Liquid circulating mechanism, liquid circulating device, and liquid ejecting device

Abstract

The present application provides a liquid circulating mechanism, a liquid circulating device, and a liquid ejecting device that can be downsized. The liquid circulating mechanism (39) includes: a first reservoir (41) configured to be capable of storing a liquid supplied to a liquid ejecting head (21); a second reservoir (42) configured to be capable of storing a liquid recovered from the liquid ejecting head (21); a third reservoir (42) configured to be capable of storing a liquid between the second reservoir (42) and the first reservoir (41); a first one-way valve (44) on a second recovery flow path (35B) that allows the flow of the liquid from the second reservoir (42) to the third reservoir (43) and restricts the flow of the liquid from the third reservoir (43) to the second reservoir (42); and a second one-way valve (45) on a third recovery flow path (35C) that allows the flow of the liquid from the third reservoir (43) to the first reservoir (41) and restricts the flow of the liquid from the first reservoir (41) to the third reservoir (43).

Description

TECHNICAL FIELD

[0001] The present application relates to a liquid circulating mechanism, a liquid circulating device, and a liquid ejecting apparatus each of which is provided with a supply flow path that supplies liquid in a liquid supply source to a liquid ejecting head, and a recovery flow path that recovers liquid in the liquid ejecting head to the supply flow path. BACKGROUND

[0002] For example, as in Patent Literature 1, a liquid circulating mechanism is disclosed that circulates liquid for supply to a liquid ejecting head in a liquid ejecting apparatus provided with the liquid ejecting head that ejects liquid, by using a supply flow path that supplies liquid in a liquid supply source to the liquid ejecting head, and a recovery flow path that recovers liquid from the liquid ejecting head to the supply flow path.

[0003] In such a liquid circulating mechanism, a pump for circulating liquid is provided on at least either one of the supply flow path and the recovery flow path, and a pressure adjusting portion that opens the flow path when the pressure on the liquid ejecting head side becomes a predetermined pressure. Thus, liquid can be circulated at a predetermined flow rate.

[0004] However, in such a liquid circulating mechanism, a pump for circulating liquid needs to be provided on the flow path of at least either one of the supply flow path and the recovery flow path, and thus there is a possibility of causing a large size.

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2017-159668 SUMMARY

[0006] A liquid circulating mechanism that solves the above-described problem is provided with: a first reservoir configured to be able to store liquid for supply to a liquid ejecting head that ejects liquid; a supply flow path that communicates the first reservoir with the liquid ejecting head; a second reservoir configured to be able to store liquid recovered from the liquid ejecting head; a first recovery flow path that communicates the liquid ejecting head with the second reservoir; a third reservoir configured to be able to store liquid between the second reservoir and the first reservoir; a second recovery flow path that communicates the second reservoir with the third reservoir; a third recovery flow path that communicates the third reservoir with the first reservoir; a first check valve that allows flow of liquid from the second reservoir to the third reservoir and restricts flow of liquid from the third reservoir to the second reservoir on the second recovery flow path; and a second check valve that allows flow of liquid from the third reservoir to the first reservoir and restricts flow of liquid from the first reservoir to the third reservoir on the third recovery flow path.

[0007] A liquid circulation device that solves the above-described problem includes a liquid circulation mechanism and a circulation device. The liquid circulation mechanism includes a first reservoir configured to be able to store a liquid supplied to a liquid ejection head that ejects the liquid, a supply flow path that communicates the first reservoir with the liquid ejection head, a second reservoir configured to be able to store a liquid recovered from the liquid ejection head, a first recovery flow path that communicates the liquid ejection head with the second reservoir, a third reservoir configured to be able to store a liquid between the second reservoir and the first reservoir, a second recovery flow path that communicates the second reservoir with the third reservoir, a third recovery flow path that communicates the third reservoir with the first reservoir, a first check valve that allows a flow of the liquid from the second reservoir to the third reservoir and restricts a flow of the liquid from the third reservoir to the second reservoir on the second recovery flow path, and a second check valve that allows a flow of the liquid from the third reservoir to the first reservoir and restricts a flow of the liquid from the first reservoir to the third reservoir on the third recovery flow path. The circulation device includes a decompression unit configured to be able to decompress the second reservoir and the third reservoir, a decompression switching unit configured to be able to switch at least a first decompression state in which the decompression unit communicates with the second reservoir and a second decompression state in which the decompression unit communicates with the third reservoir, a pressurization unit configured to be able to pressurize the third reservoir and the first reservoir, and a pressurization switching unit configured to be able to switch at least a first pressurization state in which the pressurization unit communicates with the first reservoir and a second pressurization state in which the pressurization unit communicates with the third reservoir.

[0008] A liquid ejection device that solves the above-described problem includes a liquid ejection head that ejects a liquid, the above-described liquid circulation device, and a control unit that controls the liquid ejection head and the liquid circulation device. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 A perspective view of one embodiment of a liquid ejection device.

[0010] Figure 2 A schematic view showing an internal structure of a liquid ejection device.

[0011] Figure 3 A schematic view showing an internal structure of a liquid ejection device.

[0012] Figure 4 A schematic view showing an internal structure of a liquid ejection device.

[0013] Figure 5A schematic view for showing an internal structure of a liquid ejecting apparatus.

[0014] Figure 6 A schematic view for showing an internal structure of a liquid ejecting apparatus.

[0015] Figure 7 A schematic view for showing an internal structure of a liquid ejecting apparatus.

[0016] Figure 8 A schematic view for showing an internal structure of a liquid ejecting apparatus.

[0017] Figure 9 A schematic view for showing an internal structure of a liquid ejecting apparatus.

[0018] Figure 10 A plan view schematically showing an internal structure of a liquid ejecting apparatus.

[0019] Figure 11 A block diagram for showing an electric structure of a liquid ejecting apparatus.

[0020] Figure 12 A flowchart for showing a cycle control process of a liquid ejecting apparatus.

[0021] Figure 13 A flowchart for showing a cycle control process of a liquid ejecting apparatus.

[0022] Figure 14 A schematic view for showing a control content of a liquid ejecting apparatus.

[0023] Figure 15 A schematic view for showing an internal structure of a liquid ejecting apparatus.

[0024] Figure 16 A schematic view for showing an internal structure of a liquid ejecting apparatus. DETAILED DESCRIPTION

[0025] Hereinafter, one embodiment of a liquid circulating mechanism, a liquid circulating device, and a liquid ejecting apparatus will be described with reference to the drawings. In the present embodiment, the liquid circulating mechanism and the liquid circulating device are mounted on a liquid ejecting apparatus that ejects a liquid such as ink onto a medium such as paper. In the present embodiment, the liquid ejecting apparatus is mounted on, for example, an inkjet-type large-format printer that ejects ink onto a long sheet of paper to perform printing.

[0026] In the accompanying drawings, the liquid ejection device 10 is assumed to be placed on a horizontal plane, and the direction of gravity is represented by Z. The X-axis and Y-axis represent the directions along the plane intersecting the Z-axis. When the X-axis, Y-axis, and Z-axis are orthogonal to each other, the X-axis and Y-axis are along the horizontal plane. In the following description, the direction along the X-axis will be referred to as the width direction X, the direction along the Y-axis will be referred to as the depth direction Y, and the direction along the Z-axis will be referred to as the vertical direction Z.

[0027] like Figure 1 As shown, the liquid ejection device 10 has a pair of feet 11 and a housing 12. The housing 12 is assembled onto the feet 11.

[0028] The liquid ejection device 10 includes an unwinding section 13, a guide plate 14, a winding section 15, a tensioning mechanism 16, and an operation panel 17. The unwinding section 13 unwinds the medium M, which is coiled on the roller body, into the housing 12. The guide plate 14 guides the medium M discharged from the housing 12. The winding section 15 winds the medium M guided by the guide plate 14 onto the roller body. The tensioning mechanism 16 applies tension to the medium M wound on the winding section 15. The operation panel 17 is operated by the user.

[0029] The liquid dispensing device 10 includes a printing section 20. The printing section 20 is housed within a housing 12. The printing section 20 includes a liquid dispensing head 21 and a carriage 22. The liquid dispensing head 21 dispenses liquid. The carriage 22 carries the liquid dispensing head 21.

[0030] The liquid dispensing device 10 includes a liquid supply source 18. The liquid supply source 18 is disposed outside the housing 12. The liquid supply source 18 is a supply source for supplying liquid to the printing section 20. The liquid supply source 18 is, for example, a container for collecting liquid. The liquid supply source 18 can be a replaceable box or a canister for replenishing liquid. Furthermore, for example, the liquid supply source 18 can be disposed inside the housing 12, or it can be disposed independently of the liquid dispensing device 10. The liquid supply source 18 has multiple supply sources corresponding to the type of liquid ejected from the liquid nozzle 21. In this embodiment, the liquid supply source 18 has four supply sources.

[0031] The liquid ejection device 10 includes a supply channel 19. The supply channel 19 is a channel for supplying liquid from the liquid supply source 18 to the printing unit 20 in order to supply liquid to the printing unit 20. The supply channel 19 has multiple channels corresponding to the type of liquid ejected from the liquid ejection head 21. In this embodiment, the supply channel 19 has four channels. Alternatively, if the type of liquid ejected from the liquid ejection head 21 is only one type, the liquid ejection device 10 may also have only one supply channel 19.

[0032] Next, refer toFigure 2 The structure of the inside of the liquid discharge apparatus 10 will be described. Also, in Figure 2 the drawing, only the structure of one of the systems corresponding to the kinds of liquid discharged from the liquid discharge head 21 is shown representatively.

[0033] As shown in Figure 2 , the printing section 20 is provided with a guide shaft 23. The guide shaft 23 guides the carriage 22 in the width direction X. The carriage 22 is configured to be able to move back and forth in the width direction X in conjunction with the driving of a carriage motor 24. In the present embodiment, it can be said that the width direction X is the main scanning direction.

[0034] The liquid discharge head 21 is mounted at the lower end portion of the carriage 22. The printing section 20 can also be provided with a plurality of liquid discharge heads 21. The liquid discharge head 21 discharges liquid from a plurality of nozzles 21B formed on a nozzle face 21A, thereby implementing printing on the medium M.

[0035] The liquid discharge apparatus 10 is provided with a support table 25 and a conveyance section 26. The support table 25 is disposed at a position opposite the liquid discharge head 21. The conveyance section 26 conveys the medium M in the depth direction Y. The conveyance section 26 is provided with a first conveyance roller pair 27A and a second conveyance roller pair 27B. The first conveyance roller pair 27A is located at the upstream side compared to the support table 25 in the depth direction Y. The second conveyance roller pair 27B is located at the downstream side compared to the support table 25 in the depth direction Y. The first conveyance roller pair 27A and the second conveyance roller pair 27B are rotated by being driven by a conveyance motor 28. The first conveyance roller pair 27A and the second conveyance roller pair 27B convey the medium M along the surface of the support table 25 and the surface of the guide plate 14 by being rotated while sandwiching the medium M. In the present embodiment, it can be said that the depth direction Y is the conveyance direction and the sub scanning direction.

[0036] The liquid discharge apparatus 10 is provided with a liquid circulation apparatus 30. The liquid circulation apparatus 30 is mounted on the carriage 22. The liquid circulation apparatus 30 is an apparatus that supplies liquid to the liquid discharge head 21 via the supply flow path 19 and recovers liquid from the liquid discharge head 21 to the supply flow path 19.

[0037] The liquid circulation apparatus 30 is provided with the supply flow path 19. The supply flow path 19 supplies liquid from the liquid supply source 18, which is the upstream side, to the liquid discharge head 21, which is the downstream side, in the supply direction A of the liquid. That is, the supply flow path 19 is a flow path that communicates the liquid supply source 18 and the liquid discharge head 21 to supply the liquid in the liquid supply source 18 to the liquid discharge head 21.

[0038] The liquid circulating device 30 has a recovery flow path 35. The recovery flow path 35 recovers liquid in a recovery direction B from the liquid ejection head 21 on the upstream side to the supply flow path 19 on the downstream side. That is, the recovery flow path 35 communicates the liquid ejection head 21 with the supply flow path 19 to recover liquid in the liquid ejection head 21 into the supply flow path 19. The recovery flow path 35 has a plurality of flow paths in a manner corresponding to the kind of liquid ejected from the liquid ejection head 21. The recovery flow path 35 of the present embodiment has four flow paths. In addition, the liquid ejection device 10 can have one recovery flow path 35 in the case where the kind of liquid ejected from the liquid ejection head 21 is one kind.

[0039] The liquid circulating device 30 has a storage portion 40. The storage portion 40 stores liquid. In the present embodiment, the storage portion 40 constitutes a part of the supply flow path 19. The storage portion 40 stores liquid from the liquid supply source 18 via the supply flow path 19. In the present embodiment, the storage portion 40 constitutes a part of the recovery flow path 35. The storage portion 40 stores liquid recovered from the liquid ejection head 21 via the recovery flow path 35. That is, the recovery flow path 35 connects the liquid ejection head 21 and the supply flow path 19 via the storage portion 40. The storage portion 40 has a plurality of storage portions in a manner corresponding to the kind of liquid ejected from the liquid ejection head 21. The storage portion 40 of the present embodiment has four storage portions. In addition, the liquid ejection device 10 can have one storage portion 40 in the case where the kind of liquid ejected from the liquid ejection head 21 is one kind.

[0040] Thus, a part of the supply flow path 19 and the recovery flow path 35 constitute a circulation flow path 36 that circulates liquid. The circulation flow path 36 has a plurality of flow paths in a manner corresponding to the kind of liquid ejected from the liquid ejection head 21. The circulation flow path 36 of the present embodiment has four flow paths. In addition, the liquid ejection device 10 can have one circulation flow path 36 in the case where the kind of liquid ejected from the liquid ejection head 21 is one kind.

[0041] The liquid circulating device 30 has a pressurizing pump 51 as one example of a pressurizing portion. The pressurizing pump 51 causes liquid to flow along the supply flow path 19 in a supply direction A from the storage portion 40 toward the liquid ejection head 21. The pressurizing pump 51 is shared in accordance with the kind of liquid ejected from the liquid ejection head 21. The pressurizing pump 51 of the present embodiment has one pump.

[0042] The liquid circulating device 30 has a depressurizing pump 52 as one example of a depressurizing portion. The depressurizing pump 52 causes liquid to flow along the recovery flow path 35 in a recovery direction B from the liquid ejection head 21 toward the storage portion 40. The depressurizing pump 52 is shared in accordance with the kind of liquid ejected from the liquid ejection head 21. The depressurizing pump 52 of the present embodiment has one pump.

[0043] The liquid circulation device 30 includes a pressure regulating device 60. The pressure regulating device 60 is mounted on a carriage 22. Specifically, in this embodiment, the pressure regulating device 60 is positioned above the liquid nozzle 21. In other words, the pressure regulating device 60 is positioned overlapping a plane that passes through the liquid nozzle 21 along a direction orthogonal to the width direction X. The pressure regulating device 60 is connected to the upstream side of the liquid nozzle 21 in the supply channel 19 and regulates the pressure of the liquid supplied to the liquid nozzle 21. The pressure regulating device 60 is connected to the downstream side of the liquid nozzle 21 in the recovery channel 35 and regulates the pressure of the liquid recovered from the liquid nozzle 21. The pressure regulating device 60 has multiple storage sections corresponding to the type of liquid ejected from the liquid nozzle 21. In this embodiment, the pressure regulating device 60 has four pressure regulating devices. Alternatively, if the type of liquid ejected from the liquid nozzle 21 is only one type, the liquid ejection device 10 may also include one pressure regulating device 60.

[0044] In addition, in this embodiment, a filter unit (not shown) is provided in the supply channel 19. The filter unit captures air bubbles or foreign objects in the liquid.

[0045] Next, refer to Figure 3 The liquid ejection head 21 and the liquid circulation device 30 in the liquid ejection device 10 will be described. Additionally, in Figure 3 In this section, the structure of one of the multiple systems corresponding to the type of liquid ejected from the liquid ejector head 21 will be used as an example for explanation.

[0046] like Figure 3 As shown, the liquid nozzle 21 includes a common liquid chamber 90 into which liquid is supplied. Liquid is supplied from the liquid supply source 18 to the common liquid chamber 90 via a supply channel 19. The supply channel 19 is connected to the common liquid chamber 90. A filter 91 may also be provided on the common liquid chamber 90 to capture air bubbles, foreign matter, etc., in the supplied liquid. The common liquid chamber 90 stores the liquid passing through the filter 91.

[0047] The liquid nozzle 21 has multiple pressure chambers 92 communicating with a common liquid chamber 90. The nozzle 21B is arranged corresponding to the multiple pressure chambers 92. The pressure chambers 92 communicate with both the common liquid chamber 90 and the nozzle 21B. A portion of the wall of each pressure chamber 92 is formed by a vibrating plate 93. The common liquid chamber 90 and the pressure chambers 92 are interconnected via a supply-side communication channel 94.

[0048] The liquid ejection head 21 has a plurality of actuators 95 provided in a manner corresponding to the plurality of pressure chambers 92. The actuators 95 are provided on a surface of the vibration plate 93 opposite to a surface facing the pressure chambers 92. The actuators 95 are housed in housing chambers 96 provided at positions different from the common liquid chamber 90. The liquid ejection head 21 ejects the liquid of the pressure chambers 92 from the nozzles 21B as liquid droplets by driving of the actuators 95. The liquid ejection head 21 performs a printing process on the medium M by ejecting the liquid from the nozzles 21B toward the medium M.

[0049] The actuator 95 of the present embodiment is composed of a piezoelectric element that contracts when a driving voltage is applied thereto. When the application of the driving voltage to the actuator 95 is released after the vibration plate 93 is deformed in conjunction with the contraction of the actuator 95 caused by the application of the driving voltage, the liquid in the pressure chamber 92 whose volume has changed is ejected from the nozzle 21B as a liquid droplet.

[0050] The liquid ejection head 21 has a discharge flow path 97. The discharge flow path 97 is connected to the common liquid chamber 90 and the recovery flow path 35 to discharge the liquid in the common liquid chamber 90 to the outside without passing through the pressure chambers 92. In this way, the discharge flow path 97 can discharge the liquid in the liquid ejection head 21 to the recovery flow path 35 without passing through the pressure chambers 92 that communicate with the nozzles 21B. Here, the discharge flow path 97 can also be configured to discharge the liquid to the outside via the pressure chambers 92.

[0051] The reservoir 40 has a replenishment reservoir 31, a suction valve 32, and an ejection valve 33. The replenishment reservoir 31, the suction valve 32, and the ejection valve 33 are located on the supply flow path 19. The replenishment reservoir 31 is configured to be able to store the liquid supplied from the liquid supply source 18. The liquid stored in the replenishment reservoir 31 is supplied to the liquid ejection head 21 via a first reservoir 41 described later. That is, the replenishment reservoir 31 stores the liquid for replenishment to the first reservoir 41. The suction valve 32 is located on the supply flow path 19 upstream of the replenishment reservoir 31 in the supply direction A. The ejection valve 33 is located on the supply flow path 19 downstream of the replenishment reservoir 31 in the supply direction A. The suction valve 32 is configured to permit the flow of the liquid from the upstream to the downstream on the supply flow path 19, and restrict the flow of the liquid from the downstream to the upstream. The ejection valve 33 is configured to permit the flow of the liquid from the upstream to the downstream on the supply flow path 19, and restrict the flow of the liquid from the downstream to the upstream.

[0052] The reservoir 40 includes a first reservoir 41, a second reservoir 42, and a third reservoir 43. The first reservoir 41 is provided on the supply flow path 19. The first reservoir 41 is located downstream of the ejection valve 33 in the supply direction A and is connected to the replenishment reservoir 31 via the ejection valve 33 on the supply flow path 19. The liquid stored in the replenishment reservoir 31 is supplied to the first reservoir 41 via the ejection valve 33. In this way, the first reservoir 41 is configured to be able to store the liquid supplied from the liquid supply source 18. The supply flow path 19 communicates the first reservoir 41 with the liquid ejection head 21. Therefore, the first reservoir 41 is configured to be able to store the liquid supplied to the liquid ejection head 21 via the supply flow path 19.

[0053] The recovery flow path 35 includes a first recovery flow path 35A, a second recovery flow path 35B, and a third recovery flow path 35C. The first recovery flow path 35A is a flow path connecting the second reservoir 42 from the liquid ejection head 21 side. The second recovery flow path 35B is a flow path connecting the second reservoir 42 and the third reservoir 43. The third recovery flow path 35C is a flow path connecting the third reservoir 43 and the first reservoir 41. That is, the first recovery flow path 35A communicates the liquid ejection head 21 with the second reservoir 42. The second recovery flow path 35B communicates the second reservoir 42 with the third reservoir 43. The third recovery flow path 35C communicates the third reservoir 43 with the first reservoir 41.

[0054] The second reservoir 42 is provided on the recovery flow path 35. The second reservoir 42 is able to store the liquid recovered from the liquid ejection head 21 via the first recovery flow path 35A.

[0055] The third reservoir 43 is provided on the recovery flow path 35. The third reservoir 43 is able to store the liquid recovered from the liquid ejection head 21 via the second recovery flow path 35B. That is, the third reservoir 43 is configured to be able to store the liquid recovered from the liquid ejection head 21 between the second reservoir 42 and the first reservoir 41.

[0056] The first reservoir 41 is able to store the liquid recovered from the liquid ejection head 21 via the third recovery flow path 35C. In this way, in the present embodiment, the first reservoir 41 corresponds to one example of the connection portion of the supply flow path 19 to which the recovery flow path 35 is connected.

[0057] The reservoir 40 includes a first check valve 44 and a second check valve 45. The first check valve 44 is provided on the second recovery flow passage 35B. The first check valve 44 is configured to allow the flow of liquid from the upstream to the downstream on the recovery flow passage 35, and restrict the flow of liquid from the downstream to the upstream. The second check valve 45 is provided on the third recovery flow passage 35C. The second check valve 45 is configured to allow the flow of liquid from the upstream to the downstream on the recovery flow passage 35, and restrict the flow of liquid from the downstream to the upstream. That is, the first check valve 44 allows the flow of liquid from the second reservoir 42 toward the third reservoir 43, and restricts the flow of liquid from the third reservoir 43 toward the second reservoir 42 on the second recovery flow passage 35B. The second check valve 45 allows the flow of liquid from the third reservoir 43 toward the first reservoir 41, and restricts the flow of liquid from the first reservoir 41 toward the third reservoir 43 on the third recovery flow passage 35C.

[0058] The reservoir 40 includes a first reservoir amount detection section 46. The first reservoir amount detection section 46 is capable of detecting the amount of liquid stored in the first reservoir 41. In the present embodiment, the first reservoir amount detection section 46 is capable of detecting at least the case where the amount of liquid stored in the first reservoir 41 is equal to or less than a first prescribed amount, and the case where the amount of liquid stored in the first reservoir 41 is equal to or less than a second prescribed amount. The first prescribed amount is a reference amount at which the first reservoir 41 needs to be replenished with liquid. The second prescribed amount is a reference amount used to determine whether the liquid stored in the first reservoir 41 has been sufficiently replenished. The second prescribed amount is greater than the first prescribed amount.

[0059] The reservoir 40 includes a replenishment reservoir amount detection section 39. The replenishment reservoir amount detection section 39 is capable of detecting the amount of liquid stored in the replenishment reservoir 31. In the present embodiment, the replenishment reservoir amount detection section 39 is capable of detecting at least the case where the amount of liquid stored in the replenishment reservoir 31 is equal to or less than a third prescribed amount. The third prescribed amount is a reference amount that is an upper limit for the supply of liquid to the replenishment reservoir 31.

[0060] In the case where liquid is being supplied to the liquid ejection head 21 from the first reservoir 41, when the amount of liquid stored in the first reservoir 41 becomes the first prescribed amount, liquid is replenished to the first reservoir 41 from the third reservoir 43 over a second time period, the details of which will be described later.

[0061] In the present embodiment, when the amount of liquid stored in at least one of the first reservoirs 41 becomes the first prescribed amount, liquid is replenished to the first reservoirs 41 from the third reservoirs 43, respectively.

[0062] As a result of the liquid being replenished from the third reservoir 43 to the first reservoir 41 over the second time, in a case where the amount of liquid stored in the first reservoir 41 is not less than the second prescribed amount, the liquid is not replenished from the liquid supply source 18 to the replenishment reservoir 31. On the other hand, as a result of the liquid being replenished from the third reservoir 43 to the first reservoir 41 over the second time, in a case where the amount of liquid stored in the first reservoir 41 is less than the second prescribed amount, the liquid is supplied from the liquid supply source 18 to the replenishment reservoir 31 that communicates with the first reservoir 41 that is less than the second prescribed amount.

[0063] In a case where the liquid is supplied from the liquid supply source 18 to the replenishment reservoir 31, when the amount of liquid stored in the replenishment reservoir 31 becomes the third prescribed amount, the supply of liquid from the liquid supply source 18 to the replenishment reservoir 31 is ended.

[0064] The reservoir 40 is provided with a first temperature adjustment section 47, a second temperature adjustment section 48, a third temperature adjustment section 49, and a replenishment temperature adjustment section 34. The first temperature adjustment section 47 is provided on the first reservoir 41. The first temperature adjustment section 47 adjusts the temperature in a manner that heats the liquid stored in the first reservoir 41. The second temperature adjustment section 48 is provided on the second reservoir 42. The second temperature adjustment section 48 adjusts the temperature in a manner that heats the liquid stored in the second reservoir 42. The third temperature adjustment section 49 is provided on the third reservoir 43. The third temperature adjustment section 49 adjusts the temperature in a manner that heats the liquid stored in the third reservoir 43. The replenishment temperature adjustment section 34 is provided on the replenishment reservoir 31. The replenishment temperature adjustment section 34 adjusts the temperature in a manner that heats the liquid stored in the replenishment reservoir 31. Although in the present embodiment, each of the temperature adjustment sections 34, 47 to 49 is, for example, a structure in which a heater is operated to cause the heat generated by the heater to be transmitted to the liquid of each reservoir via a metal plate, but is not limited thereto. In addition, the heater and the metal plate are provided on the wall surface of each reservoir, and can also be integrally formed with each reservoir, thereby enabling a reduction in space. In the present embodiment, the first temperature adjustment section 47, the second temperature adjustment section 48, the third temperature adjustment section 49, and the replenishment temperature adjustment section 34 correspond to one example of the heating section.

[0065] The reservoir 40 is provided with a second atmosphere communication passage 38G and a pressurization opening section 56. The second atmosphere communication passage 38G is connected to the first reservoir 41. That is, in the present embodiment, the second atmosphere communication passage 38G is provided on the first reservoir 41. The second atmosphere communication passage 38G communicates with the atmosphere.

[0066] The pressurization opening portion 56 is provided on the second atmosphere communication passage 38G. The pressurization opening portion 56 is connected with the first storage portion 41 via the second atmosphere communication passage 38G. The pressurization opening portion 56 is capable of switching whether or not to communicate with the atmosphere. The pressurization opening portion 56, when the positive pressure on the first storage portion 41 side via the second atmosphere communication passage 38G exceeds a predetermined positive pressure, opens the second atmosphere communication passage 38G and causes the first storage portion 41 to communicate with the atmosphere. In this way, since the first storage portion 41 communicates with the atmosphere when it becomes the predetermined positive pressure, it is possible to suppress the case of excessive pressurization that significantly exceeds the predetermined positive pressure. In the present embodiment, although 45 kPa is conformed to as this predetermined positive pressure, it is not limited thereto.

[0067] The storage portion 40 is provided with a replenishment communication flow passage 38H, a first atmosphere communication passage 38I, a first negative pressure opening portion 57, and a second negative pressure opening portion 59. The replenishment communication flow passage 38H is connected with the second storage portion 42 and the replenishment storage portion 31. The replenishment communication flow passage 38H is a flow passage that communicates the second storage portion 42 with the replenishment storage portion 31.

[0068] The first negative pressure opening portion 57 is located at the second storage portion 42 side on the replenishment communication flow passage 38H. The first negative pressure opening portion 57 opens the replenishment communication flow passage 38H when the negative pressure on the second storage portion 42 side via the replenishment communication flow passage 38H is lower than a predetermined negative pressure. In the present embodiment, although -35 kPa is conformed to as this predetermined negative pressure, it is not limited thereto.

[0069] The first atmosphere communication passage 38I is connected with the replenishment communication flow passage 38H via the replenishment switching portion 58 described later. The first atmosphere communication passage 38I communicates with the atmosphere at the replenishment communication flow passage 38H.

[0070] The second negative pressure opening portion 59 opens the first atmosphere communication passage 38I when the negative pressure on the replenishment communication flow passage 38H side via the replenishment communication flow passage 38H is lower than a predetermined negative pressure. In the present embodiment, although -35 kPa is conformed to as this predetermined negative pressure, it is not limited thereto.

[0071] In the present embodiment, the flow passage 38E that connects the decompression switching portion 54 and the replenishment storage portion 31 via the second storage portion 42 and the replenishment communication flow passage 38H are denoted as a second communication flow passage 38J. The second communication flow passage 38J is constituted by the flow passage 38E and the replenishment communication flow passage 38H, and can be said to include the replenishment communication flow passage 38H.

[0072] The liquid circulating device 30 is provided with a circulating device 50. The circulating device 50 is provided with a pressurization pump 51, a decompression pump 52, a pressurization switching portion 53, a decompression switching portion 54, a first atmosphere opening portion 55A, a second atmosphere opening portion 55B, and a replenishment switching portion 58.

[0073] The pressurization switching section 53 is connected to the pressurization pump 51 via the flow path 38A. The pressurization switching section 53 is configured to be connectable to the replenishment reservoir 31 via a first communication flow path 38B. That is, the first communication flow path 38B communicates the pressurization switching section 53 with the replenishment reservoir 31. The pressurization switching section 53 is configured to be connectable to the third reservoir 43 via a flow path 38C. The pressurization switching section 53 is capable of switching between connecting the pressurization pump 51 to the replenishment reservoir 31 and connecting the pressurization pump 51 to the third reservoir 43 according to an instruction of a control section 100 described later. That is, the pressurization switching section 53 is capable of switching the subject to be pressurized by the pressurization pump 51 according to the instruction of the control section 100. Further, the pressurization pump 51 is configured to be capable of pressurizing the third reservoir 43 and the replenishment reservoir 31. The pressurization switching section 53 is shared in accordance with the kind of liquid to be ejected from the liquid ejection head 21. The pressurization switching section 53 of the present embodiment has one switching section.

[0074] The depressurization switching section 54 is connected to the depressurization pump 52 via a flow path 38D. The depressurization switching section 54 is configured to be connectable to the second reservoir 42 via a flow path 38E. The depressurization switching section 54 is configured to be connectable to the third reservoir 43 via a flow path 38F. The depressurization switching section 54 is capable of switching between connecting the depressurization pump 52 to the second reservoir 42 and connecting the depressurization pump 52 to the second reservoir 42 according to an instruction of the control section 100. That is, the depressurization switching section 54 is capable of switching the subject to be depressurized by the depressurization pump 52 according to the instruction of the control section 100. Further, the depressurization pump 52 is configured to be capable of depressurizing the second reservoir 42 and the third reservoir 43. The depressurization switching section 54 is shared in accordance with the kind of liquid to be ejected from the liquid ejection head 21. The depressurization switching section 54 of the present embodiment has one switching section. Although the flow path 38C and the flow path 38F are flow paths that are merged at the third reservoir 43 side in the present embodiment, the present embodiment is not limited thereto.

[0075] The first atmosphere opening section 55A is connected to the flow path 38C and the flow path 38F. The first atmosphere opening section 55A is capable of switching whether to communicate the flow path 38C and the flow path 38F with the atmosphere according to an instruction of the control section 100. That is, the first atmosphere opening section 55A is configured to be capable of opening the flow paths 38C, 38F that communicate the third reservoir 43 with the pressurization switching section 53 and the depressurization switching section 54 to the atmosphere. In other words, the first atmosphere opening section 55A is connected to the third reservoir 43 and is capable of switching whether to communicate the third reservoir 43 with the atmosphere according to the instruction of the control section 100. The first atmosphere opening section 55A is shared in accordance with the kind of liquid to be ejected from the liquid ejection head 21. The first atmosphere opening section 55A of the present embodiment has one opening section.

[0076] The second atmosphere opening portion 55B is connected to the first communication flow path 38B. The second atmosphere opening portion 55B is capable of switching whether or not the first communication flow path 38B is communicated with the atmosphere, according to an instruction of the control portion 100. That is, the second atmosphere opening portion 55B is configured to be capable of opening the first communication flow path 38B to the atmosphere. In other words, the second atmosphere opening portion 55B is connected to the supplementary reservoir portion 31, and is capable of switching whether or not the supplementary reservoir portion 31 is communicated with the atmosphere, according to an instruction of the control portion 100.

[0077] In the present embodiment, the flow path 38A is constituted by one flow path, and is shared in accordance with the kind of liquid to be ejected from the liquid ejection head 21. The first communication flow path 38B is branched from one flow path to a plurality of flow paths at the side of the supplementary reservoir portion 31 compared to the second atmosphere opening portion 55B, and the branched plurality of flow paths are connected to the plurality of supplementary reservoir portions 31, respectively. The flow path 38C is branched from one flow path to a plurality of flow paths at the side of the third reservoir portion 43 compared to the first atmosphere opening portion 55A, and the branched plurality of flow paths are connected to the plurality of third reservoir portions 43, respectively. The flow path 38D is constituted by one flow path, and is shared in accordance with the kind of liquid to be ejected from the liquid ejection head 21. The flow path 38E is branched from one flow path to a plurality of flow paths, and the branched plurality of flow paths are connected to the plurality of second reservoir portions 42, respectively. The flow path 38F is branched from one flow path to a plurality of flow paths at the side of the third reservoir portion 43 compared to the first atmosphere opening portion 55A, and the branched plurality of flow paths are connected to the plurality of third reservoir portions 43, respectively.

[0078] The supplementary switching portion 58 is provided on the supplementary communication flow path 38H. The supplementary switching portion 58 is located on the supplementary communication flow path 38H between the first negative pressure opening portion 57 and the supplementary reservoir portion 31. The supplementary switching portion 58 is configured to be capable of being connected to the first atmosphere communication passage 38I. The supplementary switching portion 58 is capable of switching whether or not the second reservoir portion 42 is communicated with the supplementary reservoir portion 31, according to an instruction of the control portion 100. That is, the supplementary switching portion 58 is configured to be capable of switching a first communication state in which the second reservoir portion 42 and the supplementary reservoir portion 31 are communicated, and a second communication state in which the second reservoir portion 42 and the first atmosphere communication passage 38I are communicated. In this way, the supplementary switching portion 58 is capable of switching whether or not the supplementary reservoir portion 31 is depressurized, according to an instruction of the control portion 100. In the present embodiment, the supplementary switching portion 58 is provided in plurality in a manner corresponding to the kind of liquid to be ejected from the liquid ejection head 21. The supplementary switching portion 58 of the present embodiment is provided with four supplementary switching portions 58. In addition, in a case where the kind of liquid to be ejected from the liquid ejection head 21 is one kind, the liquid ejection apparatus 10 can be provided with one supplementary switching portion 58.

[0079] In this embodiment, when the second reservoir 42 is depressurized by the pressure reducing pump 52, the first negative pressure opening section 57 opens the supplementary communication channel 38H when the negative pressure on the second reservoir 42 side is lower than a predetermined negative pressure. In this case, when the supplementary switching section 58 is controlled to the first communication state, the first negative pressure opening section 57 and the supplementary reservoir 31 are connected. Therefore, the supplementary reservoir 31 is depressurized by the pressure reducing pump 52, and liquid in the liquid supply source 18 is supplied to the supplementary reservoir 31. On the other hand, when the supplementary switching section 58 is controlled to the second communication state, the first negative pressure opening section 57 and the second negative pressure opening section 59 are connected. Therefore, the supplementary reservoir 31 is not depressurized by the pressure reducing pump 52, and liquid in the liquid supply source 18 is not supplied to the supplementary reservoir 31. Furthermore, the second negative pressure opening section 59 opens the first atmospheric communication channel 38I when the negative pressure on the supplementary communication channel 38H side is lower than a predetermined negative pressure. As a result, the second reservoir 42 is opened to the atmosphere, thereby preventing the second reservoir 42 from becoming excessively negative, significantly lower than the predetermined negative pressure.

[0080] In this embodiment, during the control state where the pressurization switching unit 53 is controlled according to the instruction of the control unit 100, there are a first pressurization state and a second pressurization state. In this embodiment, during the control state where the depressurization switching unit 54 is controlled according to the instruction of the control unit 100, there are a first depressurization state and a second depressurization state. In this embodiment, during the control state where the supplementary switching unit 58 is controlled according to the instruction of the control unit 100, there are a first connection state and a second connection state.

[0081] like Figure 4 As shown, the first pressurization state is a state in which the pressurization pump 51 and the replenishment reservoir 31 are connected, and the replenishment reservoir 31 is pressurized by the pressurization pump 51. The first reservoir 41 is connected to the pressurization pump 51 via the replenishment reservoir 31. Therefore, the first pressurization state is a state in which the pressurization pump 51 and the first reservoir 41 are connected via the replenishment reservoir 31, and the first reservoir 41 is pressurized by the pressurization pump 51 via the replenishment reservoir 31. In addition, if there is no liquid stored in the replenishment reservoir 31, no liquid is replenished from the replenishment reservoir 31 to the first reservoir 41.

[0082] When the first reservoir 41 is pressurized by the pressurizing pump 51, the liquid stored in the first reservoir 41 is restricted from flowing to the third recovery channel 35C by the second check valve 45. Therefore, the liquid stored in the first reservoir 41 flows in the supply channel 19 along the supply direction A toward the liquid nozzle 21.

[0083] The second depressurization state is characterized by the depressurization pump 52 and the third reservoir 43 being connected, with the third reservoir 43 being depressurized by the depressurization pump 52. When the third reservoir 43 is depressurized by the depressurization pump 52, the liquid stored in the first reservoir 41 is restricted from flowing to the third recovery channel 35C by the second check valve 45. Therefore, the liquid stored in the second reservoir 42 flows to the third reservoir 43 via the second recovery channel 35B and along the recovery direction B.

[0084] The second connection state is a state in which the second reservoir 42 and the second negative pressure opening 59 can be connected via the supplementary connection channel 38H and the first atmospheric connection channel 38I. The second connection state is a state in which the second reservoir 42 and the supplementary reservoir 31 are not connected via the supplementary connection channel 38H. Thus, the second connection state is a state in which even if the second reservoir 42 is depressurized by the pressure reducing pump 52, the supplementary reservoir 31, which is not connected to the second reservoir 42, will not be depressurized.

[0085] On the other hand, such as Figure 5 As shown, the first depressurization state is when the depressurization pump 52 is connected to the second reservoir 42 and the second reservoir 42 is depressurized by the depressurization pump 52. When the second reservoir 42 is depressurized by the depressurization pump 52, the flow of liquid stored in the third reservoir 43 to the second recovery channel 35B is restricted by the first check valve 44. Therefore, liquid from the liquid nozzle 21 flows to the second reservoir 42 via the first recovery channel 35A and along the recovery direction B.

[0086] The second pressurization state is characterized by the pressurization pump 51 being connected to the third reservoir 43 and the third reservoir 43 being pressurized by the pressurization pump 51. When the third reservoir 43 is pressurized by the pressurization pump 51, the flow of liquid stored in the third reservoir 43 to the second recovery channel 35B is restricted by the first check valve 44. Therefore, the liquid stored in the third reservoir 43 flows towards the first reservoir 41 in the third recovery channel 35C along the recovery direction B.

[0087] In addition, such as Figure 6 As shown, the first pressurization state is when the replenishment reservoir 31 is pressurized by the pressurization pump 51. When liquid is stored in the replenishment reservoir 31, and the system is controlled to be in the first pressurization state, liquid is replenished from the replenishment reservoir 31 to the first reservoir 41. In this case, the first reservoir 41 is pressurized by the pressurization pump 51 via the replenishment reservoir 31 and the supply channel 19.

[0088] On the other hand, such as Figure 7As shown, the first connection state is when the second reservoir 42 and the replenishment reservoir 31 are connected via the replenishment connection channel 38H. The first connection state is when the second reservoir 42 and the second negative pressure opening 59 are not connected via the replenishment connection channel 38H and the first atmospheric connection channel 38I. Thus, the first connection state is when the replenishment reservoir 31 is depressurized via the second reservoir 42 when the second reservoir 42 is depressurized by the pressure reducing pump 52.

[0089] When the pressure in the replenishment reservoir 31 is reduced by the pressure reducing pump 52, the flow of liquid stored in the first reservoir 41 to the replenishment reservoir 31 is restricted by the ejection valve 33. In addition, liquid in the liquid supply source 18 flows to the replenishment reservoir 31 via the supply channel 19 and along the supply direction A.

[0090] like Figure 3 As shown, the pressure regulating device 60, serving as the supply channel 19, includes a supply branch 61A, a first positive pressure supply channel 62A, a second positive pressure supply channel 62B, and a supply manifold 61B. The supply branch 61A is provided on the supply channel 19 at the side of the first reservoir 41. The supply branch 61A branches the supply channel 19 into the first positive pressure supply channel 62A and the second positive pressure supply channel 62B. The supply manifold 61B is provided on the supply channel 19 at the side of the liquid nozzle 21. The supply manifold 61B merges the first positive pressure supply channel 62A and the second positive pressure supply channel 62B. Thus, the supply branch 61A, the first positive pressure supply channel 62A, the second positive pressure supply channel 62B, and the supply manifold 61B are provided between the first reservoir 41 and the liquid nozzle 21 within the supply channel 19.

[0091] The pressure regulating device 60 includes a positive pressure regulating section 63 and a positive pressure on / off valve 64. The positive pressure regulating section 63 includes a first positive pressure regulating section 63A and a second positive pressure regulating section 63B. The positive pressure on / off valve 64 includes a first positive pressure on / off valve 64A and a second positive pressure on / off valve 64B.

[0092] The first positive pressure on / off valve 64A is provided on the supply branch 61A side of the first positive pressure supply channel 62A. The first positive pressure on / off valve 64A is configured to open and close the first positive pressure supply channel 62A according to the instruction of the control unit 100.

[0093] The second positive pressure on / off valve 64B is provided on the supply branch 61A side of the second positive pressure supply channel 62B. The second positive pressure on / off valve 64B is configured to open and close the second positive pressure supply channel 62B according to the instruction of the control unit 100.

[0094] Thus, in the present embodiment, the positive pressure on-off valve 64 is configured to be able to switch the flow path of the liquid flowing to the first positive pressure supply flow path 62A and the second positive pressure supply flow path 62B in the supply flow path 19. In the present embodiment, the positive pressure on-off valve 64 includes a first positive pressure on-off valve 64A and a second positive pressure on-off valve 64B that are respectively provided on the first positive pressure supply flow path 62A and the second positive pressure supply flow path 62B in the supply flow path 19.

[0095] The first positive pressure regulating portion 63A is provided on the first positive pressure supply flow path 62A at a position downstream of the first positive pressure on-off valve 64A in the supply direction A. The first positive pressure regulating portion 63A is an on-off valve that opens the first positive pressure supply flow path 62A by causing the pressure on the liquid ejection head 21 side to be a first positive pressure. In the present embodiment, although 5.64 kPa, for example, is conformed to as the first positive pressure, it is not limited thereto.

[0096] The second positive pressure regulating portion 63B is provided on the second positive pressure supply flow path 62B at a position downstream of the second positive pressure on-off valve 64B in the supply direction A. The second positive pressure regulating portion 63B is an on-off valve that opens the second positive pressure supply flow path 62B by causing the pressure on the liquid ejection head 21 side to be a second positive pressure. In the present embodiment, although 31.23 kPa, for example, is conformed to as the second positive pressure that is greater than the first positive pressure, it is not limited thereto.

[0097] Thus, in the present embodiment, the first positive pressure regulating portion 63A and the second positive pressure regulating portion 63B are a plurality of positive pressure regulating portions 63 that open the flow path by causing the pressure on the liquid ejection head 21 side to be lower than a predetermined positive pressure. In the present embodiment, the first positive pressure regulating portion 63A and the second positive pressure regulating portion 63B cause the predetermined positive pressure at which the flow path is opened to be different for each of the first positive pressure supply flow path 62A and the second positive pressure supply flow path 62B.

[0098] The pressure regulating device 60 is provided with a recovery branch portion 66A, a first negative pressure recovery flow path 67A, a second negative pressure recovery flow path 67B, and a recovery confluence portion 66B as the recovery flow path 35. The recovery branch portion 66A is provided on the recovery flow path 35 at the liquid ejection head 21 side. The recovery branch portion 66A branches the recovery flow path 35 into the first positive pressure supply flow path 62A and the second positive pressure supply flow path 62B. The recovery confluence portion 66B is provided on the recovery flow path 35 at the second reservoir portion 42 side. The recovery confluence portion 66B confluences the first negative pressure recovery flow path 67A and the second negative pressure recovery flow path 67B. Thus, between the liquid ejection head 21 and the first reservoir portion 41 in the recovery flow path 35, the recovery branch portion 66A, the first negative pressure recovery flow path 67A, the second negative pressure recovery flow path 67B, and the recovery confluence portion 66B are provided.

[0099] The pressure adjusting device 60 has a negative pressure adjusting section 68 and a negative pressure on-off valve 69. The negative pressure adjusting section 68 has a first negative pressure adjusting section 68A and a second negative pressure adjusting section 68B. The negative pressure on-off valve 69 has a first negative pressure on-off valve 69A and a second negative pressure on-off valve 69B.

[0100] The first negative pressure on-off valve 69A is provided on the first negative pressure recovery flow passage 67A at the recovery branch section 66A side. The first negative pressure on-off valve 69A is an on-off valve configured to be able to open and close the first negative pressure recovery flow passage 67A according to an instruction of the control section 100.

[0101] The second negative pressure on-off valve 69B is provided on the second negative pressure recovery flow passage 67B at the recovery branch section 66A side. The second negative pressure on-off valve 69B is an on-off valve configured to be able to open and close the second negative pressure recovery flow passage 67B according to an instruction of the control section 100.

[0102] Thus, in the present embodiment, the negative pressure on-off valve 69 is configured to be able to switch the flow passage of the liquid to the first negative pressure recovery flow passage 67A and the second negative pressure recovery flow passage 67B in the recovery flow passage 35. In the present embodiment, the negative pressure on-off valve 69 includes the first negative pressure on-off valve 69A and the second negative pressure on-off valve 69B provided on each of the first negative pressure recovery flow passage 67A and the second negative pressure recovery flow passage 67B in the recovery flow passage 35.

[0103] The first negative pressure adjusting section 68A is provided on the first negative pressure recovery flow passage 67A at an upstream side of the recovery direction B compared to the first negative pressure on-off valve 69A. The first negative pressure adjusting section 68A is an on-off valve that opens the first negative pressure recovery flow passage 67A by making the pressure of the liquid ejection head 21 side a first negative pressure. In the present embodiment, although -2.76 kPa corresponds thereto as the first negative pressure, it is not limited thereto.

[0104] The second negative pressure adjusting section 68B is provided on the second negative pressure recovery flow passage 67B at an upstream side of the recovery direction B compared to the second negative pressure on-off valve 69B. The second negative pressure adjusting section 68B is an on-off valve that opens the second negative pressure recovery flow passage 67B by making the pressure of the liquid ejection head 21 side a second negative pressure. In the present embodiment, although -8.27 kPa corresponds thereto as the second negative pressure that is smaller than the first positive pressure, it is not limited thereto.

[0105] In the present embodiment, the supply flow passage 19, the reservoir 40, the pressure adjusting device 60, the recovery flow passage 35, and the various flow passages 38G to 38I function as the liquid circulation mechanism 37. The liquid circulation device 30 has a plurality of liquid circulation mechanisms 37. The plurality of liquid circulation mechanisms 37 are configured to be able to be pressurized by the common pressurizing pump 51 and to be depressurized by the common depressurizing pump 52.

[0106] In this embodiment, at least one of the supply branch 61A and the recovery branch 66A corresponds to an example of a branch. In this embodiment, at least one of the first positive pressure supply channel 62A and the second positive pressure supply channel 62B as the supply channel 19, and the first negative pressure recovery channel 67A and the second negative pressure recovery channel 67B as the recovery channel 35, corresponds to an example of a plurality of channels. In this embodiment, at least one of the supply manifold 61B and the recovery manifold 66B corresponds to an example of a manifold.

[0107] In this embodiment, the positive pressure on / off valve 64 and the negative pressure on / off valve 69 correspond to an example of a flow channel switching unit. In this embodiment, the positive pressure on / off valve 64 corresponds to an example of a first flow channel switching unit. That is, the flow channel switching unit includes a first flow channel switching unit. In this embodiment, the negative pressure on / off valve 69 corresponds to an example of a second flow channel switching unit. That is, the flow channel switching unit includes a second flow channel switching unit.

[0108] Next, refer to Figure 8 as well as Figure 9 The various pressure regulating sections of the pressure regulating device 60 will be described. Here, the first positive pressure regulating section 63A and the first negative pressure regulating section 68A will be used as examples.

[0109] like Figure 8 As shown, the first positive pressure regulating unit 63A includes a pressure regulating mechanism 71. The pressure regulating mechanism 71 forms part of the supply channel 19. The pressure regulating mechanism 71 includes a main body 73. A liquid inlet 74 and a liquid outlet 75 are formed on the main body 73. Liquid supplied from the liquid supply source 18 via the supply channel 19 flows into the liquid inlet 74. The liquid outlet 75 is configured to internally collect liquid. In this embodiment, the liquid outlet 75 corresponds to a liquid storage chamber communicating with the liquid nozzle 21. The liquid outlet 75 is included in the pressure regulating device 60. Therefore, in this embodiment, the liquid outlet 75 is positioned in the same manner as the pressure regulating device 60, overlapping the plane of the liquid nozzle 21 along a direction orthogonal to the width direction X.

[0110] At least a portion of the wall surface of the liquid outflow portion 75 is constituted by a diaphragm 76. The diaphragm 76 receives the pressure of the liquid in the liquid outflow portion 75 by a first face 76A which becomes the inner surface of the liquid outflow portion 75. The diaphragm 76 receives the atmospheric pressure by a second face 76B which becomes the outer surface of the liquid outflow portion 75. Therefore, the diaphragm 76 is displaced according to the pressure in the liquid outflow portion 75. The liquid outflow portion 75 changes the volume by the displacement of the diaphragm 76. The liquid inflow portion 74 and the liquid outflow portion 75 are communicated with each other by the communication path 77.

[0111] The pressure adjusting mechanism 71 is provided with a pressure adjusting on-off valve 78. The pressure adjusting on-off valve 78 is capable of switching between a closed valve state in which the liquid inflow portion 74 and the liquid outflow portion 75 are shut off on the communication path 77, and an open valve state in which the liquid inflow portion 74 and the liquid outflow portion 75 are communicated. The pressure adjusting on-off valve 78 is provided with a valve portion 78A and a pressure receiving portion 78B. The valve portion 78A is configured to be capable of shutting off the communication path 77. The pressure receiving portion 78B receives the pressure from the diaphragm 76. The pressure adjusting on-off valve 78 is displaced by the diaphragm 76 pressing the pressure receiving portion 78B. That is, the pressure receiving portion 78B also functions as a displacement member which is capable of being displaced in a state in which the diaphragm 76 which is displaced in the direction in which the volume of the liquid outflow portion 75 is reduced is contacted.

[0112] A pressing member 79 is provided in the liquid inflow portion 74. The pressing member 79 is capable of pressing the pressure adjusting on-off valve 78 in the direction in which it is closed. The pressure adjusting on-off valve 78 changes from the closed valve state to the open valve state when the pressure applied to the first face 76A is lower than the pressure applied to the second face 76B, and the difference between the pressure applied to the first face 76A and the pressure applied to the second face 76B becomes a predetermined value or more. As the predetermined value of the first positive pressure adjusting portion 63A, for example, 5.64 kPa which is the first positive pressure is conformed to.

[0113] The predetermined value is a value which is decided according to the force of the pressing force of the pressing member 79, the force which is required in order to displace the diaphragm 76, the pressing force which is required in order to shut off the communication path 77 by the valve portion 78A, i.e. the sealing load, the pressure in the liquid inflow portion 74 which acts on the surface of the valve portion 78A, and the pressure in the liquid outflow portion 75. That is, the greater the pressing force of the pressing member 79, the greater the predetermined value which is used in order to change from the closed valve state to the open valve state.

[0114] In the present embodiment, in a case where the pressure regulating open / close valve 78 is in the closed valve state in the pressure regulating mechanism 71, the pressure of the liquid on the upstream side of the pressure regulating mechanism 71 is normally set to positive pressure by the pressure pump 51. In detail, in a case where the pressure regulating open / close valve 78 is in the closed valve state, the pressure of the liquid at the liquid inflow portion 74 and the liquid inflow portion 74 on the upstream side is normally set to positive pressure by the pressure pump 51.

[0115] In the present embodiment, in a case where the pressure regulating open / close valve 78 is in the closed valve state in the pressure regulating mechanism 71, the pressure of the liquid on the downstream side of the pressure regulating mechanism 71 is normally set to positive pressure by the diaphragm 76. In detail, in a case where the pressure regulating open / close valve 78 is in the closed valve state, the pressure of the liquid at the liquid outflow portion 75 and the liquid outflow portion 75 on the downstream side is normally set to positive pressure by the diaphragm 76.

[0116] When the liquid ejection head 21 ejects liquid, the liquid housed in the liquid outflow portion 75 is supplied to the liquid ejection head 21 via the supply flow path 19. In this case, the pressure in the liquid outflow portion 75 will decrease. Thus, when the difference between the pressure applied to the first face 76A in the diaphragm 76 and the pressure applied to the second face 76B becomes equal to or greater than a predetermined value, the diaphragm 76 is deformed in a direction in which the volume of the liquid outflow portion 75 decreases. When the pressure receiving portion 78B moves due to being pressed in conjunction with the deformation of the diaphragm 76, the pressure regulating open / close valve 78 becomes in the open valve state.

[0117] When the pressure regulating open / close valve 78 becomes in the open valve state, since the liquid in the liquid inflow portion 74 is pressurized by the pressure pump 51, the liquid is supplied from the liquid inflow portion 74 to the liquid outflow portion 75. Thus, the pressure in the liquid outflow portion 75 will increase. When the pressure in the liquid outflow portion 75 increases, the diaphragm 76 is deformed in a manner in which the volume of the liquid outflow portion 75 increases. When the difference between the pressure applied to the first face 76A in the diaphragm 76 and the pressure applied to the second face 76B is less than a predetermined value, the pressure regulating open / close valve 78 becomes in the closed valve state from the open valve state. As a result, the pressure regulating open / close valve 78 hinders the flow of the liquid from the liquid inflow portion 74 to the liquid outflow portion 75.

[0118] As described above, the pressure of the liquid supplied to the liquid ejection head 21 is regulated by the displacement of the diaphragm 76 by the pressure regulating mechanism 71, and thus the pressure in the liquid ejection head 21, which becomes the back pressure of the nozzle 21B, is regulated.

[0119] The first positive pressure regulating portion 63A includes a pressing mechanism 72. The pressing mechanism 72 presses the pressure regulating mechanism 71 via the diaphragm 76. The pressing mechanism 72 includes a pressing member 72A.

[0120] The push member 72A is formed, for example, in a bottomed cylindrical shape. The push member 72A forms an air chamber 72B. The air chamber 72B covers the second face 76B of the diaphragm 76. The air chamber 72B is configured to communicate with the atmosphere through an insertion hole 72C formed in the bottom of the push member 72A. The pressure in the air chamber 72B is set to the atmospheric pressure. Thus, the atmospheric pressure acts on the second face 76B of the diaphragm 76.

[0121] The pressing mechanism 72 is provided with a pressing member 72D. The pressing member 72D is disposed in the air chamber 72B. The pressing member 72D presses the second face 76B side of the diaphragm 76. The pressing member 72D presses the diaphragm 76 in the direction in which the volume of the liquid outflow portion 75 is reduced. At this time, the pressing member 72D pushes the portion of the diaphragm 76 that is contacted by the pressure receiving portion 78B. The area of the portion of the diaphragm 76 that is contacted by the pressure receiving portion 78B is larger than the cross-sectional area of the communication path 77.

[0122] On the pressure regulating on-off valve 78, the pressing force of the pressing member 79 and the force generated by the hydraulic pressure applied to the first face 76A of the diaphragm 76 are mainly generated as the force in the closing direction. Further, on the pressure regulating on-off valve 78, the pressing force of the pressing member 72D and the force generated by the atmospheric pressure applied to the second face 76B of the diaphragm 76 are mainly generated as the force in the opening direction. The set pressure of the first positive pressure regulating portion 63A at the time of opening, that is, the positive pressure, is set such that the pressing force (acting force) of the pressing members 79, 72D in the opening direction prevails over the force in the closing direction when the hydraulic pressure in the liquid outflow portion 75 is lower than the set pressure of the positive pressure. Although the second positive pressure regulating portion 63B is substantially the same structure as the first positive pressure regulating portion 63A in the present embodiment, the acting force of the pressing member 79 that defines the positive pressure at which it opens, for example, is different.

[0123] As Figure 9As shown, the first negative pressure adjusting section 68A is provided with a pressure adjusting mechanism 81. The pressure adjusting mechanism 81 constitutes a part of the recovery flow path 35. The pressure adjusting mechanism 81 is provided with a main body section 83. In the main body section 83, a liquid inflow section 84 and a liquid outflow section 85 are formed. In the liquid inflow section 84, liquid recovered from the liquid ejection head 21 via the recovery flow path 35 flows in. The liquid outflow section 85 is configured to be able to accommodate liquid inside. In the present embodiment, the liquid inflow section 84 corresponds to a liquid reservoir chamber that communicates with the liquid ejection head 21. The liquid outflow section 85 is configured to be able to accommodate liquid inside. The liquid inflow section 84 is included in the pressure adjusting device 60. Therefore, in the present embodiment, the liquid inflow section 84 is provided at a position overlapping a plane that passes through the liquid ejection head 21 in a direction orthogonal to the width direction X, in the same manner as the pressure adjusting device 60.

[0124] At least a part of a wall surface of the liquid inflow section 84 is constituted by a diaphragm 86. The diaphragm 86 receives the pressure of the liquid inside the liquid inflow section 84 by a first face 86A that is an inner surface of the liquid inflow section 84. The diaphragm 86 receives atmospheric pressure by a second face 86B that is an outer surface of the liquid inflow section 84. Therefore, the diaphragm 86 is displaced according to the pressure inside the liquid inflow section 84. The liquid inflow section 84 changes in volume by the displacement of the diaphragm 86. The liquid inflow section 84 and the liquid outflow section 85 communicate with each other via a communication path 87.

[0125] The diaphragm 86 is provided with a pressure adjusting on-off valve section 86C. The pressure adjusting on-off valve section 86C is able to switch between a closed valve state in which the liquid inflow section 84 and the liquid outflow section 85 are blocked on the communication path 87, and an open valve state in which the liquid inflow section 84 and the liquid outflow section 85 communicate with each other. The pressure adjusting on-off valve section 86C is configured to be able to block the communication path 87. The pressure adjusting on-off valve section 86C is moved by the displacement of the diaphragm 86.

[0126] A pressing member 89 is provided inside the liquid inflow section 84. The pressing member 89 presses the pressure adjusting on-off valve section 86C in a direction in which it is opened. When the pressure applied to the first face 86A is higher than the pressure applied to the second face 86B, and the difference between the pressure applied to the first face 86A and the pressure applied to the second face 86B becomes equal to or greater than a predetermined value, the pressure adjusting on-off valve section 86C changes from the closed valve state to the open valve state. As the predetermined value of the first positive pressure adjusting section 63A, for example, -2.76 kPa as the first negative pressure is matched.

[0127] The predetermined value is a value determined in accordance with a force that is the pressing force of the pressing member 89, the force required to displace the diaphragm 86, the pressing force, i.e., the sealing load, required to shut off the communication path 87 by the pressure-regulating on-off valve section 86C, the pressure within the liquid inflow section 84 acting on the surface of the pressure-regulating on-off valve section 86C, and the pressure within the liquid outflow section 85. That is, the smaller the pressing force of the pressing member 89, the larger the predetermined value for changing from the closed valve state to the open valve state.

[0128] In the present embodiment, in the case where the pressure-regulating on-off valve section 86C is in the closed valve state in the pressure-regulating mechanism 81, the pressure of the liquid on the downstream side of the pressure-regulating mechanism 81 is normally set to negative pressure by the pressure-reducing pump 52. In detail, in the case where the pressure-regulating on-off valve section 86C is in the closed valve state, the pressure of the liquid on the downstream side compared to the liquid outflow section 85 and the liquid outflow section 85 is normally set to negative pressure by the pressure-reducing pump 52.

[0129] In the present embodiment, in the case where the pressure-regulating on-off valve section 86C is in the closed valve state in the pressure-regulating mechanism 81, the pressure of the liquid on the upstream side of the pressure-regulating mechanism 81 is normally set to negative pressure by the diaphragm 86. In detail, in the case where the pressure-regulating on-off valve section 86C is in the closed valve state, the pressure of the liquid on the upstream side compared to the liquid inflow section 84 and the liquid inflow section 84 is normally set to negative pressure by the diaphragm 86.

[0130] When the liquid is recovered from the liquid ejecting head 21, the liquid from the liquid ejecting head 21 is recovered to the liquid inflow section 84. In this case, the pressure within the liquid inflow section 84 will rise. Thus, when the difference between the pressure applied to the first face 86A in the diaphragm 86 and the pressure applied to the second face 86B becomes equal to or greater than the predetermined value, the diaphragm 86 is deformed in a direction in which the volume of the liquid inflow section 84 increases. Along with this deformation of the diaphragm 86, the pressure-regulating on-off valve section 86C changes to the open valve state.

[0131] When the pressure-regulating on-off valve section 86C changes to the open valve state, since the liquid within the liquid outflow section 85 is reduced in pressure by the pressure-reducing pump 52, the liquid is recovered from the liquid inflow section 84 to the liquid outflow section 85. Thus, the pressure within the liquid inflow section 84 will drop. When the pressure within the liquid inflow section 84 drops, the diaphragm 86 is deformed in a manner in which the volume of the liquid inflow section 84 decreases. When the difference between the pressure applied to the first face 86A in the diaphragm 86 and the pressure applied to the second face 86B is less than the predetermined value, the pressure-regulating on-off valve section 86C changes from the open valve state to the closed valve state. As a result, the pressure-regulating on-off valve section 86C hinders the flow of the liquid from the liquid inflow section 84 to the liquid outflow section 85.

[0132] As described above, the pressure regulating mechanism 81 regulates the pressure of the liquid recovered from the liquid nozzle 21 by the displacement of the diaphragm 86, thereby regulating the pressure inside the liquid nozzle 21 that becomes the back pressure of the nozzle 21B.

[0133] The first negative pressure regulating unit 68A includes a pressing mechanism 82. The pressing mechanism 82 presses the pressure regulating mechanism 81 via a diaphragm 86. The pressing mechanism 82 includes a pushing member 82A.

[0134] The pressing member 82A is formed, for example, in the shape of a bottomed cylinder. The pressing member 82A forms an air chamber 82B. The air chamber 82B covers the second surface 86B of the diaphragm 86. The air chamber 82B is configured to communicate with the atmosphere through an insertion hole 82C formed at the bottom of the pressing member 82A. The pressure inside the air chamber 82B is set to atmospheric pressure. Therefore, atmospheric pressure acts on the second surface 86B of the diaphragm 86.

[0135] In the diaphragm 86, the force generated by atmospheric pressure applied to the second surface 86B of the diaphragm 86 as the force in the closing direction of the pressure regulating valve section 86C, and the force from the liquid outflow section 85 side in the pressure regulating valve section 86C of the diaphragm 86 are mainly generated. Furthermore, in the diaphragm 86, the pressing force of the pressing member 89 and the force generated by hydraulic pressure applied to the first surface 86A of the diaphragm 86 are mainly generated as the force in the opening direction of the pressure regulating valve section 86C. Regarding the set pressure, i.e., the negative pressure, when the first negative pressure regulating section 68A opens, when the hydraulic pressure in the liquid inflow section 84 is higher than the set negative pressure, the pressing force (applied force) of the pressing member 89 is set such that the force in the opening direction exceeds the force in the closing direction. Although the second negative pressure regulating section 68B in this embodiment has a structure basically the same as the first negative pressure regulating section 68A, the force of the pressing member 89 that determines the negative pressure for opening the valve is different, for example.

[0136] like Figure 10 As shown, the liquid dispensing device 10 includes a maintenance device 150. The maintenance device 150 may also include a cover mechanism 151 and a wiping mechanism 152. In this embodiment, the cover mechanism 151 and the wiping mechanism 152 are disposed in a non-recording area within the liquid dispensing device 10. In this embodiment, the non-recording area is the area where the liquid nozzle 21 is not opposed to the medium M being transported. The non-recording area is the area where liquid is not sprayed onto the medium M. That is, the non-recording area is the area adjacent to the support platform 25 in the width direction X.

[0137] When not recording, the cover mechanism 151 presses the nozzle 21B into contact with the nozzle surface 21A of the liquid ejector head 21. Furthermore, the cover 153 also serves as a liquid reservoir, which contains the liquid ejected from the nozzle 21B of the liquid ejector head 21 during rinsing. Rinsing refers to the action of ejecting liquid unrelated to printing from the nozzle 21B for purposes such as preventing and eliminating clogging of the nozzle 21B. The cover 153 is formed in a box shape with an opening 154 that opens toward the moving area of ​​the carriage 22. During rinsing, the liquid ejector head 21 ejects liquid into the opening 154 of the cover 153.

[0138] The wiping mechanism 152 is configured to wipe the nozzle surface 21A when the liquid nozzle 21 is positioned above it. Wiping refers to the action of wiping the nozzle surface 21A to remove liquid, dust, or other foreign matter adhering to it. The wiping mechanism 152 wipes the nozzle surface 21A via the wiping part 155.

[0139] Next, refer to Figure 11 The electrical structure of the liquid ejection device 10 will be explained.

[0140] like Figure 11 As shown, the liquid ejection device 10 includes a control unit 100 that comprehensively controls the structural elements of the liquid ejection device 10.

[0141] The control unit 100 includes a CPU and a storage unit. The CPU is an arithmetic processing device that performs predetermined arithmetic operations. The storage unit is a storage device capable of allocating the area or working area where the CPU's program is stored. The storage unit includes storage elements such as RAM (Random Access Memory) and EEPROM (Electrically Erasable Programmable Read-Only Memory). The CPU performs various controls on the liquid dispensing device 10 according to the program stored in the storage unit.

[0142] The control unit 100 is connected to the operation panel 17, the first storage level detection unit 46, and the replenishment storage level detection unit 39. The control unit 100 performs various controls based on signals from the operation panel 17, the first storage level detection unit 46, and the replenishment storage level detection unit 39. The control unit 100 is connected to the liquid nozzle 21, the carriage motor 24, the conveying motor 28, and the maintenance device 150. The control unit 100 performs various controls by sending control signals to the liquid nozzle 21, the carriage motor 24, the conveying motor 28, and the maintenance device 150. The control unit 100 is connected to the pressurizing pump 51, the depressurizing pump 52, the temperature regulating units 34, 47-49, the pressurizing switching unit 53, the depressurizing switching unit 54, the replenishment switching unit 58, the first atmospheric opening unit 55A, the second atmospheric opening unit 55B, the positive pressure on / off valve 64, and the negative pressure on / off valve 69. The control unit 100 implements various controls by sending control signals to the pressurizing pump 51, the depressurizing pump 52, the temperature regulating units 34, 47-49, the pressurizing switching unit 53, the depressurizing switching unit 54, the supplementary switching unit 58, the first atmospheric opening unit 55A, the second atmospheric opening unit 55B, the positive pressure opening and closing valve 64, and the negative pressure opening and closing valve 69.

[0143] Thus, in this embodiment, the control unit 100 controls at least the liquid nozzle 21 and the liquid circulation device 30. Furthermore, the control unit 100 implements liquid circulation by controlling the depressurization implemented by the pressure reducing pump 52, the pressurization implemented by the pressurizing pump 51, the switching implemented by the pressure reducing switching unit 54, and the switching implemented by the pressurizing switching unit 53.

[0144] Here, refer to Figure 12 as well as Figure 13 The loop control process will now be explained. The loop control process is a subroutine that is called every predetermined period by the control unit 100.

[0145] like Figure 12 As shown, in step S10, the control unit 100 determines whether the loop control condition has been met. In this embodiment, the loop control condition is met when printing is performed, when the power is turned on, or when resuming from a sleep state. If the control unit 100 determines that the loop control condition has not been met, it ends the loop control process. On the other hand, if the control unit 100 determines that the loop control condition has been met, it proceeds to step S11.

[0146] In step S11, the control unit 100 determines, based on the signal from the first retention level detection unit 46, whether each of the plurality of first retention levels 41 is a first retention level 41 with a liquid retention level below a second predetermined amount. If the control unit 100 determines that a first retention level 41 is a liquid retention level below the second predetermined amount, it causes the storage unit to store information enabling identification of that first retention level 41. Thus, the control unit 100 is able to identify first retention levels 41 with a liquid retention level below the second predetermined amount. Upon completion of this process, the control unit 100 proceeds to step S12.

[0147] In step S12, the control unit 100 performs switching control between a first pressurization state and a second depressurization state. Specifically, the control unit 100 controls the switching by switching the pressurization switching unit 53 to the first pressurization state, thereby pressurizing the replenishment storage unit 31 using the pressurization pump 51. The control unit 100 also controls the switching by switching the depressurization switching unit 54 to the second depressurization state, thereby depressurizing the third storage unit 43 using the depressurization pump 52.

[0148] Therefore, as Figure 4 As shown, the control unit 100 can supply the liquid stored in the first storage unit 41 to the liquid nozzle 21 through the supply channel 19. The control unit 100 can also recover the liquid stored in the second storage unit 42 to the third storage unit 43 through the second recovery channel 35B.

[0149] In addition, such as Figure 6 As shown, when liquid is stored in the replenishment storage unit 31, the control unit 100 can also supply the liquid stored in the replenishment storage unit 31 to the first storage unit 41 via the supply channel 19. When this process is completed, the control unit 100 moves to step S13.

[0150] In step S13, the control unit 100 performs an opening control to open the first atmospheric opening section 55A and connects the atmosphere to the third storage section 43. Therefore, even if the third storage section 43 has been pressurized by the pressurization pump 51 up to this point, the control unit 100 can quickly switch the third storage section 43 from pressurization to depressurization. Upon completion of this process, the control unit 100 proceeds to step S14.

[0151] In step S14, the control section 100 determines whether or not the supplemental reservoir 31 has been depressurized up to the moment. In this processing, when at least any one of the plurality of supplemental switching sections 58 has been controlled to the first communication state up to the moment, the control section 100 determines that the supplemental reservoir 31 has been depressurized up to the moment. The control section 100, in the case where it is determined that the supplemental reservoir 31 has not been depressurized up to the moment, does not execute step S15, and shifts to step S16. On the other hand, the control section 100, in the case where it is determined that the supplemental reservoir 31 has been depressurized up to the moment, shifts to step S15.

[0152] In step S15, the control section 100 implements the opening control of opening the second atmospheric opening section 55B, and causes the atmosphere to communicate with the supplemental reservoir 31. Thereby, even if the supplemental reservoir 31 has been depressurized up to the moment by the depressurizing pump 52, the control section 100 can promptly implement the switching of the supplemental reservoir 31 from depressurization to pressurization. In the case where this processing ends, the control section 100 shifts to step S16.

[0153] In step S16, the control section 100 executes the elapsed time counting processing of counting the elapsed time from when the switching control of switching to the first pressurization state and the second depressurization state was implemented. In the case where this processing ends, the control section 100 shifts to step S17.

[0154] In step S17, the control section 100 determines, based on the counting result of the elapsed time, whether or not the predetermined time has elapsed. In the present embodiment, the predetermined time is the control time of opening the first atmospheric opening section 55A and the second atmospheric opening section 55B, and corresponds to, for example, 1 s, but is not limited thereto. The control section 100, in the case where it is determined that the predetermined time has not elapsed, does not execute step S18, and shifts to step S19. On the other hand, the control section 100, in the case where it is determined that the predetermined time has elapsed, shifts to step S18.

[0155] In step S18, the control section 100 implements the closing control of closing the atmospheric opening section that is being subjected to the opening control. In detail, the control section 100 implements the closing control of closing the first atmospheric opening section 55A that is being subjected to the opening control. The control section 100 implements the closing control of closing the second atmospheric opening section 55B that is being subjected to the opening control, in the case where the second atmospheric opening section 55B is being subjected to the opening control. In the case where this processing ends, the control section 100 shifts to step S19.

[0156] In step S19, the control unit 100 determines, based on the signal from the first retention amount detection unit 46, whether there are first retention units 41 in which the liquid retention amount is below a first predetermined amount. In this embodiment, the first predetermined amount is the amount of liquid that has not been used up in the first retention units 41, based on the switching time required for switching the pressurization switching unit 53 and the depressurization switching unit 54, the liquid flow rate, etc. If the control unit 100 determines that there are no first retention units 41 in which the liquid retention amount is below the first predetermined amount, it does not proceed to step S20, but proceeds to step S16. If the control unit 100 determines that there are first retention units 41 in which the liquid retention amount is below the first predetermined amount, it proceeds to step S20. Thus, the control unit 100 repeatedly executes steps S16 to S19 until it determines that there are first retention units 41 in which the liquid retention amount is below the first predetermined amount.

[0157] In this embodiment, the plurality of first reservoirs 41 have the same shape, the amount of liquid stored is proportional to the height of the liquid level, and when the amount of liquid stored is a first predetermined amount, the liquid level reaches a predetermined height. Based on this, when the pressurizing pump 51 pressurizes the plurality of first reservoirs 41, if there are first reservoirs 41 where the liquid level is lower than the predetermined height, the control unit 100 switches the pressurization switching unit 53 to a second pressurization state. As a result, liquid is recovered from the plurality of third reservoirs 43 to the plurality of first reservoirs 41.

[0158] In step S20, the control unit 100 performs a control time calculation process. In this process, the control unit 100 calculates the control time for the subsequent switching control based on the elapsed time counted in step S16. In this embodiment, the control unit 100 calculates the control time as, for example, 1.2 times the counted elapsed time. In this embodiment, the control time is calculated to ensure that all liquid stored in the third storage section 43 is recovered to the first storage section 41. Upon completion of this process, the control unit 100 switches to... Figure 13 Step S21.

[0159] like Figure 13 As shown, in step S21, the control unit 100 performs switching control between a second pressurization state and a first depressurization state. Specifically, the control unit 100 switches the pressurization switching unit 53 to the second pressurization state, thereby controlling the pressurization pump 51 to pressurize the third reservoir 43. The control unit 100 controls the process by switching the depressurization switching unit 54 to the first depressurization state, thereby causing the depressurization pump 52 to depressurize the second reservoir 42.

[0160] Thus, as shown in Figure 5 Fig. 10, the control section 100 can recover the liquid from the liquid ejection head 21 to the second reservoir section 42 via the first recovery flow passage 35A. The control section 100 can recover the liquid stored in the third reservoir section 43 to the first reservoir section 41 via the third recovery flow passage 35C. In the case where this process ends, the control section 100 shifts to step S22.

[0161] In step S22, the control section 100 implements the opening control of opening the first atmosphere opening section 55A, and communicates the atmosphere with the third reservoir section 43. Thus, even if the third reservoir section 43 is depressurized by the depressurizing pump 52 until just now, the control section 100 can promptly implement the switching of the third reservoir section 43 from the depressurization to the pressurization. In the case where this process ends, the control section 100 shifts to step S23.

[0162] In step S23, the control section 100 judges whether or not there is the first reservoir section 41 whose liquid storage amount is equal to or smaller than the second prescribed amount, based on the result of the judgment in step Sll of Figure 12 . The control section 100 shifts to step S26 without executing steps S24 and S25 in the case where it is judged that there is not the first reservoir section 41 whose liquid storage amount is equal to or smaller than the second prescribed amount. On the other hand, the control section 100 shifts to step S24 in the case where it is judged that there is the first reservoir section 41 whose liquid storage amount is equal to or smaller than the second prescribed amount.

[0163] In step S24, the control section 100 implements the switching control of switching to the first communication state. In detail, the control section 100 controls in such a manner that the replenishment switching section 58 corresponding to the first reservoir section 41 whose liquid storage amount is equal to or smaller than the second prescribed amount is switched to the first communication state, and thereby the depressurizing pump 52 depressurizes the replenishment reservoir section 31 via the second communication flow passage 38J. On the other hand, the control section 100 does not switch the replenishment switching section 58 corresponding to the first reservoir section 41 whose liquid storage amount is not equal to or smaller than the second prescribed amount to the first communication state, but continues to control to the second communication state.

[0164] Thus, as shown in Figure 7 Fig. 10, even in the case where the liquid is not sufficiently replenished from the third reservoir section 43 to the first reservoir section 41, the control section 100 can supply the liquid from the liquid supply source 18 to the replenishment reservoir section 31 via the supply flow passage 19, and replenish the liquid from the replenishment reservoir section 31 to the first reservoir section 41. In the case where this process ends, the control section 100 shifts to step S25.

[0165] In step S25, the control section 100 implements the opening control of opening the second atmosphere opening section 55B, and causes the atmosphere to communicate with the replenishment reservoir section 31. Thereby, even if the replenishment reservoir section 31 is pressurized by the pressurizing pump 51 until just before, the control section 100 can promptly implement the switching of the replenishment reservoir section 31 from pressurization to depressurization. In the case where this processing ends, the control section 100 shifts to step S26.

[0166] In step S26, the control section 100 executes the elapsed time counting processing of counting the elapsed time from the implementation of the switching control of the second pressurization state, the first depressurization state. In the case where this processing ends, the control section 100 shifts to step S27.

[0167] In step S27, the control section 100 judges whether or not the predetermined time has elapsed, based on the counting result of the elapsed time. In the present embodiment, the predetermined time is the control time of opening the first atmosphere opening section 55A and the second atmosphere opening section 55B, and corresponds to, for example, 1 s, but is not limited thereto. The control section 100, in the case where it is judged that the predetermined time has not elapsed, does not execute step S28, and shifts to step S29. On the other hand, the control section 100, in the case where it is judged that the predetermined time has elapsed, shifts to step S28.

[0168] In step S28, the control section 100 implements the closing control of closing the atmosphere opening section which is being subjected to the opening control. In detail, the control section 100 implements the closing control of closing the first atmosphere opening section 55A which is being subjected to the opening control. The control section 100 implements the closing control of closing the second atmosphere opening section 55B which is being subjected to the opening control, in the case where the second atmosphere opening section 55B is subjected to the opening control. In the case where this processing ends, the control section 100 shifts to step S29.

[0169] In step S29, the control section 100 judges whether or not there is the replenishment reservoir section 31 which is depressurized by the depressurizing pump 52 and whose liquid storage amount becomes the third prescribed amount, among the plurality of replenishment reservoir sections 31, based on the signal from the replenishment storage amount detection section 39. The control section 100, in the case where it is judged that there is no replenishment reservoir section 31 whose liquid storage amount becomes the third prescribed amount, does not shift to step S30, but shifts to step S31. On the other hand, the control section 100, in the case where it is judged that there is the replenishment reservoir section 31 whose liquid storage amount becomes the third prescribed amount, shifts to step S30.

[0170] In step S30, the control section 100 implements switching control to switch to the second communication state. In detail, the control section 100 controls in such a manner that the replenishment switching section 58 corresponding to the replenishment reservoir 31 whose liquid storage amount is the third prescribed amount is switched to the second communication state, so that the pressure-reducing pump 52 does not depressurize the replenishment reservoir 31 via the second communication flow passage 38J. On the other hand, the control section 100 does not switch the replenishment switching section 58 corresponding to the replenishment reservoir 31 whose liquid storage amount is not the third prescribed amount to the second communication state, but continues to control to the first communication state. In the case where this processing ends, the control section 100 shifts to step S31.

[0171] In step S31, the control section 100 judges, based on the count result of the elapsed time, whether or not the control time decided in step S20 of the first cycle has elapsed. The control section 100, in the case where it judges that the control time has not elapsed, does not shift to step S32, but shifts to step S26. On the other hand, the control section 100, in the case where it judges that the control time has elapsed, shifts to step S32. Thus, the control section 100 repeatedly executes steps S26 to S31 until the control time elapses. Figure 12 In step S32, the control section 100 implements switching control to switch to the second communication state. In detail, the control section 100 controls in such a manner that the plurality of replenishment switching sections 58 corresponding to the plurality of replenishment reservoirs 31 are switched to the second communication state, so that the pressure-reducing pump 52 does not depressurize the replenishment reservoirs 31 via the second communication flow passage 38J. The control section 100 continues to control to the second communication state in the case where the plurality of replenishment switching sections 58 corresponding to the plurality of replenishment reservoirs 31 are already in the second communication state. In the case where this processing ends, the control section 100 shifts to step S10.

[0172] In the present embodiment, according to the calculation of the control time in step S20, the time during which the third reservoir 43 is controlled to the second pressure-increasing state and the first pressure-reducing state is longer than the time during which the third reservoir 43 is controlled to the first pressure-increasing state and the second pressure-reducing state. In this way, the control section 100 depressurizes the third reservoir 43 by switching the pressure-reducing switching section 54 to the second pressure-reducing state and keeping it in the second pressure-reducing state for the first time, so as to recover the liquid from the second reservoir 42 to the third reservoir 43. Thereafter, the control section 100 pressurizes the third reservoir 43 by switching the pressure-increasing switching section 53 to the second pressure-increasing state and keeping it in the second pressure-increasing state for the second time which is longer than the first time, so as to recover the liquid from the third reservoir 43 to the first reservoir 41.

[0173]

[0174] ​In this embodiment, the control unit 100 controls the first positive pressure on / off valve 64A, the second positive pressure on / off valve 64B, the first negative pressure on / off valve 69A, and the second negative pressure on / off valve 69B according to the control status of the liquid ejection device 10.

[0175] Although in this embodiment, the opening control of the first atmospheric opening section 55A and the second atmospheric opening section 55B is implemented after the switching control to the first pressurization state and the second depressurization state is implemented, the opening control can be implemented simultaneously with the switching control, or the switching control can be implemented after the opening control is implemented.

[0176] Although in this embodiment, the opening control of the first atmospheric opening section 55A and the second atmospheric opening section 55B is implemented after the switching control to the second pressurization state and the first depressurization state is implemented, the opening control can be implemented simultaneously with the switching control, or the switching control can be implemented after the opening control is implemented.

[0177] Here, refer to Figure 14 The control content executed through the control unit 100 will be explained.

[0178] like Figure 14 As shown, when printing is performed under the control of the liquid ejection device 10, the control unit 100 performs normal cycle control. In normal cycle control, the control unit 100 controls the system by opening the first positive pressure on / off valve 64A and the first negative pressure on / off valve 69A, and closing the second positive pressure on / off valve 64B and the second negative pressure on / off valve 69B.

[0179] Next, when the power is turned on as the control state of the liquid ejection device 10, the control unit 100 performs high-speed cycle control upon recovery from the dormant state. In the high-speed cycle control, the control unit 100 controls the device by opening the second positive pressure on / off valve 64B and the second negative pressure on / off valve 69B and closing the first positive pressure on / off valve 64A and the first negative pressure on / off valve 69A.

[0180] Next, when bubble discharge is implemented from nozzle 21B as part of the control state of the liquid ejection device 10, the control unit 100 implements nozzle air discharge circulation control. When bubble discharge is implemented from nozzle 21B, the control unit 100 causes the liquid in the liquid ejection head 21 to be ejected at high speed. In nozzle air discharge circulation control, the control unit 100 controls the process by opening the second positive pressure on / off valve 64B and closing the first positive pressure on / off valve 64A, the first negative pressure on / off valve 69A, and the second negative pressure on / off valve 69B.

[0181] Next, in a case where wiping of the nozzle face 21A is implemented, the control section 100 implements wiping cycle control. In the wiping cycle control, the control section 100 is controlled in a manner that the first positive pressure on-off valve 64A, the second positive pressure on-off valve 64B, the first negative pressure on-off valve 69A, and the second negative pressure on-off valve 69B are closed.

[0182] Finally, in a case where the placement is implemented as the control condition of the liquid ejection apparatus 10 other than the above-described control conditions, the control section 100 implements placement cycle control. In the placement cycle control, the control section 100 is controlled in a manner that the first negative pressure on-off valve 69A is opened and the first positive pressure on-off valve 64A, the second positive pressure on-off valve 64B, and the second negative pressure on-off valve 69B are closed.

[0183] The operation of the present embodiment will be described.

[0184] First, as shown in FIG. 6, the pressurization switching section 53 is controlled to the first pressurization state, the depressurization switching section 54 is controlled to the second depressurization state, and the replenishment switching section 58 is controlled to the second communication state. Figure 4 In a case where the pressurization switching section 53 is controlled to the first pressurization state, the pressurization pump 51 and the replenishment reservoir 31 are in communication. The replenishment reservoir 31 is pressurized by the pressurization pump 51. The first reservoir 41 is in communication with the replenishment reservoir 31. The first reservoir 41 is pressurized by the pressurization pump 51. Thus, the liquid stored in the first reservoir 41 is supplied to the liquid ejection head 21 via the supply flow path 19.

[0185] In a case where the depressurization switching section 54 is controlled to the second depressurization state, the depressurization pump 52 and the third reservoir 43 are in communication. The third reservoir 43 is depressurized by the depressurization pump 52. Thus, the liquid stored in the second reservoir 42 is recovered to the third reservoir 43 via the second recovery flow path 35B. In this case, the second one-way valve 45 is provided on the third recovery flow path 35C that communicates the first reservoir 41 and the third reservoir 43, so that the liquid stored in the first reservoir 41 does not flow to the third reservoir 43, and the liquid does not backflow in the recovery flow path 35.

[0186] In a case where the replenishment switching section 58 is controlled to the second communication state, the replenishment communication flow path 38H is not in communication with the replenishment reservoir 31, but is in communication with the first atmosphere communication passage 38I. Therefore, the replenishment reservoir 31 is not depressurized by the depressurization pump 52. When the negative pressure in the second reservoir 42 is lower than a predetermined negative pressure, the atmosphere is sucked into the second reservoir 42 by the first negative pressure opening section 57 and the second negative pressure opening section 59 being opened. Thus, it is possible to suppress the overpressure of the second reservoir 42.

[0187]

[0188] ​Next, as Figure 5 As shown, when the amount of liquid stored in at least one of the plurality of first storage sections 41 reaches a first predetermined amount, the pressurization switching section 53 is controlled to a second pressurization state, the depressurization switching section 54 is controlled to a first depressurization state, and the replenishment switching section 58 is controlled to a second connection state.

[0189] When the pressurization switching unit 53 is controlled to the second pressurization state, the pressurization pump 51 is connected to the third storage unit 43. The third storage unit 43 is pressurized by the pressurization pump 51. As a result, the liquid stored in the third storage unit 43 is recovered to the first storage unit 41 via the third recovery channel 35C.

[0190] When the pressure reduction switching unit 54 is controlled to the first pressure reduction state, the pressure reduction pump 52 and the second storage unit 42 are connected. The second storage unit 42 is pressure-reduced by the pressure reduction pump 52. As a result, the liquid in the liquid nozzle 21 is recovered to the second storage unit 42 via the first recovery channel 35A. In this case, a first one-way valve 44 is provided on the second recovery channel 35B that connects the second storage unit 42 and the third storage unit 43, so that the liquid stored in the third storage unit 43 will not flow to the second storage unit 42, and the liquid will not flow back in the recovery channel 35.

[0191] like Figure 6 As shown, when liquid is stored in the replenishment storage section 31, and the pressurization switching section 53 is controlled to the first pressurization state, the pressurization pump 51 is connected to the replenishment storage section 31. The replenishment storage section 31 is pressurized by the pressurization pump 51. As a result, the liquid stored in the replenishment storage section 31 is supplied to the first storage section 41.

[0192] like Figure 7 As shown, as a result of the pressurization switching unit 53 being controlled to the second pressurization state and the depressurization switching unit 54 being controlled to the first depressurization state, when there is a first storage unit 41 in which the amount of liquid stored is below a second predetermined amount, the replenishment switching unit 58 corresponding to the first storage unit 41 is controlled to the first communication state.

[0193] When the replenishment switching unit 58 is controlled to the first connected state, the replenishment connection channel 38H is connected to the replenishment storage unit 31. Therefore, the replenishment storage unit 31 is depressurized via the second storage unit 42 and the pressure reducing pump 52. As a result, the liquid in the liquid supply source 18 is supplied to the replenishment storage unit 31 via the supply channel 19. In this case, a discharge valve 33 is provided on the supply channel 19 between the replenishment storage unit 31 and the first storage unit 41, so that the liquid stored in the first storage unit 41 will not flow to the replenishment storage unit 31, and the liquid will not flow back in the supply channel 19.

[0194] When the replenishment switching unit 58 is controlled in the first connected state, if the amount of liquid stored in the replenishment storage unit 31 reaches a third predetermined amount, the replenishment switching unit 58 is controlled in the second connected state. Therefore, liquid exceeding the third predetermined amount is not supplied to the replenishment storage unit 31.

[0195] In this way, through repeated... Figure 4 The state shown and Figure 5 The indicated state is switched so that the liquid can circulate along the path through the liquid nozzle 21 via the supply channel 19 and the return channel 35. Furthermore, when the liquid flowing in the circulation channel 36 is insufficient due to liquid consumption caused by the liquid nozzle 21, the flow is controlled to... Figure 6 as well as Figure 7 The state shown allows for the replenishment of liquid from the liquid supply source 18 to the circulation channel 36.

[0196] Because the pressurization switching unit 53 is controlled to the second pressurization state, the third reservoir 43 is pressurized by the pressurization pump 51. Because the depressurization switching unit 54 is controlled to the second depressurization state, the third reservoir 43 is depressurized by the depressurization pump 52. Thus, when switching between pressurization and depressurization in the third reservoir 43, the first atmospheric opening part 55A is opened after a predetermined time, thereby allowing air to be drawn into the third reservoir 43. As a result, the switching between pressurization and depressurization in the third reservoir 43 can be carried out quickly.

[0197] Since the pressurization switching unit 53 is controlled to the first pressurization state, the replenishment storage unit 31 is pressurized by the pressurization pump 51. Since the replenishment switching unit 58 is controlled to the first connected state, the replenishment storage unit 31 is depressurized by the depressurization pump 52. Thus, when switching between pressurization implemented by the pressurization pump 51 and depressurization implemented by the depressurization pump 52, the second atmospheric opening unit 55B is opened for a predetermined period of time, thereby allowing air to be drawn into the replenishment storage unit 31. As a result, the switching between pressurization and depressurization in the replenishment storage unit 31 can be carried out quickly.

[0198] Since the pressurization switching unit 53 is controlled to the first pressurization state, the first reservoir 41 is pressurized via the replenishment reservoir 31 and the pressurization pump 51. When the positive pressure in the first reservoir 41 exceeds a predetermined positive pressure, the pressurization opening unit 56 is opened, thereby allowing air to be drawn into the first reservoir 41. This suppresses over-pressurization of the first reservoir 41.

[0199] Further, in the pressure adjusting device 60, the first positive pressure on-off valve 64A, the second positive pressure on-off valve 64B, the first negative pressure on-off valve 69A, and the second negative pressure on-off valve 69B are controlled in accordance with the control state of the liquid ejection device 10.

[0200] Specifically, in a case where printing is performed, the first positive pressure on-off valve 64A is opened on the supply flow path 19, and the first negative pressure on-off valve 69A is opened on the recovery flow path 35. When the first positive pressure on-off valve 64A is opened, in the first positive pressure adjusting section 63A, if the pressure on the liquid ejection head 21 side becomes the first positive pressure, the first positive pressure adjusting section 63A is opened. Thus, in a state subjected to the first positive pressure, the liquid flows in the supply flow path 19. When the first negative pressure on-off valve 69A is opened, in the first negative pressure adjusting section 68A, if the pressure on the liquid ejection head 21 side becomes the first negative pressure, the first negative pressure adjusting section 68A is opened. Thus, in a state subjected to the first negative pressure, the liquid flows in the recovery flow path 35.

[0201] Next, at the time of power-on, at the time of recovery from the sleep state, the second positive pressure on-off valve 64B is opened on the supply flow path 19, and the second negative pressure on-off valve 69B is opened on the recovery flow path 35. When the second positive pressure on-off valve 64B is opened, in the second positive pressure adjusting section 63B, if the pressure on the liquid ejection head 21 side becomes the second positive pressure, the second positive pressure adjusting section 63B is opened. Thus, in a state subjected to the second positive pressure, the liquid flows in the supply flow path 19. When the second negative pressure on-off valve 69B is opened, in the second negative pressure adjusting section 68B, if the pressure on the liquid ejection head 21 side becomes the second negative pressure, the second negative pressure adjusting section 68B is opened. Thus, in a state subjected to the second negative pressure, the liquid flows in the recovery flow path 35.

[0202] The second positive pressure is greater than the first positive pressure. The second negative pressure is greater in absolute value than the first negative pressure. At the time of power-on, at the time of recovery from the sleep state, compared to the normal time, the possibility of generation of air bubbles in the supply flow path 19 and the recovery flow path 35 is high. At the time of power-on, at the time of recovery from the sleep state, compared to the normal time, the possibility of settlement of the pigment or the like in the supply flow path 19 and the recovery flow path 35 is increased. Therefore, at the time of power-on, at the time of recovery from the sleep state, by circulating the liquid at a high speed compared to the normal time, it is possible to remove the air bubbles in the supply flow path 19 and the recovery flow path 35 and increase the possibility of recovery of the settlement.

[0203] Next, in the case where the bubble is discharged from the nozzle 21B, the second positive pressure opening and closing valve 64B is opened. Thereby, by applying the second positive pressure to the liquid supplied from the supply flow path 19 and closing the recovery flow path 35, it is possible to efficiently increase the flow rate of the liquid discharged from the nozzle 21B of the liquid discharge head 21. Therefore, it is possible to efficiently remove the bubble of the nozzle 21B. Further, it is possible to shorten the time until the liquid flows at high speed, and it is possible to reduce the useless liquid.

[0204] Next, in the case where the wiping of the nozzle face 21A is performed, the first positive pressure opening and closing valve 64A and the second positive pressure opening and closing valve 64B are closed on the supply flow path 19, and the first negative pressure opening and closing valve 69A and the second negative pressure opening and closing valve 69B are closed on the recovery flow path 35. Thereby, the supply flow path 19 and the recovery flow path 35 are closed. In this way, by closing the supply flow path 19, the useless liquid does not flow from the supply flow path 19. Further, since the supply flow path 19 and the recovery flow path 35 are closed, by applying the upward force to the liquid in the liquid discharge head 21, it is possible to suppress the discharge of the useless liquid from the nozzle 21B, and it is also possible to suppress the intrusion of the liquid to the adjacent nozzle 21B.

[0205] Finally, in the case of the stand-by, the first negative pressure opening and closing valve 69A is opened on the recovery flow path 35. Thereby, the supply flow path 19 is closed, and the useless liquid does not flow from the supply flow path 19. In the stand-by, the liquid discharge head 21 is set to the gland state in which the cap 153 contacts the nozzle face 21A. Further, the first negative pressure opening and closing valve 69A is opened, and the pressure release of the nozzle 21B is performed, and thereby it is possible to suppress the case where the liquid from the nozzle 21B is dropped due to the expansion of the liquid in the liquid discharge head 21 caused by the environmental change such as the change of the environmental temperature. Further, the useless liquid does not flow from the supply flow path 19, and in order to efficiently perform the pressure release of the nozzle 21B, it is preferable that the first negative pressure opening and closing valve 69A is opened.

[0206] Further, the carriage 22 moves back and forth in the width direction X, and the liquid is discharged from the nozzle 21B of the liquid discharge head 21 in the movement of the carriage 22, and thereby the printing is performed on the medium. In this way, when the carriage 22 moves back and forth in the width direction X, the liquid stored in the liquid outflow portion 75 of the pressure adjusting device 60 is applied with the pressure according to the acceleration of the carriage 22 with respect to the width direction X. The liquid stored in the liquid outflow portion 75 is the liquid to which the pressure adjustment is performed by the pressure adjusting device 60.

[0207] In the present embodiment, the liquid outflow portion 75 is provided at a position overlapping with a plane that passes through the liquid ejection head 21 along a direction orthogonal to the width direction X, and the flow passage between the liquid outflow portion 75 and the liquid ejection head 21 is shortened with respect to the width direction X. When the flow passage between the liquid outflow portion 75 and the liquid ejection head 21 is shortened with respect to the width direction X, the pressure applied in accordance with the acceleration of the carriage 22 with respect to the width direction X becomes small. In this way, it is possible to reduce the external pressure applied to the liquid subjected to pressure adjustment by the pressure adjustment device 60, and it is possible to suppress pressure fluctuation of the liquid in the liquid ejection head 21, in conjunction with the reciprocating movement of the carriage 22 in the width direction X.

[0208] The effects of the present embodiment will be described.

[0209] (1) Conventionally, a pump for circulating liquid has been required to be provided in at least either of the supply flow passage and the recovery flow passage, which can have led to a large size. Therefore, by using the first to third reservoirs 41 to 43, the supply flow passage 19, the first to third recovery flow passages 35A to 35C, the first one-way valve 44, and the second one-way valve 45, it is possible to form a flow passage for circulating liquid even when a pump is not provided in the flow passage for circulating liquid, for example, and thus it is possible to achieve a small size.

[0210] (2) In particular, by depressurizing the third reservoir 43, it is possible to recover the liquid stored in the second reservoir 42 to the third reservoir 43 without causing the liquid stored in the first reservoir 41 to flow back to the third reservoir 43. Further, by pressurizing the third reservoir 43, it is possible to recover the liquid stored in the third reservoir 43 to the first reservoir 41 without causing the liquid stored in the second reservoir 42 to flow back to the third reservoir 43. Thus, even when a pump is not provided in the flow passage for circulating liquid, it is possible to circulate liquid, and thus it is possible to achieve a small size.

[0211] (3) Further, by switching the depressurization switching portion 54 to the first depressurization state or the second depressurization state, it is possible to easily switch between depressurizing the second reservoir 42 or the third reservoir 43. Further, by switching the pressurization switching portion 53 to the first pressurization state or the second pressurization state, it is possible to easily switch between pressurizing the first reservoir 41 or the third reservoir 43.

[0212] (4) The pressurization pump 51, which can pressurize each of the plurality of liquid circulation mechanisms 37, is shared. The depressurization pump 52, which can depressurize each of the plurality of liquid circulation mechanisms 37, is shared. Therefore, compared with a configuration in which a pressurization pump 51 and a depressurization pump 52 are provided for each of the plurality of liquid circulation mechanisms 37, it is possible to achieve a small size.

[0213] (5) In the case where the first atmosphere opening portion 55A is opened, in the third reservoir portion 43 in which both the pressurization by the pressurizing pump 51 and the depressurization by the depressurizing pump 52 can be achieved, the flow passages 38C, 38F which communicate with the depressurization switching portion 54 and the pressurization switching portion 53 can be opened to the atmosphere. Thereby, the pressurization and the switching of the depressurization of the third reservoir portion 43 can be rapidly performed.

[0214] (6) By communicating the pressurization switching portion 53 with the replenishment reservoir portion 31 via the first communication flow passage 38B, the replenishment reservoir portion 31 can be pressurized via the first communication flow passage 38B, and the liquid of the replenishment reservoir portion 31 which is stored for replenishing the first reservoir portion 41 can be pressurized.

[0215] (7) By communicating the depressurization switching portion 54 with the replenishment reservoir portion 31 via the second communication flow passage 38J, the replenishment reservoir portion 31 can be depressurized via the second communication flow passage 38J. Therefore, the liquid from the liquid supply source 18 can be supplied to the replenishment reservoir portion 31 by depressurizing the replenishment reservoir portion 31.

[0216] (8) In the replenishment reservoir portion 31 in which both the pressurization by the pressurizing pump 51 and the depressurization by the depressurizing pump 52 can be achieved, by opening the first communication flow passage 38B to the atmosphere, the pressurization and the switching of the depressurization of the replenishment reservoir portion 31 can be rapidly performed.

[0217] (9) By the pressurization of the pressurizing pump 51, the replenishment reservoir portion 31 can be pressurized via the first communication flow passage 38B, and the first reservoir portion 41 can be pressurized via the first communication flow passage 38B and the replenishment reservoir portion 31. Thereby, the liquid stored in the replenishment reservoir portion 31 can be replenished to the first reservoir portion 41. Therefore, the pressurizing pump 51 can be used for both the replenishment of the liquid from the replenishment reservoir portion 31 to the first reservoir portion 41 and the supply of the liquid from the first reservoir portion 41 to the liquid ejection head 21, and thus miniaturization can be achieved.

[0218] (10) By the depressurization of the depressurizing pump 52, the second reservoir portion 42 can be depressurized, and the replenishment reservoir portion 31 can be depressurized via the second reservoir portion 42 and the replenishment communication flow passage 38H. Thereby, the liquid can be sucked from the liquid supply source 18 to the replenishment reservoir portion 31. Therefore, the depressurizing pump 52 can be used for both the recovery of the liquid from the liquid ejection head 21 to the second reservoir portion 42, the recovery of the liquid from the second reservoir portion 42 to the third reservoir portion 43, and the supply of the liquid from the liquid supply source 18 to the replenishment reservoir portion 31, and thus miniaturization can be achieved.

[0219] (11) Even when the second atmospheric opening portion 55B is opened and the replenishment reservoir portion 31 is opened to the atmosphere, the replenishment communication flow path 38H is not opened when the negative pressure on the second reservoir portion 42 side is not lower than the predetermined negative pressure. Thus, it is possible to suppress a case where the second reservoir portion 42 is opened to the atmosphere due to the replenishment reservoir portion 31 being opened to the atmosphere.

[0220] (12) By switching the replenishment switching portion 58 between the first communication state and the second communication state, it is possible to easily switch whether or not the replenishment reservoir portion 31 is depressurized via the replenishment communication flow path 38H.

[0221] (13) When switched to the second communication state and the replenishment reservoir portion 31 is not depressurized via the second communication flow path 38J, in the first atmospheric communication passage 38I that communicates with the second reservoir portion 42, when the negative pressure of the second communication flow path 38J is lower than the predetermined negative pressure, it is possible to suck the atmosphere instead of not sucking the liquid.

[0222] (14) When the positive pressure on the first reservoir portion 41 side exceeds the predetermined positive pressure, the second atmospheric communication passage 38G that communicates with the atmosphere is opened by the pressurization opening portion 56. Thus, it is possible to suppress excessive pressurization of the first reservoir portion 41 in which the positive pressure on the first reservoir portion 41 side exceeds the predetermined positive pressure.

[0223] (15) By controlling the depressurization by the depressurization pump 52, the pressurization by the pressurization pump 51, the switching by the depressurization switching portion 54, and the switching by the pressurization switching portion 53, it is possible to implement circulation of the liquid.

[0224] (16) In a case where there is a first reservoir portion 41 in which the liquid level of the liquid in a plurality of first reservoir portions 41 is higher than a predetermined height, the liquid is recovered from the plurality of third reservoir portions 43 to the plurality of first reservoir portions 41 including the first reservoir portion 41 in which the liquid level of the liquid in the plurality of first reservoir portions 41 is not lower than the predetermined height. Thus, compared to a structure in which the liquid is not recovered to the first reservoir portion 41 in which the liquid level of the liquid in the plurality of first reservoir portions 41 is not lower than the predetermined height, it is possible to reduce the number of times of driving the pressurization pump 51, and thus it is possible to suppress deterioration of the pressurization portion due to changes over time.

[0225] (17) The time for which the pressurization switching portion 53 is switched to the second pressurization state to recover the liquid from the third reservoir portion 43 to the first reservoir portion 41 is longer than the time for which the depressurization switching portion 54 is switched to the second depressurization state to recover the liquid from the second reservoir portion 42 to the third reservoir portion 43. Thus, it is easy to recover the liquid stored in the second reservoir portion 42 to the first reservoir portion 41 via the third reservoir portion 43, and it is possible to easily identify whether or not the liquid recovered from the liquid ejection head 21 is sufficient.

[0226] (18) In the past, in the supply flow path that supplies the liquid to the liquid ejection head, the liquid is supplied at a fixed flow rate, and in the recovery flow path that recovers the liquid from the liquid ejection head, the liquid is recovered at a fixed flow rate. Therefore, in the liquid circulating mechanism, it is desirable to circulate the liquid at a flow rate corresponding to a control condition in which there is a difference between a flow rate required when printing is stably performed and a flow rate required for discharge of a bubble. Therefore, it is possible to make predetermined positive pressures of the open flow paths in each of the first positive pressure supply flow path 62A and the second positive pressure supply flow path 62B branched by the supply branch 61A in the supply flow path 19 different. The first positive pressure supply flow path 62A and the second positive pressure supply flow path 62B are configured in a manner that enables switching of the flow path through which the liquid flows. Therefore, in the first positive pressure supply flow path 62A and the second positive pressure supply flow path 62B in which the positive pressures of the open flow paths are different, it is possible to selectively switch the flow path through which the liquid flows, and it is possible to circulate the liquid at a flow rate corresponding to the control condition among a plurality of flow rates.

[0227] (19) It is possible to control the first positive pressure on-off valve 64A and the second positive pressure on-off valve 64B provided on each of the first positive pressure supply flow path 62A and the second positive pressure supply flow path 62B provided in the supply flow path 19, and thereby it is possible to easily switch the flow path through which the liquid flows.

[0228] (20) It is configured so that it is possible to make predetermined negative pressures of the open flow paths in each of the first negative pressure recovery flow path 67A and the second negative pressure recovery flow path 67B branched by the recovery branch 66A in the recovery flow path 35 different, and thereby it is possible to switch the flow path through which the liquid flows in the first negative pressure recovery flow path 67A and the second negative pressure recovery flow path 67B. Therefore, in the first negative pressure recovery flow path 67A and the second negative pressure recovery flow path 67B in which the negative pressures of the open flow paths are different, it is possible to selectively switch the flow path through which the liquid flows, and thereby it is possible to circulate the liquid at a flow rate corresponding to the control condition among a plurality of flow rates.

[0229] (21) It is possible to control the first negative pressure on-off valve 69A and the second negative pressure on-off valve 69B provided on each of the first negative pressure recovery flow path 67A and the second negative pressure recovery flow path 67B provided in the recovery flow path 35, and thereby it is possible to easily switch the flow path through which the liquid flows.

[0230] (22) There is the first reservoir 41 that stores the liquid in the supply flow path 19, and there is the second reservoir 42 that stores the liquid in the recovery flow path 35. Therefore, in both of the supply flow path 19 and the recovery flow path 35, it is possible to store the liquid, and it is possible to easily circulate the liquid.

[0231] (23) Further, the first reservoir portion 41 is provided at a connection portion of the supply flow path 19 to which the recovery flow path 35 is connected. Therefore, it is possible to store both the liquid supplied from the liquid supply source 18 and the liquid recovered from the liquid ejection head 21 by the first reservoir portion 41, and it is possible to easily circulate the liquid.

[0232] (24) The pressurizing pump 51 configured to be able to pressurize the first reservoir portion 41 and the depressurizing pump 52 configured to be able to depressurize the second reservoir portion 42 are provided, and the liquid is circulated by pressurization and depressurization of each of the reservoir portions 41 and 42, and it is possible to achieve simplification of the flow path structure.

[0233] (25) In the first reservoir portion 41 and the second reservoir portion 42, the liquid stored therein is heated, and it is possible to smoothly perform supply of the liquid by adjusting the viscosity of the liquid.

[0234] (26) By mounting the liquid circulation mechanism 37 and the liquid ejection head 21 on the carriage 22 configured to be able to move back and forth in the main scanning direction, it is possible to shorten the distance between the liquid circulation mechanism 37 and the liquid ejection head 21, and thus it is possible to easily perform the layout of the flow path in the liquid ejection apparatus 10.

[0235] (27) By mounting the liquid circulation mechanism 30 and the liquid ejection head 21 on the carriage 22, it is possible to shorten the distance between the liquid circulation mechanism 30 and the liquid ejection head 21, and thus it is possible to easily perform the layout of the flow path in the liquid ejection apparatus 10.

[0236] (28) Even in a case where each of the pressure adjusting portions 63A, 63B, 68A, and 68B is mounted on the carriage 22, it is possible to shorten the distance of the flow path in which the liquid outflow portion 75 and the liquid ejection head 21 are communicated with each other with respect to the main scanning direction of the carriage 22. Therefore, it is possible to suppress the pressure variation of the liquid in the flow path in which the liquid outflow portion 75 and the liquid ejection head 21 are communicated with each other, along with the movement of the carriage 22 in the main scanning direction.

[0237] The present embodiment can be implemented in the following manner. The present embodiment and the following modified examples can be implemented in combination with each other within a range in which they are not technically contradictory.

[0238] • In the above-described embodiments, for example, as Figure 15As shown, instead of the first negative pressure opening section 57, the replenishment switching section 58, and the second negative pressure opening section 59, a flow channel opening and closing section 157 can be provided on the replenishment communication flow channel 38H. The flow channel opening and closing section 157 has multiple opening and closing sections corresponding to the type of liquid ejected from the liquid nozzle 21. Each of the multiple flow channel opening and closing sections 157 is configured as an opening and closing valve capable of opening and closing the replenishment communication flow channel 38H according to the instruction of the control unit 100. Thus, the circulation device 50 can also include the flow channel opening and closing section 157, which is configured to be capable of opening and closing the replenishment communication flow channel 38H. According to this structure, even when the second atmospheric opening section 55B is opened, allowing the replenishment storage section 31 to be opened to the atmosphere, the replenishment communication flow channel 38H can be closed by using the flow channel opening and closing section 157, thereby preventing communication between the replenishment storage section 31 and the second storage section 42. Therefore, it is possible to prevent the second storage section 42 from being opened to the atmosphere due to the opening of the replenishment storage section 31 to the atmosphere. Moreover, by opening and closing the replenishment communication channel 38H through the channel opening and closing section 157, it is possible to easily switch whether the replenishment storage section 31 is depressurized via the replenishment communication channel 38H.

[0239] In the above embodiments, for example, such as Figure 16 As shown, an opening / closing section 158 can be provided on the first atmospheric communication channel 38I instead of the replenishment switching section 58 and the second negative pressure opening section 59. The opening / closing section 158 is configured to be able to open and close the first atmospheric communication channel 38I. The opening / closing section 158 has multiple opening / closing sections corresponding to the type of liquid ejected from the liquid nozzle 21. Each of the multiple opening / closing sections 158 is configured as an opening / closing valve that can open and close the replenishment communication channel 38H according to the instruction of the control unit 100. In this way, the circulation device 50 includes the opening / closing section 158. According to this structure, by opening and closing the first atmospheric communication channel 38I through the opening / closing section 158, it is possible to easily switch whether the replenishment storage section 31 is depressurized via the replenishment communication channel 38H.

[0240] While the first atmospheric opening portion 55A is connected to flow channels 38C and 38F in the above embodiment, it is not limited thereto. For example, the first atmospheric opening portion 55A may be connected to flow channel 38C but not to flow channel 38F. For example, the first atmospheric opening portion 55A may be connected to flow channel 38F but not to flow channel 38C. For example, the first atmospheric opening portion 55A may be connected to the flow channel connected to the third storage portion 43 independently of flow channels 38C and 38F. In other words, the first atmospheric opening portion 55A only needs to be connected to the flow channel connected to the third storage portion 43.

[0241] • Although in the above-described embodiment, the second atmosphere opening portion 55B is connected to the first communication flow passage 38B, it is not limited thereto. For example, the second atmosphere opening portion 55B can also be connected to the supplementary communication flow passage 38H. That is, the second atmosphere opening portion 55B can also be connected to the second communication flow passage 38J. Further, for example, the second atmosphere opening portion 55B can also be connected to both the first communication flow passage 38B and the second communication flow passage 38J. For example, the second atmosphere opening portion 55B can also be connected to a flow passage connected to the supplementary reservoir portion 31 independently of the first communication flow passage 38B and the second communication flow passage 38J. That is, the second atmosphere opening portion 55B can be configured to open at least one of the first communication flow passage 38B and the second communication flow passage 38J to the atmosphere, and can be connected to a flow passage connected to the supplementary reservoir portion 31.

[0242] • In the above-described embodiment, for example, the liquid circulating device 30 can also be provided with at least any one of the plurality of pressurizing pumps 51, the plurality of depressurizing pumps 52, the pressurizing switching portion 53, the depressurizing switching portion 54, the first atmosphere opening portion 55A, and the second atmosphere opening portion 55B in a manner corresponding to the kind of liquid ejected from the liquid ejection head 21.

[0243] • In the above-described embodiment, for example, the liquid circulating device 30 can also be provided with one supplementary switching portion 58 that is commonly used in accordance with the kind of liquid ejected from the liquid ejection head 21. In this case, the supplementary switching portion 58 can switch the communication state in accordance with all kinds of liquid ejected from the liquid ejection head 21. Further, for example, in a case where liquid is supplied from a plurality of liquid supply sources 18 to a plurality of supplementary reservoir portions 31, respectively, when the amount of liquid stored in at least any one of the plurality of supplementary reservoir portions 31 becomes the third prescribed amount, the supply of liquid to all of the plurality of supplementary reservoir portions 31 can also be stopped.

[0244] • In the above-described embodiment, for example, the liquid circulating device 30 can also be provided with a supplementary pump instead of the supplementary reservoir portion 31, the supplementary pump being used to supply liquid from the liquid supply source 18 to the first reservoir portion 41 via the supply flow passage 19. In this case, for example, the first communication flow passage 38B is directly connected to the first reservoir portion 41. Further, for example, the liquid circulating device 30 can not be provided with the supplementary communication flow passage 38H.

[0245] • In the above-described embodiment, for example, the first time and the second time can be the same time, and for example, the first time can be longer than the second time.

[0246] • In the above-described embodiment, for example, the first pressurizing state and the second depressurizing state can be controlled for a first time that is prescribed in advance. In this case, it is preferable that the second time be longer than the first time.

[0247] • In the above-described embodiment, for example, in a case where the amount of liquid stored in the first storage portion 41 becomes the second prescribed amount or less after the amount of liquid stored in the replenishment storage portion 31 becomes the third prescribed amount in the above-described embodiment, the liquid can not be supplied from the liquid supply source 18 to the replenishment storage portion 31 again. This is a control content in consideration of a state where the liquid stored in the replenishment storage portion 31 has not been supplied to the first storage portion 41. Thus, it is possible to reduce the number of switching of the replenishment switching portion 58, and thereby it is possible to suppress deterioration of the replenishment switching portion 58 due to switching by the replenishment switching portion 58.

[0248] • In the above-described embodiment, for example, the third storage portion 43 can also be a storage portion provided with a diaphragm. In detail, the third storage portion 43 can also be a structure provided with an air chamber and a liquid chamber divided by a diaphragm, the air chamber communicates with the pressurizing pump and the depressurizing pump via each switching valve, and the liquid chamber stores liquid.

[0249] • In the above-described embodiment, for example, as a position at which the recovery flow passage 35 and the supply flow passage 19 are connected, it can not be the first storage portion 41, but a position on the upstream side of the first storage portion 41. That is, the first storage portion 41 can also be provided in the supply flow passage 19 at a position on the liquid ejection head side compared to the connection portion at which the recovery flow passage 35 is connected.

[0250] • In the above-described embodiment, for example, the supply flow passage 19 and the recovery flow passage 35 can also be configured in a manner of being branched into three or more flow passages. Further, for example, the pressure adjusting portion can also be configured in a manner of being opened by different pressures in each of the three or more flow passages.

[0251] • In the above-described embodiment, for example, a branching portion, a plurality of flow passages, and a confluence portion can also be provided in either one of between the first storage portion 41 and the liquid ejection head 21 in the supply flow passage 19 and between the liquid ejection head 21 and the second storage portion 42 in the recovery flow passage 35. That is, as long as a branching portion, a plurality of flow passages, and a confluence portion are provided in at least one of between the first storage portion 41 and the liquid ejection head 21 in the supply flow passage 19 and between the liquid ejection head 21 and the first storage portion 41 in the recovery flow passage 35.

[0252] • In the above-described embodiment, for example, a pressure adjusting portion can be provided in either one of the supply flow passage 19 and the recovery flow passage 35, and a pressure adjusting portion can not be provided in the other one.

[0253] • In the above-described embodiment, for example, a positive pressure on-off valve 64 can also be provided downstream of the positive pressure adjusting portion 63 in the supply flow passage 19. Further, for example, a negative pressure on-off valve 69 can also be provided upstream of the negative pressure adjusting portion 68 in the recovery flow passage 35.

[0254] In the above-described embodiments, for example, an on-off valve can not be provided in each of the branched flow passages. In this case, for example, a flow passage switching section that switches which of the flow passages is opened can be provided on the branching section. Further, for example, a flow passage switching section that switches which of the flow passages is opened can be provided on the merging section.

[0255] In the above-described embodiments, for example, the first storage amount detection section 46 can have a structure including at least a lower limit sensor that detects a case where the storage amount of the liquid is equal to or less than a first prescribed amount, and a replenishment judgment sensor that detects a case where the storage amount of the liquid is equal to or less than a second prescribed amount.

[0256] In the above-described embodiments, for example, the first storage amount detection section 46 and the replenishment storage amount detection section 39 can be float sensors. In this case, the first storage section 41 and the replenishment storage section 31 can have a shape in which the size in the vertical direction Z is longer than the size in the horizontal direction. Thereby, it is possible to increase the displacement amount of the float with respect to the change in the storage amount of the liquid, and thus it is possible to improve the detection accuracy of the first storage amount detection section 46 and the replenishment storage amount detection section 39.

[0257] • In the above-described embodiments, for example, the temperature adjustment section can also vary the manner of heating the liquid depending on the situation. For example, the first temperature adjustment section 47 can also heat the liquid in conjunction with the situation in which the liquid is supplied to the first reservoir section 41 from the liquid supply source 18. For example, the first temperature adjustment section 47 can also heat the liquid in conjunction with the situation in which the liquid is recovered to the first reservoir section 41 from the third reservoir section 43. In particular, the first reservoir section 41 is provided on the flow passage near the liquid ejection head 21, and can heat the liquid supplied or recovered to the first reservoir section 41. Thus, even in the case where the liquid at a low temperature is supplied or recovered to the first reservoir section 41, the liquid can be effectively heated before being supplied to the liquid ejection head 21, and a drastic change in the temperature of the liquid can be suppressed. Further, for example, each temperature adjustment section can heat the liquid based on various parameters. Among the various parameters, at least any one of the working condition such as the continuous working time of the liquid ejection apparatus 10, the actual temperature of the liquid, the environmental temperature in which the liquid ejection apparatus 10 is set, and the storage amount of the liquid stored in the reservoir section can be included. In this case, the liquid circulation mechanism 37 can also be provided with a sensor type that detects the actual temperature of the liquid and the environmental temperature in which the liquid ejection apparatus 10 is set. Further, for example, each temperature adjustment section can vary the duty ratio of the heat generation amount based on the above-described various parameters, and adjust the heat amount for heating the liquid. Further, for example, the control section can predict the heat generation amount based on the above-described various parameters, and control each temperature adjustment section.

[0258] • In the above-described embodiments, for example, if the temperature adjustment section is provided on the first reservoir section 41 provided on the flow passage near the liquid ejection head 21, the temperature adjustment section can not be provided on at least any one of the second reservoir section 42, the third reservoir section 43, and the replenishment reservoir section 31. Further, for example, the temperature adjustment section can not be provided on the first reservoir section 41.

[0259] • In the above-described embodiments, the temperature adjustment section can be provided on at least any one of the supply flow passage 19 and the pressure adjustment section.

[0260] • Although the pressure adjustment device 60, the liquid outflow section 75, and the liquid inflow section 84 are arranged in the vertical direction Z of the liquid ejection head 21 in the above-described embodiments, the present application is not limited thereto. If the pressure adjustment device 60, the liquid outflow section 75, and the liquid inflow section 84 are provided, for example, on a position overlapping a plane passing through the liquid ejection head 21 along a direction orthogonal to the width direction X in order to shorten the flow passage toward the width direction X, the pressure adjustment device 60, the liquid outflow section 75, and the liquid inflow section 84 can not be arranged in the vertical direction Z of the liquid ejection head 21.

[0261] • In the above-described embodiments, for example, the liquid supply source 18 can also be mounted on the carriage 22. Also, for example, at least a part of the structure of the liquid circulating device 30 can not be mounted on the carriage 22.

[0262] • In the above-described embodiments, for example, in a case where the bubbles are discharged from the nozzle 21B, suction cleaning can also be performed. The suction cleaning is cleaning in which liquid in the nozzle 21B is sucked from the nozzle face 21A side and the liquid is ejected from the nozzle 21B. For example, in a case where the bubbles are discharged from the nozzle 21B, pressurization cleaning can also be performed. The pressurization cleaning is cleaning in which the liquid is pressurized in the liquid ejection head 21, and the liquid is ejected from the nozzle 21B. Also, for example, in a case where the bubbles are discharged from the nozzle 21B, flushing can also be performed.

[0263] • In the above-described embodiments, for example, the ink is only a substance that can perform printing on the medium M by being attached to the medium M. Specifically, the ink is, for example, a substance in which particles of a functional material composed of a solid such as a pigment or a metal particle are dissolved, dispersed, or mixed in a solvent, and the like, and includes various compositions of ink such as water-based ink, oil-based ink, gel ink, hot-melt ink, and the like. Also, for example, if the liquid is a substance that can perform printing on the medium M by being attached to the medium M, it can also be a substance other than the ink.

[0264] • In the above-described embodiments, as the medium M, for example, paper, synthetic resin, metal, cloth, ceramic, rubber, or a composite thereof can also be provided.

[0265] • In the above-described embodiments, the liquid ejection device 10 is only a device that performs printing by ejecting liquid to the medium M. The liquid ejection device 10 can also be, for example, a serial printer, a horizontal printer, a line printer, a page printer, a flexographic printing device, a textile printing device, or the like.

[0266] Hereinafter, the technical ideas grasped according to the above-described embodiments and the modified examples and the effects thereof will be described.

[0267] The liquid circulation mechanism includes: a first reservoir configured to store liquid supplied to a liquid ejection head that ejects liquid; a supply flow path that communicates the first reservoir with the liquid ejection head; a second reservoir configured to store liquid recovered from the liquid ejection head; a first recovery flow path that communicates the liquid ejection head with the second reservoir; a third reservoir configured to store liquid between the second reservoir and the first reservoir; a second recovery flow path that communicates the second reservoir with the third reservoir; a third recovery flow path that communicates the third reservoir with the first reservoir; a first check valve on the second recovery flow path that allows liquid to flow from the second reservoir to the third reservoir and restricts liquid from flowing from the third reservoir to the second reservoir; and a second check valve on the third recovery flow path that allows liquid to flow from the third reservoir to the first reservoir and restricts liquid from flowing from the first reservoir to the third reservoir.

[0268] According to this configuration, by using the first to third reservoirs, the supply flow path, the first to third recovery flow paths, the first check valve, and the second check valve, it is possible to form a flow path for circulating liquid even if no pump is provided on the flow path for circulating liquid, for example, thereby enabling downsizing.

[0269] A liquid circulating device includes a liquid circulating mechanism and a circulating device. The liquid circulating mechanism includes a first reservoir configured to store liquid supplied to a liquid ejection head that ejects liquid, a supply flow path that communicates the first reservoir with the liquid ejection head, a second reservoir configured to store liquid recovered from the liquid ejection head, a first recovery flow path that communicates the liquid ejection head with the second reservoir, a third reservoir configured to store liquid between the second reservoir and the first reservoir, a second recovery flow path that communicates the second reservoir with the third reservoir, a third recovery flow path that communicates the third reservoir with the first reservoir, a first check valve that allows flow of liquid from the second reservoir to the third reservoir and restricts flow of liquid from the third reservoir to the second reservoir in the second recovery flow path, and a second check valve that allows flow of liquid from the third reservoir to the first reservoir and restricts flow of liquid from the first reservoir to the third reservoir in the third recovery flow path. The circulating device includes a decompression unit configured to decompress the second reservoir and the third reservoir, a decompression switching unit configured to switch at least between a first decompression state in which the decompression unit communicates with the second reservoir and a second decompression state in which the decompression unit communicates with the third reservoir, a pressurization unit configured to pressurize the third reservoir and the first reservoir, and a pressurization switching unit configured to switch at least between a first pressurization state in which the pressurization unit communicates with the first reservoir and a second pressurization state in which the pressurization unit communicates with the third reservoir.

[0270] According to this structure, by using the first to third reservoirs, the supply flow path, the first to third recovery flow paths, the first and second check valves, a flow path for circulating liquid can be formed even if no pump is provided in the flow path for circulating liquid, and thus the device can be downsized.

[0271] Further, by decompressing the third reservoir, liquid stored in the second reservoir can be recovered to the third reservoir without backflow of liquid stored in the first reservoir to the third reservoir. Further, by pressurizing the third reservoir, liquid stored in the third reservoir can be recovered to the first reservoir without backflow of liquid stored in the third reservoir to the second reservoir. Thus, liquid can be circulated even if no pump is provided in the flow path for circulating liquid, and thus the device can be downsized.

[0272] Further, by switching the pressure reducing switch section to the first pressure reducing state or the second pressure reducing state, it is possible to easily switch between reducing the pressure of the second storage section or reducing the pressure of the third storage section. Further, by switching the pressure increasing switch section to the first pressure increasing state or the second pressure increasing state, it is possible to easily switch between increasing the pressure of the first storage section or increasing the pressure of the third storage section.

[0273] The liquid circulating device can also include a plurality of the liquid circulating mechanisms, each of the plurality of the liquid circulating mechanisms configured to be able to be pressurized by the shared pressure increasing section and configured to be able to be depressurized by the shared pressure reducing section.

[0274] According to this structure, the pressure increasing section that is able to pressurize each of the plurality of the liquid circulating mechanisms is shared. Also, the pressure reducing section that is able to depressurize each of the plurality of the liquid circulating mechanisms is shared. Therefore, compared to a structure in which the pressure increasing section and the pressure reducing section are provided for each of the plurality of the liquid circulating mechanisms, miniaturization is able to be achieved.

[0275] In the liquid circulating device, the circulating device can also include a first atmosphere opening section configured to be able to open a flow passage that communicates the third storage section with the pressure reducing switch section and the pressure increasing switch section to the atmosphere.

[0276] According to this structure, in the third storage section in which both pressurization by the pressure increasing section and depressurization by the pressure reducing section are able to be achieved, by opening the flow passage that communicates with the pressure reducing switch section and the pressure increasing switch section to the atmosphere, it is possible to rapidly implement switching of the pressurization and the depressurization of the third storage section.

[0277] In the liquid circulating device, the liquid circulating mechanism can also include a replenishment storage section that stores liquid for replenishing the first storage section, and a first communication flow passage that communicates the pressure increasing switch section with the replenishment storage section.

[0278] According to this structure, by communicating the pressure increasing switch section with the replenishment storage section via the first communication flow passage, it is possible to pressurize the replenishment storage section via the first communication flow passage, and pressurize the liquid stored in the replenishment storage section for replenishing the first storage section.

[0279] In the liquid circulating device, the replenishment storage section can also be configured to be able to store liquid supplied from a liquid supply source, and the liquid circulating mechanism can include a second communication flow passage that communicates the pressure reducing switch section with the replenishment storage section.

[0280] According to this structure, by communicating the pressure reducing switching section with the replenishment reservoir via the second communication flow path, the replenishment reservoir can be depressurized via the second communication flow path, and by depressurizing the replenishment reservoir, liquid from the liquid supply source can be supplied to the replenishment reservoir.

[0281] In the liquid circulating device, the second atmospheric opening section can be configured to open at least one of the first communication flow path and the second communication flow path to the atmosphere.

[0282] According to this structure, in the replenishment reservoir in which both the pressurization by the pressurizing section and the depressurization by the depressurizing section are possible, by opening at least one of the first communication flow path and the second communication flow path to the atmosphere, the pressurization and the depressurization of the replenishment reservoir can be switched quickly.

[0283] In the liquid circulating device, the first reservoir can communicate with the pressurizing section via the replenishment reservoir.

[0284] According to this structure, by the pressurization by the pressurizing section, the replenishment reservoir can be pressurized via the first communication flow path, and the first reservoir can be pressurized via the first communication flow path and the replenishment reservoir, and liquid stored in the replenishment reservoir can be replenished to the first reservoir. Therefore, the pressurizing section can be used for both the replenishment of liquid from the replenishment reservoir to the first reservoir and the supply of liquid from the first reservoir to the liquid ejection head, and thus miniaturization can be achieved.

[0285] In the liquid circulating device, the second communication flow path can include a replenishment communication flow path that communicates the second reservoir with the replenishment reservoir.

[0286] According to this structure, by the depressurization by the depressurizing section, the second reservoir can be depressurized, and the replenishment reservoir can be depressurized via the second reservoir and the replenishment communication flow path, and liquid can be sucked from the liquid supply source to the replenishment reservoir. Therefore, the depressurizing section can be used for both the recovery of liquid from the liquid ejection head to the second reservoir and the recovery of liquid from the second reservoir to the third reservoir and the supply of liquid from the liquid supply source to the replenishment reservoir, and thus miniaturization can be achieved.

[0287] In the liquid circulating device, the liquid circulating mechanism can have a first negative pressure opening section on the replenishment communication flow path, and the first negative pressure opening section can open the replenishment communication flow path when the negative pressure on the second reservoir side is lower than a predetermined negative pressure.

[0288] According to this structure, even in a case where the second atmospheric opening portion is opened and the supplement reservoir portion is opened to the atmosphere, the supplement communication flow passage is not opened when the negative pressure on the second reservoir portion side is not lower than the predetermined negative pressure. Therefore, it is possible to suppress a case where the second reservoir portion is opened to the atmosphere due to the supplement reservoir portion being opened to the atmosphere.

[0289] In the liquid circulating device, the liquid circulating mechanism can have a first atmospheric communication passage that communicates with the atmosphere on the supplement communication flow passage, and the circulating device can have a supplement switching portion configured to be able to switch between a first communication state in which the second reservoir portion communicates with the supplement reservoir portion and a second communication state in which the second reservoir portion communicates with the first atmospheric communication passage.

[0290] According to this structure, by switching the supplement switching portion to the first communication state or the second communication state, it is possible to easily switch whether or not to depressurize the supplement reservoir portion via the supplement communication flow passage.

[0291] In the liquid circulating device, the liquid circulating mechanism can have a second negative pressure opening portion on the first atmospheric communication passage, the second negative pressure opening portion opening the first atmospheric communication passage when the negative pressure on the second communication flow passage side is lower than a predetermined negative pressure.

[0292] According to this structure, when the second communication state is switched and the supplement reservoir portion is not depressurized via the second communication flow passage, in the first atmospheric communication passage that communicates with the second reservoir portion, when the negative pressure on the second communication flow passage side is lower than the predetermined negative pressure, it is possible to suck the atmosphere instead of not sucking the liquid.

[0293] In the liquid circulating device, the circulating device can have a flow passage opening and closing portion configured to be able to open and close the supplement communication flow passage.

[0294] According to this structure, even in a case where the second atmospheric opening portion is opened and the supplement reservoir portion is opened to the atmosphere, since the supplement communication flow passage is closed by the flow passage opening and closing portion, the supplement reservoir portion does not communicate with the second reservoir portion. Therefore, it is possible to suppress a case where the second reservoir portion is opened to the atmosphere due to the supplement reservoir portion being opened to the atmosphere. Moreover, by the flow passage opening and closing portion opening and closing the supplement communication flow passage, it is possible to easily switch whether or not to depressurize the supplement reservoir portion via the supplement communication flow passage.

[0295] In the liquid circulating device, the liquid circulating mechanism can have a first atmospheric communication passage that communicates with the atmosphere on the supplement communication flow passage, and the circulating device can have an opening and closing portion configured to be able to open and close the first atmospheric communication passage.

[0296] According to this structure, the first atmosphere communication passage is opened and closed by the opening and closing section, so that it is possible to easily switch whether or not the supplemental reservoir portion is depressurized via the supplemental communication flow path.

[0297] In the liquid circulation device, the liquid circulation mechanism can have a second atmosphere communication passage provided in the first reservoir portion and communicating with the atmosphere, and a pressurization opening section provided in the second atmosphere communication passage and opening the second atmosphere communication passage when the positive pressure on the first reservoir portion side exceeds a predetermined positive pressure.

[0298] According to this structure, the second atmosphere communication passage communicating with the atmosphere is opened by the pressurization opening section when the positive pressure on the first reservoir portion side is higher than the predetermined positive pressure. Therefore, it is possible to suppress excessive pressurization of the first reservoir portion in which the positive pressure on the first reservoir portion side exceeds the predetermined positive pressure.

[0299] The liquid ejection device can have the liquid ejection head, the above-described liquid circulation device, and a control section that controls the liquid ejection head and the liquid circulation device.

[0300] According to this structure, the same effects as the above-described liquid circulation device are achieved.

[0301] In the liquid circulation device, the control section can control the depressurization by the depressurization section, the pressurization by the pressurization section, the switching by the depressurization switching section, and the switching by the pressurization switching section, so as to perform circulation of the liquid.

[0302] According to this structure, the depressurization by the depressurization section, the pressurization by the pressurization section, the switching by the depressurization switching section, and the switching by the pressurization switching section are controlled, so as to perform circulation of the liquid.

[0303] The liquid ejection device can have a plurality of the above-described liquid circulation mechanisms, each of the plurality of liquid circulation mechanisms being configured to be able to be pressurized by the pressurization section that is shared, and the control section can switch the pressurization switching section to the second pressurization state in which the pressurization section communicates with the plurality of third reservoir portions, in a case where a first reservoir portion in which a liquid surface of the liquid in the plurality of first reservoir portions is lower than a predetermined height occurs during pressurization of the plurality of first reservoir portions by the pressurization section.

[0304] According to this structure, in a case where, among the plurality of first reservoirs, there is a first reservoir in which the liquid level of the liquid is lower than the predetermined height, the liquid is recovered from the plurality of third reservoirs to the plurality of first reservoirs including the first reservoir in which the liquid level of the liquid is not lower than the predetermined height. Therefore, compared with a structure in which the liquid is not recovered to the first reservoir in which the liquid level of the liquid is not lower than the predetermined height among the plurality of first reservoirs, the number of times of driving the pressurizing section can be reduced, and thus deterioration of the pressurizing section due to a change over time can be suppressed.

[0305] In the liquid circulating device, the control section can switch the pressure reducing switching section to the second pressure reducing state in which the pressure reducing section is in communication with the third reservoir, and after the third reservoir is reduced in pressure for a first time in the second pressure reducing state, the control section can switch the pressure increasing switching section to the second pressure increasing state in which the pressure increasing section is in communication with the third reservoir, and the third reservoir is increased in pressure for a second time that is longer than the first time in the second pressure increasing state.

[0306] According to this structure, the time for recovering the liquid from the third reservoir to the first reservoir by switching the pressure increasing switching section to the second pressure increasing state is longer than the time for recovering the liquid from the second reservoir to the third reservoir by switching the pressure reducing switching section to the second pressure reducing state. Therefore, it is easy to recover the liquid stored in the second reservoir to the first reservoir via the third reservoir, and it is easy to identify whether the liquid recovered from the liquid ejection head is sufficient.

[0307] Symbol explanation

[0308] A…supply direction; B…recovery direction; M…medium; X…width direction; Y…depth direction; Z…vertical direction; 10…liquid discharge device; 18…liquid supply source; 19…supply flow passage; 21…liquid discharge head; 22…carriage; 30…liquid circulating device; 31…supplement storage portion; 34…supplement temperature adjustment portion; 35…recovery flow passage; 38B…first communication flow passage; 38G…second atmosphere communication passage; 38H…supplement communication flow passage; 38I…first atmosphere communication passage; 38J…second communication flow passage; 37…liquid circulating mechanism; 39…supplement storage amount detection portion; 41…first storage portion; 42…second storage portion; 43…third storage portion; 46…first storage amount detection portion; 47…first temperature adjustment portion; 48…second temperature adjustment portion; 49…third temperature adjustment portion; 50…circulating device; 51…pressure increasing pump; 52…pressure reducing pump; 53…pressure increasing switching portion; 54…pressure reducing switching portion; 55A…first atmosphere opening portion; 55B…second atmosphere opening portion; 56…pressure increasing opening portion; 57…first negative pressure opening portion; 58…supplement switching portion; 59…second negative pressure opening portion; 61A…supply branch portion; 61B…supply junction portion; 62A…first positive pressure supply flow passage; 62B…second positive pressure supply flow passage; 63A…first positive pressure adjustment portion; 63B…second positive pressure adjustment portion; 63B…pressure adjustment portion; 64A…first positive pressure on-off valve; 64B…second positive pressure on-off valve; 66A…recovery branch portion; 66B…recovery junction portion; 67A…first negative pressure recovery flow passage; 67B…second negative pressure recovery flow passage; 68A…first negative pressure adjustment portion; 68B…second negative pressure adjustment portion; 69A…first negative pressure on-off valve; 69B…second negative pressure on-off valve; 75…liquid outflow portion; 84…liquid inflow portion; 100…control portion; 150…maintenance device; 157…flow passage on-off portion; 158…on-off portion.

Claims

1. A liquid circulating apparatus characterized by comprising: a liquid circulating mechanism and a circulating device, the liquid circulating mechanism has: a first storage portion configured to be able to store a liquid supplied to a liquid ejection head that ejects a liquid; a supply flow passage that communicates the first storage portion with the liquid ejection head; a second storage portion configured to be able to store a liquid recovered from the liquid ejection head; a first recovery flow passage that communicates the liquid ejection head with the second storage portion; a third storage portion configured to be able to store a liquid between the second storage portion and the first storage portion; a second recovery flow passage that communicates the second storage portion with the third storage portion; a third recovery flow passage that communicates the third storage portion with the first storage portion; a first one-way valve on the second recovery flow passage that allows a flow of the liquid from the second storage portion to the third storage portion and restricts a flow of the liquid from the third storage portion to the second storage portion; a second one-way valve on the third recovery flow passage that allows a flow of the liquid from the third storage portion to the first storage portion and restricts a flow of the liquid from the first storage portion to the third storage portion, the circulating device has: a decompression portion configured to be able to decompress the second storage portion and the third storage portion; a decompression switching portion configured to be able to switch at least a first decompression state in which the decompression portion communicates with the second storage portion and a second decompression state in which the decompression portion communicates with the third storage portion; a pressurization portion configured to be able to pressurize the third storage portion and the first storage portion; a pressurization switching portion configured to be able to switch at least a first pressurization state in which the pressurization portion communicates with the first storage portion and a second pressurization state in which the pressurization portion communicates with the third storage portion.

2. The liquid circulating apparatus according to claim 1, characterized by comprising: a plurality of the liquid circulating mechanisms, each of the plurality of the liquid circulating mechanisms is configured to be pressurized by the pressurization portion that is common and is configured to be decompressed by the decompression portion that is common.

3. The liquid circulating apparatus according to claim 1, characterized in that the circulating device has a first atmosphere opening portion configured to be able to open a flow passage that communicates the third storage portion with the decompression switching portion and the pressurization switching portion to an atmosphere.

4. The liquid circulating apparatus according to claim 1, characterized in that the liquid circulating mechanism has: a replenishment storage portion that stores a liquid for replenishing the first storage portion; a first communication flow passage that communicates the pressurization switching portion with the replenishment storage portion.

5. The liquid circulating apparatus according to claim 4, characterized in that the replenishment storage portion is configured to be able to store a liquid supplied from a liquid supply source, the liquid circulating mechanism has a second communication flow passage that communicates the decompression switching portion with the replenishment storage portion.

6. The liquid circulating device according to claim 5, wherein the circulating device has a second atmosphere opening portion configured to open at least one of the first communication flow passage and the second communication flow passage to the atmosphere.

7. The liquid circulating device according to claim 4, wherein the first reservoir portion communicates with the pressurizing portion via the replenishment reservoir portion.

8. The liquid circulating device according to claim 5, wherein the second communication flow passage includes a replenishment communication flow passage that communicates the second reservoir portion with the replenishment reservoir portion.

9. The liquid circulating device according to claim 8, wherein the liquid circulating mechanism has a first negative pressure opening portion on the replenishment communication flow passage that opens the replenishment communication flow passage when a negative pressure on the second reservoir portion side is lower than a predetermined negative pressure.

10. The liquid circulating device according to claim 8, wherein the liquid circulating mechanism has a first atmosphere communication passage that communicates with the atmosphere on the replenishment communication flow passage, and the circulating device has a replenishment switching portion configured to switch between a first communication state in which the second reservoir portion communicates with the replenishment reservoir portion and a second communication state in which the second reservoir portion communicates with the first atmosphere communication passage.

11. The liquid circulating device according to claim 10, wherein the liquid circulating mechanism has a second negative pressure opening portion on the first atmosphere communication passage that opens the first atmosphere communication passage when a negative pressure on the second communication flow passage side is lower than a predetermined negative pressure.

12. The liquid circulating device according to claim 8, wherein the circulating device has a flow passage opening and closing portion configured to open and close the replenishment communication flow passage.

13. The liquid circulating device according to claim 8, wherein the liquid circulating mechanism has a first atmosphere communication passage that communicates with the atmosphere on the replenishment communication flow passage, and the circulating device has an opening and closing portion configured to open and close the first atmosphere communication passage.

14. The liquid circulating device according to claim 1, wherein the liquid circulating mechanism has: a second atmosphere communication passage provided in the first reservoir portion and communicating with the atmosphere; and a pressurizing opening portion provided on the second atmosphere communication passage and opening the second atmosphere communication passage when a positive pressure on the first reservoir portion side exceeds a predetermined positive pressure. a liquid ejection head that ejects liquid; the liquid circulating device according to claim 1; a control portion that controls the liquid ejection head and the liquid circulating device.

16. The liquid ejection device according to claim 15, wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ 15. A liquid ejection device, comprising: ​ ​ ​ ​ ​ The control section controls the pressure reduction by the pressure reduction section, the pressure increase by the pressure increase section, the switching by the pressure reduction switching section, and the switching by the pressure increase switching section, thereby implementing circulation of the liquid.

17. The liquid discharge apparatus according to claim 15, wherein a plurality of the liquid circulation mechanisms are provided, each of the plurality of the liquid circulation mechanisms is configured to be able to be pressurized by the pressure increase section that is shared, the control section switches the pressure increase switching section to the second pressure increase state in which the pressure increase section communicates with the plurality of the third reservoirs, in a case where a first reservoir in which a liquid level of the liquid in the plurality of the first reservoirs is lower than a predetermined height occurs during pressurization of the plurality of the first reservoirs by the pressure increase section.

18. The liquid discharge apparatus according to claim 15, wherein the control section switches the pressure reduction switching section to the second pressure reduction state in which the pressure reduction section communicates with the third reservoir, and after the third reservoir is depressurized for a first time in the second pressure reduction state, switches the pressure increase switching section to the second pressure increase state in which the pressure increase section communicates with the third reservoir, and pressurizes the third reservoir for a second time that is longer than the first time in the second pressure increase state.

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