Liquid circulation device and liquid discharge device

Abstract

This suppresses pressure pulsation caused by pressure fluctuations in both the supply tank and the recovery tank. [Solution] The liquid circulation device is a liquid circulation device that circulates a liquid and supplies it to a target object, and includes a supply tank for storing the liquid to be supplied to the target object, and a recovery tank for storing the liquid recovered from the target object, and has a supply unit that supplies the liquid to the target object by the differential pressure between the supply tank and the recovery tank, a liquid supply pump that sends the liquid from the recovery tank to the supply tank, a positive pressure pump that supplies gas to the supply tank, a negative pressure pump that draws gas from the recovery tank, and a gas supply pump that sends the gas in the supply tank into the recovery tank.

Description

[Technical Field]

[0001] This invention relates to a liquid circulation device and a liquid discharge device. [Background technology]

[0002] A liquid circulation device is known that supplies liquid to a target object. Furthermore, a liquid dispensing device is known that includes the liquid circulation device and a liquid dispensing head that discharges the liquid supplied from the liquid circulation device.

[0003] For example, a liquid circulation device is known that creates a pressure difference between a negative-pressure recovery tank and a positive-pressure supply tank, transferring liquid from the supply tank to the recovery tank via a liquid discharge head, and returning the liquid from the recovery tank to the supply tank (see Patent Document 1). [Overview of the project] [Problems that the invention aims to solve]

[0004] However, Patent Document 1 may not be able to suppress pulsations in the liquid flow rate caused by pressure fluctuations in the supply tank and the recovery tank.

[0005] The present invention aims to suppress pulsation of liquid flow rate caused by pressure fluctuations in the supply tank and the recovery tank. [Means for solving the problem]

[0006] To solve the above problems, the present invention provides a liquid circulation device for circulating liquid and supplying it to a target object, comprising: a supply tank for storing the liquid to be supplied to the target object; and a recovery tank for storing the liquid recovered from the target object, wherein the device includes: a supply unit for supplying the liquid to the target object based on the differential pressure between the supply tank and the recovery tank; a liquid pump for sending the liquid from the recovery tank to the supply tank; a positive pressure pump for supplying gas to the supply tank; a negative pressure pump for drawing gas from the recovery tank; and a gas pump for sending the gas in the supply tank into the recovery tank. [Effects of the Invention]

[0007] According to the present invention, it is possible to suppress pulsations in the liquid flow rate caused by pressure fluctuations in the supply tank and the recovery tank. [Brief explanation of the drawing]

[0008] [Figure 1] This figure schematically shows an example of the configuration of a liquid circulation device according to the first embodiment of the present invention. [Figure 2] This figure shows the change in the flow rate of liquid or gas by the pump of a liquid circulation device according to the first embodiment of the present invention. [Figure 3] This figure schematically shows another example of the configuration of a liquid circulation device according to a second embodiment of the present invention. [Figure 4] This is a schematic diagram illustrating a printing apparatus, which is an example of a liquid dispensing apparatus according to a third embodiment of the present invention. [Figure 5] This is a block diagram showing the configuration of the printing means in a liquid dispensing device according to a third embodiment of the present invention. [Figure 6] This is a plan view illustrating an example of a head unit for a liquid dispensing device according to a third embodiment of the present invention. [Figure 7] This is an external perspective view illustrating an example of a liquid discharge head of a liquid discharge device according to a third embodiment of the present invention. [Figure 8]It is a cross-sectional explanatory diagram in a direction perpendicular to the nozzle arrangement direction (liquid chamber longitudinal direction) of a liquid ejection head of a liquid ejection apparatus according to a third embodiment of the present invention. [Figure 9] It is a schematic diagram showing an example of an electrode manufacturing apparatus according to a fourth embodiment of the present invention.

Mode for Carrying Out the Invention

[0009] Hereinafter, a liquid ejection apparatus according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and can be modified within the range conceivable by those skilled in the art, such as other embodiments, additions, modifications, and deletions. Any aspect is included within the scope of the present invention as long as the functions and effects of the present invention are exhibited.

[0010] [First Embodiment] <Configuration of Liquid Circulation Apparatus According to First Embodiment> FIG. 1 is an explanatory diagram schematically showing the configuration of a liquid circulation apparatus 100 according to the first embodiment of the present invention. Note that the arrows in the figure indicate the movement directions of liquid and gas.

[0011] The liquid circulation apparatus 100 is a liquid circulation apparatus that circulates liquid and supplies the liquid to a supply target object 200. The liquid circulation apparatus 100 includes a supply tank 11 that stores liquid to be supplied to the supply target object 200, and a recovery tank 12 that stores liquid recovered from the supply target object 200, and has a supply unit 1 that supplies liquid to the supply target object 200 by a differential pressure between the supply tank 11 and the recovery tank 12. The liquid circulation apparatus 100 also includes a liquid feed pump 2 that feeds liquid from the recovery tank 12 to the supply tank 11, a positive pressure pump 3 that supplies gas to the supply tank 11, a negative pressure pump 4 that sucks gas from the recovery tank 12, and an air feed pump 5 that feeds gas inside the supply tank 11 into the recovery tank 12.

[0012] The liquid circulation apparatus 100 is, for example, an apparatus that is mounted on a liquid ejection apparatus and supplies liquid to a liquid ejection head included in the liquid ejection apparatus. In this case, the liquid ejection head corresponds to the supply target object 200.

[0013] In the liquid circulation device 100, the supply unit 1 supplies liquid to a supply target 200 based on the pressure difference between a supply tank 11 and a recovery tank 12. Further, in the liquid circulation device 100, the liquid recovered from the supply target 200 is fed from the recovery tank 12 to the supply tank 11 by a liquid feed pump 2, whereby the liquid can be circulated.

[0014] When liquid is supplied toward the supply target 200 and the amount of liquid in the supply tank 11 decreases, the volume of a gas space 11a in the supply tank 11 increases, and the internal pressure of the supply tank 11 decreases. In contrast, in the liquid circulation device 100, the internal pressure of the supply tank 11 is adjusted by operating a positive pressure pump 3 to supply gas into the supply tank 11.

[0015] On the other hand, when liquid is recovered in the recovery tank 12 and the amount of liquid increases, the volume of a gas space 12a in the recovery tank 12 decreases, and the internal pressure of the recovery tank 12 increases. In contrast, in the liquid circulation device 100, the internal pressure of the recovery tank 12 is adjusted by operating a negative pressure pump 4 to suck gas out of the recovery tank 12.

[0016] When the amount of liquid in the supply tank 11 decreases and the amount of liquid in the recovery tank 12 increases, liquid is fed from the recovery tank 12 toward the supply tank 11 by the liquid feed pump 2. The operation in which the liquid feed pump 2 is driven to feed liquid from the recovery tank 12 toward the supply tank 11 is referred to as a liquid feeding operation by the liquid feed pump 2. When liquid is supplied and the amount of liquid in the supply tank 11 increases, the volume of the gas space 11a in the supply tank 11 decreases, and the internal pressure of the supply tank 11 increases. On the other hand, when the amount of liquid in the recovery tank 12 decreases, the volume of the gas space 12a in the recovery tank 12 increases, and the internal pressure of the recovery tank 12 decreases.

[0017] In a liquid circulation system that supplies liquid to a target material using the pressure difference between a supply tank and a recovery tank, operating a positive pressure pump to supply gas to the supply tank may not lower the internal pressure of the supply tank, and pulsation of the liquid flow rate may occur until the internal pressure decreases due to the decrease in liquid. Similarly, operating a negative pressure pump to draw gas from the recovery tank may not raise the internal pressure of the recovery tank, and pulsation of the liquid flow rate may occur until the internal pressure increases due to the increase in liquid.

[0018] In the liquid circulation device 100 according to this embodiment, the air pump 5 supplies gas from the supply tank 11 to the recovery tank 12. As a result, even if the liquid supply pump 2 operates and the liquid in the supply tank 11 increases and the liquid in the recovery tank 12 decreases, the air pump 5 supplies gas from the gas space 11a to the gas space 12a. By supplying gas from the gas space 11a to the gas space 12a, the increase in internal pressure in the supply tank 11 and the decrease in internal pressure in the recovery tank 12 are suppressed, and the pulsation of the liquid flow rate is suppressed. In this way, in this embodiment, pressure pulsation caused by pressure fluctuations in the supply tank and the recovery tank can be suppressed. Note that the operation of the air pump 5 to send liquid from the supply tank 11 to the supply tank 220 is called the liquid supply operation by the liquid supply pump 213.

[0019] When the liquid transfer pump 2 is not operating, the transfer of liquid stops and the internal pressure of the supply tank 11 decreases. However, by operating the positive pressure pump 3 to supply gas to the supply tank 11, the internal pressure of the supply tank 11 is adjusted. Also, although the internal pressure of the recovery tank 12 increases, by operating the negative pressure pump 4 to draw gas out of the recovery tank 12, the internal pressure of the recovery tank 12 is adjusted.

[0020] Figure 2 shows the flow rate changes of liquid or gas supplied by the pumps of the liquid circulation device 100. Figure 2(A) shows the flow rate changes of the liquid supplied by the liquid supply pump 2. Figure 2(B) shows the flow rate changes of the gas supplied by the air supply pump 5. As shown in Figures 2(A) and 2(B), the positive pressure pump 3, negative pressure pump 4, liquid supply pump 2, and air supply pump 5 operate periodically. The flow rate of the liquid or gas supplied by each pump is not constant and pulsates. In Figures 2(A) and 2(B), the vertical axis represents the flow rate of the pumps, and the horizontal axis represents time. T=0 is the start timing of the liquid supply and air supply operations, and T=t is the end timing of the liquid supply and air supply operations.

[0021] In Figures 2(A) and 2(C), the flow rate from T=0 to T=t1 is the area L1 enclosed by the solid line of the waveform and the horizontal axis from T=0 to T=t1, and the flow rate from T=t1 to T=t2 is the area L2 enclosed by the solid line of the waveform and the horizontal axis from T=t1 to T=t2. At this time, the flow rate from the start (T=0) to the end (T=t) of the liquid delivery operation is L A Therefore, L A It can be expressed by the following formula. L A =L1+L2

[0022] In Figures 2(B) and 2(D), the flow rate from the start (T=0) to the end (T=t) of the operation is L. B Therefore, L B It can be expressed by the following formula. L B =L1+L2+···+Ln(n is an integer greater than or equal to 3)

[0023] In this embodiment, it is preferable that the start timing of the liquid supply operation of the liquid supply pump 2 and the start timing of the air supply operation of the air supply pump 5 are both T=0. In other words, it is preferable that the start timing of the liquid supply operation by the liquid supply pump 2 and the start timing of the air supply operation by the air supply pump 5 are the same. Furthermore, if the start timing of the liquid supply operation by the liquid supply pump 2 and the start timing of the air supply operation by the air supply pump 5 are the same, the timing of T=t may be different, as shown in Figure 2(C) for the change in flow rate of the liquid supply pump 2 and Figure 2(D) for the change in flow rate of the air supply pump 5. By having the start timing of the liquid supply operation of the liquid supply pump 2 and the start timing of the air supply operation of the air supply pump 5 be the same, fluctuations in the amount of liquid and gas in the supply tank 11 and the amount of liquid and gas in the recovery tank 12 can be suppressed, and the pulsation of the liquid flow rate is further suppressed.

[0024] Furthermore, it is preferable that the end timing of the liquid supply operation of the liquid supply pump 2 and the end timing of the air supply operation of the air supply pump 5 are both T=0. In other words, it is preferable that the end timing of the liquid supply operation by the liquid supply pump 2 and the end timing of the air supply operation by the air supply pump 5 are the same. By having the start timing of the liquid supply operation of the liquid supply pump 2 and the start timing of the air supply operation of the air supply pump 5 be the same, and by having the end timing of the liquid supply operation of the liquid supply pump 2 and the end timing of the air supply operation of the air supply pump 5 be the same, fluctuations in the amount of liquid and gas in the supply tank 11 and the amount of liquid and gas in the recovery tank 12 are reduced. As a result, pulsation of the liquid flow rate is further suppressed. In the examples shown in Figures 2(A) and 2(B), the period of the liquid supply operation and the period of the air supply operation are different. However, since the start timings of the liquid supply operation and the air supply operation are the same, and the end timings of the liquid supply operation and the air supply operation are the same, pulsation of the liquid flow rate due to pressure fluctuations in the supply tank and the recovery tank is further suppressed.

[0025] Furthermore, it is preferable that the amount of liquid delivered by the liquid delivery pump 2 from the start of its delivery operation until the end of its delivery operation is the same as the amount of gas delivered by the air delivery pump 5 from the start of its delivery operation until the end of its delivery operation. Flow rate L of the liquid delivery pump 2 from the start (T=0) to the end (T=t) of its delivery operation. A, the flow rate L from the start (T=0) to the end (T=t) of the air supply operation of the air supply pump 5 B preferably satisfies the relationship of the following formula. L A =L B

[0026] When the amount L of liquid delivered by the liquid feed pump 2 during the liquid feeding operation A and the amount L of gas delivered by the air supply pump 5 during the air supply operation B are equal, fluctuations in the amounts of liquid and gas in the supply tank 11 and the amounts of liquid and gas in the recovery tank 12 can be suppressed, and pulsation of the liquid flow rate is further reduced.

[0027] Further, it is preferable that the phase of the flow rate change of the liquid fed by the liquid feeding operation of the liquid feed pump 2 and the phase of the flow rate change of the gas fed by the air feeding operation of the air feed pump 5 are in phase. For example, if both the phase diagram of the liquid feed pump 2 and the phase diagram of the air feed pump 5 are as shown in FIG. 3(A), the amounts of liquid and gas in the supply tank 11 and the amounts of liquid and gas in the recovery tank 12 can be kept constant, and pressure pulsation can be further suppressed.

[0028] [Second Embodiment] Next, a liquid circulation device according to a second embodiment of the present invention will be described. Note that the same names and reference numerals as those in the already described embodiments indicate the same or equivalent members or configurations, and detailed descriptions thereof will be omitted as appropriate. This shall also apply to the embodiments described hereinafter.

[0029] FIG. 3 is a diagram schematically showing another example of the configuration of the liquid circulation device according to the second embodiment of the present invention.

[0030] FIG. 3 is an explanatory diagram schematically showing the configuration of a liquid circulation device 100a according to the second embodiment. Note that the arrows in the figure indicate the moving directions of liquid and gas.

[0031] The liquid circulation device of this embodiment includes a replenishment tank 7 for storing liquid to be replenished in the recovery tank 12, and a replenishment pump 6 for replenishing liquid from the replenishment tank 7 to the recovery tank 12.

[0032] Here, for example, if the object to be supplied 200 is a liquid discharge head that discharges liquid, the amount of liquid in the liquid circulation device decreases as liquid is discharged from the liquid discharge head. The decreased liquid needs to be replenished. At this time, in response to the replenishment of liquid, the amount of liquid in the recovery tank increases, the pressure in the recovery tank increases, and pulsation of the liquid flow rate may occur. For example, the replenishment pump 6, like the positive pressure pump 3, negative pressure pump 4, liquid transfer pump 2, and air supply pump 5, is driven periodically, and the flow rate is not constant, but pulsates, resulting in flow rate changes as shown in Figures 2(A) and 2(B).

[0033] In this embodiment, the start timings of the intake operation of the negative pressure pump 4, the liquid delivery operation of the liquid delivery pump 2, the air delivery operation of the air delivery pump 5, and the replenishment operation of the replenishment pump 6 are all equal. In the phase diagrams of Figures 2(A) and 2(B), it is preferable that the start timing of the intake operation of the negative pressure pump 4, the liquid delivery operation of the liquid delivery pump 2, the air delivery operation of the air delivery pump 5, and the replenishment operation of the replenishment pump 6 is T=0. By having equal start timings, fluctuations in the amounts of liquid and gas in the supply tank 11 and the recovery tank 12 can be suppressed, and pulsation of the liquid flow rate is further suppressed.

[0034] Furthermore, it is preferable that the end timings of the intake operation of the negative pressure pump 4, the liquid delivery operation of the liquid delivery pump 2, the air delivery operation of the air delivery pump 5, and the replenishment operation of the replenishment pump 6 are equal to each other. By having the start and end timings of the intake operation of the negative pressure pump 4, the liquid delivery operation of the liquid delivery pump 2, the air delivery operation of the air delivery pump 5, and the replenishment operation of the replenishment pump 6 be equal, fluctuations in the amount of liquid and gas in the supply tank 11 and the amount of liquid and gas in the recovery tank 12 can be suppressed, and the pulsation of the liquid flow rate is further suppressed.

[0035] For example, if Figure 2(A) is the phase diagram of the negative pressure pump 4 and the liquid delivery pump 2, and Figure 2(B) is the phase diagram of the air delivery pump 5 and the replenishment pump 6, then although the phases are different, the start and end timings of the liquid delivery operation and the start and end timings of the air delivery operation are the same, so the pulsation of the liquid flow rate due to pressure fluctuations in the supply tank and the recovery tank is further suppressed.

[0036] It is preferable that the amount of gas drawn in by the negative pressure pump 4 from the start of its intake operation until it ends, the amount of liquid delivered by the liquid delivery pump 2 from the start of its liquid delivery operation until it ends, the amount of gas delivered by the air delivery pump 5 from the start of its intake operation until it ends, and the amount of liquid delivered by the replenishment pump 6 from the start of its replenishment operation until it ends are equal to each other.

[0037] Figure 2(A) is a phase diagram of the liquid delivery pump 2 and the negative pressure pump 4, and Figure 2(B) is a phase diagram of the air delivery pump 5 and the replenishment pump 6, and the amount of liquid delivered by the liquid delivery pump 2 is L. A Let 2 be the amount of gas supplied by the negative pressure pump 4, and L A Let 4 be the amount of gas supplied by the air pump 5, and L B Let 5 be the amount of gas supplied by the replenishment pump 6, and L B If we set it to 6, it is preferable that the following relationship holds. L A 2 = L A 4=L B 5=L B 6 This relationship allows for suppression of fluctuations in the amounts of liquid and gas in the supply tank 11 and the recovery tank 12, thereby further suppressing pulsations in the liquid flow rate.

[0038] Furthermore, it is preferable that the negative pressure pump 4, the liquid delivery pump 2, the air delivery pump 5, and the replenishment pump 6 are in the same phase. For example, if Figure 2(A) is the phase diagram for the negative pressure pump 4, the liquid delivery pump 2, the air delivery pump 5, and the replenishment pump 6, then the amounts of liquid and gas in the supply tank 11 and the amounts of liquid and gas in the recovery tank 12 can be kept constant, and the pulsation of the liquid flow rate is further suppressed.

[0039] [Third Embodiment] A liquid dispensing device according to a third embodiment of the present invention will be described with reference to Figures 4 and 5. Figure 4 is a schematic diagram of the liquid dispensing device 1000 according to the third embodiment of the present invention. Figure 5 is a block diagram showing the configuration of the printing means 5A in the liquid dispensing device 1000.

[0040] The liquid dispensing device 1000 shown in Figure 4 is a printing device that dispenses liquid onto a continuous body, which is the dispensing target (dispensing medium), and forms an image on the continuous body 10. The continuous body is, for example, a continuous sheet of paper, which is a series of sheets of paper joined together.

[0041] The liquid dispensing device 1000 includes a loading means 1A for loading the continuous body 10, a guiding and transporting means 3A for guiding and transporting the continuous body 10 loaded from the loading means 1A to the printing means 5A, a printing means 5A for performing printing to form an image by dispensing liquid onto the continuous body 10, a drying means 7A for drying the continuous body 10, and a discharge means 9 for discharging the continuous body 10. The printing means 5A also includes a head unit 50 for dispensing liquid for forming an image and a head unit 55 for dispensing processing liquid for post-processing. The head units 50 and 55 are equipped with the liquid circulation device of the first or second embodiment.

[0042] The continuous body 10 is fed out from the main winding roller 11A of the loading means 1A, guided and transported by the rollers of the loading means 1A, the guiding and transporting means 3A, the drying means 7A, and the discharge means 9, and then wound up by the winding roller 91 of the discharge means 9.

[0043] In the printing means 5A, this continuum 10 is transported on a transport guide member 59 facing the head unit 50 and the head unit 55, an image is formed by the liquid discharged from the head unit 50, and post-processing is performed by the processing liquid discharged from the head unit 55.

[0044] Here, the head unit 50 has, for example, four full-line head arrays 51K, 51C, 51M, and 51Y (hereinafter referred to as "head array 51" when color is not distinguished) arranged from the upstream side in the media transport direction.

[0045] Each head array 51 is a liquid dispensing means, and each dispenses a liquid (e.g., ink) of black K, cyan C, magenta M, or yellow Y onto the conveyed continuum 10. However, the types and number of colors are not limited to these.

[0046] The head array 51 is, for example, arranged in a staggered pattern on a base member 52, as shown in Figure 6, but is not limited to this configuration.

[0047] Next, an example of a liquid discharge head will be described with reference to Figures 7 and 8. The liquid discharge head in this embodiment is a circulating type liquid discharge head. Figure 7 is an external perspective view of the liquid discharge head, and Figure 8 is a cross-sectional view of the head in a direction perpendicular to the nozzle arrangement direction (liquid chamber longitudinal direction).

[0048] This liquid discharge head is constructed by laminating and joining a nozzle plate 101, a flow path plate 102, and a vibrating plate member 103 as a wall member. It also includes a piezoelectric actuator 111 that displaces the vibration region (vibrating plate) 130 of the vibrating plate member 103, a common liquid chamber member 120 that also serves as the frame member of the head, and a cover 129. The portion composed of the flow path plate 102 and the vibrating plate member 103 is referred to as the flow path member 140.

[0049] The nozzle plate 101 has a plurality of nozzles 104 for discharging liquid.

[0050] The flow path plate 102 has through holes and grooves that form individual liquid chambers 106 connected to the nozzle 104 via a nozzle communication passage 105, a supply-side fluid resistance section 107 connected to the individual liquid chambers 106, and a liquid introduction section 108 connected to the supply-side fluid resistance section 107. The nozzle communication passage 105 is a flow path that connects to the nozzle 104 and the individual liquid chambers 106, respectively. The liquid introduction section 108 is connected to the supply-side common liquid chamber 110 via an opening 109 in the diaphragm member 103.

[0051] The diaphragm member 103 has a deformable vibration region 130 that forms the wall surface of the individual liquid chambers 106 of the flow channel plate 102. Here, the diaphragm member 103 has a two-layer structure (not limited to this), and is formed of a first layer that forms a thin-walled portion from the flow channel plate 102 side and a second layer that forms a thick-walled portion, with the first layer forming a deformable vibration region 130 in the portion corresponding to the individual liquid chambers 106.

[0052] On the opposite side of the individual liquid chambers 106 of the diaphragm member 103, a piezoelectric actuator 111 is positioned, which includes an electromechanical conversion element as a driving means (actuator means, pressure generating means) for deforming the vibration region 130 of the diaphragm member 103.

[0053] This piezoelectric actuator 111 is formed by grooving a piezoelectric member joined to a base member 113 using half-cut dicing to create a required number of columnar piezoelectric elements 112 at predetermined intervals in a comb-like pattern.

[0054] The piezoelectric element 112 is joined to a protrusion 130a, which is an island-shaped thickened portion formed in the vibration region 130 of the diaphragm member 103. A flexible wiring member 115 is also connected to the piezoelectric element 112.

[0055] The common liquid chamber member 120 forms a supply-side common liquid chamber 110 and a discharge-side common liquid chamber 150. The supply-side common liquid chamber 110 is connected to the supply port 171, and the discharge-side common liquid chamber 150 is connected to the discharge port 181.

[0056] In this configuration, the common liquid chamber member 120 is composed of a first common liquid chamber member 121 and a second common liquid chamber member 122. The first common liquid chamber member 121 is joined to the diaphragm member 103 side of the flow path member 140, and the second common liquid chamber member 122 is laminated and joined to the first common liquid chamber member 121.

[0057] The first common liquid chamber member 121 forms a downstream common liquid chamber 110A, which is part of the supply-side common liquid chamber 110 that leads to the liquid introduction section 108, and a discharge-side common liquid chamber 150 that leads to the discharge channel 151. The second common liquid chamber member 122 forms an upstream common liquid chamber 110B, which is the remaining part of the supply-side common liquid chamber 110.

[0058] Furthermore, the flow channel plate 102 has a discharge channel 151 that runs along the surface direction of the flow channel plate 102 and leads to each individual liquid chamber 106 via a nozzle communication passage 105. The discharge channel 151 leads to a common liquid chamber 150 on the discharge side.

[0059] In this liquid discharge head, for example, by lowering the voltage applied to the piezoelectric element 112 from the reference potential (intermediate potential), the piezoelectric element 112 contracts, the vibration region 130 of the diaphragm member 103 is pulled, and the volume of the individual liquid chamber 106 expands, causing liquid to flow into the individual liquid chamber 106.

[0060] Subsequently, the voltage applied to the piezoelectric element 112 is increased to stretch the piezoelectric element 112 in the stacking direction, and the vibration region 130 of the diaphragm member 103 is deformed toward the nozzle 104, thereby contracting the volume of the individual liquid chamber 106. As a result, the liquid inside the individual liquid chamber 106 is pressurized and the liquid is discharged from the nozzle 104.

[0061] Furthermore, any liquid that is not discharged from the nozzle 104 passes through the nozzle 104 and is discharged from the discharge channel 151 to the discharge-side common liquid chamber 150, and is then supplied again from the discharge-side common liquid chamber 150 to the supply-side common liquid chamber 110 through an external circulation path.

[0062] Furthermore, the method of driving the head is not limited to the example above (pull-push-shot); it is also possible to perform pull-shot, push-shot, etc., depending on the way the drive waveform is applied.

[0063] The liquid circulation device of this embodiment may have a circulating liquid discharge head that has individual liquid chambers in which the liquid circulates near the nozzle, or it may have a head in which the liquid circulates only in a common liquid chamber.

[0064] In this specification, "liquid dispensing device" refers to a device equipped with a liquid dispensing head that drives the liquid dispensing head to dispense liquid, and is not limited to the example of the printing device shown in Figure 1.

[0065] In this application, "liquid" is not particularly limited as long as it has viscosity and surface tension that can be dispensed from the head, but it is preferable that its viscosity becomes 30 mPa·s or less at room temperature and atmospheric pressure, or when heated or cooled. More specifically, it is a solution, suspension, emulsion, etc. containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a polymerizable compound, a resin, a functional material such as a surfactant, a biocompatible material such as DNA, amino acids or proteins, calcium, or an edible material such as a natural pigment. These can be used, for example, as inkjet inks, surface treatment liquids, liquids for forming components of electronic elements and light-emitting elements or electronic circuit resist patterns, and material liquids for 3D molding.

[0066] A "liquid discharge head" includes devices that use piezoelectric actuators (multilayer piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a diaphragm and a counter electrode as energy sources for discharging liquid.

[0067] A "liquid dispensing device" includes devices that drive a liquid dispensing head to dispense liquid. Liquid dispensing devices include not only devices that can dispense liquid onto surfaces to which liquid can adhere, but also devices that dispense liquid into air or into liquid.

[0068] This "liquid dispensing device" may also include means for feeding, transporting, and dispensing paper onto materials to which liquid can adhere, as well as pre-treatment devices, post-treatment devices, etc.

[0069] For example, "liquid ejection devices" include image forming devices that eject ink to form images on paper, and three-dimensional molding devices that eject molding liquid into a powder layer formed in layers to create three-dimensional objects.

[0070] Furthermore, the term "liquid dispensing device" is not limited to those that visualize meaningful images such as letters or figures through the dispensed liquid. For example, it also includes devices that form patterns that do not have meaning in themselves, or devices that create three-dimensional images.

[0071] <Electrode Manufacturing Equipment> The "liquid dispensing apparatus" according to the present invention also includes apparatus for manufacturing electrodes and electrochemical elements. The electrode manufacturing apparatus will be described below.

[0072] Figure 9 is a schematic diagram showing an example of an electrode manufacturing apparatus according to the fourth embodiment. The electrode manufacturing apparatus is an apparatus for manufacturing an electrode including a layer having electrode material by discharging a liquid composition using a head module including the liquid discharging head 122 described in the first embodiment.

[0073] <Means for forming a layer containing electrode material, process for forming a layer containing electrode material> The discharge means provided in the electrode manufacturing apparatus shown in Figure 9 is a head module according to the embodiment of the present invention described above. A liquid composition is discharged from the discharge head of the head module, thereby applying the liquid composition to an object and forming a liquid composition layer. The object (hereinafter sometimes referred to as the "discharge target") is not particularly limited as long as it is an object on which a layer containing electrode material is formed, and can be appropriately selected according to the purpose. For example, the object can be an electrode substrate (current collector), an active material layer, or a layer containing solid electrode material. The object may also be an electrode composite layer containing active material on an electrode substrate (current collector). Furthermore, the discharge means and discharge process may be means and processes for forming a layer containing electrode material by directly discharging the liquid composition, as long as it is possible to form a layer containing electrode material on the discharge target. Alternatively, the discharge means and discharge process may be means and processes for forming a layer containing electrode material by indirectly discharging the liquid composition.

[0074] <Other components, other processes> Other components included in the electrode composite layer manufacturing apparatus are not particularly limited as long as they do not impair the effects of the present invention and can be appropriately selected according to the purpose. Similarly, other steps included in the electrode composite layer manufacturing method are not particularly limited as long as they do not impair the effects of the present invention and can be appropriately selected according to the purpose. For example, components and steps included in the electrode composite layer manufacturing apparatus and manufacturing method include heating means and heating steps.

[0075] <Heating means, heating process> The heating means included in the electrode composite layer manufacturing apparatus is a means for heating the liquid composition discharged by the discharge means. Furthermore, the heating step included in the electrode composite layer manufacturing method is a step for heating the liquid composition discharged in the discharge step. By heating the liquid composition, the liquid composition layer can be dried.

[0076] <Configuration that forms a layer containing electrode material by direct discharge of a liquid composition> Here, as an example of an electrode manufacturing apparatus, an electrode manufacturing apparatus that forms an electrode composite layer containing an active material on an electrode substrate (current collector) will be described. As shown in Figure 9, the electrode manufacturing apparatus includes an ejection process section 150 which includes a step of applying a liquid composition onto a printing substrate 704 having an object to be ejected to form a liquid composition layer, and a heating process section 130 which includes a heating step of heating the liquid composition layer to obtain an electrode composite layer.

[0077] The electrode manufacturing apparatus includes a transport unit 705 for transporting the printing substrate 704. The transport unit 705 transports the printing substrate 704 at a preset speed in the order of the discharge process unit 150 and the heating process unit 130. There are no particular restrictions on the method for manufacturing the printing substrate 704 having an object to be discharged, such as an active material layer, and known methods can be appropriately selected. The discharge process unit 150 includes a liquid discharge head 122 that performs a dispensing process for applying a liquid composition onto the printing substrate 704, a container 281b that contains the liquid composition 707, and a supply tube 281c that supplies the liquid composition 707 contained in the container 281b to the liquid discharge head 122.

[0078] In the discharge process section 150, the liquid composition 707 is discharged from the liquid discharge head 122 and applied to the printing substrate 704, forming a thin film layer of the liquid composition. The containment container 281b may be integrated with the electrode composite layer manufacturing apparatus, or it may be detachable from the electrode composite layer manufacturing apparatus. Alternatively, the containment container 281b may be a container used for adding to a containment container integrated with the electrode composite layer manufacturing apparatus, or a containment container detachable from the electrode composite layer manufacturing apparatus.

[0079] The containment container 281b and the supply tube 281c can be arbitrarily selected as long as they are capable of stably containing and supplying the liquid composition 707.

[0080] In the heating section 130, a solvent removal step is performed in which the solvent remaining in the liquid composition layer is heated and removed. Specifically, the solvent remaining in the liquid composition layer is heated and dried by the heating device 703 of the heating section 130, thereby removing the solvent from the liquid composition layer. This forms the electrode composite layer. Furthermore, the solvent removal step in the heating section 130 may be performed under reduced pressure.

[0081] There are no particular restrictions on the heating device 703, and it can be appropriately selected according to the purpose. For example, the heating device 703 can be a substrate heater, an IR heater, or a hot air heater. Alternatively, the heating device 703 may be a combination of at least two of the substrate heater, IR heater, and hot air heater. Furthermore, the heating temperature and heating time can be appropriately selected according to the boiling point of the solvent contained in the liquid composition 707 or the film thickness to be formed.

[0082] By using the electrode manufacturing apparatus according to the embodiment of the present invention, a liquid composition can be discharged to a target location. The electrode mixture layer can be suitably used, for example, as part of the configuration of an electrochemical element. There are no particular restrictions on components other than the electrode mixture layer in the electrochemical element, and known components can be appropriately selected. For example, components other than the electrode mixture layer include a positive electrode, a negative electrode, a separator, etc.

[0083] The term "materials to which liquid can adhere" above refers to materials to which liquid can adhere, at least temporarily, including materials that adhere and solidify, or materials that adhere and penetrate. Specific examples include recording media such as paper, recording paper, film, and cloth; electronic components such as electronic circuit boards and piezoelectric elements; powder layers; organ models; and inspection cells. Unless otherwise specified, it includes all materials to which liquid can adhere.

[0084] The materials referred to as "materials to which liquid can adhere" above include paper, thread, fibers, fabrics, leather, metal, plastic, glass, wood, ceramics, and any other material to which liquid can adhere, even temporarily.

[0085] Furthermore, while "liquid dispensing device" includes devices in which the liquid dispensing head and the object to which the liquid can adhere move relative to each other, it is not limited to these. Specific examples include serial-type devices in which the liquid dispensing head moves, and line-type devices in which the liquid dispensing head does not move.

[0086] Other examples of "liquid dispensing devices" include processing liquid coating devices that dispense processing liquid onto the surface of paper for purposes such as modifying the paper surface, and injection granulation devices that granulate fine particles of raw materials by spraying a compositional liquid, in which raw materials are dispersed in a solution, through a nozzle.

[0087] In this application, the terms image formation, recording, printing, copying, printing, and shaping are all considered synonymous.

[0088] Although preferred embodiments have been described in detail above, the present invention is not limited to the embodiments described above, and various modifications and substitutions can be made to the embodiments described above without departing from the scope of the claims.

[0089] The ordinal numbers, quantities, and other figures used in the description of the embodiments of the present invention are all illustrative to specifically illustrate the technology of the present invention, and the present invention is not limited to these illustrative figures. Furthermore, the connection relationships between the components are illustrative to specifically illustrate the technology of the present invention, and do not limit the connection relationships that realize the functions of the present invention.

[0090] Examples of the present invention are as follows: <1> A liquid circulation device for circulating liquid and supplying it to a target object, comprising: a supply tank for storing the liquid to be supplied to the target object; and a recovery tank for storing the liquid recovered from the target object, wherein the device has a supply unit that supplies the liquid to the target object based on the differential pressure between the supply tank and the recovery tank; a liquid pump for sending the liquid from the recovery tank to the supply tank; a positive pressure pump for supplying gas to the supply tank; a negative pressure pump for drawing gas from the recovery tank; and an air pump for sending the gas in the supply tank into the recovery tank. <2> The start timing of the liquid supply operation by the liquid supply pump and the start timing of the air supply operation by the air supply pump are the same. <1> This is the liquid circulation device described in [reference]. <3> The aforementioned liquid supply pump terminates at the same time as the air supply pump terminates at the same time. <2> This is the liquid circulation device described in [reference]. <4> The amount of liquid delivered by the liquid delivery pump from the start of its delivery operation until it ends is the same as the amount of gas delivered by the air delivery pump from the start of its delivery operation until it ends. <3> This is the liquid circulation device described in [reference]. <5> The liquid pump performs liquid delivery periodically, and the air pump performs air delivery periodically, and the phase of the change in the flow rate of the liquid delivered by the liquid delivery operation of the liquid pump and the phase of the change in the flow rate of the liquid delivered by the air delivery operation of the air pump are the same. <4> This is the liquid circulation device described in [reference]. <6> The device comprises a replenishment tank for storing the liquid to be replenished in the recovery tank, and a replenishment pump for supplying the liquid from the replenishment tank to the recovery tank, wherein the start timings of the intake operation by the negative pressure pump, the supply operation by the supply pump, the supply operation by the air supply pump, and the replenishment operation by the replenishment pump are equal to each other. <1> from the above <5> It is a liquid circulation device described in any one of the following. <7> The end times of the intake operation by the negative pressure pump, the liquid delivery operation by the liquid delivery pump, the air delivery operation by the air delivery pump, and the replenishment operation by the replenishment pump are all equal to each other. <7> This is the liquid circulation device described in [reference]. <8> The amount of gas drawn in by the negative pressure pump from the start of its intake operation until it ends, the amount of liquid delivered by the liquid delivery pump from the start of its liquid delivery operation until it ends, the amount of gas supplied by the air delivery pump from the start of its air delivery operation until it ends, and the amount of liquid delivered by the replenishment pump from the start of its replenishment operation until it ends are all equal, characterized in that <7> This is the liquid circulation device described in [reference]. <9> The negative pressure pump performs an intake operation periodically, the liquid delivery pump performs a liquid delivery operation periodically, the air delivery pump performs an air delivery operation periodically, and the replenishment pump performs a replenishment operation periodically, wherein the phase of the change in the flow rate of the gas drawn in by the intake operation of the negative pressure pump, the phase of the change in the flow rate of the liquid delivered by the liquid delivery operation of the liquid delivery pump, the phase of the change in the flow rate of the gas delivered by the air delivery operation of the air delivery pump, and the phase of the change in the flow rate of the liquid delivered by the replenishment pump are the same as each other. <8> This is the liquid circulation device described in [reference]. <10> The aforementioned <1> ~the aforementioned <9> A liquid dispensing device characterized by comprising one of the liquid circulation devices and a liquid dispensing head that discharges the liquid supplied from the liquid circulation device, which is the object to be supplied. [Explanation of Symbols]

[0091] 1 Supply section 1A Delivery method 2. Liquid transfer pump 3. Positive pressure pump 3A Guide and transport means 4. Vacuum pump 5. Air supply pump 5A Printing means 6. Refill pump 7 Refill tank 7A Drying means 10 continuum 11 Supply Tank 11a Gas space 12 Recovery Tanks 12a Gas space 50 Head Units 51Y, 51M, 51C, 51K head arrays 52 Base member 55 Head Unit 59 Conveyor guide member 91 Winding roller 100, 100a liquid circulation equipment 100A Liquid Discharge Head 101 Nozzle Plate 102 Flow channel plate 103 Diaphragm component 111 Piezoelectric Actuator 120 Common liquid chamber member 129 Cover 130 Vibration area 140 Flow channel member 150 Common liquid chamber on discharge side 171 supply ports 181 Discharge Port 200 Items to be supplied 1000 liquid dispensing device L1, L2 area t1, t2, t3 time [Prior art documents] [Patent Documents]

[0092] [Patent Document 1] Japanese Patent Publication No. 2022-020024

Claims

1. A liquid circulation device that circulates a liquid and supplies it to a target object, A supply unit comprising a supply tank for storing the liquid to be supplied to the object to be supplied, and a recovery tank for storing the liquid recovered from the object to be supplied, wherein the liquid is supplied to the object to be supplied by the differential pressure between the supply tank and the recovery tank, A liquid transfer pump that transfers the liquid from the recovery tank to the supply tank, A positive pressure pump that supplies gas to the supply tank, A negative pressure pump for drawing gas from the aforementioned recovery tank, A liquid circulation device characterized by having an air pump that sends the gas in the supply tank into the recovery tank.

2. The liquid circulation device according to claim 1, characterized in that the start timing of the liquid supply operation by the liquid supply pump and the start timing of the air supply operation by the air supply pump are the same.

3. The liquid circulation device according to claim 2, characterized in that the timing of the termination of the liquid supply operation by the liquid supply pump and the timing of the termination of the air supply operation by the air supply pump are the same.

4. The liquid circulation device according to claim 3, characterized in that the amount of liquid delivered by the liquid delivery pump from the time it starts its delivery operation until it finishes its delivery operation is the same as the amount of gas delivered by the air delivery pump from the time it starts its air delivery operation until it finishes its air delivery operation.

5. The aforementioned liquid transfer pump performs liquid transfer operations periodically. The aforementioned air supply pump performs the air supply operation periodically. The liquid circulation device according to claim 4, characterized in that the phase of the change in the flow rate of the liquid supplied by the liquid supply operation of the liquid supply pump and the phase of the change in the flow rate of the liquid supplied by the air supply operation of the air supply pump are the same.

6. A replenishment tank for storing the liquid to be replenished in the recovery tank, The system includes a replenishment pump that delivers the liquid from the replenishment tank to the recovery tank for replenishment, The liquid circulation device according to claim 1, characterized in that the start timings of the intake operation by the negative pressure pump, the liquid supply operation by the liquid supply pump, the air supply operation by the air supply pump, and the replenishment operation by the replenishment pump are all equal to each other.

7. The liquid circulation device according to claim 6, characterized in that the completion timings of the intake operation by the negative pressure pump, the liquid supply operation by the liquid supply pump, the air supply operation by the air supply pump, and the replenishment operation by the replenishment pump are all equal to each other.

8. The amount of gas drawn in by the aforementioned negative pressure pump from the time it starts its intake operation until it finishes its intake operation, The amount of liquid delivered by the aforementioned liquid delivery pump from the time it starts to finish its operation, The amount of gas supplied by the aforementioned air pump from the time it started its air supply operation until it finished its air supply operation, The liquid circulation device according to claim 7, characterized in that the amount of liquid delivered by the replenishment pump from the time it starts the replenishment operation until it finishes the replenishment operation is equal to each other.

9. The aforementioned negative pressure pump performs intake operations periodically. The aforementioned liquid transfer pump performs liquid transfer operations periodically. The aforementioned air supply pump performs the air supply operation periodically. The aforementioned replenishment pump performs the replenishment operation periodically. The liquid circulation device according to claim 8, characterized in that the phase of the change in the flow rate of the gas drawn in by the intake operation of the negative pressure pump, the phase of the change in the flow rate of the liquid delivered by the delivery operation of the delivery pump, the phase of the change in the flow rate of the gas delivered by the delivery operation of the air supply pump, and the phase of the change in the flow rate of the liquid delivered by the replenishment operation of the replenishment pump are the same as each other.

10. A liquid circulation device according to any one of claims 1 to 9, A liquid dispensing device characterized by comprising the above-mentioned object to be supplied, and a liquid dispensing head that discharges the liquid supplied from the liquid circulation device.

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