Liquid ejection apparatus, film formation apparatus, electrode manufacturing apparatus, and electrode manufacturing method

Abstract

To provide a liquid discharge device which is excellent in discharge stability.SOLUTION: A liquid discharge device has: a first storage part for storing a liquid composition; a discharge part for discharging the liquid composition supplied from the first storage part to an object; and a first pressure variable mechanism which is provided on a side opposite to the discharge part across the first storage part, and changes a supply pressure applied to the liquid composition supplied to the discharge part from the first storage part on the basis of a discharge frequency of the liquid composition by the discharge part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection apparatus, a film forming apparatus, an electrode manufacturing apparatus, and an electrode manufacturing method. [Background technology]

[0002] 2. Description of the Related Art Conventionally, liquid ejection devices that eject a liquid composition supplied to an ejection portion onto a target object have been known. Liquid ejection devices are used for various purposes such as image formation and film formation.

[0003] As a liquid ejection device, a configuration has been disclosed in which, in order to prevent ejection from becoming unstable due to a delay in the supply of the liquid composition to the ejection section, the supply pressure is changed according to the ejection frequency by a control mechanism provided between the ejection section and a supply pressure source that supplies the liquid composition to the ejection section (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] A liquid ejection device is required to have excellent ejection stability.

[0005] An object of the present invention is to provide a liquid ejection device that has excellent ejection stability. [Means for solving the problem]

[0006] A liquid ejection device according to one aspect of the present invention includes a first storage section that stores a liquid composition, a ejection section that ejects the liquid composition supplied from the first storage section onto a target object, and a first pressure variable mechanism that is provided on the opposite side of the ejection section to the ejection section and that changes a supply pressure applied to the liquid composition supplied from the first storage section to the ejection section based on an ejection frequency of the liquid composition by the ejection section. a pressure generating mechanism that generates the supply pressure of the liquid composition; and an adjusting mechanism that adjusts the supply pressure generated by the pressure generating mechanism. With The adjustment mechanism is disposed between the pressure generating mechanism and the first storage portion. . [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a liquid ejection device that has excellent ejection stability. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a configuration of a liquid ejection device according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the functional configuration of a control unit according to the first embodiment. [Figure 3] FIG. 4 is a flowchart illustrating the operation of the liquid ejection device according to the first embodiment. [Figure 4] FIG. 10 is a diagram illustrating an example of a change in supply pressure depending on the ejection frequency. [Figure 5] FIG. 10 is a diagram illustrating correspondence information between ejection frequency and supply pressure. [Figure 6] FIG. 10 is a diagram illustrating the configuration of a liquid ejection device according to a second embodiment. [Figure 7] FIG. 10 is a diagram illustrating the configuration of a liquid ejection device according to a third embodiment. [Figure 8] FIG. 10 is a diagram illustrating an example of the functional configuration of a control unit according to a third embodiment. [Figure 9] FIG. 11 is a flowchart illustrating the operation of the liquid ejection device according to the third embodiment. [Figure 10] FIG. 10 is a diagram illustrating the configuration of a liquid ejection device according to a fourth embodiment. [Figure 11] FIG. 10 is a diagram illustrating an example of the functional configuration of a control unit according to a fourth embodiment. [Figure 12] FIG. 10 is a first diagram illustrating first and second circulation paths according to a fourth embodiment. [Figure 13] FIG. 2 is a second diagram illustrating the first and second circulation paths according to the fourth embodiment. [Figure 14] FIG. 10 is a flowchart illustrating the operation of the liquid ejection device according to the fourth embodiment. [Figure 15] FIG. 10 is a diagram illustrating the configuration of an electrode manufacturing apparatus according to a fifth embodiment. [Figure 16] FIG. 11 is a plan view of a discharge section according to a fifth embodiment, viewed from the discharge direction side. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes in detail the preferred embodiments of the present invention with reference to the accompanying drawings. In the drawings, the same components are designated by the same reference numerals, and redundant explanations will be omitted where appropriate.

[0010] Furthermore, the embodiments shown below are illustrative of a liquid ejection apparatus, a film forming apparatus, an electrode manufacturing apparatus, and an electrode manufacturing method for embodying the technical concept of the present invention, and the present invention is not limited to the embodiments shown below. Unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described below are intended to be illustrative and not to limit the scope of the present invention. Furthermore, the sizes and positional relationships of components shown in the drawings may be exaggerated for clarity of explanation.

[0011] [First embodiment] <Configuration example of liquid ejection device 100> 1 is a diagram showing an example of the configuration of a liquid ejection device 100 according to the first embodiment. The liquid ejection device 100 has a head 1, a first tank 2, and a first pressure variable mechanism 10.

[0012] The liquid ejection device 100 is a device that supplies a liquid composition Q from a first tank 2 to a head 1 and ejects the liquid composition Q from the head 1 onto a target T, for example, as droplets R. The liquid ejection device 100 is not only used to form and visualize significant images such as characters and figures on the target T using the ejected liquid composition Q, but also to form films such as patterns and functional layers that have no meaning in themselves, and to create three-dimensional images. Note that in the embodiments, there are cases where it is stated that "droplets R are ejected from the head 1," but since droplets R are droplets of the liquid composition Q, this is included in "ejecting the liquid composition Q from the head 1."

[0013] The object T refers to an object to which the liquid composition Q ejected from the head 1 can adhere at least temporarily, such as an object to which the liquid composition Q adheres and sticks, or an object to which the liquid composition Q adheres and penetrates. Specific examples include media such as paper, recording paper, film, and cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all objects to which the liquid composition Q can adhere. The material of the object T may be paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like, as long as the liquid composition Q can adhere at least temporarily.

[0014] Liquid composition Q is a liquid that achieves a desired function, such as an image or film. Liquid composition Q may have any viscosity and surface tension that allows it to be ejected from head 1. However, it is preferable that the viscosity of the liquid composition Q be 100 mPa·s or less at room temperature and pressure, or upon heating or cooling. More specifically, the liquid composition Q may be a solution, suspension, emulsion, or the like containing a solvent such as water or an organic solvent; an electrode material such as a dye, pigment, or active material; a functionalizing material such as a polymerizable compound, resin, or surfactant; a biocompatible material such as DNA, amino acids, proteins, or calcium; or an edible material such as a natural dye. These may be used, for example, as printing liquids, surface treatment liquids, or liquids for forming various devices, such as components of electronic elements or light-emitting elements, or resist patterns for electronic circuits.

[0015] The first tank 2 is an example of a first storage section that stores the liquid composition Q. There are no particular restrictions on the material of the first tank 2, but metal, resin, or the like can be used.

[0016] The head 1 is an example of a discharge unit that discharges the liquid composition Q supplied from the first tank 2 onto the target T. The head 1 is preferably positioned horizontally relative to or slightly above the liquid level of the first tank 2. Because the pressure from the first tank 2 to the head 1 is controlled, by reducing the pressure difference between the first tank 2 and the head 1 when the control is stopped, it is possible to prevent the liquid composition Q from leaking out of the head 1 and the liquid composition Q from flowing back from the head 1 into the first tank 2.

[0017] The means for applying a stimulus to the liquid composition Q in the head 1 to eject the liquid composition Q can be appropriately selected depending on the purpose, and can be, for example, a pressure device, a piezoelectric element, a vibration generator, an ultrasonic oscillator, a light, etc. Specifically, the means for ejecting the liquid composition Q can be a piezoelectric actuator such as a piezoelectric element, a shape memory alloy actuator that uses a metal phase change due to a temperature change, an electrostatic actuator that uses an electrostatic force, etc.

[0018] Among the above, preferred is one that applies a voltage to a piezoelectric element bonded to a position called a pressure chamber (also referred to as a liquid chamber, etc.) within a flow path through which liquid composition Q flows within head 1. In this head 1, the piezoelectric element is deflected by application of a voltage, and the volume of the pressure chamber is reduced, thereby pressurizing the liquid composition Q within the pressure chamber and ejecting the liquid composition Q from a nozzle provided in head 1. In this embodiment, head 1 is equipped with multiple nozzles, and liquid composition Q is selectively ejected from the multiple nozzles. However, there is no particular limit to the number of nozzles, and head 1 may be equipped with one nozzle and eject liquid composition Q from that single nozzle.

[0019] The head 1 may include a head unit. The head unit is a collection of functional parts and mechanisms related to the ejection of the liquid composition Q from the head 1. The head unit includes a combination of the head 1 with at least one of a supply mechanism, a maintenance and recovery mechanism, and a mechanism for moving the head 1.

[0020] The first pressure variable mechanism 10 is an example of a pressure variable mechanism that is provided on the opposite side of the head 1 across the first tank 2, and that changes the supply pressure P applied to the liquid composition Q supplied from the first tank 2 to the head 1 in accordance with the ejection frequency of the liquid composition Q by the head 1. The ejection frequency means the number of times the liquid composition Q is ejected per unit time by the head 1. In this embodiment, the first pressure variable mechanism 10 changes the supply pressure P by using air to change the pressure applied to the liquid composition Q in the first tank 2.

[0021] Liquid composition Q is ejected from head 1, and as the amount of liquid composition Q in head 1 decreases, liquid composition Q is supplied from first tank 2 to head 1 to replenish the liquid composition Q in head 1. In this configuration, for example, if the ejection frequency increases, the rate at which liquid composition Q in head 1 decreases increases, and the supply of liquid composition Q to head 1 may be delayed.

[0022] If the supply of liquid composition Q to the head 1 is delayed, air gets mixed into the head 1, and the pressure for ejection is not properly transmitted to the liquid composition Q in the head 1. As a result, droplets R may not be ejected from the head 1, the volume of the ejected droplets R may be reduced, the ejection speed of the droplets R ejected from the head 1 may be slowed, or the ejection direction of the droplets R may deviate from the desired direction, resulting in ejection defects. In particular, if the liquid composition Q contains a solid component and the specific gravity of this solid component is greater than the specific gravity of the components other than the solid component in the liquid composition Q, it may be difficult for the liquid composition Q to be delivered from the first tank 2 to the head 1, and ejection defects may easily occur.

[0023] The liquid ejection device 100 changes the supply pressure P according to the ejection frequency of the liquid composition Q using the first pressure variable mechanism 10, thereby changing the supply speed of the liquid composition Q from the first tank 2 to the head 1. This prevents delays in the supply of the liquid composition Q to the head 1 and suppresses ejection defects.

[0024] In this embodiment, the supply pressure P includes a negative pressure. The negative pressure is a pressure that acts in a direction that sucks the liquid composition Q from the head 1 toward the first tank 2. By making the supply pressure P a negative pressure, the liquid composition Q can be ejected from the head 1 while preventing leakage of the liquid composition Q from the nozzles of the head 1, for example, preventing dripping.

[0025] Even if the supply pressure P is negative, as the liquid composition Q in the head 1 decreases with the ejection of the liquid composition Q from the head 1, the liquid composition Q is supplied from the first tank 2 to the head 1 to replenish the liquid composition Q in the head 1.

[0026] The first pressure variable mechanism 10 can change the supply pressure P by changing the negative pressure applied to the liquid composition Q in the first tank 2. For example, if the supply of the liquid composition Q from the first tank 2 to the head 1 is delayed, the first pressure variable mechanism 10 can increase the supply rate of the liquid composition Q from the first tank 2 to the head 1 by reducing the negative pressure applied to the liquid composition Q in the first tank 2.

[0027] Furthermore, when the first pressure variable mechanism 10 applies positive pressure to the liquid composition Q in the first tank 2, the positive pressure can be increased to increase the supply rate of the liquid composition Q from the first tank 2 to the head 1.

[0028] The first pressure variable mechanism 10 has a first pressure reducing valve 3, a first pressure increasing pump 4, a first vacuum pump 5, a first pressure adjustment valve 6, a first pressure switching mechanism 7, and a first pressure gauge 8. The first pressure reducing pump 4 and the first pressure reducing valve 3 constitute a first positive pressure mechanism 11. The first vacuum pump 5 and the first pressure adjustment valve 6 constitute a first negative pressure mechanism 12.

[0029] The first pressure variable mechanism 10 can use the first pressure switching mechanism 7 to switch the component connected to the first tank 2 so that the liquid composition Q can flow between either the first positive pressure mechanism 11 or the first negative pressure mechanism 12.

[0030] The first pressure pump 4 is an example of a pressure generating mechanism that generates a supply pressure P for the liquid composition Q. The first pressure pump 4 generates a positive supply pressure P for pumping out the liquid composition Q stored in the first tank 2. There are no particular limitations on the configuration of the first pressure pump 4 as long as it is capable of generating a positive supply pressure P, and various types of pressure pumps such as a piston pump or a rotary pump can be used.

[0031] The first pressure reducing valve 3 is an example of an adjustment mechanism that adjusts the supply pressure P generated by the first pressure reducing pump 4. The first pressure reducing valve 3 is disposed between the first pressure reducing pump 4 and the first tank 2.

[0032] The first pressure reducing valve 3 is a valve element that adjusts the positive supply pressure P generated by the first pressure reducing pump 4. There are no particular limitations on the configuration of the first pressure reducing valve 3 as long as it is capable of adjusting the supply pressure P. In this embodiment, the first pressure reducing valve 3 is a solenoid valve whose valve element is controlled to be open or closed in response to a control signal from the control unit 20.

[0033] The first vacuum pump 5 is an example of a pressure generating mechanism that generates a supply pressure P for the liquid composition Q. The first vacuum pump 5 generates a negative supply pressure P that draws the liquid composition Q stored in the first tank 2 toward the first vacuum pump 5. There are no particular limitations on the configuration of the first vacuum pump 5 as long as it is capable of generating the negative supply pressure P, and various types of vacuum pumps such as a piston pump or a rotary pump can be used.

[0034] The first pressure regulation valve 6 is an example of an adjustment mechanism that adjusts the supply pressure P generated by the first vacuum pump 5. The first pressure regulation valve 6 is disposed between the first vacuum pump 5 and the first tank 2. The first pressure regulation valve 6 is a valve body for adjusting the magnitude of the negative supply pressure P. There are no particular limitations on the configuration of the first pressure regulation valve 6 as long as it is capable of adjusting the pressure. In this embodiment, the first pressure regulation valve 6 is a solenoid valve whose valve body is controlled to be open or closed in response to a control signal from the control unit 20.

[0035] The first pressure switching mechanism 7 is an example of a pressure switching mechanism that switches the supply pressure P between positive pressure and negative pressure. The first pressure switching mechanism 7 is a three-way valve or the like that has fluid inlets and outlets in three directions and is a valve body that can switch the direction of fluid flow.

[0036] The liquid ejection device 100 can be switched by the first pressure switching mechanism 7 to either a state in which the liquid composition Q can flow between the first positive pressure mechanism 11 and the first tank 2, or a state in which the liquid composition Q can flow between the first negative pressure mechanism 12 and the first tank 2. There are no particular limitations on the configuration of the first pressure switching mechanism 7 as long as it is capable of switching the flow direction of the liquid composition Q. In this embodiment, the first pressure switching mechanism 7 is a solenoid valve whose switching operation is controlled in response to a control signal from the control unit 20.

[0037] The first pressure gauge 8 is a sensor that detects the supply pressure P from the first pressure variable mechanism 10 to the first tank 2 and outputs the detected pressure to the control unit 20. There are no particular limitations on the method of pressure detection by the first pressure gauge 8, and various methods such as a liquid column method, a weighted piston method, or an elastic element method can be applied.

[0038] The first pressure buffer 9 is provided between the first tank 2 and the head 1, and is an example of a first reducing member that reduces the amount of transient pressure fluctuation that occurs when the supply pressure P is changed by the first pressure variable mechanism .

[0039] The first pressure buffer 9 is configured to include a portion of a flow path, such as a liquid supply tube through which the liquid composition Q flows, where the cross-sectional area of the flow path is partially increased, thereby locally increasing the flow rate of the liquid composition Q. However, the configuration is not limited to this. The first pressure buffer 9 enables the liquid ejection device 100 to reduce transient fluctuations in the supply pressure P when the first pressure switching mechanism 7 switches.

[0040] The control unit 20 controls the operation of the liquid ejection device 100. The control unit 20 is electrically connected to the control target, such as the head 1, via a wired or wireless connection. There are no particular restrictions on the location of the control unit 20, and the control unit 20 may be installed remotely.

[0041] <Example of functional configuration of control unit 20> 2 is a block diagram showing an example of the functional configuration of the control unit 20 of the liquid ejection device 100. The control unit 20 controls the operation of the liquid ejection device 100 as a whole.

[0042] 2, the control unit 20 has an input / output unit 21, a frequency determination unit 22, a pressure determination unit 23, a storage unit 24, a discharge control unit 25, a pressure switching control unit 26, and a pressure control unit 27. Note that at least some of the functions of the control unit 20 may be provided by a component other than the control unit 20, such as the head 1.

[0043] The control unit 20 realizes the functions of the input / output unit 21, frequency determination unit 22, pressure determination unit 23, discharge control unit 25, pressure switching control unit 26, and pressure control unit 27 among the above components by electrical circuits, and can also realize some of these functions by software (CPU; Central Processing Unit). The control unit 20 may realize these functions by multiple circuits or multiple pieces of software. Furthermore, the control unit 20 can realize the function of the storage unit 24 by a storage device such as an HDD (Hard Disk Drive) or SSD (Solid State Drive).

[0044] The input / output unit 21 has an interface function that controls input and output between the control unit 20 and external devices. In this embodiment, the input / output unit 21 inputs ejection printing condition data Im from an external device such as a client PC (Personal Computer), or from a storage unit 24 that has the printing condition data Im stored in advance. The printing condition data Im is information that serves as the basis for forming an image or pattern on the target T. The printing condition data Im may be image data that includes multiple pixels and has information for each pixel such as whether or not to eject or the volume of the ejected droplets R, or it may be data that shows the whether or not to eject, the volume of the droplets R, etc. in the form of a table, for example.

[0045] The frequency determination unit 22 determines the ejection frequency f of droplets R from the head 1 based on the printing condition data Im input via the input / output unit 21. For example, the frequency determination unit 22 determines a high ejection frequency f in a high-resolution region of the printing condition data Im and a low ejection frequency f in a low-resolution region. Alternatively, the ejection frequency f may be determined to be high in a region where a film formed by the liquid composition Q is to be high-density and low in a region where a film is to be low-density. By ejecting droplets R at the ejection frequency f determined in this manner, the liquid ejection device 100 can form an image or the like on the target T at a substantially constant speed, regardless of differences in resolution or film density between regions in the printing condition data Im. The frequency determination unit 22 may determine the ejection frequency f by acquiring information on the predetermined ejection frequency f based on the printing condition data Im from an external device, the storage unit 24, or the like.

[0046] The pressure determination unit 23 determines the supply pressure P by the first pressure variable mechanism 10 based on the discharge frequency f determined by the frequency determination unit 22, with reference to correspondence information 241 stored in the storage unit 24. The correspondence information 241 stored in the storage unit 24 is information indicating the correspondence relationship between the discharge frequency f and the supply pressure P, or information related to the correspondence relationship between the discharge frequency f and the supply pressure P. The correspondence information 241 includes information such as a table or a formula, but is not limited to these and may include information in other formats.

[0047] In this embodiment, the correspondence information 241 between the ejection frequency f and the supply pressure P varies depending on the flow path resistance for the liquid composition Q within the liquid ejection device 100, the physical properties of the liquid composition Q, and the like.

[0048] For example, if the viscosity of the liquid composition Q is high or the flow path resistance is large, the liquid composition Q will have difficulty flowing through the flow path in the liquid ejection device 100. For this reason, if the ejection frequency f becomes high, the supply of the liquid composition Q to the head 1 cannot keep up, which may cause air to get into the head 1 and result in ejection defects.

[0049] Therefore, when the viscosity of the liquid composition Q is high or the flow path resistance is high, the supply pressure P corresponding to the ejection frequency f needs to be increased compared to when the viscosity of the liquid composition Q is low or the flow path resistance is low. For example, when the ejection frequency f and the supply pressure P are approximately proportional to each other, the proportionality coefficient in this approximately proportional relationship needs to be increased. For this reason, the storage unit 24 can store, as the correspondence information 241 between the ejection frequency f and the supply pressure P, a plurality of pieces of correspondence information 241 that differ depending on the flow path resistance in the liquid ejection device 100 for the liquid composition Q and the physical properties of the liquid composition Q. The pressure determination unit 23 can refer to the plurality of pieces of correspondence information 241 that differ depending on the flow path resistance in the liquid ejection device 100 for the liquid composition Q and the physical properties of the liquid composition Q.

[0050] The discharge control unit 25 controls the discharge of the liquid composition Q by the head 1 based on the printing condition data Im and the discharge frequency f input via the input / output unit 21. In this embodiment, the discharge control unit 25 applies a drive voltage having a predetermined voltage waveform to the head 1, thereby causing the head 1 to discharge droplets R.

[0051] The pressure switching control unit 26 controls the switching by the first pressure switching mechanism 7 of the first pressure variable mechanism 10. For example, the pressure switching control unit 26 can control the switching by the first pressure switching mechanism 7 based on the supply pressure P determined by the pressure determination unit 23, etc.

[0052] The pressure control unit 27 controls the adjustments made by the first pressure regulating valve 6 and the first pressure reducing valve 3. For example, the pressure control unit 27 can control the adjustments made by the first pressure regulating valve 6 and the first pressure reducing valve 3 based on the supply pressure P determined by the pressure determination unit 23, etc.

[0053] <Operation of the liquid ejection device 100> 1 and 2, among the operations of the liquid ejection device 100, the operation of filling the head 1 with the liquid composition Q and the operation of ejecting droplets R of the liquid composition Q from the head 1 will be described.

[0054] When filling the head 1 with the liquid composition Q, the liquid ejection device 100 switches the first pressure switching mechanism 7 using the pressure switching control unit 26 to create a state in which the liquid composition Q can flow between the first positive pressure mechanism 11 and the first tank 2. Thereafter, the liquid ejection device 100 controls the adjustment by the first pressure reducing valve 3 using the pressure control unit 27 to supply a positive supply pressure P to the first tank 2, and delivers the liquid composition Q from the first tank 2 to the head 1, thereby filling the head 1 with the liquid composition Q.

[0055] Before ejecting droplets R of liquid composition Q from the head 1, the liquid ejection device 100 switches the first pressure switching mechanism 7 using the pressure switching control unit 26 to enable the liquid composition Q to flow between the first negative pressure mechanism 12 and the first tank 2. Thereafter, the liquid ejection device 100 controls the adjustment by the first pressure regulating valve 6 using the pressure control unit 27 to reduce the pressure inside the flow path between the first negative pressure mechanism 12 and the first tank 2, thereby applying negative pressure to the liquid composition Q in the head 1 and the first tank 2. However, in cases where a positive pressure is required as the supply pressure P, such as when the supply of liquid composition Q is delayed under negative pressure, the liquid ejection device 100 switches the first pressure switching mechanism 7 using the pressure switching control unit 26 to enable the liquid composition Q to flow between the first positive pressure mechanism 11 and the first tank 2.

[0056] When the liquid ejection device 100 ejects droplets R of the liquid composition Q from the head 1, the pressure control unit 27 controls the supply pressure P by changing the pressure in the flow path between the first tank 2 and the first negative pressure mechanism 12 or the first positive pressure mechanism 11, in accordance with the ejection frequency f determined by the frequency determination unit 22. With the desired supply pressure P applied to the liquid composition Q in the head 1 and the first tank 2, the liquid ejection device 100 applies a drive voltage to the head 1 using the ejection control unit 25, causing the head 1 to eject droplets R.

[0057] Fig. 3 is a flowchart showing an example of the operation of the liquid ejection device 100. In Fig. 3, the state in which the liquid composition Q can flow between the first positive pressure mechanism 11 and the first tank 2 is represented as "first positive pressure mechanism side open," and the state in which the liquid composition Q can flow between the first negative pressure mechanism 12 and the first tank 2 is represented as "first negative pressure mechanism side open."

[0058] The liquid ejection apparatus 100 starts the operation of FIG. 3 in response to input of printing condition data Im to the liquid ejection apparatus 100 or input of an operation to start image formation via an operation unit of the liquid ejection apparatus 100 .

[0059] First, in step S31, the liquid ejection device 100 determines, via the control unit 20, whether or not to fill the head 1 with the liquid composition Q. For example, the control unit 20 can determine whether or not to fill the head 1 with the liquid composition Q based on the output result of a remaining amount sensor in the head 1, etc.

[0060] If it is determined in step S31 that no filling will be performed (step S31, No), the liquid ejection device 100 proceeds to step S34. On the other hand, if it is determined that filling will be performed (step S31, Yes), in step S32, the liquid ejection device 100 switches the first pressure switching mechanism 7 using the pressure switching control unit 26 to open the first positive pressure mechanism 11 side.

[0061] Next, in step S33, the liquid ejection device 100 controls the adjustment by the first pressure reducing valve 3 using the pressure control unit 27 to supply a positive supply pressure P to the first tank 2, and delivers the liquid composition Q from the first tank 2 to the head 1, thereby filling the head 1 with the liquid composition Q.

[0062] Subsequently, in step S34, the liquid ejection device 100 switches the first pressure switching mechanism 7 by the pressure switching control unit 26, and opens the first negative pressure mechanism 12 side.

[0063] Next, in step S35, the liquid ejection device 100 reduces the pressure in the flow path between the first negative pressure mechanism 12 and the first tank 2 by controlling the adjustment by the first pressure regulating valve 6 using the pressure control unit 27, thereby applying negative pressure to the liquid composition Q in the first tank 2 and the head 1.

[0064] Subsequently, in step S36, the liquid ejection device 100 applies a drive voltage to the head 1 by the ejection control unit 25, and causes the head 1 to start ejecting droplets R.

[0065] Subsequently, in step S37, the liquid ejection device 100 determines the ejection frequency f of the droplets R from the head 1 using the frequency determination unit 22 based on the printing condition data Im input via the input / output unit 21.

[0066] Next, in step S38, the liquid ejection device 100 determines the supply pressure P by the first pressure variable mechanism 10 using the pressure determination unit 23 based on the ejection frequency f determined by the frequency determination unit 22 and by referring to the correspondence information 241 stored in the storage unit 24.

[0067] Subsequently, in step S39, the liquid discharger 100 determines by the control unit 20 whether or not the pressure P supplied to the first tank 2 at that time, as detected by the first pressure gauge 8, is insufficient.

[0068] If it is determined in step S39 that there is no shortage (step S39, No), the liquid ejection device 100 proceeds to step S45. On the other hand, if it is determined that there is a shortage (step S39, Yes), in step S40, the liquid ejection device 100 adjusts the negative pressure by the first pressure adjustment valve 6 via the pressure control unit 27 so that the supply pressure P to the first tank 2 becomes approximately equal to the supply pressure P determined by the pressure determination unit 23.

[0069] Next, in step S41, the liquid ejection device 100 determines, via the control unit 20, whether the supply pressure P to the first tank 2 at that time detected by the first pressure gauge 8 is insufficient compared to the supply pressure P determined by the pressure determination unit 23.

[0070] If it is determined in step S41 that there is no shortage (step S41, No), the liquid ejection device 100 proceeds to step S45. On the other hand, if it is determined that there is a shortage (step S41, Yes), in step S42, the liquid ejection device 100 determines, via the control unit 20, whether or not the negative pressure can be adjusted by the first pressure adjustment valve 6. For example, the control unit 20 can determine whether or not the negative pressure can be adjusted by detecting whether or not the adjustment to reduce the negative pressure by the first pressure adjustment valve 6 has reached its limit.

[0071] If it is determined in step S42 that the negative pressure can be adjusted (step S42, Yes), the liquid ejection device 100 performs the operations from step S40 onwards again. On the other hand, if it is determined that the negative pressure cannot be adjusted (step S42, No), in step S43, the liquid ejection device 100 switches the first pressure switching mechanism 7 using the pressure switching control unit 26 to open the first positive pressure mechanism 11 side.

[0072] Next, in step S44, the liquid ejection device 100 adjusts the positive pressure by the first pressure reducing valve 3 via the pressure control unit 27 so that the supply pressure P to the first tank 2 is approximately equal to the supply pressure P determined by the pressure determination unit 23.

[0073] Next, in step S45, the liquid ejection device 100 determines whether or not to end image formation using the control unit 20. For example, the control unit 20 can determine whether or not to end image formation based on whether or not ejection of the liquid composition Q corresponding to all pixels included in the printing condition data Im has been completed, or based on an operation input to end image formation via the operation unit of the liquid ejection device 100.

[0074] If it is determined in step S45 that the operation should be ended (step S45, Yes), the liquid ejection device 100 ends the operation. On the other hand, if it is determined that the operation should not be ended (step S45, No), the liquid ejection device 100 performs the operations from step S31 onwards again.

[0075] In this way, the liquid ejection device 100 can form an image on the target T. Note that while Fig. 3 illustrates an example of operation when the ejection frequency f increases and the supply pressure P is insufficient, the operation of Fig. 3 can also be applied to a case where the ejection frequency f decreases and the supply pressure P exceeds the required value. However, if the supply pressure P exceeds the required value, the liquid ejection device 100 determines in steps S39 and S41 whether the supply pressure P to the first tank 2 at that time, detected by the first pressure gauge 8, exceeds the supply pressure P determined by the pressure determination unit 23. If the supply pressure P exceeds the required value, the liquid ejection device 100 adjusts the negative pressure to be larger in step S40, or adjusts the positive pressure to be smaller in step S44.

[0076] <Example of the relationship between discharge frequency f and supply pressure P> The relationship between the discharge frequency f and the supply pressure P will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a diagram illustrating an example of a change in the supply pressure P according to the discharge frequency f. Fig. 5 is a diagram illustrating correspondence information 241 between the discharge frequency f and the supply pressure P.

[0077] 4 and 5, the horizontal axis represents the ejection frequency f [kHz], and the vertical axis represents the supply pressure P [kPa]. Note that the supply pressure P in Fig. 4 refers to the pressure applied to the liquid composition Q stored in the first tank 2, and does not refer to the pressure applied to the liquid composition Q inside the head 1.

[0078] Figure 4 shows the results of measuring the supply pressure P while changing the ejection frequency f when the supply pressure P was set to three different values: -0.10 kPa, -0.70 kPa, and -1.00 kPa. In the example in Figure 4, the ejection frequency f was changed from a low state to a high state until ejection defects occurred.

[0079] The solid line graph 71 shows the case where the supply pressure P is -0.10 [kPa], the dashed line graph 72 shows the case where the supply pressure P is -0.70 [kPa], and the dotted line graph 73 shows the case where the supply pressure P is -1.00 [kPa].

[0080] 4, at supply pressures P of -0.10 [kPa], -0.70 [kPa], and -1.00 [kPa], as the ejection frequency f increased, the rate at which the liquid composition Q in the head 1 decreased increased, and the measured value of the supply pressure applied to the first tank 2 decreased. When the supply pressure P was -1.0 [kPa], ejection defects occurred when the ejection frequency f was approximately 13.0 [kHz]. When the supply pressure P was -0.70 [kPa], ejection defects occurred when the ejection frequency f was approximately 15.0 [kHz]. When the supply pressure P was -0.10 [kPa], ejection defects occurred when the ejection frequency f was approximately 18.0 [kHz].

[0081] FIG. 5 shows the ejection frequency f plotted when ejection defects occur when the supply pressure P is −0.10 [kPa], −0.70 [kPa], and −1.00 [kPa].

[0082] In Figure 5, plot 81 is when the supply pressure P is -0.10 [kHz] (corresponding to graph 71 in Figure 4), plot 82 is when the supply pressure P is -0.70 [kHz] (corresponding to graph 72 in Figure 4), and plot 83 is when the supply pressure P is -1.0 [kHz] (corresponding to graph 73 in Figure 4).

[0083] In Fig. 5, the approximated line 84 shown by the dashed line is an approximated line obtained by linearly approximating the plots 81, 82, and 83. As shown in Fig. 5, it was found that there is a correlation between the supply pressure P and the ejection frequency f at which ejection defects occurred in the head 1, and that the two are approximately proportional.

[0084] In this embodiment, when the liquid composition Q is being supplied from the first tank 2 to the head 1 at a predetermined supply pressure P, if the ejection frequency f at which ejection defects occur is reached, the supply pressure P is changed to facilitate the supply of the liquid composition Q. For example, when a negative pressure is being supplied, the supply pressure P is changed to decrease (weaken) the negative pressure, and when a positive pressure is being supplied, the supply pressure P is changed to increase (stronger) the positive pressure. Specifically, for example, when the liquid composition Q is being supplied from the first tank 2 to the head 1 at a supply pressure of −1.0 kPa, if the ejection frequency at which ejection defects occur is reached, the supply pressure is changed from −1.0 kPa to −0.8 kPa. In this embodiment, the “supply pressure at which supply is facilitated” and the ejection frequency f at which ejection defects occur are associated and defined in advance as correspondence information 241. When the ejection frequency f at which ejection defects occur is reached, the liquid ejection device 100 changes the supply pressure P to the predetermined “supply pressure at which supply is facilitated.”

[0085] The storage unit 24 can store, as the correspondence information 241, a table that associates multiple values of ejection frequency f with multiple values of supply pressure P that form pairs with the ejection frequency f, or a formula that represents an approximation line of the approximation line 84. The pressure determination unit 23 can determine the supply pressure P by referring to the table or formula stored in the storage unit 24 based on the ejection frequency f determined by the frequency determination unit 22. Note that the correspondence information 241 illustrated in FIG. 5 is an example, and the correspondence information 241 will vary depending on the flow path resistance within the liquid ejection device 100 for the liquid composition Q, the physical properties of the liquid composition Q, and the like. The storage unit 24 can store multiple pieces of correspondence information 241 that vary depending on the flow path resistance within the liquid ejection device 100 for the liquid composition Q, the physical properties of the liquid composition Q, and the like.

[0086] <Effects of the liquid ejection device 100> The effects of the liquid ejection device 100 will be described.

[0087] In a liquid ejection device, for example, when the ejection frequency of the liquid composition from the head increases, the liquid composition in the ejection section decreases at a faster rate, which may delay the supply of the liquid composition to the head and result in ejection failure.

[0088] To prevent the above-described ejection defects, it is conceivable to change the supply pressure according to the ejection frequency by using a control mechanism provided between the ejection section and a supply pressure source that supplies the liquid composition to the ejection section, such as the head 1. However, in this case, the distance between the supply pressure source and the ejection section becomes longer by the amount of the control mechanism provided between the supply pressure source and the ejection section. As a result, when the ejection frequency becomes high, the supply of the liquid composition Q to the head is likely to be delayed, making ejection defects more likely to occur. In particular, if the liquid composition contains a solid component and the specific gravity of the solid component is greater than the specific gravity of the other components in the liquid composition, the solid component is likely to settle or aggregate in the flow path of the liquid composition between the supply pressure source and the discharge portion. Examples of solid components include metal particles. If the solid component settles or aggregates and blocks at least a portion of the flow path of the liquid composition Q, poor discharge of the liquid composition Q is likely to occur.

[0089] The liquid ejection device 100 according to this embodiment includes a first tank 2 (storage section) that stores a liquid composition Q, and a head 1 (ejection section) that ejects the liquid composition Q supplied from the first tank 2 onto a target T. The liquid ejection device 100 also includes a first pressure variable mechanism 10 (pressure variable mechanism) that is provided on the opposite side of the head 1 across the first tank 2 and that changes the supply pressure P applied to the liquid composition Q supplied from the first tank 2 to the head 1 in accordance with the ejection frequency f of the liquid composition Q by the head 1.

[0090] The liquid ejection device 100 changes the supply speed of the liquid composition Q from the first tank 2 to the head 1 by changing the supply pressure P according to the ejection frequency of the liquid composition Q using the first pressure variable mechanism 10. Furthermore, because the first pressure variable mechanism 10 is provided on the opposite side of the first tank 2 from the head 1, the distance between the first tank 2 and the head 1 can be shortened compared to a configuration in which a control mechanism is provided between the supply pressure source and the ejection section. Therefore, even when the ejection frequency f of the liquid composition Q increases, the liquid ejection device 100 can prevent delays in the supply of the liquid composition Q to the head 1 and suppress ejection defects. In other words, a liquid ejection device 100 can be provided that is capable of stably ejecting the liquid composition Q.

[0091] In particular, when the liquid composition Q contains a solid component and the specific gravity of the solid component is greater than the specific gravity of the other components in the liquid composition Q, the liquid ejection device 100 can suppress the settling or aggregation of the solid component and can stably eject the liquid composition Q containing the solid component, thereby achieving particularly significant effects. However, the liquid composition Q ejected by the liquid ejection device 100 is not limited to one containing a solid component. Even when ejecting a liquid composition Q that does not contain a solid component, the liquid ejection device 100 can stably eject the liquid composition Q because the distance between the first tank 2 and the head 1 is short and the length of the flow path for the liquid composition Q is short.

[0092] Here, for example, if the liquid composition is supplied from the supply pressure source to the discharge portion using only positive supply pressure, the liquid composition may drip from the nozzle of the discharge portion, contaminating the target object. Furthermore, if negative pressure is applied to the liquid composition in the discharge portion to prevent dripping of the liquid composition, the liquid composition may backflow from the discharge portion, making it impossible to stably discharge the liquid composition. If a component such as a check valve is provided in the liquid discharge device to prevent backflow, the distance between the supply pressure source and the discharge portion increases depending on the location of the component, making discharge defects more likely to occur.

[0093] In this embodiment, the supply pressure P includes at least a negative pressure, and the head 1 is preferably disposed horizontally relative to or slightly above the liquid level in the first tank 2. Because the pressure from the first tank 2 to the head 1 is controlled, by reducing the pressure difference between the first tank 2 and the head 1 when control is stopped, it is possible to prevent the liquid composition Q from leaking out of the head 1 and the liquid composition Q from flowing back from the head 1 to the first tank 2. Note that, although this embodiment has been exemplified as a configuration in which the supply pressure P includes a negative pressure, the effect of enabling the liquid composition Q to be stably ejected can also be obtained if the supply pressure P is a configuration in which only a positive pressure is used.

[0094] Furthermore, in this embodiment, the liquid ejection device 100 has a first pressure pump 4 and a first vacuum pump 5 (pressure generation mechanism) that generate a supply pressure P of the liquid composition Q, and a first pressure reduction valve 3 and a first pressure adjustment valve 6 (adjustment mechanism) that adjust the supply pressure P generated by the first pressure pump 4 and the first vacuum pump 5. The first pressure reduction valve 3 is disposed between the first pressure pump 4 and the first tank 2, and the first pressure adjustment valve 6 is disposed between the first vacuum pump 5 and the first tank 2. With this configuration, the liquid ejection device 100 can change the supply pressure P in accordance with the ejection frequency f.

[0095] In this embodiment, the first pressure variable mechanism 10 includes a first pressurizing pump 4 and a first vacuum pump 5 that generate a supply pressure P of the liquid composition Q. With this configuration, the first pressure variable mechanism 10 can change the supply pressure P in accordance with the discharge frequency f. The first pressure variable mechanism 10 may not include adjustment mechanisms such as the first pressure reducing valve 3 and the first pressure regulating valve 6, and may instead change the supply pressure P by controlling the generation of the supply pressure P by either the first pressurizing pump 4 or the first vacuum pump 5. For example, if the first pressurizing pump 4 and the first vacuum pump 5 are rotary pumps, the generation of the supply pressure P can be controlled by controlling the rotation speed of the blades in the rotary pumps. Alternatively, if the first pressurizing pump 4 and the first vacuum pump 5 are piston pumps, the generation of the supply pressure P can be controlled by controlling the movement of the pistons in the piston pumps.

[0096] Furthermore, in this embodiment, it is preferable to have a first pressure buffer 9 (first reducing member) provided between the first tank 2 and the head 1, which reduces transient pressure fluctuations when the supply pressure P is changed by the first pressure variable mechanism 10. The liquid ejection device 100 can reduce transient fluctuations in the supply pressure P when the first pressure switching mechanism 7 switches by using the first pressure buffer 9, and therefore can stably supply the liquid composition Q to the head 1 and stably eject the liquid composition Q from the head 1.

[0097] Furthermore, in this embodiment, the supply pressure P includes positive pressure and negative pressure, and the liquid ejection device 100 has a first pressure switching mechanism 7 (pressure switching mechanism) that switches the supply pressure P between positive pressure and negative pressure. With this configuration, the liquid ejection device 100 can supply a negative supply pressure P to the liquid composition Q in the first tank 2 to prevent the liquid composition Q from dripping from the head 1, and when the desired supply pressure P cannot be obtained by adjusting the negative pressure alone, the first pressure switching mechanism 7 can switch to supply a positive supply pressure P to the liquid composition Q in the first tank 2. As a result, the range over which the supply pressure P can be changed by the first pressure variable mechanism 10 can be expanded.

[0098] Furthermore, in this embodiment, the liquid ejection device 100 increases the supply pressure P by the first pressure variable mechanism 10 as the ejection frequency f by the head 1 increases. This makes it possible to increase the supply speed of the liquid composition Q to the head 1, even when the ejection frequency f is high and the supply of the liquid composition Q to the head 1 is delayed, and to stably eject the liquid composition Q from the head 1. Note that, although this embodiment has exemplified a configuration in which the supply pressure P to the first pressure variable mechanism 10 is changed using the pressure control unit 27, the present invention is not limited to this, and the supply pressure P may also be changed, for example, by manually adjusting the first pressure reducing valve 3 or the first pressure regulating valve 6 in the first pressure variable mechanism 10.

[0099] [Second embodiment] Next, a liquid ejection device 100a according to a second embodiment will be described. Components identical to those in the previously described embodiments will be assigned the same reference numerals, and duplicated descriptions will be omitted where appropriate. Furthermore, components having the same or similar functions as those in the first embodiment will be omitted where appropriate. This also applies to the other embodiments described below.

[0100] 6 is a diagram illustrating the configuration of a liquid ejection device 100a. The liquid ejection device 100a has a first circulation mechanism 30 that circulates the liquid composition Q through a first circulation path 31 that passes through the head 1 and the first tank 2. The first circulation mechanism 30 has the first circulation path 31, a first liquid feed pump 32, and a first flow meter 33.

[0101] The first circulation path 31 is a flow path that passes through the head 1 and the first tank 2, and more specifically, is a flow path that delivers and circulates the liquid composition Q from the first tank 2 to the head 1 and from the head 1 to the first tank 2. The first circulation path 31 is configured to include, for example, a tube made of a resin material.

[0102] The first liquid-feed pump 32 is a mechanism that generates a liquid-feeding force for circulating the liquid composition Q through the first circulation path 31. There are no particular limitations on the configuration of the first liquid-feed pump 32 as long as it is capable of generating a liquid-feeding force, and various liquid-feed pumps such as a piston pump or a rotary pump can be used.

[0103] The first flow meter 33 is a sensor that detects the flow rate of the liquid composition Q circulating through the first circulation path 31. There are no particular limitations on the configuration of the first flow meter 33, as long as it can detect the flow rate of the liquid composition Q, and flow meters using various methods, such as a volumetric flow meter or a mass flow meter, can be used.

[0104] The liquid ejection device 100a can circulate the liquid composition Q at a substantially constant flow rate by using the control unit 20a to acquire flow rate information of the liquid composition Q flowing through the first circulation path 31 based on the detection results of the first flow meter 33, and by controlling the first liquid delivery pump 32 based on this flow rate information.

[0105] The head 1 ejects from the nozzles the liquid composition Q circulating through the first circulation path 31 that is supplied from the first tank 2 to the head 1 and passes through the head 1 as droplets R. The liquid composition Q that is not ejected from the head 1 while passing through the head 1 is sent from the head 1 toward the first tank 2, and then supplied again from the first tank 2 to the head 1.

[0106] For example, if liquid composition Q contains a solid component and the specific gravity of the solid component is greater than the specific gravity of the components other than the solid component in liquid composition Q, the solid component may settle or condense in the flow path between first tank 2 and head 1, causing the flow path to become blocked.

[0107] The liquid ejection device 100a can suppress sedimentation and condensation of the liquid composition Q by circulating the liquid composition Q through the first circulation path 31 that passes through the head 1 and the first tank 2 using the first circulation mechanism 30.This allows the liquid ejection device 100a to suppress blockage of the flow path and to stably eject the liquid composition Q.

[0108] For example, the liquid ejection device 100a can stably eject the liquid composition Q by circulating the liquid composition Q at a flow rate corresponding to the ejection speed, which is the speed of the droplets R when the liquid composition Q is ejected from the head 1, and the settling speed of the solid components contained in the liquid composition Q.

[0109] The other effects are the same as those described in the first embodiment.

[0110] [Third embodiment] Next, a liquid ejection device 100b according to a third embodiment will be described.

[0111] <Configuration Example of Liquid Ejection Apparatus 100b> 7 is a diagram showing an example of the configuration of a liquid ejection device 100b. The liquid ejection device 100b has a second tank 14, a second pressure variable mechanism 10b, and a supply path switching mechanism 13. The first supply path 101 is a supply path through which the liquid composition Q is supplied from the first tank 2 to the head 1. The second supply path 102 is a supply path through which the liquid composition Q is supplied from the second tank 14 to the head 1.

[0112] In the liquid ejection device 100b, while the liquid composition Q supplied from the first supply path 101 is being ejected from the head 1 at a first ejection frequency, the supply pressure P of the liquid composition Q supplied from the second supply path 102 to the head 1 is changed in advance by the second pressure variable mechanism 10b in accordance with a second ejection frequency different from the first ejection frequency. Then, when the ejection frequency f is changed from the first ejection frequency to the second ejection frequency, the liquid ejection device 100b switches the supply path through which the liquid composition Q is supplied to the head 1 from the first supply path 101 to the second supply path 102 by the supply path switching mechanism 13.

[0113] Alternatively, the liquid ejection device 100b changes in advance the supply pressure P of the liquid composition Q supplied from the first supply path 101 to the head 1 in accordance with a second ejection frequency different from the first ejection frequency by the first pressure variable mechanism 10 while the liquid composition Q supplied from the second supply path 102 is being ejected from the head 1 at a first ejection frequency. Then, when the ejection frequency f changes from the first ejection frequency to the second ejection frequency, the liquid ejection device 100b switches the supply path through which the liquid composition Q is supplied to the head 1 from the second supply path 102 to the first supply path 101 by the supply path switching mechanism 13.

[0114] For example, if a liquid ejection device has only one supply path, when changing the supply pressure according to the ejection frequency, it may take time to reach the desired supply pressure, and the change in supply pressure may not be in time for the next ejection. In this embodiment, there are two supply paths, a first supply path 101 and a second supply path 102, and the supply pressure P in the supply path not involved in the ejection is changed in advance according to the ejection frequency f for the next ejection, and the supply pressure P is changed by switching the supply path. In this way, the liquid ejection device 100b changes the supply pressure P at high speed and suppresses delays in the change in supply pressure P.

[0115] The second tank 14 is an example of a second storage section that stores the liquid composition Q. There are no particular restrictions on the material of the second tank 14, but metal, resin, or the like can be used.

[0116] The second pressure variable mechanism 10b is an example of a pressure variable mechanism that is provided on the opposite side of the head 1 across the second tank 14, and that changes the supply pressure P applied to the liquid composition Q supplied from the second tank 14 to the head 1 in accordance with the ejection frequency of the liquid composition Q by the head 1. In this embodiment, the second pressure variable mechanism 10b changes the supply pressure P by using air to change the pressure applied to the liquid composition Q in the second tank 14.

[0117] The second pressure variable mechanism 10b has a second pressure reducing valve 15, a second pressurizing pump 16, a second vacuum pump 17, a second pressure adjustment valve 18, a second pressure switching mechanism 19, and a second pressure gauge 8b. The second pressurizing pump 16 and the second pressure reducing valve 15 constitute a second positive pressure mechanism 11b. The second vacuum pump 17 and the second pressure adjustment valve 18 constitute a second negative pressure mechanism 12b. The second pressure variable mechanism 10b can use the second pressure switching mechanism 19 to switch between the second positive pressure mechanism 11b and the second negative pressure mechanism 12b as the component connected to the second tank 14 so that the liquid composition Q can flow therethrough.

[0118] The second pressure pump 16 is an example of a pressure generating mechanism that generates a supply pressure P for the liquid composition Q. The second pressure pump 16 generates a positive supply pressure P for pumping out the liquid composition Q stored in the second tank 14. There are no particular limitations on the configuration of the second pressure pump 16, as long as it is capable of generating a positive supply pressure P, and various types of pressure pumps such as a piston pump or a rotary pump can be used.

[0119] The second pressure reducing valve 15 is an example of an adjustment mechanism that adjusts the supply pressure P generated by the second pressure reducing pump 16. The second pressure reducing valve 15 is disposed between the second pressure reducing pump 16 and the second tank 14. The second pressure reducing valve 15 is a valve body that adjusts the positive supply pressure P generated by the second pressure reducing pump 16. There are no particular limitations on the configuration of the second pressure reducing valve 15 as long as it is capable of adjusting the supply pressure P. In this embodiment, the second pressure reducing valve 15 is a solenoid valve whose open / closed state is controlled in response to a control signal from the control unit 20b.

[0120] The second vacuum pump 17 is an example of a pressure generating mechanism that generates a supply pressure P for the liquid composition Q. The second vacuum pump 17 generates a negative supply pressure P that draws the liquid composition Q stored in the second tank 14 toward the second vacuum pump 17. There are no particular limitations on the configuration of the second vacuum pump 17 as long as it is capable of generating the negative supply pressure P, and various types of vacuum pumps such as a piston pump or a rotary pump can be used.

[0121] The second pressure regulation valve 18 is an example of an adjustment mechanism that adjusts the supply pressure P generated by the second vacuum pump 17. The second pressure regulation valve 18 is disposed between the second vacuum pump 17 and the second tank 14. The second pressure regulation valve 18 is a valve body that adjusts the magnitude of the negative supply pressure P. There are no particular limitations on the configuration of the second pressure regulation valve 18 as long as it is capable of adjusting the pressure. In this embodiment, the second pressure regulation valve 18 is a solenoid valve whose valve body is controlled to be open or closed in response to a control signal from the control unit 20b.

[0122] The second pressure switching mechanism 19 is an example of a pressure switching mechanism that switches the supply pressure P between positive pressure and negative pressure. The second pressure switching mechanism 19 is, for example, a three-way valve. By switching using the second pressure switching mechanism 19, the liquid ejection device 100b can be set to either a state in which the liquid composition Q can flow between the second positive pressure mechanism 11b and the second tank 14, or a state in which the liquid composition Q can flow between the second negative pressure mechanism 12b and the second tank 14. There are no particular limitations on the configuration of the second pressure switching mechanism 19, as long as it can switch the flow direction of the liquid composition Q. In this embodiment, the second pressure switching mechanism 19 is a solenoid valve whose switching operation is controlled in response to a control signal from the control unit 20b.

[0123] The second pressure gauge 8b is a sensor that detects the supply pressure P from the second pressure variable mechanism 10b to the second tank 14 and outputs the detected pressure to the control unit 20b. There are no particular limitations on the method of pressure detection by the second pressure gauge 8b, and various methods such as a liquid column method, a weight piston method, or an elastic element method can be applied.

[0124] The supply path switching mechanism 13 is, for example, a three-way valve that switches between a first supply path 101 through which the liquid composition Q is supplied from the first tank 2 to the head 1 and a second supply path 102 through which the liquid composition Q is supplied from the second tank 14 to the head 1.

[0125] The second pressure buffer 9a is an example of a second reduction member that is provided between the supply path switching mechanism 13 and the head 1 and reduces transient pressure fluctuations when the supply path switching mechanism 13 switches from the first supply path 101 to the second supply path 102.

[0126] The liquid ejection device 100b uses the second pressure buffer 9a to reduce transient pressure fluctuations that occur when switching from the first supply path 101 to the second supply path 102, thereby enabling the liquid composition Q to be stably supplied to the head 1 and the liquid composition Q to be stably ejected from the head 1.

[0127] <Example of functional configuration of control unit 20b> 8 is a block diagram showing an example of the functional configuration of the control unit 20b. The control unit 20b has a pressure control unit 27b and a supply path switching control unit 28. The control unit 20b controls the change in supply pressure by the second pressure variable mechanism and the switching by the supply path switching mechanism. The control unit 20b not only realizes each of these functions by electric circuits, but can also realize some of these functions by software (CPU). The control unit 20b may realize the above functions by multiple circuits or multiple pieces of software.

[0128] The pressure control unit 27b changes in advance the supply pressure P of the liquid composition Q supplied from the second supply path 102 to the head 1 in accordance with a second ejection frequency f2 different from the first ejection frequency f1 using the second pressure variable mechanism 10b while the liquid composition Q supplied from the first supply path 101 is being ejected from the head 1 at the first ejection frequency f1. Alternatively, the pressure control unit 27b changes in advance the supply pressure P of the liquid composition Q supplied from the first supply path 101 to the head 1 in accordance with a second ejection frequency f2 different from the first ejection frequency f1 using the first pressure variable mechanism 10 while the liquid composition Q supplied from the second supply path 102 is being ejected from the head 1 at the first ejection frequency f1. In addition to this function, the pressure control unit 27b has the function of the pressure control unit 27 for the first pressure variable mechanism 10 described in the first embodiment for both the first pressure variable mechanism 10 and the second pressure variable mechanism 10b.

[0129] When the liquid composition Q supplied from the first supply path 101 is being ejected from the head 1 at the first ejection frequency f1, the supply path switching control unit 28 switches the supply path through which the liquid composition Q is supplied to the head 1 from the first supply path 101 to the second supply path 102 by the supply path switching mechanism 13 when the ejection frequency f changes from the first ejection frequency f1 to the second ejection frequency f2. Alternatively, when the liquid composition Q supplied from the second supply path 102 is being ejected from the head 1 at the first ejection frequency f1, the supply path switching control unit 28 switches the supply path through which the liquid composition Q is supplied to the head 1 from the second supply path 102 to the first supply path 101 by the supply path switching mechanism 13 when the ejection frequency f changes from the first ejection frequency f1 to the second ejection frequency f2.

[0130] <Example of Operation of Liquid Ejector 100b> Fig. 9 is a flowchart showing an example of the operation of the liquid ejection device 100b. In Fig. 9, the state in which the liquid composition Q can flow between the second positive pressure mechanism 11b and the second tank 14 is represented as "second positive pressure mechanism side open."

[0131] When the liquid ejection device 100b supplies liquid composition Q from the first supply path 101 to the head 1 and ejects the liquid composition Q from the head 1 at a first ejection frequency f1, and when the ejection frequency f for the next ejection is changed based on the printing condition data Im, the liquid ejection device 100b starts the supply path switching control operation of Fig. 9. Note that Fig. 9 describes a case where ejection is performed from the head 1 when the supply pressure P is in a positive pressure state, but even when the supply pressure P is in a negative pressure state, the operation of the liquid ejection device 100b is the same except for the difference in the mechanism for adjusting the supply pressure P.

[0132] First, in step S91, the liquid ejection device 100b determines the ejection frequency f of the droplets R from the head 1 using the frequency determination unit 22 based on the printing condition data Im input via the input / output unit .

[0133] Next, in step S92, the liquid ejection device 100b determines the supply pressure P by the second pressure variable mechanism 10b by the pressure determination unit 23 based on the ejection frequency f determined by the frequency determination unit 22 and by referring to the correspondence information 241 stored in the storage unit 24.

[0134] Next, in step S93, the liquid ejection device 100b adjusts the second pressure reducing valve 15 via the pressure control unit 27 to increase the positive pressure, so that the supply pressure P to the second tank 14 becomes approximately equal to the supply pressure P determined by the pressure determination unit 23.

[0135] Subsequently, in step S94, the liquid ejection device 100b switches the second pressure switching mechanism 19 by the pressure switching control unit 26 to open the second positive pressure mechanism 11b side. As a result, a supply pressure P substantially equal to the supply pressure P determined by the pressure determination unit 23 is supplied to the second tank 14.

[0136] Next, in step S95, the liquid ejection device 100b switches the supply path switching mechanism 13 via the supply path switching control unit 28 approximately in synchronization with the timing at which the ejection frequency f is switched from the first ejection frequency f1 to the second ejection frequency f2, and switches the supply path through which the liquid composition Q is supplied to the head 1 from the first supply path 101 to the second supply path 102.

[0137] In this way, the liquid ejection device 100b can switch the supply path through which the liquid composition Q is supplied to the head 1 from the first supply path 101 to the second supply path 102. During the period from step S91 to step S94 in Fig. 9, the liquid composition Q is continuously ejected from the head 1 at the first ejection frequency f1. Then, by the switching in step S95, the ejection frequency f of the head 1 is switched from the first ejection frequency f1 to the second ejection frequency f2.

[0138] <Operation and Effects of Liquid Ejection Device 100b> As described above, in this embodiment, the liquid ejection device 100b has a second tank 14 (second storage section) that stores liquid composition Q, and a second pressure variable mechanism 10b that is provided on the opposite side of the second tank 14 from the head 1 and that changes the supply pressure P applied to the liquid composition Q that is supplied from the second tank 14 to the head 1 in accordance with the ejection frequency f of the liquid composition Q by the head 1. The liquid ejection device 100b also has a supply path switching mechanism 13 that switches between a first supply path 101 through which the liquid composition Q is supplied from the first tank 2 to the head 1 and a second supply path 102 through which the liquid composition Q is supplied from the second tank 14 to the head 1, and a control unit 20b that controls the change in supply pressure P by the second pressure variable mechanism 10b and the switching by the supply path switching mechanism 13.

[0139] The control unit 20b controls the second pressure variable mechanism 10b to change in advance the supply pressure P of the liquid composition Q supplied from the second supply path 102 to the head 1 in accordance with a second ejection frequency f2 different from the first ejection frequency f1 while the liquid composition Q supplied from the first supply path 101 is being ejected from the head 1 at the first ejection frequency f1. Then, when the ejection frequency f changes from the first ejection frequency f1 to the second ejection frequency f2, the control unit 20b controls the supply path switching mechanism 13 to switch the supply path through which the liquid composition Q is supplied to the head 1 from the first supply path 101 to the second supply path 102.

[0140] The liquid ejection device 100b changes the supply pressure P in the supply path not involved in the ejection in advance according to the ejection frequency f for the next ejection, and changes the supply pressure P by switching the supply path, thereby enabling high-speed changes in the supply pressure P. As a result, the liquid ejection device 100b can suppress delays in the change in the supply pressure P and suppress the occurrence of ejection defects, thereby enabling stable ejection of the liquid composition Q.

[0141] The other effects are the same as those described in the first embodiment.

[0142] [Fourth embodiment] Next, a liquid ejection device 100c according to a fourth embodiment will be described.

[0143] <Configuration Example of Liquid Ejection Apparatus 100c> Fig. 10 is a diagram showing an example of the configuration of a liquid ejection device 100c. In Fig. 10, the X-axis and Y-axis are indicated by arrows, with the direction of the X-axis arrow being +X, the direction opposite to +X being -X, the direction of the Y-axis arrow being +Y, and the direction opposite to +Y being -Y. This also applies to Figs. 12 and 13, which will be described later.

[0144] 10, the liquid ejection device 100c has a first circulation mechanism 30, a second circulation mechanism 40, a first change mechanism 51, and a second change mechanism 52. The first circulation mechanism 30 is the same as that described in FIG.

[0145] The second circulation mechanism 40 includes a second circulation path 41, a second liquid feed pump 42, and a second flow meter 43. The second circulation mechanism 40 is a mechanism that circulates the liquid composition Q through the second circulation path 41 that passes through the head 1 and the second tank 14.

[0146] The second circulation path 41 is a flow path that passes through the head 1 and the second tank 14, and more specifically, is a flow path that delivers and circulates the liquid composition Q from the second tank 14 to the head 1 and from the head 1 to the second tank 14. The second circulation path 41 is configured to include, for example, a tube made of a resin material.

[0147] The second liquid feed pump 42 is a mechanism that generates a liquid feed force for circulating the liquid composition Q through the second circulation path 41. There are no particular limitations on the configuration of the second liquid feed pump 42 as long as it is capable of generating a liquid feed force, and various liquid feed pumps such as a piston pump or a rotary pump can be used.

[0148] The second flow meter 43 is a sensor that detects the flow rate of the liquid composition Q circulating through the second circulation path 41. There are no particular limitations on the configuration of the second flow meter 43, as long as it can detect the flow rate of the liquid composition Q, and flow meters using various methods, such as a volumetric flow meter or a mass flow meter, can be used.

[0149] The first change mechanism 51 includes a first switching valve 50, a second switching valve 34, and a third switching valve 35. The first change mechanism 51 is a mechanism that changes the path of the first circulation path 31. The first circulation path 31 can be changed to either a first ejection circulation path 31a when the liquid composition Q supplied from the first supply path 101 is ejected from the head 1, or a first non-ejection circulation path 31b when the liquid composition Q is not ejected.

[0150] The second change mechanism 52 includes a first switching valve 50, a fourth switching valve 44, and a fifth switching valve 45. The second change mechanism 52 is a mechanism that changes the path of the second circulation path 41. The second circulation path 41 can be changed to either a second ejection circulation path 41a when the liquid composition Q supplied from the second supply path 102 is ejected from the head 1, or a second non-ejection circulation path 41b when the liquid composition Q is not ejected.

[0151] Each of the first selector valve 50, the second selector valve 34, the third selector valve 35, the fourth selector valve 44, and the fifth selector valve 45 is, for example, a three-way valve.

[0152] The configurations of the first change mechanism 51 and the second change mechanism 52 are not limited to those described above, and the number and arrangement of the switching valves can be changed as appropriate. Furthermore, although the first switching valve 50 overlaps between the first change mechanism 51 and the second change mechanism 52, this does not necessarily have to be the case, and there may be two or more overlapping components.

[0153] <Example of functional configuration of control unit 20c> 11 is a block diagram showing an example of the functional configuration of the control unit 20c. The control unit 20c has a circulation path switching control unit 29. The control unit 20c can realize the circulation path switching control unit 29 not only by an electric circuit but also by software (CPU). The control unit 20c may realize the function of the circulation path switching control unit 29 by multiple circuits or multiple pieces of software.

[0154] In response to switching by the supply path switching mechanism 13, the circulation path switching control unit 29 changes the path of the first circulation path 31 using the first change mechanism 51 and changes the path of the second circulation path 41 using the second change mechanism 52.

[0155] For example, when the liquid composition Q supplied from the first supply path 101 is to be ejected from the head 1, the circulation path switching control unit 29 switches the first circulation path 31 and the second circulation path 41 so that the first circulation path 31 becomes the first ejection-time circulation path 31a and the second circulation path 41 becomes the second non-ejection-time circulation path 41b. On the other hand, for example, when the liquid composition Q supplied from the second supply path 102 is to be ejected from the head 1, the circulation path switching control unit 29 switches the first circulation path 31 and the second circulation path 41 so that the first circulation path 31 becomes the first non-ejection-time circulation path 31b and the second circulation path 41 becomes the second ejection-time circulation path 41a.

[0156] <Example of Operation of Liquid Ejector 100c> 12 and 13 are diagrams illustrating the first circulation path 31 and the second circulation path 41, with FIG. 12 being FIG. 1 and FIG. 13 being FIG. 2.

[0157] 12 shows the states of the first circulation path 31 and the second circulation path 41 when liquid composition Q supplied from the first supply path 101 is ejected from the head 1. In this state, the first circulation path 31 becomes a first ejection-time circulation path 31a that includes the head 1 within the circulation path. By circulating the liquid composition Q through the first ejection-time circulation path 31a, the liquid ejection device 100c can suppress settling and aggregation of the liquid composition Q and stably eject the liquid composition Q from the head 1.

[0158] On the other hand, the second circulation path 41 becomes a second non-ejection circulation path 41b that does not include the head 1 within the circulation path. By circulating the liquid composition Q through the second non-ejection circulation path 41b, the liquid ejection device 100c can suppress settling and aggregation of the liquid composition Q when it is not ejected from the head 1, and can suppress ejection defects when the liquid composition Q supplied from the second supply path 102 is next ejected from the head 1.

[0159] 13 shows the states of the first circulation path 31 and the second circulation path 41 when the liquid composition Q supplied from the second supply path 102 is ejected from the head 1. In this state, the first circulation path 31 becomes the first non-ejection circulation path 31b that does not include the head 1 within the circulation path. By circulating the liquid composition Q through the first non-ejection circulation path 31b, the liquid ejection device 100c can suppress settling and aggregation of the liquid composition Q when it is not ejected from the head 1, and can suppress ejection defects when the liquid composition Q supplied from the second supply path 102 is next ejected from the head 1.

[0160] On the other hand, the second circulation path 41 becomes a second discharge circulation path 41a that includes the head 1 within the circulation path. By circulating the liquid composition Q through the second discharge circulation path 41a, the liquid discharge device 100c can suppress sedimentation, aggregation, and the like of the liquid composition Q, and can stably discharge the liquid composition Q from the head 1.

[0161] Tables 1 and 2 shown below are tables illustrating the states of the first pressure switching mechanism 7, supply path switching mechanism 13, second pressure switching mechanism 19, first switching valve 50, second switching valve 34, third switching valve 35, fourth switching valve 44, and fifth switching valve 45. Table 1 shows the state of each of the above components when liquid composition Q supplied from first supply path 101 is ejected from head 1 (corresponding to FIG. 11). Table 2 shows the state of each of the above components when liquid composition Q supplied from second supply path 102 is ejected from head 1 (corresponding to FIG. 12). In Tables 1 and 2, "symbol" indicates the symbol of each component, and "opening direction" indicates the direction in which liquid composition Q is delivered from each component.

[0162] [Table 1]

[0163] [Table 2]

[0164] Fig. 14 is a flowchart showing an example of the operation of the liquid ejection device 100c. In Fig. 14, the state in which the liquid composition Q can flow between the second positive pressure mechanism 11b and the second tank 14 is represented as "second positive pressure mechanism side open."

[0165] The liquid ejection device 100c supplies liquid composition Q from the first supply path 101 to the head 1, and while ejecting the liquid composition Q from the head 1 at a first ejection frequency f1, when changing the ejection frequency f for the next ejection based on the printing condition data Im, starts the supply path switching control operation of Figure 14.

[0166] 14 starts, the first pressure switching mechanism 7, supply path switching mechanism 13, second pressure switching mechanism 19, first switching valve 50, second switching valve 34, third switching valve 35, fourth switching valve 44, and fifth switching valve 45 are in the states shown in Table 1. Note that Fig. 14 describes a case where liquid is discharged from the head 1 when the supply pressure P is in a positive pressure state, but even when the supply pressure P is in a negative pressure state, the operation of the liquid discharger 100c is the same, except for the difference in the mechanism for adjusting the supply pressure P.

[0167] First, in step S141, the liquid ejection device 100c determines the ejection frequency f of the droplets R from the head 1 by the frequency determination unit 22 based on the printing condition data Im input via the input / output unit .

[0168] Next, in step S142, the liquid ejection device 100c determines the supply pressure P by the second pressure variable mechanism 10b by the pressure determination unit 23 based on the ejection frequency f determined by the frequency determination unit 22 and by referring to the correspondence information 241 stored in the storage unit 24.

[0169] Next, in step S143, the liquid ejection device 100c adjusts the positive pressure by the second pressure reducing valve 15 via the pressure control unit 27 so that the supply pressure P to the second tank 14 is approximately equal to the supply pressure P determined by the pressure determination unit 23.

[0170] Subsequently, in step S144, the liquid ejection device 100c switches the second pressure switching mechanism 19 by the pressure switching control unit 26 to open the second positive pressure mechanism 11b side. As a result, a supply pressure P substantially equal to the supply pressure P determined by the pressure determination unit 23 is supplied to the second tank 14.

[0171] Next, in step S145, at the timing when the liquid ejection device 100c switches the ejection frequency f from the first ejection frequency f1 to the second ejection frequency f2, the liquid ejection device 100c switches the supply path switching mechanism 13 via the supply path switching control unit 28, and switches the supply path through which the liquid composition Q is supplied to the head 1 from the first supply path 101 to the second supply path 102.

[0172] Next, in step S146, in response to the switching by the supply path switching mechanism 13, the liquid ejection device 100c changes the path of the first circulation path 31 by the first change mechanism 51 via the circulation path switching control unit 29, and changes the path of the second circulation path 41 by the second change mechanism 52. As a result of this change, the first pressure switching mechanism 7, supply path switching mechanism 13, second pressure switching mechanism 19, first switching valve 50, second switching valve 34, third switching valve 35, fourth switching valve 44, and fifth switching valve 45 become in the states shown in Table 2 above.

[0173] As described above, the liquid ejection device 100c switches the supply path through which the liquid composition Q is supplied to the head 1 from the first supply path 101 to the second supply path 102, and in response to this switching, the circulation paths of the first circulation path 31 and the second circulation path 41 can be changed. Note that the order of the operations of steps S145 and S146 may be reversed, or both may be performed in parallel. Furthermore, during the period from step S141 to step S144 in FIG. 14, the liquid composition Q is continuously ejected from the head 1 at the first ejection frequency f1. Then, due to the switching in step S145, the ejection frequency f of the head 1 is switched from the first ejection frequency f1 to the second ejection frequency f2.

[0174] <Effects of the liquid ejection device 100c> As described above, in this embodiment, the liquid ejection device 100c has a first circulation mechanism 30 that circulates the liquid composition Q through a first circulation path 31 that passes through the head 1 and the first tank first reservoir, and a second circulation mechanism 40 that circulates the liquid composition Q through a second circulation path 41 that passes through the head 1 and the second tank 14. The liquid ejection device 100c also has a first change mechanism 51 that changes the path of the first circulation path 31, and a second change mechanism 52 that changes the path of the second circulation path 41. In response to switching by the supply path switching mechanism 13, the control unit 20c changes the path of the first circulation path 31 using the first change mechanism 51, and changes the path of the second circulation path using the second change mechanism 52.

[0175] The liquid ejection device 100c circulates the liquid composition Q even in supply paths that are not involved in ejection, thereby suppressing settling and aggregation of the liquid composition Q during periods when the liquid composition is not being ejected, and thereby suppressing ejection defects during ejection. This allows the liquid ejection device 100c to stably eject the liquid composition Q.

[0176] The other effects are the same as those described in the first embodiment.

[0177] [Fifth embodiment] Next, an electrode manufacturing apparatus 200 according to a fifth embodiment will be described. The electrode manufacturing apparatus 200 has a liquid ejection apparatus 100, and ejects a liquid composition Q containing electrode materials such as a conductive material for forming a current collector, an active material, and a functional material for imparting, for example, an insulating function to the active material provided on the current collector, to form an electrode material layer on an electrode substrate Ta, thereby manufacturing an electrode for use in an electrochemical element.

[0178] Having "liquid ejection device 100" means having at least components that are the same as or of the same quality as components of liquid ejection device 100. In this embodiment, an electrode manufacturing device 200 having liquid ejection device 100 will be described, but the electrode manufacturing device 200 may have at least one of liquid ejection devices 100a, 100b, and 100c instead of or in addition to liquid ejection device 100.

[0179] The electrode manufacturing apparatus 200 is also an example of a film forming apparatus that forms a functional film on the electrode substrate Ta using the liquid composition Q ejected by the liquid ejection apparatus 100 to form a film on the electrode substrate Ta to manufacture an electrode.

[0180] The electrode substrate Ta is a current collector used in, for example, electricity storage devices such as batteries and capacitors, power generation devices such as fuel cells, solar power generation devices, etc. The electrode manufacturing apparatus 200 discharges onto the electrode substrate Ta a liquid in which various materials, including a powdered active substance and a catalyst composition, are dispersed, and then fixes and dries the liquid to form an electrode material layer on the electrode substrate Ta.

[0181] <Example of Overall Configuration of Electrode Manufacturing Apparatus 200> Fig. 15 is a diagram illustrating an example of the overall configuration of an electrode manufacturing apparatus 200. Fig. 15 shows the inside of the electrode manufacturing apparatus 200 seen through from a direction perpendicular to the transport direction 220 of the electrode substrate Ta.

[0182] 15, the electrode manufacturing apparatus 200 has an unwinding section 201, an application section 203, an irradiation section 204, a heating section 205, and a winding section 206. The application section 203 has a plurality of liquid discharge sections 230a, 230b, 230c, and 230d.

[0183] The electrode manufacturing apparatus 200 conveys the electrode substrate Ta along a conveyance direction 220 using the unwinding unit 201 and the winding unit 206, while applying the liquid composition Q discharged by each of the liquid dischargers 230a, 230b, 230c, and 230d included in the application unit 203 onto the electrode substrate Ta. The electrode substrate Ta is an example of an object onto which the liquid composition Q is discharged by each of the liquid dischargers 230a, 230b, 230c, and 230d.

[0184] The electrode manufacturing apparatus 200 forms a continuous, uniform film on the electrode substrate Ta by irradiating the liquid composition Q applied to the electrode substrate Ta with ultraviolet light from the irradiation unit 204 to cure the liquid composition Q, and by blowing warm air from the heating unit 205 to heat and dry the liquid composition Q. Note that, although the present embodiment illustrates a configuration having both the irradiation unit 204 and the heating unit 205, a configuration having either one of them may also be used.

[0185] The unwinding section 201 rotates the unwinding roll 212, which can rotate with the electrode substrate Ta wound around it, and unwinds the electrode substrate Ta wound around the roll, thereby moving and transporting the electrode substrate Ta from the unwinding section 201 toward the coating section 203. The winding section 206 winds the electrode substrate Ta around the rotated winding roll 207 to wind up the electrode substrate Ta, thereby moving and transporting the electrode substrate Ta from the heating section 205 toward the winding section 206.

[0186] The electrode manufacturing apparatus 200 uses not only the unwinding section 201 and the winding section 206, but also unreferenced transport rollers and the like as a transport section for transporting the electrode substrate Ta. The transport rollers, the unwinding section 201, and the winding section constitute the transport section for the electrode substrate Ta.

[0187] The electrode substrates Ta are continuous along the conveying direction 220. The electrode manufacturing apparatus 200 conveys the electrode substrates Ta along a conveying path between an unwinding section 201 and a winding section 206. The length of the electrode substrates Ta along the conveying direction 220 is at least longer than the conveying path between the unwinding section 201 and the winding section 206. The electrode manufacturing apparatus 200 continuously forms a film on the electrode substrates Ta that are continuous along the conveying direction 220.

[0188] The coating unit 203 coats the electrode substrate Ta with the liquid composition Q discharged by each of the liquid discharge units 230a, 230b, 230c, and 230d.

[0189] The liquid ejection units 230a, 230b, 230c, and 230d each have the same configuration, and therefore will be collectively referred to as liquid ejection unit 230 unless otherwise distinguished. In this embodiment, the liquid ejection units 230a, 230b, 230c, and 230d eject the same type of liquid composition Q. "Type" refers to differences in composition, color, or the like. However, they are not limited to the same type, and the liquid ejection units 230 may eject different types of liquid compositions Q. Furthermore, the number of liquid ejection units 230 is not limited to four, and may be any number.

[0190] The liquid discharge unit 230 has a plurality of nozzle rows in which a plurality of nozzles are arranged. The electrode manufacturing apparatus 200 has the liquid discharge unit 230 such that the discharge direction of the liquid composition Q discharged from the nozzles is directed toward the electrode substrate Ta.

[0191] The electrode substrate Ta is, for example, a non-permeable substrate such as a metal sheet on which a layer mainly made of particles is provided. The layer mainly made of particles provided on the non-permeable substrate is, for example, a graphite layer.

[0192] The impermeable substrate includes metal sheets such as aluminum, copper, stainless steel, nickel, and platinum, and resin films such as polypropylene film, polyethylene terephthalate film, and nylon film.

[0193] The wiping devices 250a, 250b, 250c, and 250d are provided in pairs with the liquid dischargers 230a, 230b, 230c, and 230d, and maintain the discharge state of the heads of the liquid dischargers 230a, 230b, 230c, and 230d, respectively.

[0194] The wiping devices 250a, 250b, 250c, and 250d have the same configuration, and therefore, when no distinction is made, they will be collectively referred to as the wiping device 250. The number of wiping devices 250 provided corresponds to the number of liquid dischargers 230.

[0195] Furthermore, the number of wiping devices 250 may be equal to or less than the number of liquid dischargers 230, and one wiping device 250 may wipe a plurality of liquid dischargers 230.

[0196] The number of wiping devices 250 is preferably set to the number corresponding to the number of liquid discharge sections 230, in terms of being able to perform wiping operations according to each liquid discharge section 230, and from the standpoint of operational efficiency, it is preferable to have one wiping device 250 wipe multiple liquid discharge sections 230.

[0197] The irradiation unit 204 has light sources 245a and 245b. When there is no need to distinguish between the light sources 245a and 245b, they are collectively referred to as light source 245. The light source 245 has a curing function of irradiating the liquid composition Q applied to the electrode substrate Ta with ultraviolet light to cure the liquid composition layer into a resin layer.

[0198] The light source 245 may be, for example, a mercury lamp such as a low-, medium-, or high-pressure mercury lamp, a tungsten lamp, an arc lamp, an excimer lamp, an excimer laser, a semiconductor laser, a high-power UV-LED, a YAG laser, a laser system combining a laser with a nonlinear optical crystal, a high-frequency induced ultraviolet light generator, an electron beam irradiation device such as EB cure, an X-ray irradiation device, etc. Among these, from the viewpoint of simplifying the system, a high-frequency induced ultraviolet light generator, a high- or low-pressure mercury lamp, a semiconductor laser, etc. are preferable. The light source 245 may also be equipped with a focusing mirror and a sweeping optical system.

[0199] The heating unit 205 has heaters 280a, 280b, and 280c. When the heaters 280a, 280b, and 280c are not distinguished from one another, they are collectively referred to as heater 280. The heater 280 heats the liquid composition Q formed on the electrode substrate Ta to dry any remaining solvent in the liquid composition Q, thereby accelerating or drying the curing of the liquid composition Q. The heater 280 functions as a curing or drying mechanism or a heating or heating mechanism.

[0200] The heater 280 is, for example, an infrared lamp, a roller (heat roller) incorporating a heating element, a blower that blows out warm or hot air, or a furnace that introduces boiler-type hot air using steam or the like.

[0201] <Configuration Example of Liquid Discharge Unit 230> Fig. 16 is a diagram illustrating the configuration of the liquid discharger 230. Fig. 16 is a diagram illustrating the liquid dischargers 230a, 230b, 230c, and 230d as viewed from the liquid discharge direction side. The electrode substrate Ta is transported along the transport direction 220 while facing the liquid dischargers 230a, 230b, 230c, and 230d.

[0202] The liquid discharger 230 is a line-type liquid discharger. A "line-type liquid discharger" is one in which nozzles for discharging the liquid composition Q are arranged across the entire width of the electrode substrate Ta in the width direction (a direction substantially perpendicular to the transport direction 220).

[0203] 16, each of the liquid dischargers 230a, 230b, 230c, and 230d has four heads 1a arranged in a direction substantially perpendicular to the transport direction 220. The heads 1a are an example of a discharger that discharges the liquid composition Q supplied from the first tank 2 onto the electrode substrate Ta.

[0204] The head 1a has a nozzle surface 211 in which a plurality of nozzles 210 for ejecting the liquid composition Q are formed. The plurality of nozzles 210 are arranged in a direction substantially perpendicular to the transport direction 220. The head 1a can eject the liquid composition Q from each of the plurality of nozzles 210. Note that the head 1a is a collective term for the heads possessed by the liquid ejection units 230a, 230b, 230c, and 230d.

[0205] By arranging four heads 1a in a direction substantially perpendicular to the transport direction 220, the liquid composition Q can be ejected across the entire width of the electrode substrate Ta. Here, a configuration in which one liquid ejection section 230 has four heads 1a is exemplified, but it is sufficient for the liquid ejection section 230 to be equipped with at least one head 1a. The width of the liquid ejection section 230 does not necessarily have to be the entire width of the electrode substrate Ta and can be determined appropriately.

[0206] <Actions and Effects of the Electrode Manufacturing Apparatus 200> As described above, in this embodiment, the electrode manufacturing apparatus 200 includes the liquid ejection apparatus 100. The electrode manufacturing apparatus 200 can prevent delays in supplying the liquid composition Q to the head 1a and prevent ejection defects, even when the ejection frequency f of the liquid composition Q increases. In other words, an electrode manufacturing apparatus 200 can be provided that can stably eject the liquid composition Q.

[0207] In particular, the electrode manufacturing apparatus 200 discharges a liquid composition Q containing an electrode material such as an active material, which is an example of a solid component. The specific gravity of this electrode material is greater than the specific gravity of components other than the electrode material in the liquid composition Q, and therefore the electrode material is likely to settle or aggregate in the flow path of the liquid composition Q. The electrode manufacturing apparatus 200 prevents the electrode material from settling or agglomerating in the flow path, and can stably discharge the liquid composition Q containing the electrode material such as the active material, thereby improving the quality and productivity of electrode manufacturing.

[0208] Although the embodiments have been described above, the present invention is not limited to the specifically disclosed above embodiments, and various modifications and changes are possible without departing from the scope of the claims.

[0209] The ordinal numbers, quantities, and other figures used in the description of the embodiments are all provided as examples to specifically explain the technology of the present invention, and the present invention is not limited to the illustrated figures. Furthermore, the connection relationships between components are provided as examples to specifically explain the technology of the present invention, and the connection relationships for realizing the functions of the present invention are not limited to these.

[0210] The embodiments also include an electrode manufacturing method. For example, the electrode manufacturing method is a method for manufacturing an electrode using an electrode manufacturing apparatus, in which the electrode manufacturing apparatus stores a liquid composition in a storage unit, discharges the liquid composition supplied from the storage unit onto an object using a discharge unit, and changes the supply pressure applied to the liquid composition supplied from the storage unit to the discharge unit using a pressure variable mechanism provided on the opposite side of the storage unit from the discharge unit, depending on the discharge frequency of the liquid composition by the discharge unit. Such an electrode manufacturing method can achieve the same effects as the electrode manufacturing apparatus 200 described above.

[0211] Each function of the above-described embodiments can be realized by one or more processing circuits. Here, the term "processing circuit" in this specification includes a processor programmed to perform each function by software, such as a processor implemented by an electronic circuit, as well as devices such as an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or a conventional circuit module designed to perform each of the above-described functions. [Explanation of symbols]

[0212] 1, 1a Head (an example of a discharge part) 2. First tank (an example of a first storage section, an example of a storage section) 3. First pressure reducing valve (an example of an adjustment mechanism) 4. First pressure pump (an example of a pressure generating mechanism) 5. First vacuum pump (an example of a pressure generating mechanism) 6. First pressure control valve (an example of a control mechanism) 7. First pressure switching mechanism 8. First pressure gauge 8b Second pressure gauge 9. First pressure buffer (an example of a first pressure reducing member) 9a Second pressure buffer (an example of a first pressure reducing member) 10 First pressure variable mechanism (an example of a pressure variable mechanism) 10b Second pressure variable mechanism 11 First positive pressure mechanism 12 First negative pressure mechanism 13 Supply path switching mechanism 14 Second tank (example of first storage section) 15 Second pressure reducing valve (an example of an adjustment mechanism) 16 Second pressure pump (an example of a pressure generating mechanism) 17 Second vacuum pump (an example of a pressure generating mechanism) 18 Second pressure control valve (an example of a control mechanism) 19 Second pressure switching mechanism 20 Control Unit 20b control section 21 Input / output section 22 Frequency determination unit 23 Pressure determination unit 24 Storage area 241 Support Information 25 Discharge control section 26 Pressure switching control section 27 Pressure control section 28 Supply path switching control unit 30 1st circulation mechanism 31 1st circulation route 31a 1st discharge circulation path 31b 1st non-discharge circulation path 32 First liquid delivery pump 33 1st flow meter 34 Second switching valve 35 Third switching valve 40 Second circulation mechanism 41 Second circulation route 41a 2nd discharge circulation path 41b 2nd non-discharge circulation path 42 Second liquid delivery pump 43 2nd flow meter 44 Fourth switching valve 45 5th switching valve 50 First switching valve 51 First change mechanism 52 Second Change Mechanism Graphs 71, 72, and 73 81, 82, 83 Plots 84 Approximate straight line 100, 100a, 100b, 100c liquid dispensing device 101 1st supply route 102 2nd supply route 201 Unwinding section 212 Unwinding roll Ta electrode base 203 Application section 230, 230a, 230b, 230c, 230d Liquid discharge part 204 Irradiation unit 205 Heating section 206 Winding section 207 Winding roll 291 Head Base 210 nozzle 211 Nozzle surface 220 Conveying direction 245 Light source 250 Wiping device 280 Heater 200 Electrode manufacturing equipment (example of film formation equipment) f Discharge frequency f1 First discharge frequency f2 2nd discharge frequency Im printing condition data P supply pressure Q Liquid Composition R droplet T object Ta electrode base [Prior art documents] [Patent documents]

[0213] [Patent Document 1] Special Publication No. 07-008567

Claims

1. a first reservoir configured to store a liquid composition; a discharge unit that discharges the liquid composition supplied from the first reservoir onto a target; a first pressure varying mechanism that is provided on the opposite side of the ejection portion with the first storage portion interposed therebetween and that varies a supply pressure applied to the liquid composition that is supplied from the first storage portion to the ejection portion based on an ejection frequency of the liquid composition by the ejection portion; a pressure generating mechanism that generates the supply pressure of the liquid composition; an adjustment mechanism that adjusts the supply pressure generated by the pressure generating mechanism, The liquid ejection device, wherein the adjustment mechanism is disposed between the pressure generation mechanism and the first storage section.

2. A first storage section for storing a liquid composition; a discharge unit that discharges the liquid composition supplied from the first reservoir onto a target; a first pressure varying mechanism that is provided on the opposite side of the ejection portion with the first storage portion interposed therebetween and that varies a supply pressure applied to the liquid composition that is supplied from the first storage portion to the ejection portion based on an ejection frequency of the liquid composition by the ejection portion; a second reservoir for storing the liquid composition; a second pressure variable mechanism that is provided on the opposite side of the second storage section from the ejection section, and that changes the supply pressure applied to the liquid composition that is supplied from the second storage section to the ejection section in accordance with the ejection frequency of the liquid composition by the ejection section; a supply channel switching mechanism that switches between a first supply channel through which the liquid composition is supplied from the first storage section to the discharge section and a second supply channel through which the liquid composition is supplied from the second storage section to the discharge section; a control unit that controls the change in the supply pressure by the second pressure variable mechanism and the switching by the supply path switching mechanism, The control unit while the liquid composition supplied from the first supply path is being ejected from the ejection portion at a first ejection frequency, the supply pressure of the liquid composition supplied from the second supply path to the ejection portion is changed in advance by the second pressure variable mechanism in accordance with a second ejection frequency different from the first ejection frequency; a supply path switching mechanism for switching the supply path through which the liquid composition is supplied to the ejection section from the first supply path to the second supply path when the ejection frequency changes from the first ejection frequency to the second ejection frequency.

3. The liquid ejection device according to claim 1 or 2, wherein the liquid composition contains a solid component.

4. 4. The liquid ejection apparatus according to claim 1, wherein the supply pressure includes at least a negative pressure.

5. 5. The liquid ejection device according to claim 1, wherein the first pressure variable mechanism increases the supply pressure as the ejection frequency increases.

6. 6. The liquid ejection device according to claim 1, wherein the first pressure variable mechanism includes a pressure generating mechanism that generates the supply pressure of the liquid composition.

7. The liquid ejection device according to claim 1 , further comprising a first circulation mechanism that circulates the liquid composition through a flow path that passes through the ejection portion and the first storage portion.

8. A liquid ejection device described in any one of claims 1 to 7, further comprising a first reduction member provided between the first storage section and the ejection section, which reduces transient pressure fluctuations when the supply pressure is changed by the first pressure variable mechanism.

9. the supply pressure includes a positive pressure and a negative pressure; 9. The liquid ejection device according to claim 1, further comprising a pressure switching mechanism that switches the supply pressure between a positive pressure and a negative pressure.

10. The liquid ejection device according to claim 2 , further comprising a second reducing member provided between the supply path switching mechanism and the ejection section, which reduces transient pressure fluctuations when the supply path switching mechanism switches from the first supply path to the second supply path.

11. a first circulation mechanism that circulates the liquid composition through a first circulation path that passes through the discharge portion and the first storage portion; a second circulation mechanism that circulates the liquid composition through a second circulation path that passes through the discharge portion and the second storage portion; a first change mechanism that changes the path of the first circulation path; a second change mechanism that changes the route of the second circulation path, The liquid ejection device according to claim 2 or claim 10, wherein the control unit changes the route of the first circulation path using the first change mechanism and changes the route of the second circulation path using the second change mechanism in response to switching by the supply path switching mechanism.

12. A liquid ejection device according to any one of claims 1 to 11, a film forming device that forms a functional film on the object using the liquid composition discharged by the liquid discharge device;

13. A liquid ejection device according to any one of claims 1 to 11, An electrode manufacturing apparatus for manufacturing an electrode by forming an electrode material layer on the object.

14. An electrode manufacturing method using an electrode manufacturing apparatus, the electrode manufacturing apparatus comprising: The reservoir stores the liquid composition; a discharge unit discharging the liquid composition supplied from the storage unit onto a target object; a pressure varying mechanism provided on the opposite side of the discharge portion across the storage portion to vary a supply pressure applied to the liquid composition supplied from the storage portion to the discharge portion in accordance with a discharge frequency of the liquid composition by the discharge portion; generating the supply pressure of the liquid composition by a pressure generating mechanism; an adjustment mechanism adjusting the supply pressure generated by the pressure generating mechanism; The electrode manufacturing method, wherein the adjustment mechanism is disposed between the pressure generating mechanism and the reservoir.

15. A method for manufacturing an electrode using an electrode manufacturing apparatus, the electrode manufacturing apparatus comprising: The first reservoir stores a liquid composition; a discharge unit discharging the liquid composition supplied from the first reservoir onto a target object; a pressure varying mechanism provided on the opposite side of the ejection portion across the first storage portion to vary a supply pressure applied to the liquid composition supplied from the first storage portion to the ejection portion in accordance with an ejection frequency of the liquid composition by the ejection portion; The second reservoir stores the liquid composition; a second pressure variable mechanism, which is provided on the opposite side of the second storage section from the ejection section, and which applies a supply pressure to the liquid composition supplied from the second storage section to the ejection section in accordance with the ejection frequency of the liquid composition by the ejection section; a supply path switching mechanism switches between a first supply path through which the liquid composition is supplied from the first storage portion to the discharge portion and a second supply path through which the liquid composition is supplied from the second storage portion to the discharge portion; a control unit controls the change in the supply pressure by the second pressure variable mechanism and the switching by the supply path switching mechanism; The control unit while the liquid composition supplied from the first supply path is being ejected from the ejection portion at a first ejection frequency, the supply pressure of the liquid composition supplied from the second supply path to the ejection portion is changed in advance by the second pressure variable mechanism in accordance with a second ejection frequency different from the first ejection frequency; an electrode manufacturing method, wherein when the ejection frequency changes from the first ejection frequency to the second ejection frequency, the supply path through which the liquid composition is supplied to the ejection section is switched from the first supply path to the second supply path by the supply path switching mechanism.

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