Liquid ejection device and control method for liquid ejection device

Abstract

To provide a liquid ejection device that is able to grasp a failure in a pressure adjusting valve in an early stage, and to provide a control method for the liquid ejection device.SOLUTION: A liquid ejection device includes: a discharge unit having a nozzle surface in which a nozzle is open, and configured to discharge liquid from the nozzle; a supply flow passage connected to the discharge unit and configured to supply the liquid to the discharge unit; a pressure adjusting valve located in the supply flow passage and configured to adjust a pressure in the discharge unit; a pressurizing unit configured to pressurize the liquid located upstream of the pressure adjusting valve in the supply flow passage; a detection unit configured to detect that the liquid is overflowing from the nozzle; and a control unit. The pressure adjusting valve is configured to open the supply flow passage in a case where the pressure in the discharge unit is equal to or lower than a predetermined pressure. The control unit pressurizes the liquid in the supply flow passage by the pressuring unit and, in a case where the detection unit detects that the liquid is overflowing from the nozzle with the pressurizing unit pressurizing the liquid, notifies that a failure in the pressure adjusting valve may have been arising.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection apparatus and a method for controlling the liquid ejection apparatus. [Background technology]

[0002] Patent Document 1 describes a liquid discharge device that includes a discharge portion that discharges liquid and a pressure adjustment valve that adjusts the pressure inside the discharge portion. The pressure adjustment valve opens when the pressure inside the discharge portion drops. When the pressure adjustment valve opens, liquid is supplied to the discharge portion through the pressure adjustment valve. When liquid is supplied to the discharge portion, the pressure inside the discharge portion rises. This causes the pressure adjustment valve to close. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-86535 Summary of the Invention [Problem to be solved by the invention]

[0004] In such liquid ejection devices, the pressure adjustment valve may malfunction. When a malfunction occurs in the pressure adjustment valve, the ejection performance of the ejection section is affected. Therefore, it is preferable to be able to detect a malfunction in the pressure adjustment valve early. [Means for solving the problem]

[0005] A liquid ejection device that solves the above problem comprises an ejection section having a nozzle surface where a nozzle opens and ejecting liquid from the nozzle, a supply flow path connected to the ejection section and supplying liquid to the ejection section, a pressure adjustment valve located in the supply flow path and adjusting the pressure within the ejection section, a pressurizing section that pressurizes liquid located upstream of the pressure adjustment valve in the supply flow path, a detection section that detects liquid overflowing from the nozzle, and a control section, wherein the pressure adjustment valve is configured to open the supply flow path when the pressure within the ejection section falls below a predetermined pressure, and the control section pressurizes the liquid in the supply flow path using the pressurizing section, and when the detection section detects liquid overflowing from the nozzle while the pressurizing section is pressurizing the liquid, reports that there may be a malfunction in the pressure adjustment valve.

[0006] A control method for 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 supply flow path connected to the ejection section and supplying liquid to the ejection section, a pressure adjustment valve located in the supply flow path and adjusting the pressure in the ejection section by opening the supply flow path when the pressure in the ejection section falls below a predetermined pressure, a pressurizing section that pressurizes liquid located upstream of the pressure adjustment valve in the supply flow path, and a detection section that detects liquid overflowing from the nozzle, the control method including pressurizing the liquid in the supply flow path with the pressurizing section, and reporting that there may be a malfunction in the pressure adjustment valve when the detection section detects that liquid is overflowing from the nozzle while the pressurizing section is pressurizing the liquid. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing an embodiment of a liquid ejection device. [Figure 2] FIG. 2 is a flowchart of the inspection process. [Figure 3] FIG. 3 is a flowchart of the cleaning unit inspection. [Figure 4]Figure 4 is a flowchart of the electrical inspection. [Figure 5] FIG. 5 is a flowchart of the nozzle recovery test. [Figure 6] Figure 6 is a flowchart of the pressure regulating valve inspection. DETAILED DESCRIPTION OF THE INVENTION

[0008] 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.

[0009] <Liquid discharge device> 1, the liquid ejection device 11 includes an ejection unit 12. The ejection unit 12 is configured to eject a liquid onto a medium 99. The ejection unit 12 records an image on the medium 99 by ejecting the liquid onto the medium 99.

[0010] The ejection unit 12 has a nozzle surface 13. The nozzle surface 13 is a surface that faces the medium 99. One or more nozzles 14 are opened in the nozzle surface 13. The ejection unit 12 ejects liquid from the nozzles 14.

[0011] The ejection section 12 forms one or more liquid chambers 15. The ejection section 12 forms the same number of liquid chambers 15 as the nozzles 14. The liquid chambers 15 are spaces within the ejection section 12. The liquid chambers 15 communicate with the nozzles 14. The ejection section 12 is configured so that liquid is supplied to the liquid chambers 15 from the outside.

[0012] The ejection section 12 has a vibration plate 16. The vibration plate 16 forms part of the wall surface that defines the liquid chamber 15. The vibration plate 16 faces the liquid chamber 15. The vibration plate 16 is configured to be deformable. The vibration plate 16 deforms so as to change the volume of the liquid chamber 15. The deformation of the vibration plate 16 pressurizes the liquid located in the liquid chamber 15. This causes the liquid to be ejected from the nozzle 14.

[0013] The ejection section 12 has an actuator 17. The actuator 17 is attached to the vibration plate 16. More specifically, the actuator 17 is attached to one of the two surfaces of the vibration plate 16 opposite the surface facing the liquid chamber 15.

[0014] The actuator 17 is configured to deform the diaphragm 16. The actuator 17 bends when a voltage is applied. After bending, the actuator 17 returns to its original shape. As the actuator 17 bends, the diaphragm 16 deforms. More specifically, when the bent actuator 17 returns to its original shape, the diaphragm 16 bends so as to pressurize the liquid in the liquid chamber 15. The ejection unit 12 ejects liquid from the nozzle 14 by the actuator 17 deforming the diaphragm 16.

[0015] The ejection unit 12 has a drive circuit 18. The drive circuit 18 is a circuit that drives the actuator 17. The drive circuit 18 drives the actuator 17 by applying a voltage to the actuator 17. More specifically, the drive circuit 18 drives the actuator 17 by inputting a predetermined drive waveform to the actuator 17. The drive circuit 18 can generate various drive waveforms, such as a drive waveform that drives the actuator 17 so as to eject liquid from the nozzle 14, and a drive waveform that drives the actuator 17 to such an extent that liquid is not ejected from the nozzle 14.

[0016] The liquid ejection device 11 includes a supply unit 21. The supply unit 21 is configured to supply liquid to the ejection unit 12. The supply unit 21 is connected to the ejection unit 12. The supply unit 21 supplies liquid toward the liquid chamber 15.

[0017] The supply unit 21 has an attachment unit 22. The attachment unit 22 is configured to have a liquid container 100 attached thereto. The liquid container 100 is configured to contain liquid. The liquid container 100 is, for example, an ink cartridge. By attaching the liquid container 100 to the attachment unit 22, it becomes possible to supply liquid from the liquid container 100 to the ejection unit 12.

[0018] The supply unit 21 has a supply flow path 23. The supply flow path 23 is a flow path that supplies liquid to the discharge unit 12. The supply flow path 23 is connected to the discharge unit 12. The supply flow path 23 is connected to the attachment unit 22. The supply flow path 23 connects the discharge unit 12 and the attachment unit 22. In the supply flow path 23, liquid flows from the attachment unit 22 toward the discharge unit 12.

[0019] The supply unit 21 may have a storage unit instead of the mounting unit 22. The storage unit is a tank configured to store liquid. The supply flow path 23 may connect the ejection unit 12 and the storage unit. The storage unit is configured to be able to be replenished with liquid from the liquid container 100, for example.

[0020] The supply unit 21 has a pressure regulating valve 24. The pressure regulating valve 24 is located in the supply flow path 23. In one example, the pressure regulating valve 24 is located in the supply flow path 23 between the discharge unit 12 and the mounting unit 22.

[0021] The pressure regulating valve 24 is configured to open and close the supply flow path 23. When the pressure regulating valve 24 opens the supply flow path 23, liquid can be supplied from the mounting portion 22 to the discharge portion 12. When the pressure regulating valve 24 closes the supply flow path 23, the supply of liquid from the mounting portion 22 to the discharge portion 12 is cut off.

[0022] The pressure regulating valve 24 is configured to regulate the pressure inside the discharge portion 12. The pressure regulating valve 24 regulates the pressure inside the discharge portion 12 by opening and closing the supply flow path 23. More specifically, the pressure regulating valve 24 regulates the pressure in the liquid chamber 15.

[0023] The pressure regulating valve 24 is configured to open the supply flow path 23 when the pressure inside the discharge part 12 becomes equal to or lower than a predetermined pressure. The pressure regulating valve 24 adjusts the pressure inside the discharge part 12 to become equal to or lower than the predetermined pressure. The pressure regulating valve 24 adjusts the pressure inside the discharge part 12 to become a predetermined negative pressure. This causes a meniscus to be formed in the nozzle 14. By forming a meniscus in the nozzle 14, the discharge part 12 can appropriately discharge the liquid.

[0024] The pressure regulating valve 24 has a main body member 25. The main body member 25 forms a pressure chamber 26, a supply chamber 27, and a through-hole 28. The pressure chamber 26 is a space that communicates with the inside of the discharge portion 12. Therefore, the pressure of the pressure chamber 26 is approximately the same as the pressure of the liquid chamber 15. The pressure regulating valve 24 adjusts the pressure of the pressure chamber 26, thereby adjusting the pressure of the liquid chamber 15. The supply chamber 27 is a space located upstream of the pressure chamber 26. More specifically, the supply chamber 27 is a space located upstream of the pressure chamber 26 in the direction in which the liquid is supplied. The through-hole 28 is an opening that connects the pressure chamber 26 and the supply chamber 27. Liquid is supplied from the supply chamber 27 to the pressure chamber 26 through the through-hole 28. The pressure regulating valve 24 adjusts the pressure of the discharge portion 12 by opening and closing the through-hole 28.

[0025] The pressure regulating valve 24 has a valve member 29. The valve member 29 is housed in the main body member 25. The valve member 29 is positioned to pass through the through-hole 28. The valve member 29 is positioned across the pressure chamber 26 and the supply chamber 27. The valve member 29 is a valve that opens and closes the through-hole 28. When the valve member 29 opens the through-hole 28, liquid is supplied from the supply chamber 27 to the pressure chamber 26. In other words, when the valve member 29 opens the through-hole 28, the supply flow path 23 is opened. When the valve member 29 closes the through-hole 28, the supply flow path 23 is closed.

[0026] The pressure regulating valve 24 has a pressing member 30. The pressing member 30 is a member that presses the valve member 29. More specifically, the pressing member 30 presses the valve member 29 so that the valve member 29 closes the through-hole 28. The pressing member 30 is, for example, a spring. The pressing member 30 is housed in the main body member 25. The pressing member 30 is located in the supply chamber 27. The pressing member 30 presses the valve member 29 from the supply chamber 27 toward the pressure chamber 26.

[0027] The pressure regulating valve 24 has a membrane member 31. The membrane member 31 is flexible. The membrane member 31 is attached to the main body member 25. The membrane member 31 constitutes part of the wall surface that defines the pressure chamber 26. The membrane member 31 faces the pressure chamber 26. The membrane member 31 deforms in response to the pressure in the pressure chamber 26. That is, the membrane member 31 deforms in response to the pressure inside the discharge portion 12. More specifically, the membrane member 31 deforms in response to the pressure difference between the pressure in the pressure chamber 26 and atmospheric pressure. When the pressure in the pressure chamber 26 decreases, the membrane member 31 deforms so that the volume of the pressure chamber 26 decreases.

[0028] The membrane member 31 deforms to reduce the volume of the pressure chamber 26, thereby pressing the valve member 29. More specifically, the membrane member 31 presses the valve member 29 so that the valve member 29 opens the through-hole 28. The membrane member 31 presses the valve member 29 from the pressure chamber 26 toward the supply chamber 27. When the force with which the membrane member 31 presses the valve member 29 becomes greater than the force with which the pressing member 30 presses the valve member 29, the valve member 29 opens the through-hole 28. In this way, the pressure regulating valve 24 adjusts the pressure inside the discharge portion 12.

[0029] The supply unit 21 has a channel pump 32. The channel pump 32 is located in the supply channel 23. Specifically, the channel pump 32 is located upstream of the pressure adjustment valve 24 in the supply channel 23. The channel pump 32 is located between the attachment unit 22 and the pressure adjustment valve 24 in the supply channel 23. The channel pump 32 is, for example, a diaphragm pump. The channel pump 32 may also be a tube pump, a syringe pump, or the like. The channel pump 32 is configured to supply liquid from the attachment unit 22 toward the discharge unit 12.

[0030] The flow path pump 32 has a flexible member 33. The flexible member 33 is flexible. The flexible member 33 divides the inside of the flow path pump 32 into an air chamber 34 and a pump chamber 35. Air is stored in the air chamber 34. Liquid is stored in the pump chamber 35. The flexible member 33 deforms to pressurize the pump chamber 35. The flexible member 33 deforms to reduce the volume of the pump chamber 35, thereby pressurizing the pump chamber 35.

[0031] The flexible member 33 has a detection portion 36. The detection portion 36 extends so as to protrude toward the air chamber 34. The detection portion 36 is used to detect when the remaining amount of liquid is low. The detection portion 36 is detected by a remaining amount sensor 44, which will be described later.

[0032] The supply unit 21 may have a buffer 37. The buffer 37 is located in the supply flow path 23. Specifically, the buffer 37 is located in the supply flow path 23 between the flow path pump 32 and the pressure adjustment valve 24. The buffer 37 is configured to suppress a sudden change in pressure in the supply flow path 23 due to pressurization by the flow path pump 32.

[0033] The buffer 37 has a deformable member 38. The deformable member 38 is flexible. The deformable member 38 divides the buffer 37 into a storage chamber 39 and a buffer chamber 40. An elastic member 41, which will be described later, is stored in the storage chamber 39. The buffer chamber 40 stores a liquid. The deformable member 38 reduces pressure fluctuations in the supply flow path 23 by deforming. The deformable member 38 deforms so as to increase the volume of the buffer chamber 40, thereby preventing a sudden increase in pressure in the supply flow path 23.

[0034] The buffer 37 has an elastic member 41. The elastic member 41 is located in the storage chamber 39. The elastic member 41 presses the deformable member 38. The elastic member 41 presses the deformable member 38 so that the volume of the buffer chamber 40 decreases. This causes liquid to be supplied from the buffer 37 toward the pressure regulating valve 24. The elastic member 41 is, for example, a spring.

[0035] The supply unit 21 has an on-off valve 42. The on-off valve 42 is located in the supply flow path 23. Specifically, the on-off valve 42 is located upstream of the flow path pump 32 in the supply flow path 23. The on-off valve 42 is located between the attachment unit 22 and the flow path pump 32 in the supply flow path 23. The on-off valve 42 is configured to open and close the supply flow path 23. When the on-off valve 42 closes the supply flow path 23, the supply of liquid from the attachment unit 22 to the flow path pump 32 is cut off.

[0036] The supply unit 21 may have one or more one-way valves 43. In one example, the supply unit 21 has four one-way valves 43. The one-way valves 43 are located in the supply flow path 23. The one-way valves 43 are configured to allow liquid to flow from the attachment portion 22 toward the discharge portion 12, and not allow liquid to flow from the discharge portion 12 toward the attachment portion 22. The four one-way valves 43 are located in the supply flow path 23 between the attachment portion 22 and the on-off valve 42, between the on-off valve 42 and the flow path pump 32, between the flow path pump 32 and the buffer 37, and between the buffer 37 and the pressure adjustment valve 24, respectively.

[0037] The supply unit 21 has a remaining amount sensor 44. The remaining amount sensor 44 is configured to detect the remaining amount of liquid. The remaining amount sensor 44 detects the remaining amount of liquid in the supply unit 21. In one example, the remaining amount sensor 44 detects that the remaining amount of liquid in the liquid container 100 is very low.

[0038] The remaining amount sensor 44 is located within the flow path pump 32. More specifically, the remaining amount sensor 44 is located in the air chamber 34. The remaining amount sensor 44 is configured to detect the detection portion 36. The remaining amount sensor 44 detects that the remaining amount of liquid in the liquid container 100 is low based on the position of the detection portion 36. In one example, the on-off valve 42 closes, allowing the remaining amount sensor 44 to detect the remaining amount of liquid in the flow path pump 32 based on the position of the detection portion 36.

[0039] The remaining amount sensor 44 is an optical sensor. The remaining amount sensor 44 has a light-emitting element 45 and a light-receiving element 46. The light-emitting element 45 and the light-receiving element 46 are positioned to face each other. The light-emitting element 45 is configured to emit light toward the light-receiving element 46. The light-receiving element 46 is configured to receive the light emitted from the light-emitting element 45.

[0040] The remaining amount sensor 44 detects that the remaining amount of liquid is low when the light-receiving element 46 detects the light emitted by the light-emitting element 45. When the remaining amount of liquid in the pump chamber 35 is low, the detection portion 36 retracts from between the light-emitting element 45 and the light-receiving element 46. At this time, the light-receiving element 46 detects the light from the light-emitting element 45. When the remaining amount of liquid in the pump chamber 35 is sufficient, the detection portion 36 is positioned between the light-emitting element 45 and the light-receiving element 46. At this time, the detection portion 36 of the remaining amount sensor 44 blocks light.

[0041] The remaining amount sensor 44 may be a weight sensor that detects the weight of the liquid container 100. For example, the remaining amount sensor 44 detects that the remaining amount of liquid in the liquid container 100 is small based on the weight of the liquid container 100. The remaining amount sensor 44 may also be configured to detect the remaining amount of liquid using other methods.

[0042] The liquid ejection device 11 includes a pressurizing unit 51. The pressurizing unit 51 is configured to pressurize the supply unit 21. The pressurizing unit 51 is configured to pressurize the liquid in the supply flow path 23. The pressurizing unit 51 is configured to pressurize the liquid located upstream of the pressure adjustment valve 24 in the supply flow path 23. The pressurizing unit 51 is configured to pressurize the supply flow path 23 from upstream of the pressure adjustment valve 24. In other words, the pressurizing unit 51 is configured to pressurize the liquid in the supply chamber 27. The pressurizing unit 51 supplies the liquid toward the pressure adjustment valve 24 by pressurizing the liquid in the supply flow path 23.

[0043] The pressurizing unit 51 is connected to the supply unit 21. In one example, the pressurizing unit 51 is connected to the flow path pump 32. More specifically, the pressurizing unit 51 communicates with the air chamber 34. The pressurizing unit 51 is configured to send air to the air chamber 34. The pressurizing unit 51 is, for example, an air pump. The pressurizing unit 51 pressurizes the air chamber 34, thereby pressurizing the pump chamber 35. This pressurizes the liquid in the supply flow path 23.

[0044] The pressurizing unit 51 may be configured to be able to depressurize the air chamber 34 in addition to pressurizing the air chamber 34. When the air chamber 34 is depressurized, the pump chamber 35 is depressurized. This causes liquid to be drawn from the attachment portion 22 into the flow path pump 32. As a result, liquid is stored in the flow path pump 32.

[0045] The pressurizing unit 51 may be connected to the mounting unit 22. The pressurizing unit 51 may be configured to pressurize the inside of the mounting unit 22. For example, the pressurizing unit 51 may pressurize the liquid container 100 by sending air into the mounting unit 22. In this case as well, the liquid in the supply flow path 23 is pressurized.

[0046] The liquid ejection device 11 includes a maintenance mechanism 61. The maintenance mechanism 61 is configured to perform maintenance on the ejection section 12. By the maintenance mechanism 61 performing maintenance on the ejection section 12, the ejection performance of the ejection section 12 is maintained in good condition.

[0047] The maintenance mechanism 61 is configured to receive the liquid used for cleaning and thereby perform maintenance on the discharge portion 12. Cleaning is an operation for discharging the liquid from the discharge portion 12. By cleaning, thickened liquid, solidified liquid, air bubbles, and the like are discharged from the discharge portion 12.

[0048] The cleaning may include pressure cleaning or suction cleaning. Pressure cleaning is cleaning in which liquid is discharged from the discharge portion 12 by applying pressure to the inside of the discharge portion 12. Suction cleaning is cleaning in which liquid is discharged from the discharge portion 12 by suctioning the inside of the discharge portion 12.

[0049] The maintenance mechanism 61 is configured to receive the liquid from flushing to perform maintenance on the discharge portion 12. Flushing is an operation of appropriately discharging the liquid from the nozzle 14. Flushing prevents the nozzle 14 from clogging.

[0050] The maintenance mechanism 61 is configured to perform maintenance on the ejection section 12 by wiping. Wiping is an operation of wiping off the nozzle surface 13. By wiping, foreign matter such as liquid and dust adhering to the nozzle surface 13 is removed.

[0051] The maintenance mechanism 61 is configured to perform maintenance on the discharge part 12 by capping. Capping is an operation of contacting the discharge part 12 so as to cover the nozzle 14, thereby forming a space communicating with the nozzle 14. Capping keeps the nozzle 14 moist.

[0052] The maintenance mechanism 61 has a cleaning unit 62. The cleaning unit 62 is configured to receive a liquid used for cleaning. The cleaning unit 62 may also be configured to receive a liquid used for flushing.

[0053] The cleaning unit 62 has a cap 63. The cap 63 is configured to come into contact with the ejection portion 12. The cap 63 caps the ejection portion 12 by coming into contact with the ejection portion 12. More specifically, the cap 63 caps the ejection portion 12 by coming into contact with the nozzle surface 13. The cap 63 may receive liquid used in cleaning or may receive liquid used in flushing.

[0054] The cleaning unit 62 has a suction pump 64. The suction pump 64 is connected to the cap 63. The suction pump 64 is configured to suck the inside of the cap 63. The cleaning unit 62 performs suction cleaning by driving the suction pump 64 while the cap 63 is capping the discharge part 12. When the suction pump 64 sucks the inside of the cap 63 while the discharge part 12 is capped, the pressure inside the cap 63 decreases. This causes the liquid to be discharged from the nozzle 14.

[0055] The cleaning unit 62 may perform dry suction by driving the suction pump 64 while the inside of the cap 63 is open to the atmosphere. Dry suction is an operation of discharging liquid from inside the cap 63.

[0056] The maintenance mechanism 61 has a wiping unit 65. The wiping unit 65 is configured to come into contact with the nozzle surface 13. The wiping unit 65 is configured to wipe the nozzle surface 13. The wiping unit 65 wipes the ejection unit 12 by coming into contact with the nozzle surface 13.

[0057] The wiping unit 65 has a blade 66 and a holder 67. The blade 66 is a member that comes into contact with the nozzle surface 13. The blade 66 scrapes off foreign matter from the nozzle surface 13. The holder 67 is a member that supports the blade 66. The holder 67 moves relative to, for example, the discharge unit 12. This allows the blade 66 to wipe the nozzle surface 13. The discharge unit 12 may move relative to the wiping unit 65, causing the wiping unit 65 to wipe the discharge unit 12.

[0058] The liquid ejection device 11 includes a detection unit 71. The detection unit 71 is configured to detect liquid overflowing from the nozzle 14. Liquid overflowing from the nozzle 14 refers to the liquid adhering to the nozzle surface 13 being in contact with the liquid in the nozzle 14. When liquid overflows from the nozzle 14, the meniscus of the nozzle 14 is destroyed. In other words, the detection unit 71 is configured to detect a nozzle 14 with a destroyed meniscus. In one example, the detection unit 71 is configured to detect a defective nozzle 14, such as a nozzle 14 with a destroyed meniscus, a clogged nozzle 14, or a nozzle 14 with air bubbles mixed in. If a defect occurs in the nozzle 14, the ejection unit 12 may not be able to eject liquid normally.

[0059] The detection unit 71 has a detection circuit 72. The detection circuit 72 is a circuit connected to the actuator 17. The detection circuit 72 is a circuit to which the vibration waveform caused by the diaphragm 16 is input from the actuator 17. More specifically, the detection circuit 72 is a circuit that detects the residual vibration of the diaphragm 16.

[0060] Residual vibration is vibration that occurs when the diaphragm 16, which has been bent by the actuator 17, returns to its original shape. When the diaphragm 16 is bent by the actuator 17, vibration remains in the diaphragm 16. The residual vibration changes depending on the state inside the ejection part 12. The residual vibration changes depending on the state of the liquid located in the nozzle 14 and the liquid chamber 15.

[0061] The detection circuit 72 detects the residual vibration of the diaphragm 16 through the actuator 17. The detection circuit 72 detects the residual vibration of the diaphragm 16 by detecting the voltage waveform of the actuator 17. The detection circuit 72 may be a circuit that inputs a drive waveform to the actuator 17. The detection circuit 72 generates, for example, a drive waveform for detecting a defective nozzle 14. In one example, the detection circuit 72 is configured by the drive circuit 18. It can also be said that the detection unit 71 is configured by the drive circuit 18. In this case, the risk of the configuration of the liquid ejection device 11 becoming complicated can be reduced. The detection circuit 72 may be a circuit separate from the drive circuit 18.

[0062] The detection circuit 72 is configured to detect liquid overflowing from the nozzle 14 based on the residual vibration of the diaphragm 16. In one example, the detection circuit 72 is configured to detect a defective nozzle 14 based on the residual vibration of the diaphragm 16. That is, the detection circuit 72 detects that a nozzle 14 is clogged or that air bubbles have entered the nozzle 14 based on the residual vibration of the diaphragm 16.

[0063] The vibration waveform when a nozzle 14 is defective differs from the vibration waveform when the nozzle 14 is normal. For example, the vibration waveform when air bubbles are mixed in the liquid in the nozzle 14 and the liquid chamber 15 differs from the vibration waveform when the nozzle 14 is normal. The vibration waveform when the liquid in the nozzle 14 and the liquid chamber 15 is thickened or solidified differs from the vibration waveform when the nozzle 14 is normal. The vibration waveform when paper powder is attached to the nozzle 14 differs from the vibration waveform when the nozzle 14 is normal. The vibration waveform when liquid is overflowing from the nozzle 14 differs from the vibration waveform when the nozzle 14 is normal. More specifically, when liquid is overflowing from the nozzle 14, the weight of the flowing liquid increases due to the deflection of the diaphragm 16, causing the vibration waveform to change. The vibration waveform when a nozzle 14 is defective differs depending on the cause of the defect. Therefore, the detection circuit 72 can detect a defective nozzle 14 and detect the cause of the defect based on the residual vibration.

[0064] The detection unit 71 may have an imaging unit 73. The imaging unit 73 is configured to capture an image of the nozzle surface 13. The imaging unit 73 may detect that liquid is overflowing from the nozzles 14 based on the captured image of the nozzle surface 13. The imaging unit 73 may also detect that clogging has occurred in the nozzles 14 based on the captured image of the nozzle surface 13.

[0065] The liquid ejection device 11 includes a control unit 81. The control unit 81 is configured to control the liquid ejection device 11. The control unit 81 is configured to control, for example, the ejection unit 12, the supply unit 21, the pressurizing unit 51, the maintenance mechanism 61, the detection unit 71, and the like.

[0066] The control unit 81 may be configured with one or more processors that execute various processes according to a computer program. The control unit 81 may be configured with one or more dedicated hardware circuits, such as an ASIC, that execute at least some of the various processes. The control unit 81 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 are configured to 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 dedicated computer.

[0067] The control unit 81 inspects the pressure regulating valve 24 based on the detection result of the detection unit 71. The control unit 81 determines whether a malfunction has occurred in the pressure regulating valve 24 based on the detection result of the detection unit 71. A malfunction in the pressure regulating valve 24 is mainly a leak in the valve member 29. That is, if a malfunction occurs in the pressure regulating valve 24, the valve member 29 may not be able to properly close the through-hole 28. Therefore, if a malfunction occurs in the pressure regulating valve 24, the inside of the discharge unit 12 may not be maintained at a predetermined negative pressure. In this case, liquid may overflow from the nozzle 14.

[0068] When inspecting the pressure regulating valve 24, the control unit 81 pressurizes the liquid in the supply flow path 23 using the pressurizing unit 51. This pressurizes the supply chamber 27. At this time, if a defect occurs in the pressure regulating valve 24, the pressure chamber 26 is pressurized as the supply chamber 27 is pressurized. When the pressure chamber 26 is pressurized, the inside of the discharge unit 12 is pressurized. As a result, the liquid overflows from the nozzle 14.

[0069] The control unit 81 determines that there is a possibility that the pressure adjustment valve 24 is malfunctioning when the detection unit 71 detects that the liquid is overflowing from the nozzle 14 while the pressurizing unit 51 is pressurizing the liquid. In one example, the control unit 81 applies a voltage to the actuator 17 from the detection unit 71, i.e., inputs a drive waveform, while the pressurizing unit 51 is pressurizing the liquid. The control unit 81 determines that there is a possibility that the pressure adjustment valve 24 is malfunctioning when the detection unit 71 detects that the liquid is overflowing from the nozzle 14 based on the residual vibration of the diaphragm 16 caused by the actuator 17. In this case, the control unit 81 notifies the user that there is a possibility that the pressure adjustment valve 24 is malfunctioning. This allows the user to understand that there is a possibility that the pressure adjustment valve 24 is malfunctioning.

[0070] When the detection unit 71 detects that the liquid is overflowing from the nozzle 14 while the pressurizing unit 51 is pressurizing the liquid, the control unit 81 may issue a warning to encourage replacement of the pressure adjustment valve 24. By encouraging replacement of the pressure adjustment valve 24, the control unit 81 may also issue a warning that there is a possibility that the pressure adjustment valve 24 is defective.

[0071] When the detection unit 71 detects that the liquid is overflowing from the nozzle 14 while the pressurizing unit 51 is pressurizing the liquid, the control unit 81 may issue a warning to prompt a re-inspection of the pressure adjustment valve 24. By prompting a re-inspection of the pressure adjustment valve 24, the control unit 81 may issue a warning that there is a possibility that the pressure adjustment valve 24 is defective.

[0072] The control unit 81 may notify the user through a display provided in the liquid ejection device 11, or may notify the user through a control terminal connected to the liquid ejection device 11. The control terminal may be a smartphone, a tablet, a personal computer, or the like.

[0073] When the control unit 81 determines that there is a possibility that the pressure regulation valve 24 is defective, the control unit 81 may re-inspect the pressure regulation valve 24. By re-inspecting the pressure regulation valve 24, the control unit 81 may notify the user that there is a possibility that the pressure regulation valve 24 is defective. For example, if liquid adheres to the nozzle surface 13 from the cleaning unit 62, the detection unit 71 may detect that liquid is overflowing from the nozzles 14, even though there is no defect in the pressure regulation valve 24. The control unit 81 re-inspects the pressure regulation valve 24 to confirm whether there is a defect in the pressure regulation valve 24.

[0074] When re-inspecting the pressure adjustment valve 24, the control unit 81 may use the wiping unit 65 to wipe the nozzle surface 13. By wiping the nozzle surface 13 with the wiping unit 65, the control unit 81 returns the nozzles 14 to a state where no liquid is overflowing. By wiping, the control unit 81 puts the nozzle surface 13 into a state suitable for inspecting the pressure adjustment valve 24. The control unit 81 may use the wiping unit 65 to wipe the nozzle surface 13 not only before re-inspection, but also before the first inspection.

[0075] When re-inspecting the pressure adjustment valve 24, the control unit 81 causes the pressurizing unit 51 to pressurize the liquid in the supply flow path 23 again. If the detection unit 71 again detects that liquid is overflowing from the nozzle 14 while the pressurizing unit 51 is pressurizing the liquid, the control unit 81 determines that a defect has occurred in the pressure adjustment valve 24. In this case, the control unit 81 notifies the control unit 81 that a defect has occurred in the pressure adjustment valve 24. In other words, if the control unit 81 detects that liquid is overflowing from the nozzle 14 again during the re-inspection, it determines that a defect has occurred in the pressure adjustment valve 24. Re-inspecting the pressure adjustment valve 24 reduces the risk of replacing a pressure adjustment valve 24 that is not defective.

[0076] The control unit 81 may inspect the pressure adjustment valve 24 when the liquid ejection device 11 is powered on. That is, the control unit 81 may cause the pressurizing unit 51 to pressurize the supply flow path 23 when the liquid ejection device 11 is powered on. When the detection unit 71 detects that liquid is overflowing from the nozzles 14 in a state in which the pressurizing unit 51 is pressurizing the liquid as a result of the liquid ejection device 11 being powered on, the control unit 81 may notify the user that there is a possibility of a malfunction in the pressure adjustment valve 24. The control unit 81 may inspect the pressure adjustment valve 24 at any timing, not just when the power is turned on. For example, the control unit 81 may inspect the pressure adjustment valve 24 based on the amount of liquid consumed, the number of printed sheets, the passage of time, etc.

[0077] The control unit 81 may inspect the cleaning unit 62 based on the detection result of the remaining amount sensor 44. The control unit 81 determines whether a defect has occurred in the cleaning unit 62 based on the detection result of the remaining amount sensor 44. If a defect occurs in the cleaning unit 62, there is a risk that suction cleaning will not be performed normally. In this case, there is a risk that thickened liquid, solidified liquid, air bubbles, etc. will not be discharged from the discharge unit 12.

[0078] When inspecting the cleaning unit 62, the control unit 81 causes the pressurizing unit 51 to depressurize the air chamber 34. This draws the liquid from the liquid container 100 into the pump chamber 35. After storing the liquid in the pump chamber 35, the control unit 81 closes the on-off valve 42. After closing the on-off valve 42, the control unit 81 performs suction cleaning. If the remaining amount sensor 44 does not detect that the remaining amount of liquid is small, the control unit 81 determines that a defect has occurred in the cleaning unit 62. If it is determined that a defect has occurred in the cleaning unit 62, the control unit 81 notifies the user that a defect has occurred in the cleaning unit 62. In this case, the control unit 81 may notify the user to replace the cleaning unit 62.

[0079] When suction cleaning is performed normally, the amount of liquid remaining in the flow path pump 32 decreases as the liquid is discharged from the discharge portion 12. Therefore, when suction cleaning is performed normally, the remaining amount sensor 44 detects that the remaining amount of liquid is small. If the remaining amount sensor 44 does not detect that the remaining amount of liquid in the flow path pump 32 is small, there is a risk that suction cleaning is not being performed normally.

[0080] The control unit 81 may check the electrical conduction of the discharge unit 12 based on the detection result of the detection unit 71. The control unit 81 determines whether or not there is an electrical conduction failure in the discharge unit 12 based on the detection result of the detection unit 71. If there is an electrical conduction failure in the discharge unit 12, there is a risk that the actuator 17 will not be driven.

[0081] The control unit 81 drives the actuator 17 to check the electrical conductivity of the ejection unit 12. In one example, the control unit 81 drives the actuator 17 by controlling the detection circuit 72. The control unit 81 causes the detection circuit 72 to detect residual vibration. If the detection circuit 72 does not detect residual vibration, the control unit 81 determines that the ejection unit 12 is experiencing an electrical conductivity failure. If an electrical conductivity failure occurs in the ejection unit 12, the diaphragm 16 does not vibrate. Therefore, residual vibration is not detected. If the control unit 81 determines that an electrical conductivity failure occurs in the ejection unit 12, it notifies the user that an electrical conductivity failure has occurred in the ejection unit 12. In this case, the control unit 81 may issue a notification to encourage replacement of the ejection unit 12.

[0082] The control unit 81 may inspect the recovery of the nozzle 14 based on the detection result of the detection unit 71. The control unit 81 determines whether a recovery failure has occurred in the nozzle 14 based on the detection result of the detection unit 71. A nozzle 14 that has a recovery failure is a nozzle 14 in which the blockage is not cleared.

[0083] The control unit 81 performs suction cleaning when inspecting the recovery of the nozzle 14. After performing suction cleaning, the control unit 81 drives the actuator 17. In one example, the control unit 81 drives the actuator 17 by controlling the detection circuit 72. The control unit 81 causes the detection circuit 72 to detect residual vibration. When the detection circuit 72 detects that a defect has occurred in the nozzle 14, the control unit 81 determines that a recovery defect has occurred in the nozzle 14. When it is determined that a recovery defect has occurred in the nozzle 14, the control unit 81 notifies the user that a recovery defect has occurred in the nozzle 14. In this case, the control unit 81 may notify the user to encourage replacement of the discharge unit 12.

[0084] The control unit 81 inputs to the actuator 17 a drive waveform that is appropriate for each of the following tests: testing the pressure adjustment valve 24, testing the electrical continuity of the discharge unit 12, and testing the recovery of the nozzle 14. When testing the pressure adjustment valve 24, the control unit 81 inputs to the actuator 17 a drive waveform that is appropriate for detecting liquid overflow from the nozzle 14. When testing the electrical continuity of the discharge unit 12, the control unit 81 inputs to the actuator 17 a drive waveform that is appropriate for checking the electrical continuity of the discharge unit 12. When testing the recovery of the nozzle 14, the control unit 81 inputs to the actuator 17 a drive waveform that is appropriate for detecting clogging of the nozzle 14. In one example, the drive waveform input to the actuator 17 when testing the pressure adjustment valve 24 is different from the drive waveform input to the actuator 17 when discharging liquid from the nozzle 14. When testing the recovery of the nozzle 14, the drive waveform input to the actuator 17 is different from the drive waveform input to the actuator 17 when discharging liquid from the nozzle 14. The drive waveform input to the actuator 17 in the electrical continuity test of the discharge part 12 may be the same as or different from the drive waveform input to the actuator 17 in the recovery test of the nozzle 14 .

[0085] <Inspection processing> Next, the inspection process executed by the control unit 81 will be described. The inspection process is started by a user instruction. In one example, the inspection process includes an inspection of the cleaning unit 62, a continuity inspection of the discharge unit 12, a recovery inspection of the nozzle 14, and an inspection of the pressure adjustment valve 24. In the inspection process, the order of the inspection of the cleaning unit 62, the continuity inspection of the discharge unit 12, the recovery inspection of the nozzle 14, and the inspection of the pressure adjustment valve 24 may be changed as appropriate. The inspection process may be a test that executes two or three of the inspection of the cleaning unit 62, the continuity inspection of the discharge unit 12, the recovery inspection of the nozzle 14, and the inspection of the pressure adjustment valve 24. The inspection of the cleaning unit 62, the continuity inspection of the discharge unit 12, the recovery inspection of the nozzle 14, and the inspection of the pressure adjustment valve 24 may each be executed separately.

[0086] 2, in step S11, the control unit 81 prompts the user to clean the cap 63. If foreign matter adheres to the cap 63, it may affect the test results. Cleaning the cap 63 improves the accuracy of the test results.

[0087] In step S12, the control unit 81 starts inspecting the cleaning unit 62. In step S12, it inspects whether or not a defect has occurred in the cleaning unit 62. If it is determined that a defect has occurred in the cleaning unit 62, the control unit 81 suspends the inspection process until the cleaning unit 62 is replaced. The inspection of the cleaning unit 62 will be described later with reference to the flowchart shown in FIG.

[0088] In step S13, the control unit 81 starts a continuity test of the discharge unit 12. In step S13, it checks whether a continuity failure has occurred in the discharge unit 12. If it is determined that a continuity failure has occurred in the discharge unit 12, the control unit 81 suspends the test process until the discharge unit 12 is replaced. The continuity test of the discharge unit 12 will be described later with reference to the flowchart shown in FIG.

[0089] In step S14, the control unit 81 starts a recovery test of the nozzle 14 of the discharge unit 12. In step S14, it checks whether the nozzle 14 has a recovery failure. In step S13, it is ensured that the cleaning unit 62 is normal by the processing of step S11. Therefore, if a recovery failure has occurred in the nozzle 14 in step S14, there is a high possibility that the discharge unit 12 has broken down. Therefore, if it is determined that a recovery failure has occurred in the nozzle 14, the control unit 81 suspends the test process until the discharge unit 12 is replaced. The recovery test of the nozzle 14 will be described later with reference to the flowchart shown in FIG. 5.

[0090] In step S15, the control unit 81 starts inspecting the pressure regulating valve 24. In step S15, it inspects whether a defect has occurred in the pressure regulating valve 24. If it is determined that a defect has occurred in the pressure regulating valve 24, the control unit 81 suspends the inspection process until the pressure regulating valve 24 is replaced. In this case, the control unit 81 ends the inspection process when the pressure regulating valve 24 is replaced.

[0091] 3, in step S21, the control unit 81 depressurizes the flow channel pump 32 using the pressurizing unit 51. The control unit 81 depressurizes the air chamber 34 using the pressurizing unit 51. As a result, the pump chamber 35 is filled with liquid.

[0092] In step S22, the control unit 81 closes the on-off valve 42. As a result, the supply of liquid from the liquid container 100 to the channel pump 32 is cut off. In step S23, the control unit 81 executes suction cleaning. If suction cleaning is executed normally, the liquid is discharged from the discharge unit 12 to the cap 63. As a result, the amount of liquid remaining in the channel pump 32 decreases.

[0093] In step S24, the control unit 81 determines whether the remaining amount of liquid is low. The control unit 81 determines whether the remaining amount sensor 44 detects that the remaining amount of liquid is low. If the remaining amount sensor 44 detects that the remaining amount of liquid is low, the control unit 81 ends the inspection of the cleaning unit 62. If the remaining amount sensor 44 does not detect that the remaining amount of liquid is low, the control unit 81 proceeds to step S25.

[0094] In step S25, the control unit 81 notifies the user that a defect has occurred in the cleaning unit 62. The control unit 81 notifies the user to prompt replacement of the cleaning unit 62. Once the cleaning unit 62 has been replaced, the control unit 81 ends the inspection of the cleaning unit 62.

[0095] 4, in step S31, the control unit 81 inputs a drive waveform to the actuator 17. The control unit 81 inputs to the actuator 17 a drive waveform that is suitable for inspecting for a current flow failure.

[0096] In step S32, the control unit 81 determines whether residual vibration has been detected by the detection circuit 72. If the detection circuit 72 detects residual vibration, the control unit 81 ends the electrical continuity test of the discharge unit 12. If the detection circuit 72 does not detect residual vibration, the control unit 81 proceeds to step S33.

[0097] In step S33, the control unit 81 notifies the user that a power failure has occurred in the discharge unit 12. The control unit 81 notifies the user to prompt replacement of the discharge unit 12. When the discharge unit 12 is replaced, the control unit 81 ends the power test for the discharge unit 12.

[0098] 5, in step S41, the control unit 81 inputs a drive waveform to the actuator 17. The control unit 81 inputs to the actuator 17 a drive waveform that is suitable for detecting clogging of the nozzle 14.

[0099] In step S42, the control unit 81 stores the defective nozzle 14 based on the residual vibration detected by the detection circuit 72. That is, the control unit 81 detects the clogged nozzle 14 based on the residual vibration, and stores the nozzle 14.

[0100] In step S43, the control unit 81 performs suction cleaning. Typically, suction cleaning restores the clogged nozzle 14. The control unit 81 may perform suction cleaning multiple times.

[0101] In step S44, the control unit 81 inputs a drive waveform to the actuator 17. The control unit 81 inputs a drive waveform suitable for detecting clogging of the nozzle 14 to the actuator 17, similar to step S41.

[0102] In step S45, the control unit 81 stores the defective nozzle 14 based on the residual vibration detected by the detection circuit 72. That is, similar to step S42, the control unit 81 detects the clogged nozzle 14 based on the residual vibration and stores the nozzle 14.

[0103] In step S46, the control unit 81 compares the detection result before the suction cleaning with the detection result after the suction cleaning. The control unit 81 compares the position of the nozzle 14 in which a defect was detected before the suction cleaning with the position of the nozzle 14 in which a defect was detected after the suction cleaning.

[0104] In step S47, the control unit 81 determines whether the nozzle 14 has recovered. The control unit 81 determines whether the nozzle 14 that was defective before the suction cleaning has recovered after the suction cleaning. If the nozzle 14 has recovered, the control unit 81 ends the recovery test of the nozzle 14. If the nozzle 14 has not recovered, the control unit 81 proceeds to step S48.

[0105] In step S48, the control unit 81 notifies the user that a recovery failure has occurred in the nozzle 14. The control unit 81 notifies the user to prompt replacement of the discharge unit 12. Once the discharge unit 12 has been replaced, the control unit 81 ends the recovery test of the nozzle 14.

[0106] 6, in step S51, the control unit 81 causes the pressurizing unit 51 to pressurize the air chamber 34. As a result, the supply chamber 27 is pressurized. In step S52, the control unit 81 determines whether the detection unit 71 has detected that liquid is overflowing from the nozzle 14. If the detection unit 71 has detected that liquid is overflowing from the nozzle 14, the control unit 81 proceeds to step S52. If the detection unit 71 has not detected that liquid is overflowing from the nozzle 14, the control unit 81 ends the inspection of the pressure adjustment valve 24.

[0107] In step S53, the control unit 81 issues a warning that there is a possibility of a defect in the pressure regulating valve 24. The control unit 81 may issue a warning to encourage replacement of the pressure regulating valve 24, or may issue a warning to encourage re-inspection of the pressure regulating valve 24.

[0108] In step S54, the control unit 81 determines whether the pressure regulating valve 24 has been replaced. If the pressure regulating valve 24 has been replaced, the control unit 81 ends the inspection of the pressure regulating valve 24. If the pressure regulating valve 24 has not been replaced, the control unit 81 proceeds to step S55 for re-inspection.

[0109] In step S55, the control unit 81 causes the wiping unit 65 to wipe the nozzle surface 13. In step S56, the control unit 81 causes the pressurizing unit 51 to pressurize the air chamber 34, similarly to step S51.

[0110] In step S57, similarly to step S52, the control unit 81 determines whether the detection unit 71 has detected that liquid is overflowing from the nozzle 14. If the detection unit 71 has detected that liquid is overflowing from the nozzle 14, the control unit 81 proceeds to step S58. If the detection unit 71 has not detected that liquid is overflowing from the nozzle 14, the control unit 81 ends the inspection of the pressure adjustment valve 24.

[0111] In step S58, the control unit 81 notifies the user that a defect has occurred in the pressure regulating valve 24. The control unit 81 notifies the user to prompt replacement of the pressure regulating valve 24. Once the pressure regulating valve 24 has been replaced, the control unit 81 ends the inspection of the pressure regulating valve 24.

[0112] <Actions and Effects of the Example> Next, the operation and effects of the above embodiment will be described. (1) The control unit 81 causes the pressurizing unit 51 to pressurize the liquid in the supply flow path 23. When the detection unit 71 detects that the liquid is overflowing from the nozzle 14 while the liquid is pressurized by the pressurizing unit 51, the control unit 81 notifies the user that there is a possibility that the pressure adjustment valve 24 is malfunctioning. If there is a malfunction in the pressure adjustment valve 24, the pressure adjustment valve 24 may not be able to close the supply flow path 23. Therefore, if there is a malfunction in the pressure adjustment valve 24, when the pressurizing unit 51 pressurizes the liquid in the supply flow path 23, the inside of the discharge unit 12 is pressurized, which may cause the liquid to overflow from the nozzle 14. Therefore, if the detection unit 71 detects that the liquid is overflowing from the nozzle 14, there is a possibility that there is a malfunction in the pressure adjustment valve 24. According to the above configuration, the user is notified that there is a possibility that the pressure adjustment valve 24 is malfunctioning, allowing the user to quickly become aware of the malfunction in the pressure adjustment valve 24.

[0113] (2) When the detection unit 71 detects that the liquid is overflowing from the nozzle 14 while the liquid is pressurized by the pressurizing unit 51, the control unit 81 issues a notification to encourage the user to replace the pressure adjustment valve 24. According to the above configuration, the user can replace the pressure adjustment valve 24 that may be defective.

[0114] (3) When the detection unit 71 detects that the liquid is overflowing from the nozzle 14 while the liquid is being pressurized by the pressurizing unit 51, the control unit 81 causes the wiping unit 65 to wipe the nozzle surface 13. The control unit 81 causes the pressurizing unit 51 to re-pressurize the liquid in the supply flow path 23. When the detection unit 71 detects that the liquid is overflowing from the nozzle 14 while the liquid is being pressurized by the pressurizing unit 51, the control unit 81 reports that a malfunction has occurred in the pressure adjustment valve 24. With the above configuration, it is possible to confirm that a malfunction has occurred in the pressure adjustment valve 24.

[0115] (4) When the liquid ejection device 11 is powered on, the control unit 81 causes the pressurizing unit 51 to pressurize the liquid in the supply flow path 23. When the liquid ejection device 11 is powered on and the liquid is pressurized by the pressurizing unit 51, and the detection unit 71 detects that the liquid is overflowing from the nozzle 14, the control unit 81 notifies the user that there may be a malfunction in the pressure adjustment valve 24. With the above configuration, the user can be aware of a malfunction in the pressure adjustment valve 24 before using the liquid ejection device 11.

[0116] (5) The detection unit 71 is a drive circuit 18 that applies a voltage to the actuator 17, and detects that liquid is overflowing from the nozzle 14 by the residual vibration of the diaphragm 16. With the above configuration, it is possible to detect that liquid is overflowing from the nozzle 14 without complicating the configuration of the liquid ejection device 11.

[0117] <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.

[0118] The maintenance mechanism 61 may have a cap for moisture retention in addition to the cap 63 for cleaning. 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 supply flow path connected to the ejection section and supplying liquid to the ejection section; a pressure regulation valve located in the supply flow path and regulating the pressure within the ejection section; a pressurizing section that pressurizes the liquid located upstream of the pressure regulation valve in the supply flow path; a detection section that detects liquid overflowing from the nozzle; and a control section. The pressure regulation valve is configured to open the supply flow path when the pressure within the ejection section falls below a predetermined pressure. The control section pressurizes the liquid in the supply flow path using the pressurizing section, and when the detection section detects liquid overflowing from the nozzle while the pressurizing section is pressurizing the liquid, it notifies the user that the pressure regulation valve may be malfunctioning. If the pressure regulation valve is malfunctioning, the pressure regulation valve may be unable to close the supply flow path. Therefore, if the pressure regulation valve is malfunctioning, when the pressurizing section pressurizes the liquid in the supply flow path, the pressurization within the ejection section may cause liquid to overflow from the nozzle. Therefore, when the detection unit detects that liquid is overflowing from the nozzle, there is a possibility that a malfunction has occurred in the pressure adjustment valve. With the above configuration, by being notified that there is a possibility that a malfunction has occurred in the pressure adjustment valve, the user can quickly become aware of the malfunction in the pressure adjustment valve.

[0121] (B) In the liquid ejection device, when the detection unit detects that the liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid, the control unit may issue a notification to encourage the user to replace the pressure adjustment valve. With the above configuration, the user can replace the pressure adjustment valve that may be defective.

[0122] (C) The liquid ejection device may include a wiping unit that wipes the nozzle surface, and when the detection unit detects that liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid, the control unit may cause the wiping unit to wipe the nozzle surface, and when the detection unit detects that liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid, the control unit may cause the pressurizing unit to re-pressurize the liquid in the supply flow path, and when the detection unit again detects that liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid, may report that a malfunction has occurred in the pressure adjustment valve. With the above configuration, it is possible to confirm that a malfunction has occurred in the pressure adjustment valve.

[0123] (D) In ​​the liquid ejection device, the control unit may pressurize the liquid in the supply flow path using the pressurizing unit when the liquid ejection device is powered on, and if the detection unit detects that liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid when the liquid ejection device is powered on, the control unit may notify the user that there may be a malfunction in the pressure adjustment valve. With the above configuration, the user can be aware of a malfunction in the pressure adjustment valve before using the liquid ejection device.

[0124] (E) In the liquid ejection device, the ejection unit may have an actuator and a diaphragm that is deformed by the actuator, the actuator deforming the diaphragm to eject liquid from the nozzle, and the detection unit may be a drive circuit that applies a voltage to the actuator and detects liquid overflowing from the nozzle based on residual vibration of the diaphragm. With the above configuration, it is possible to detect liquid overflowing from the nozzle without complicating the configuration of the liquid ejection device.

[0125] (F) A control method for a liquid ejection device includes a discharge section having a nozzle surface where a nozzle opens and discharging liquid from the nozzle, a supply flow path connected to the discharge section and supplying liquid to the discharge section, a pressure adjustment valve located in the supply flow path and adjusting the pressure in the discharge section by opening the supply flow path when the pressure in the discharge section falls below a predetermined pressure, a pressurizing section located upstream of the pressure adjustment valve in the supply flow path and pressurizing the liquid, and a detection section detecting liquid overflow from the nozzle, the control method including pressurizing the liquid in the supply flow path with the pressurizing section, and reporting a possible malfunction of the pressure adjustment valve when the detection section detects liquid overflow from the nozzle while the pressurizing section is pressurizing the liquid. The method achieves the same effects as the liquid ejection device described above.

[0126] (G) The control method for the liquid ejection device may include issuing a notification to encourage replacement of the pressure adjustment valve when the detection unit detects that the liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid. The method can achieve the same effects as the liquid ejection device described above.

[0127] (H) In the above-described method for controlling a liquid ejection device, the liquid ejection device may include a wiping unit that wipes the nozzle surface, and when the detection unit detects that liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid, the method may include wiping the nozzle surface with the wiping unit, re-pressurizing the liquid in the supply flow path with the pressurizing unit, and when the detection unit again detects that liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid, reporting that a malfunction has occurred in the pressure adjustment valve. The above-described method can achieve the same effects as the above-described liquid ejection device.

[0128] (I) The control method for the liquid ejection device may include pressurizing the liquid in the supply flow path by the pressurizing unit when the power of the liquid ejection device is turned on, and reporting that a malfunction has occurred in the pressure adjustment valve when the detection unit detects that the liquid is overflowing from the nozzle in a state in which the pressurizing unit is pressurizing the liquid as a result of the power of the liquid ejection device being turned on. The above method can achieve the same effects as the above-mentioned liquid ejection device.

[0129] (J) In the above-described control method for a liquid ejection device, the ejection unit has an actuator and a diaphragm that is deformed by the actuator, and the actuator ejects liquid from the nozzle by deforming the diaphragm, and the detection unit is a drive circuit that applies a voltage to the actuator and detects liquid overflowing from the nozzle based on residual vibration of the diaphragm, and the control method for the liquid ejection device may include: applying a voltage from the detection unit to the actuator while the pressurizing unit is pressurizing the liquid; and, when the detection unit detects liquid overflowing from the nozzle based on the residual vibration of the diaphragm that has been deformed by the detection unit applying a voltage to the actuator, reporting a possibility of a malfunction of the pressure adjustment valve. The above-described method can achieve the same effects as the above-described liquid ejection device. [Explanation of symbols]

[0130] 11...liquid ejection device, 12...ejection portion, 13...nozzle surface, 14...nozzle, 15...liquid chamber, 16...vibration plate, 17...actuator, 18...drive circuit, 21...supply portion, 22...mounting portion, 23...supply flow path, 24...pressure regulating valve, 25...main body member, 26...pressure chamber, 27...supply chamber, 28...through hole, 29...valve member, 30...pressure member, 31...membrane member, 32...flow path pump, 33...flexible member, 34...air chamber, 35...pump chamber, 36...detection portion, 37...buffer , 38...deformable member, 39...storage chamber, 40...buffer chamber, 41...elastic member, 42...opening / closing valve, 43...one-way valve, 44...remaining amount sensor, 45...light-emitting element, 46...light-receiving element, 51...pressurizing section, 61...maintenance mechanism, 62...cleaning unit, 63...cap, 64...suction pump, 65...wiping section, 66...blade, 67...holder, 71...detection section, 72...detection circuit, 73...imaging unit, 81...control section, 99...medium, 100...liquid container.

Claims

1. a discharge unit having a nozzle surface on which nozzles are opened and configured to discharge liquid from the nozzles; a supply flow path connected to the discharge portion and supplying liquid to the discharge portion; a pressure regulating valve located in the supply flow path and regulating the pressure in the discharge portion; a pressurizing unit that pressurizes the liquid and is located upstream of the pressure regulating valve in the supply flow path; a detection unit that detects liquid overflowing from the nozzle; a control unit, the pressure regulating valve is configured to open the supply flow path when the pressure in the discharge portion is equal to or lower than a predetermined pressure, The control unit The pressurizing unit pressurizes the liquid in the supply flow path, A liquid ejection device characterized in that, when the detection unit detects that liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid, it notifies the user that there is a possibility that the pressure adjustment valve is malfunctioning.

2. The liquid ejection device according to claim 1, wherein the control unit issues an alert to encourage replacement of the pressure adjustment valve when the detection unit detects that liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid.

3. a wiping unit that wipes the nozzle surface, The control unit when the detection unit detects that the liquid is overflowing from the nozzle in a state in which the pressurizing unit is pressurizing the liquid, the wiping unit wipes the nozzle surface; The liquid in the supply flow path is pressurized again by the pressurizing unit; The liquid ejection device according to claim 1, characterized in that when the detection unit again detects that liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid, it notifies that a malfunction has occurred in the pressure adjustment valve.

4. The control unit When the power supply of the liquid ejection device is turned on, the pressurizing unit pressurizes the liquid in the supply flow path; The liquid ejection device described in claim 1, characterized in that when the liquid ejection device is turned on and the pressurizing unit pressurizes the liquid, and the detection unit detects that liquid is overflowing from the nozzle, it notifies the user that there is a possibility that the pressure adjustment valve is malfunctioning.

5. The discharge section is an actuator; and a diaphragm that is deformed by the actuator; the actuator deforms the vibration plate to eject liquid from the nozzle; The detection unit a drive circuit that applies a voltage to the actuator; 5. The liquid ejection device according to claim 1, wherein the liquid overflowing from the nozzle is detected based on residual vibration of the vibration plate.

6. a discharge unit having a nozzle surface on which nozzles are opened and configured to discharge liquid from the nozzles; a supply flow path connected to the discharge portion and supplying liquid to the discharge portion; a pressure regulating valve located in the supply flow path, the pressure regulating valve opening the supply flow path when the pressure in the discharge portion is equal to or lower than a predetermined pressure, thereby regulating the pressure in the discharge portion; a pressurizing unit that pressurizes the liquid and is located upstream of the pressure regulating valve in the supply flow path; a detection unit that detects whether liquid is overflowing from the nozzle, pressurizing the liquid in the supply flow path by the pressurizing unit; and when the detection unit detects that liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid, notifying that there is a possibility that the pressure adjustment valve is malfunctioning.

7. The control method for a liquid ejection device according to claim 6, further comprising the step of issuing an alert to prompt replacement of the pressure adjustment valve when the detection unit detects that liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid.

8. the liquid ejection device includes a wiping unit that wipes the nozzle surface, The method for controlling the liquid ejection device includes: wiping the nozzle surface with the wiping unit when the detection unit detects that the liquid is overflowing from the nozzle in a state where the pressurizing unit is pressurizing the liquid; pressurizing the liquid in the supply flow path again by the pressurizing unit; The control method for a liquid ejection device according to claim 6, further comprising: when the detection unit again detects that liquid is overflowing from the nozzle while the pressurizing unit is pressurizing the liquid, reporting that a malfunction has occurred in the pressure adjustment valve.

9. pressurizing the liquid in the supply flow path by the pressurizing unit when the power supply of the liquid ejection device is turned on; The control method for a liquid ejection device according to claim 6, further comprising: notifying that a malfunction has occurred in the pressure adjustment valve when the detection unit detects that liquid is overflowing from the nozzle when the liquid ejection device is turned on and the pressurizing unit pressurizes the liquid.

10. The discharge section is an actuator; and a diaphragm that is deformed by the actuator; the actuator deforms the vibration plate to eject liquid from the nozzle; The detection unit a drive circuit that applies a voltage to the actuator; detecting liquid overflowing from the nozzle based on residual vibration of the vibration plate; The method for controlling the liquid ejection device includes: applying a voltage from the detection unit to the actuator in a state in which the pressurizing unit pressurizes the liquid; 10. A control method for a liquid ejection device as described in any one of claims 6 to 9, characterized in that when the detection unit detects that liquid is overflowing from the nozzle based on the residual vibration of the vibration plate that has been deformed by applying a voltage to the actuator, the detection unit notifies that there is a possibility that the pressure adjustment valve is malfunctioning.

Images