed from the longitudinal direction.

[0168] This configuration allows for the efficient arrangement of the air chamber and the hydraulic pressure regulating valve. Therefore, space can be saved. [1-12] The liquid dispensing device described above comprises a circuit board having a connector for driving the liquid dispensing head, wherein the liquid dispensing head is a line head that dispenses liquid in the dispensing direction and extends in a longitudinal direction intersecting the dispensing direction, and the air chamber and the connector may be positioned to straddle a virtual line extending in the longitudinal direction when viewed from the dispensing direction.

[0169] This configuration allows for efficient placement of the air chamber and connector, thus enabling space savings. [2-1] The liquid dispensing device comprises a head unit having a liquid dispensing head for dispensing liquid in the dispensing direction, and a plurality of wiring units that are detachable from the head unit and supply electrical signals to the liquid dispensing head, wherein the head unit has a flow path joint to which the downstream end of a supply flow path for supplying liquid to the liquid dispensing head can be connected, the liquid dispensing head is a line head extending in a longitudinal direction intersecting the dispensing direction, and when viewed from the dispensing direction, the plurality of wiring units, when mounted on the head unit, do not overlap with the supply flow path connected to the flow path joint at positions that overlap with the liquid dispensing head.

[0170] With this configuration, when viewed from the discharge direction, the multiple wiring components attached to the head unit and the supply flow path connected to the flow path fitting do not overlap at the position where they overlap with the liquid discharge head. Therefore, when performing maintenance on the liquid discharge head, the removal of the multiple wiring components from the head unit and the removal of the supply flow path from the flow path fitting can be performed independently. Thus, work efficiency can be improved.

[0171] [2-2] The liquid dispensing device described above includes a relay board that is detachable from the head unit and to which the plurality of wiring sections are detachable, and when viewed from the dispensing direction, the relay board does not have to overlap with the supply channel connected to the flow path joint at a position that overlaps with the liquid dispensing head when mounted on the head unit.

[0172] With this configuration, when viewed from the discharge direction, the relay board attached to the head unit and the supply channel connected to the flow path fitting do not overlap at the position where they overlap with the liquid discharge head. Therefore, when performing maintenance on the liquid discharge head, the relay board can be removed from the head unit and the supply channel can be removed from the flow path fitting independently. In addition, by removing the relay board from the head unit, multiple wiring components can be removed from the head unit. Thus, work efficiency can be improved.

[0173] [2-3] In the above-described liquid dispensing device, the head unit has a supply unit for supplying liquid to the liquid dispensing head, the supply unit has a flow path joint, and the relay substrate does not have to overlap with the supply unit at a position that overlaps with the liquid dispensing head when viewed from the dispensing direction.

[0174] This configuration allows the relay board, which has multiple wiring sections attached, to be handled in a way that prevents it from overlapping with the supply section. This makes it possible to handle the relay board without colliding with the supply section when attaching or detaching it from the head unit. Therefore, work efficiency can be improved.

[0175] [2-4] In the above-described liquid dispensing device, the relay substrate and the supply unit may be positioned to straddle a virtual line extending in the longitudinal direction when viewed from the dispensing direction. This configuration allows for efficient placement of the relay board and the supply unit, thus enabling space savings.

[0176] [2-5] In the above-described liquid discharge device, the flow path joint is a liquid flow path joint that is detachable from the downstream end of a first supply flow path that supplies liquid to the liquid discharge head, and the head unit may have a gas flow path joint that is detachable from the downstream end of a second supply flow path that supplies gas for supplying liquid to the liquid discharge head.

[0177] This configuration improves workability even when the first supply channel is connected to a liquid channel fitting and the second supply channel is connected to a gas channel fitting. [Explanation of Symbols]

[0178] 11...Liquid dispensing device, 12...Head unit, 13...Liquid dispensing head, 14...Supply unit, 15...Nozzle, 16...Nozzle surface, 17...Liquid supply channel, 18...Liquid pressure regulating valve, 19...Negative pressure release unit, 20...Gas supply channel, 21...Liquid storage unit, 22...First supply channel, 23...Supply pump, 24...Pressure regulating unit, 25...Second supply channel, 26...Wiping unit, 27...Main body, 28...Wiping member, 29 ...control unit, 30...intermediate board unit, 31...intermediate board, 32...intermediate board case, 33...wiring section, 34...wiring connector, 35...intermediate board connector, 36...head board, 37...head board connector, 40...flow path joint, 41...liquid flow path joint, 42...gas flow path joint, 43...inlet section, 51...first liquid chamber, 51A...inner wall surface, 52...second liquid chamber, 53...air chamber, 61...first flexible member, 61A...First surface, 61B...Second surface, 62...Second flexible member, 62A...First surface, 62B...Second surface, 63...Third flexible member, 63A...First surface, 63B...Second surface, 63C...Holding part, 64...Biasing member, 65...Pressing member, 65A...Pressing surface, 65B...Protruding part, 71...First air chamber, 72...Second air chamber, 73...Communicating passage, 74...First resistance passage, 75...One-way valve, 80...Pump, 81...First 1 Air passage, 82... Second air passage, 83... Regulator, 84... Atmospheric release passage, 85... Atmospheric release valve, 86... Second resistance passage, 99... Medium, D... Supply direction, E... Discharge direction, H... Height, VL1... First virtual line, VL2... Second virtual line, X... Width direction, X1... First width direction, X2... Second width direction, Y... Front-back direction, Y1... Front, Y2... Rear, Z... Up-down direction, Z1... Up, Z2... Down.

Claims

1. A liquid dispensing head that dispenses liquid, A liquid supply channel for supplying liquid to the liquid discharge head, A first liquid chamber provided in the liquid supply channel, A second liquid chamber provided in the liquid supply channel, An air chamber into which air is supplied, A pressure adjustment unit that adjusts the air pressure in the aforementioned air chamber, Equipped with, The first liquid chamber is located upstream of the liquid discharge head in the supply direction for supplying liquid to the liquid discharge head, The second liquid chamber is located upstream of the liquid discharge head in the supply direction and downstream of the first liquid chamber in the supply direction. The air chamber comprises a first air chamber to which the pressure adjustment unit is connected, a second air chamber, and a first resistance flow path connected to the first air chamber and the second air chamber. The first liquid chamber has a first flexible member that can open and close the liquid supply channel by deforming in accordance with the pressure of the first air chamber. The second liquid chamber has a second flexible member that deforms in accordance with the pressure of the second air chamber. A liquid dispensing device characterized by the following features.

2. A liquid dispensing device according to claim 1, The first flexible member is provided with a biasing member that biases it toward the first air chamber. A liquid dispensing device characterized by the following features.

3. A liquid dispensing device according to claim 1, The first air chamber has a third flexible member that deforms in accordance with the pressure in the first air chamber. The first flexible member deforms in accordance with the deformation of the third flexible member. The diameter of the first flexible member is smaller than the diameter of the third flexible member. A liquid dispensing device characterized by the following features.

4. A liquid dispensing device according to claim 3, Viewed from a first direction intersecting the first surface of the first flexible member, at least a portion of the first flexible member overlaps with the third flexible member. A liquid dispensing device characterized by the following features.

5. A liquid dispensing device according to claim 4, The first flexible member and the third flexible member are provided so as to be centered on the same axis in the first direction. A liquid dispensing device characterized by the following features.

6. A liquid dispensing device according to claim 1, The hardness of the first flexible member is less than or equal to the hardness of the second flexible member. A liquid dispensing device characterized by the following features.

7. A liquid dispensing device according to claim 1, The volume of the second air chamber is greater than the volume of the first air chamber. A liquid dispensing device characterized by the following features.

8. A liquid dispensing device according to any one of claims 1 to 7, The aforementioned pressure adjustment unit is Pump and A first air passage connecting the pump and the first air chamber, The first air passage is provided with an atmospheric vent passage for opening it to the atmosphere, The aforementioned atmospheric opening channel is Atmospheric release valve, A second resistance flow path is provided upstream of the aforementioned atmospheric release valve, A liquid dispensing device characterized by the following features.

9. A liquid dispensing device according to claim 8, The resistance of the first resistive channel is greater than the resistance of the second resistive channel. A liquid dispensing device characterized by the following features.

10. A liquid dispensing device according to any one of claims 1 to 7, The system includes a hydraulic pressure regulating valve provided upstream of the first liquid chamber in the supply direction. A liquid dispensing device characterized by the following features.

11. A liquid dispensing device according to claim 10, The liquid discharge head is a line head that extends in the longitudinal direction, The air chamber is provided in a position that overlaps with at least a portion of the hydraulic pressure regulating valve when viewed from the longitudinal direction. A liquid dispensing device characterized by the following features.

12. A liquid dispensing device according to any one of claims 1 to 7, The circuit board includes a connector for driving the liquid discharge head, The liquid discharge head discharges liquid in the discharge direction and is a line head that extends in a longitudinal direction intersecting the discharge direction. The air chamber and the connector are positioned to straddle a virtual line extending in the longitudinal direction when viewed from the discharge direction. A liquid dispensing device characterized by the following features.

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