JP2023128340A - Liquid ejection device, liquid ejection method, article manufacturing method, control program, recording medium - Google Patents

Abstract

To provide a technique for supplying ink from a main tank to a sub-tank without decreasing production efficiency of printing.SOLUTION: A liquid ejection device includes: a first flow passage which is a first circulation passage to which a main tank is connected; a second flow passage to which a sub-tank and a liquid ejection unit are connected; a third flow passage which connects the first flow passage and the sub-tank and includes flow passage opening/closing means; and a control unit; wherein the control unit opens the flow passage opening/closing means while circulating ink in the first flow passage, replenishing the sub-tank with ink from the main tank via the third flow passage while ejecting the ink from the liquid ejection unit; and closes the flow passage opening/closing means when the replenishment of the sub-tank with the ink from the main tank is completed.SELECTED DRAWING: Figure 3

Description

The present invention relates to a liquid ejection device, a liquid ejection method using the liquid ejection device, and the like.

In the field of liquid ejection devices such as so-called inkjet printers, devices are known that include a main tank that stores liquid and a sub-tank that supplies liquid to an ejection head, and that replenishes liquid from the main tank to the sub-tank as necessary. There is.

Patent Document 1 discloses that pressure sensors are placed before and after the ejection head in a circulation flow path including the ejection head and the sub-tank, and the flow path resistance between the front and rear pressure sensors and the ejection head is made equal, thereby reducing the pressure at the nozzle position. A method for improving pressure control is disclosed.

Japanese Patent Application Publication No. 2015-157362

The device disclosed in Patent Document 1 includes a main tank for supplying ink to a sub-tank, but when supplying ink, the flow path valve of the circulation flow path is closed and the ejection head is stopped. Ink is being supplied from the main tank to the sub tank. Since the ejection head is stopped while ink is supplied from the main tank to the sub-tank, there is a problem in that printing production efficiency decreases.
Therefore, there was a need for a technology to supply ink from the main tank to the sub-tank without reducing printing production efficiency.

A first aspect of the present invention includes a first flow path which is a first circulation path to which a main tank is connected, a second flow path to which a sub tank and a liquid discharge section are connected, and the first flow path and the first flow path. a third channel connected to the sub-tank and provided with a channel opening/closing means; and a control section, the control section opening the channel opening/closing means while circulating the ink in the first channel; While discharging ink from the liquid discharge section, ink is supplied from the main tank to the sub-tank via the third channel, and when the supply of ink from the main tank to the sub-tank is completed, the channel opening/closing means A liquid ejecting device characterized in that:

Further, a second aspect of the present invention provides a first flow path which is a first circulation path to which a main tank is connected, a second flow path to which a sub-tank and a liquid discharge section are connected, and the first flow path. and a third channel connected to the sub-tank and provided with a channel opening/closing means. Opening the opening/closing means and replenishing ink from the main tank to the sub-tank via the third flow path while discharging ink from the liquid ejection section, and when replenishment of ink from the main tank to the sub-tank is completed, The liquid discharging method is characterized in that the flow path opening/closing means is closed.

According to the present invention, it is possible to supply ink from the main tank to the sub tank without reducing printing production efficiency.

(a) A schematic top view of the liquid ejection device 1 according to the first embodiment. (b) A schematic side view of the liquid ejection device 1 according to the first embodiment. FIG. 3 is a diagram for explaining the configuration of an ink supply system of the liquid ejection device 1 according to the first embodiment. FIG. 2 is a block diagram for explaining a control system of the liquid ejection device 1 according to the first embodiment. 5 is a flowchart for explaining the procedure of an ink supply operation according to the first embodiment. 7 is a diagram for explaining the configuration of an ink supply system of a liquid ejection device 1 according to a second embodiment. FIG. 7 is a diagram for explaining the configuration of an ink supply system of a liquid ejection device 1 according to Embodiment 3. FIG.

First, an outline of an embodiment of the present invention that can supply liquid from a main tank to a sub tank without reducing printing production efficiency will be described. Note that in this specification, the liquid handled by the liquid ejection device is sometimes referred to as "ink," but the ink according to the embodiments is not limited to a liquid for forming characters or images. For example, it may be a liquid containing a functional material for forming a functional thin film such as an electrode or an optical filter, or a functional element such as an organic EL element. Also, the term "recording" may refer to discharging liquid and applying it to an object, but recording here is not necessarily limited to recording information such as text or images; for example, It also includes applying a liquid to an object to form a functional thin film or functional element. In addition, although the object to which liquid is applied is sometimes described as a "recording medium," a recording medium is not limited to a medium for recording information such as characters or images, and is not limited to a medium for recording information such as a functional thin film or a functional element. It includes parts and articles that serve as base materials for forming.

The liquid ejection device of the present embodiment includes a first flow path including a main tank and a second flow path connecting the ejection head and the sub tank, but the first flow path and the second flow path are each independently capable of discharging liquid. It is constructed so that the (ink) can continue to flow. This is to enable stable ejection of ink containing insoluble particles, such as pigment ink, quantum dot ink, silver ink, and white ink, as well as ink containing soluble recording material. By continuing to flow the ink, it is possible to prevent insoluble components from settling or adhering in the main tank, sub-tank, flow path, etc., resulting in uneven ink concentration.

In the liquid ejection device of this embodiment, when the remaining amount of ink in the sub-tank becomes low, the ink in the second flow path is made to flow and the ink is continued to be ejected from the ejection portion, and the ink is sent to the ink via the third flow path. Ink can be replenished from the main tank to the sub tank by connecting the first flow path and the sub tank. When connecting, the hydraulic pressure in the first channel and the pressure in the sub-tank are measured, and the hydraulic pressure in the first channel is adjusted based on the measurement results before connection. That is, the first flow path and the sub tank are connected after controlling the pressure difference between the first flow path and the sub tank to be within a predetermined range. This maintains a pressure difference that allows ink to be refilled from the main tank to the sub-tank, while also ensuring that the ink pressure at the ejection section does not change significantly during refilling from the main tank to the sub-tank, causing fluctuations in ejection performance. It is a control for When the supply of ink from the main tank to the sub tank is completed, the first flow path and the sub tank are disconnected. Thereafter, the first flow path and the second flow path can continue to flow ink independently. According to the liquid ejection device of the embodiment, it is possible to stably and continuously perform high quality printing without reducing printing production efficiency.

Hereinafter, a plurality of embodiments will be specifically described with reference to the drawings. The embodiments shown below are illustrative, and those skilled in the art can modify and implement the detailed configurations as appropriate without departing from the spirit of the present invention. In the drawings referred to in the following description, unless otherwise specified, elements designated with the same reference numerals have similar functions. Note that these drawings are schematically expressed for the convenience of illustration and explanation, and therefore do not necessarily correspond exactly to the shape, size, arrangement, etc. of the actual objects.

[Embodiment 1]
(overall structure)
First, the overall configuration of a liquid ejection device according to Embodiment 1 will be described. FIG. 1(a) is a schematic top view of the liquid ejection device 1, and FIG. 1(b) is a schematic side view. Note that for convenience of illustration, descriptions of general components that are not directly related to the problem-solving principle of the present invention are omitted.

The liquid ejecting device 1 includes a base 9, and the base 9 is provided with a stage 10 on which a recording medium 6 (for example, a substrate for forming an organic EL element) is set. Further, a sub-scanning guide rail 7 extending in the X direction in plan view is fixed to the base 9 via a support member 8. On the sub-scanning guide rail 7, a main-scanning guide rail 5 serving as a carriage movable on the sub-scanning guide rail 7 in the X direction is placed. A main scanner 4 movable along the Y direction is mounted. The main scanner 4 is equipped with a liquid ejection unit 2 that can eject liquid toward the recording medium 6 . By moving the main scanning guide rail 5 in the X direction and the main scanner 4 in the Y direction, the liquid ejection unit 2 can freely scan in the X and Y directions on the recording medium 6 set on the stage 10. I can do it.

The liquid ejection unit 2 is equipped with a liquid ejection head 3 capable of ejecting liquid (for example, ink for forming an organic EL element) toward a recording medium 6 . The liquid ejection head 3 is equipped with a device that applies pressure to the ink using, for example, deformation of a piezo element or film boiling of a heating element to eject the ink from a nozzle. A second flow path 16 including a sub-tank for supplying ink to the liquid ejection head 3 is mounted on the liquid ejection unit 2, and the second flow path 16 will be described in detail later with reference to FIG. do.

A main tank 11 is installed on the stage 10. Ink is stored in the main tank 11 in order to be replenished when the remaining amount of ink in the sub-tank of the liquid ejection unit 2 decreases. The main tank 11 is connected to a first flow path 15 for circulating the stored ink. The first flow path 15, which is a circulation path, is equipped with a hydraulic pressure gauge 122 and the like, and the configuration of the first flow path 15 will be described in detail later with reference to FIG. 2.

The liquid ejection device 1 includes a third flow path 21 that connects the sub-tank of the liquid ejection unit 2 and the first flow path 15 in an openable and closable manner. Since the sub-tank moves as the liquid discharge unit 2 is scanned in the XY direction, the third flow path 21 is configured to include a flexible pipe portion. An on-off valve is installed in the middle of the third flow path 21, and the configuration of the third flow path 21 will be described in detail later with reference to FIG. 2.

(Ink supply system configuration)
With reference to FIG. 2, the configuration of the ink supply system of the liquid ejection apparatus 1 according to the first embodiment will be described. On the left side of FIG. 2, a first flow path 15 (which may also be referred to as a first circulation path) is shown for circulating the ink stored in the main tank 11. The main tank 11 , the first pump 17 , the filter 18 , the hydraulic pressure gauge 122 , and the branch portion BR to the third flow path 21 are connected in series to the first flow path 15 . A first pressure control unit 12 is connected to the main tank 11, and as described later, the control unit controls the drive of the first pressure control unit 12 to adjust the liquid pressure in the first flow path near the branch portion BR. can be controlled. Specifically, the first pressure control section 12 can be configured with a tube pump, a diaphragm pump, a piston pump, or the like. The first pump 17 is driven at all times except when maintaining the liquid ejection device 1, and the ink stored in the main tank 11 is constantly circulated through the first flow path 15 along the direction D1. There is. In addition, in order to improve the accuracy of hydraulic pressure control when replenishing ink from the main tank 11 to the sub-tank 13, which will be described later, the hydraulic pressure gauge 122 is installed on the upstream side of the branch part BR in the direction of the circulating flow D1. It is preferable to place them nearby.

The part surrounded by the dotted line on the right side of FIG. 2 is the part mounted on the liquid ejection unit 2, and shows the second flow path 16 for supplying ink to the liquid ejection head 3 (liquid ejection part). There is. The sub-tank 13, the second pump 20, and the liquid ejection head 3 are connected in series to the second flow path 16, forming a circulation path (which may also be referred to as a second circulation path). A second pressure control section 14 is connected to the sub-tank 13, and the control section can control the drive of the second pressure control section 14 to control the hydraulic pressure of ink supplied to the liquid ejection head 3. Specifically, the second pressure control unit 14 can be configured with a tube pump, a diaphragm pump, a piston pump, etc., but in order to improve the controllability of the liquid pressure at the connection position of the liquid discharge head 3, a piston pump It is particularly preferred to use The second pump 20 is driven at all times, except when maintaining the liquid discharge unit 2, and the ink stored in the sub tank 13 is constantly circulated through the second flow path 16 in the direction D2. .

The first flow path 15 and the second flow path 16 are connected by a third flow path 21 provided with a valve 19 (flow path opening/closing means) that can be opened and closed. Specifically, the branch portion BR of the first flow path 15 and the sub-tank 13 are connected by the third flow path 21. As will be described later, the valve 19 provided in the middle of the third flow path 21 is opened when ink is replenished from the main tank 11 to the sub tank 13, but is closed at other times.

(control system)
The control system of the liquid ejection device 1 according to this embodiment will be described with reference to the block diagram of FIG. 3. In addition, in FIG. 3, functional elements necessary to explain the features of this embodiment are represented by functional blocks, but descriptions of general functional elements that are not directly related to the problem-solving principle of the present invention are omitted. are doing. Further, each functional element illustrated in FIG. 3 is functionally conceptual, and does not necessarily need to be physically configured as illustrated. For example, the specific form of distribution and integration of each functional block is not limited to the illustrated example, but all or part of it can be configured by functionally or physically distributing or integrating it in arbitrary units depending on the usage situation, etc. It is possible to do so. Each functional block can be configured using hardware or software. That is, some of these functional blocks can be configured by the CPU reading and executing a control program stored in, for example, a storage device or a non-temporary recording medium. Alternatively, part or all of the functional blocks may be configured by hardware such as ASIC.

The control unit 100 of the liquid ejection device 1 includes a CPU 101, a ROM 102 (Read Only Memory), a RAM 103 (Random Access Memory), and an input/output interface 104. The control unit 100 is connected to a host device 110 of a recording system (or an article production system) via an interface 111. The host device 110 is constituted by a computer equipped with a printer driver, etc., and performs the creation of printing data and overall management of the entire recording system. Liquid ejection patterns, commands, status signals, and the like are transmitted and received between the host device 110 and the control unit 100 of the liquid ejection device 1 via the interface 111.

The CPU 101 is a computer that controls the operation sequence of the liquid ejection device 1 and the execution of various tasks. The CPU 101 can read and execute control programs and control information from the ROM 102 or a computer-readable recording medium (not shown). The computer-readable recording medium can be connected to the CPU 101 via the input/output interface 104, and can be, for example, a flexible disk, an optical disk, a magneto-optical disk, a magnetic tape, a nonvolatile memory such as a USB memory, an SSD, etc. . The RAM 103 is a storage device that temporarily stores the results of calculation processing by the CPU 101 and various data, and is provided with an area for developing liquid ejection patterns, a work area for replenishing ink from the main tank 11 to the sub tank 13, etc. .

The control unit 100 can obtain various measurement data from various sensors 120 included in the liquid ejection device 1 via the input/output interface 104. The various sensors 120 include a substrate sensor 121 that detects the setting of the recording medium 6, a hydraulic pressure gauge 122 provided in the first flow path 15, a pressure sensor 123 provided in the first pressure control section 12 of the main tank 11, and a pressure sensor 123 provided in the sub tank 13. The pressure sensor 124 included in the second pressure control section 14, the liquid level sensor 125 that detects the remaining amount of ink in the sub tank 13, the temperature sensor 126 that detects the temperature of the liquid ejection head 3, etc. may be included, but are not limited thereto. isn't it. The control unit 100 can acquire various measurement data from various sensors 120 and control the operation of each part of the apparatus based on the measurement data.

The control unit 100 can control various control elements included in the liquid ejection device 1 via the input/output interface 104. For example, the control unit 100 can control the ejection of ink from the liquid ejection unit 2 by sending a control signal to the head driver 130. In addition, the control unit 100 controls the X-direction position of the main scanning guide rail 5 and the Y-direction position of the main scanner 4 by sending control signals to the X-position control unit 131X and the Y-position control unit 131Y, and controls the liquid ejection. The unit 2 can be scanned to any position. Further, the control unit 100 can independently control each of the first pressure control unit 12 of the main tank 11 and the second pressure control unit 14 of the sub tank 13 by sending control signals to the driver 132 and the driver 133. . Further, the control unit 100 independently controls each of the first pump 17 in the first flow path 15 and the second pump 20 in the second flow path 16 by sending control signals to the pump driver 134 and the pump driver 135. be able to. Further, the control unit 100 can control opening and closing of the valve 19 provided in the third flow path 21 by sending a control signal to the driver 136.

(Operation of liquid discharge device)
With reference to the flowchart of FIG. 4, the procedure of the ink ejection operation and the ink supply operation performed in the liquid ejection apparatus 1 will be described.

When the liquid ejecting device 1 is powered on and starts operating, the control unit 100 executes processing to put the liquid ejecting device 1 into a standby state in step S1. The control unit 100 closes the valve 19 of the third flow path 21 and disconnects the first flow path 15 and the second flow path 16. Further, the control unit 100 controls the first pump 17 so that the ink stored in the main tank 11 circulates through the first channel 15. Thereafter, the first pump 17 continues to operate unless it receives a stop instruction from the control unit 100, and the ink stored in the main tank 11 continues to circulate through the first flow path 15. Further, the control unit 100 controls the second pump 20 so that the ink stored in the sub-tank 13 circulates through the second flow path 16 . Thereafter, the second pump 20 continues to operate unless it receives a stop instruction from the control unit 100, and the ink stored in the sub-tank 13 continues to be supplied to the liquid ejection head 3 while circulating through the second channel 16.

When the liquid ejection device 1 in the standby state receives a print instruction from the host device 110, it starts ejecting ink while scanning the liquid ejection unit 2 in the XY direction on the recording medium 6. That is, in step S2, the liquid ejection head 3 starts ejecting ink, and ejects the ink onto the recording medium 6 according to the recording pattern. Thereafter, unless a stop instruction is received from the control unit 100, such as when replacing the recording medium 6, the liquid ejection head 3 continues the ejection operation and continues to eject ink onto the recording medium 6 according to the recording pattern. When ejection onto one recording medium 6 is completed, a new recording medium 6 is set on the stage 10, and the liquid ejection head 3 continues to eject ink.

Next, in step S<b>3 , the control unit 100 obtains a measurement result from the liquid level sensor 125 of the sub-tank 13 and measures the amount of ink remaining in the sub-tank 13 . In subsequent step S4, the control unit 100 determines whether the measured value of the remaining amount of ink in the sub-tank 13 is less than or equal to a predetermined amount. In this embodiment, the determination threshold is set to 20 ml, but the determination threshold can be set as appropriate according to the specifications of the apparatus so that the timing of replenishing ink to the sub-tank 13 can be accurately determined. If the measured value of the remaining amount of ink in the sub-tank 13 is larger than the predetermined amount (step S4: NO), there is no need to replenish ink to the sub-tank 13, and therefore ink is ejected from the liquid ejection head 3 according to the recording pattern. While continuing to do so, the process returns to step S3. Thereafter, steps S3 and S4 are repeated while continuing to eject ink from the liquid ejection head 3 until the measured value of the remaining amount of ink becomes equal to or less than a predetermined amount.

If the measured value of the remaining amount of ink in the sub-tank 13 is below the predetermined amount (step S4: YES), the control unit 100 executes the processes from step S5 onwards in order to replenish ink from the main tank 11 to the sub-tank 13. do. Note that even while the processes from step S5 onwards are being executed, the liquid ejection unit 2 can continue the ejection operation and continue ejecting ink according to the recording pattern.

In step S5, the control unit 100 acquires the measured value of the pressure P2 of the sub-tank 13 from the pressure sensor 124 included in the second pressure control unit 14.

In step S6, the control unit 100 controls the first pressure control unit 12 of the main tank 11 so that the liquid pressure near the branch portion BR of the first flow path 15 satisfies the relationship of equation (1) below. .
100[Pa]+P3≦P1-P2≦300[Pa]+P3...Formula (1)

However, P1 is the hydraulic pressure in the first flow path near the branch portion BR, and specifically, is the measured value of the hydraulic pressure gauge 122. P2 is the pressure of the sub-tank 13, specifically the measured value of the pressure sensor 124 of the second pressure control unit 14 acquired in step S5. P3 is a pressure loss value occurring in the third flow path 21 from the branch portion BR to the sub-tank 13. Specifically, P3 is data that has been experimentally measured in advance by replenishing ink from the main tank 11 to the sub tank 13 and the pressure loss that occurs in the third flow path 21, and is stored in the storage section of the control section 100. If the magnitude of the pressure loss occurring in the third flow path 21 changes depending on the magnitude of (P1-P2), the pressure loss is measured while changing (P1-P2), and the pressure loss is measured while changing (P1-P2). ) and P3 may be expressed as a table or a mathematical expression and stored in the storage section of the control section 100.

In step S7, the control unit 100 checks whether the relationship of the above equation (1) is satisfied, and if it is not satisfied yet (step S7: NO), the control unit 100 steps from step S5 to step S7 until it is satisfied. repeat. If the relationship in equation (1) is satisfied (step S7: YES), the process proceeds to step S8, and the control unit 100 opens the valve 19 of the third flow path 21 to supply ink from the main tank 11 to the sub tank 13. replenish.

In this embodiment, when ink is replenished, (P1-P2) is controlled to be at least (100 [Pa] + P3), which is sufficient to cause ink to flow from the main tank 11 to the sub-tank 13. A suitable pressure difference is ensured. In addition, since (P1-P2) is controlled to be below (300 [Pa] + P3), it is possible to prevent pressure fluctuations in the sub-tank 13 from becoming excessive during ink replenishment, and the liquid that communicates with the sub-tank 13 can be Pressure fluctuations in the ejection head 3 can be suppressed. Therefore, even if the sub-tank 13 is replenished with ink while continuing to eject ink from the liquid ejection head 3, the printing quality will not deteriorate because fluctuations in the ejection characteristics are suppressed. That is, the liquid ejecting device 1 of this embodiment can supply ink from the main tank 11 to the sub tank 13 while maintaining printing quality without reducing printing production efficiency. Note that the values of 100 [Pa] and 300 [Pa] included as constants in equation (1) depend on the specific configuration of the second flow path, the time allowed for ink replenishment, and the background of the ejection characteristics of the ejection head. It can be changed as appropriate depending on pressure sensitivity, ink viscosity, etc.

When the control unit 100 detects that the predetermined amount of ink has been replenished into the sub-tank 13 by the liquid level sensor 125, the process proceeds to step S9, closes the valve 19 of the third flow path 21, and connects the first flow path 15 and the sub-tank. 13 connection is cut off.

In the following step S10, it is determined whether to continue ejecting ink. Unless there is a situation such as receiving a print stop command from the host device 110, ink is normally continued to be ejected (step S10: YES), so the process returns to step S3 and ejects while monitoring the remaining amount of ink in the sub-tank 13 again. Continue. In step S10, if a print stop instruction command is received from the host device 110 (step S10: NO), the process advances to step S11 and ink ejection is stopped.

As described above, according to the liquid ejection device of this embodiment, it is possible to supply liquid from the main tank to the sub tank without reducing printing production efficiency.

[Embodiment 2]
A liquid ejection device according to a second embodiment will be described. The liquid ejection device of the second embodiment differs from the liquid ejection device of the first embodiment in the configuration of the second flow path that supplies ink to the liquid ejection head. Regarding this embodiment, descriptions of matters common to Embodiment 1 will be simplified or omitted.

(overall structure)
The overall configuration of the liquid ejecting device according to the second embodiment is the same as that of the first embodiment described with reference to FIGS. 1(a) and 1(b), so the description thereof will be omitted.

(Ink supply system configuration)
With reference to FIG. 5, the configuration of the ink supply system of the liquid ejection device according to the second embodiment will be described. A first flow path 15 (first circulation path) for circulating the ink stored in the main tank 11 is shown on the left side of FIG. 5, and its configuration is the same as that of the first embodiment. That is, the main tank 11 , the first pump 17 , the filter 18 , the hydraulic pressure gauge 122 , and the branch portion BR to the third flow path 21 are connected in series to the first flow path 15 . A first pressure control unit 12 is connected to the main tank 11, and as described later, the control unit controls the drive of the first pressure control unit 12 to adjust the liquid pressure in the first flow path near the branch portion BR. can be controlled. Specifically, the first pressure control section 12 can be configured with a tube pump, a diaphragm pump, a piston pump, or the like. The first pump 17 is driven at all times except when maintaining the liquid ejection device 1, and the ink stored in the main tank 11 is constantly circulated through the first flow path 15 along the direction D1. There is. In addition, in order to improve the accuracy of hydraulic pressure control when replenishing ink from the main tank 11 to the sub-tank 13A, which will be described later, the hydraulic pressure gauge 122 is installed on the upstream side of the branch part BR in the direction of the circulating flow D1. It is preferable to place them nearby.

The part surrounded by the dotted line on the right side of FIG. 5 is a part mounted on the liquid ejection unit 2, and shows the second flow path 16 for supplying ink to the liquid ejection head 3. While the second flow path 16 in the first embodiment was a circulation path to which the sub-tank 13 was connected, the second flow path 16 in the present embodiment is a circulation path between the sub-tank 13A (sub-tank A) and the sub-tank 13B (sub-tank B). The difference is that it is a reciprocating flow path with a liquid ejection head 3 disposed between them.

A second pressure control section 14A is connected to the sub-tank 13A, and a second pressure control section 14B is connected to the sub-tank 13B. The control unit controls the driving of the second pressure control unit 14A and the second pressure control unit 14B to generate a pressure difference between the sub-tank 13A and the sub-tank 13B and supply ink to the liquid ejection head 3. If the pressure of the sub-tank 13A is made higher than that of the sub-tank 13B, the ink can be made to flow in the direction D3, and conversely, if the pressure of the sub-tank 13B is made higher than the sub-tank 13A, the ink can be made to flow in the direction D4. can. In this embodiment, ink is constantly made to flow between two sub-tanks using the second flow path 16 which is a reciprocating flow path, so that insoluble components settle or adhere to the ink supplied to the liquid ejection head 3. It is possible to prevent the concentration from becoming non-uniform.

Also in this embodiment, the first flow path 15 and the sub-tank 13A are connected by the third flow path 21 provided with the valve 19 that can be opened and closed. Specifically, the branch portion BR of the first flow path 15 and the sub-tank 13A are connected by the third flow path 21. As will be described later, the valve 19 provided in the middle of the third flow path 21 is opened when ink is replenished from the main tank 11 to the sub tank 13A, but is closed at other times.

(control system)
The configuration of the control system is the same as in Embodiment 1 described with reference to FIG. 3, except that there are two second pressure control units and two liquid level sensors because there are two sub-tanks.

(Operation of liquid discharge device)
The procedure of the ink supply operation performed in the liquid ejecting apparatus of this embodiment is basically the same as that of Embodiment 1 described with reference to the flowchart of FIG. However, in this embodiment, the flow of ink in the second flow path that is started in step S1 is not a circulating flow but a reciprocating flow.

Furthermore, in this embodiment, the measurement of the remaining amount of ink in step S3 involves calculating the total amount of remaining ink in both sub-tanks based on the measured value of the liquid level sensor of the sub-tank 13A and the measured value of the liquid level sensor of the sub-tank 13B. This is done by

Moreover, in this embodiment, the liquid pressure measurement of the 2nd flow path in step S5 is performed by measuring the pressure P2 of the sub-tank 13A with the pressure sensor with which 14 A of 2nd pressure control parts are provided. Then, in step S7, when determining whether the above-mentioned formula (1) is satisfied, the measured value of the pressure P2 of the sub-tank 13A is used as P2.

Also in this embodiment, when ink is replenished, (P1-P2) is controlled to be equal to or higher than (100 [Pa] + P3), so ink is not allowed to flow from the main tank 11 to the sub-tank 13A. A sufficient pressure difference is ensured. Furthermore, since (P1-P2) is controlled to be less than (300 [Pa] + P3), pressure fluctuations in the sub-tank 13A during ink replenishment can be suppressed, and the pressure of the liquid ejection head 3 communicating with the sub-tank 13A can be suppressed. It is possible to prevent pressure fluctuations from becoming excessive. Therefore, even if the sub-tank 13A is replenished with ink while continuing to eject ink from the liquid ejection head 3, the printing quality will not deteriorate because fluctuations in the ejection characteristics are suppressed. That is, the liquid ejecting device of this embodiment can supply ink from the main tank 11 to the sub tank 13A while maintaining printing quality without reducing printing production efficiency.

[Embodiment 3]
A liquid ejection device according to Embodiment 3 will be described. The liquid ejection apparatus 1 according to the first embodiment has a configuration in which ink is supplied from one main tank to one liquid ejection unit. In contrast, the present embodiment has a configuration in which ink can be replenished from one main tank to three liquid ejection units. Of course, a configuration may also be adopted in which two or four or more liquid ejection units are supplied with ink from one main tank.

(Ink supply system configuration)
The configuration of the ink supply system of the liquid ejection device according to the third embodiment will be described with reference to FIG. 6. On the left side of FIG. 6, a first flow path 15 (first circulation path) for circulating the ink stored in the main tank 11 is shown. The first channel 15 includes a main tank 11, a first pump 17, a filter 18, a hydraulic pressure gauge 122A, a branch to the third channel 21A, a hydraulic pressure gauge 122B, a branch to the third channel 21B, and a hydraulic pressure gauge. 122C and a branch portion to the third flow path 21C are connected in series. A first pressure control section 12 is connected to the main tank 11, and the control section controls the driving of the first pressure control section 12 to control the liquid pressure in the first flow path near each branch section. Can be done. Specifically, the first pressure control section 12 can be configured with a tube pump, a diaphragm pump, a piston pump, or the like. The first pump 17 is driven at all times except when maintaining the liquid ejection device, and the ink stored in the main tank 11 is constantly circulated through the first flow path 15 in the direction D1. . In order to improve the accuracy of hydraulic pressure control when replenishing ink from the main tank 11 to the sub-tanks of each liquid ejection unit, the hydraulic system at the branch part to each liquid ejection unit is operated from the branch part in the direction of the circulating D1. It is also preferable to arrange it on the upstream side near the branch.

On the right side of FIG. 6, parts mounted on three liquid ejection units are shown, but in order to distinguish between the three liquid ejection units, the reference numerals of each component are indicated by A and B at the end. , C. The ink supply system of each liquid ejection unit is similar to the ink supply system of the liquid ejection unit according to the first embodiment described with reference to the right side of FIG.

In this embodiment, each liquid ejection unit is driven independently, and when the amount of ink remaining in the sub-tank decreases, ink is replenished independently for each liquid ejection unit.

For example, the sub-tank 13A (may be called the second sub-tank), the second pump 20A, the second flow path 16A (may be called the fourth flow path), the liquid ejection head 3A (may be called the second liquid ejection section) , attention is paid to a liquid ejection unit including a second pressure control section 14A. When the remaining amount of ink in the sub-tank 13A in the liquid ejection unit decreases below a predetermined amount, ink is replenished from the main tank 11 to the sub-tank 13A via the third flow path 21A (also referred to as the fifth flow path). be done. At that time, before opening the valve 19A (which may also be referred to as a second flow path opening/closing means), in the same manner as in the first embodiment, the measured value of the pressure sensor provided in the second pressure control section 14A of the sub-tank 13A and the The first pressure control section 12 of the main tank 11 is controlled based on the measured value of the hydraulic pressure gauge 122A of the first flow path 15. Similar control is performed when ink is supplied to liquid ejection units whose reference numbers end in B or C.

In this embodiment, in a liquid ejection apparatus including a plurality of liquid ejection units, when ink is replenished into the subtank of any liquid ejection unit, (P1-P2) is (100 [Pa] + P3). Due to the above control, a pressure difference sufficient to cause ink to flow from the main tank 11 to the sub tank is ensured. In addition, since (P1-P2) is controlled to below (300 [Pa] + P3), it is possible to prevent pressure fluctuations in the sub-tank from becoming excessive during ink replenishment, and the liquid ejection head that communicates with the sub-tank pressure fluctuations can be suppressed. Therefore, even if the sub-tank is replenished with ink while continuing to eject ink from the liquid ejection head, the printing quality will not deteriorate because fluctuations in the ejection characteristics are suppressed. Further, in this embodiment, while the sub-tank of any liquid ejection unit is being replenished with ink, the ink supply system (second flow path) of another liquid ejection unit is connected to the first flow path by the valve of the third flow path. separated from Therefore, other liquid ejection units can continue to eject ink without being affected by the replenishment operation to any liquid ejection unit.

In this manner, in the liquid ejection apparatus of this embodiment, it is possible to supply ink from the main tank 11 to any liquid ejection unit while maintaining printing quality without reducing printing production efficiency. In other words, since ink can be replenished while ensuring pressure controllability of the liquid ejection head, it is possible to improve productivity by using multiple heads.

[Other embodiments]
Note that the present invention is not limited to the embodiments and examples described above, and many modifications can be made within the technical idea of the present invention. For example, the different embodiments and examples described above may be combined and implemented.

For example, in the embodiment described above, the third flow path 21 was configured to connect the first flow path 15 and the sub-tank 13, but the third flow path 21 was configured to connect the first flow path 15 and the second flow path 16 near the sub-tank 13. It is also possible to have a configuration in which In short, any configuration that can replenish ink from the main tank to the sub tank is sufficient.

Furthermore, in the third embodiment, a plurality of liquid ejection units having the same configuration as in the first embodiment are provided for one main tank, but a plurality of liquid ejection units similar to the second embodiment may be provided. Alternatively, one main tank may be provided with both a liquid ejection unit having the same configuration as in Embodiment 1 and a liquid ejection unit having the same configuration as in Embodiment 2.

Embodiments of the present invention also include "methods for manufacturing articles" in which articles are manufactured by ejecting ink containing raw materials for functional thin films or functional elements using the liquid ejection apparatus or the liquid ejection method of the embodiments. It will be done.

The present invention provides a process in which a program that implements one or more functions of the embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. But it is possible. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

1...Liquid ejection device/2...Liquid ejection unit/3, 3A, 3B, 3C...Liquid ejection head/4...Main scanner/5...Main scanning guide rail/6...・Recording medium/7...Sub-scanning guide rail/8...Support member/9...Base/10...Stage/11...Main tank/12...First pressure control section/ 13, 13A, 13B, 13C...Sub tank/14, 14A, 14B...Second pressure control section/15...First flow path/16, 16A, 16B, 16C...Second flow path/ 17...First pump/18...Filter/19, 19A, 19B, 19C...Valve/20, 20A, 20B, 20C...Second pump/21, 21A, 21B, 21C... Third flow path/100...Control unit/101...CPU/102...ROM/103...RAM/104...I/O interface/110...Host device/122, 122A, 122B , 122C...hydraulic pressure gauge

Claims (23)

a first flow path which is a first circulation path to which the main tank is connected;
a second channel to which the sub-tank and the liquid discharge section are connected;
a third flow path connecting the first flow path and the sub-tank and including a flow path opening/closing means;
comprising a control unit;
The control unit includes:
Opening the channel opening/closing means while circulating ink in the first channel, and replenishing ink from the main tank to the sub tank via the third channel while discharging ink from the liquid ejecting section;
When replenishment of ink from the main tank to the sub tank is completed, closing the flow path opening/closing means;
A liquid ejection device characterized by: The control unit opens the flow path opening/closing means when a difference between the liquid pressure in the first flow path and the pressure in the sub-tank is within a predetermined range.
The liquid ejection device according to claim 1, characterized in that: The control unit opens the channel opening/closing means when the following formula (1) is satisfied.
The liquid ejection device according to claim 1 or 2, characterized in that:
100[Pa]+P3≦P1-P2≦300[Pa]+P3...Formula (1)
P1 is the hydraulic pressure in the first channel.
P2 is the pressure of the sub-tank.
P3 is a pressure loss occurring in the third flow path. The control unit controls the pressure of the main tank so that the difference between the liquid pressure of the first flow path and the pressure of the sub tank is within a predetermined range before opening the flow path opening/closing means.
The liquid ejecting device according to any one of claims 1 to 3, characterized in that: The control unit controls the pressure of the main tank so that the following formula (2) is satisfied before opening the flow path opening/closing means.
The liquid ejection device according to any one of claims 1 to 4, characterized in that:
100[Pa]+P3≦P1-P2≦300[Pa]+P3...Formula (2)
P1 is the hydraulic pressure in the first channel.
P2 is the pressure of the sub-tank.
P3 is a pressure loss occurring in the third flow path. The second flow path is a second circulation path to which the sub-tank and the liquid discharge section are connected.
The liquid ejection device according to any one of claims 1 to 5. The sub-tank includes a sub-tank A and a sub-tank B,
The second flow path is a reciprocating flow path capable of reciprocating ink between the sub-tank A and the sub-tank B,
the third flow path connects the first flow path and the sub-tank A;
The liquid ejection device according to any one of claims 1 to 5. a fourth flow path connected to a second sub-tank and a second liquid discharge part;
Further comprising: a fifth flow path including a second flow path opening/closing means and connecting the first flow path and the second sub-tank;
The liquid ejecting device according to any one of claims 1 to 7. the ink is an ink containing insoluble particles;
The liquid ejection device according to any one of claims 1 to 8. The ink is an ink containing a functional material for forming a functional thin film or a functional element.
The liquid ejection device according to any one of claims 1 to 9. a first flow path which is a first circulation path to which the main tank is connected;
a second channel to which the sub-tank and the liquid discharge section are connected;
a third flow path connecting the first flow path and the sub-tank and including a flow path opening/closing means;
A liquid ejection method using a liquid ejection device comprising:
Opening the channel opening/closing means while circulating ink in the first channel, and replenishing ink from the main tank to the sub tank via the third channel while discharging ink from the liquid ejecting section;
When replenishment of ink from the main tank to the sub tank is completed, closing the flow path opening/closing means;
A liquid discharging method characterized by: opening the flow path opening/closing means when the difference between the liquid pressure in the first flow path and the pressure in the sub-tank is within a predetermined range;
12. The liquid ejection method according to claim 11. opening the flow path opening/closing means when the following formula (1) is satisfied;
The liquid ejection method according to claim 11 or 12, characterized in that:
100[Pa]+P3≦P1-P2≦300[Pa]+P3...Formula (1)
P1 is the hydraulic pressure in the first channel.
P2 is the pressure of the sub-tank.
P3 is a pressure loss occurring in the third flow path. Before opening the flow path opening/closing means, controlling the pressure of the main tank so that the difference between the liquid pressure of the first flow path and the pressure of the sub tank is within a predetermined range.
The liquid ejection method according to any one of claims 11 to 13. Before opening the channel opening/closing means, controlling the pressure of the main tank so that the following formula (2) is satisfied;
The liquid ejection method according to any one of claims 11 to 14.
100[Pa]+P3≦P1-P2≦300[Pa]+P3...Formula (2)
P1 is the hydraulic pressure in the first channel.
P2 is the pressure of the sub-tank.
P3 is a pressure loss occurring in the third flow path. The second flow path is a second circulation path to which the sub-tank and the liquid discharge section are connected.
The liquid ejection method according to any one of claims 11 to 15. The sub-tank includes a sub-tank A and a sub-tank B,
The second flow path is a reciprocating flow path capable of reciprocating ink between the sub-tank A and the sub-tank B,
the third flow path connects the first flow path and the sub-tank A;
The liquid ejection method according to any one of claims 11 to 15. a fourth flow path connected to a second sub-tank and a second liquid discharge part;
Further comprising: a fifth flow path including a second flow path opening/closing means and connecting the first flow path and the second sub-tank;
The liquid ejection method according to any one of claims 11 to 17. the ink is an ink containing insoluble particles;
The liquid ejection method according to any one of claims 11 to 18. The ink is an ink containing a functional material for forming a functional thin film or a functional element.
The liquid ejection method according to any one of claims 11 to 19. A method for manufacturing an article, comprising discharging ink containing a raw material for a functional thin film or a functional element onto a substrate by the liquid discharging method according to claim 20. A control program for causing a computer that controls the liquid ejection device to execute the liquid ejection method according to any one of claims 11 to 20. A computer-readable recording medium recording the control program according to claim 22.

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