Inkjet recording apparatus and management method of inkjet recording apparatus

Abstract

In the inkjet recording apparatus of the present invention, ink solidification during a stop period can be prevented, and if the viscosity of the ink in the main ink container deviates from an appropriate viscosity range, the viscosity of the ink can be adjusted to be within an appropriate range. The configuration controls the printhead and main body such that, at regular intervals during a printhead stop period, solvent stored in the solvent container is repeatedly supplied to the printhead and returned to the ink container via a circulation path and a recovery path. Furthermore, if the viscosity of the ink measured by the viscosity measuring unit is higher than a predetermined range, while the printhead is mounted in the printhead mounting unit, a portion of the ink stored in the ink container is discarded from the printhead to the interior of the printhead mounting unit via a supply path, and solvent stored in the solvent container is supplied to the ink container, thereby reducing the viscosity of the ink stored inside the ink container.

Description

Technical Field

[0001] This invention relates to an inkjet recording device and a method for managing the inkjet recording device. Background Technology

[0002] As an inkjet recording device used for printing text or graphics on products conveyed by a production line conveyor, a non-contact inkjet recording device is used where the nozzles of the printhead do not contact the printed object, but rather the ink is propelled from the nozzles towards the printed object. For example, when printing text on the surface of packaging materials such as corrugated cardboard boxes used to package goods, the inkjet recording device prints on the outer surface of the packaging material while it is being conveyed by a conveyor belt; similarly, when printing on containers holding food and beverages, the inkjet recording device prints on the outer surface of the container while it is being conveyed by a conveyor belt.

[0003] In the printhead of such an inkjet recording device, there are charged electrodes that impart a charge to ink particles ejected from the nozzles corresponding to the printed information, and deflection electrodes that deflect the charged ink particles. A flow channel is arranged opposite the nozzles to recover ink not used for printing. The nozzles are connected to an ink supply path that supplies ink to an ink container, and a recovery path is connected between the flow channel and the ink container to recover the ink recovered by the flow channel back to the ink container. Furthermore, to prevent nozzle clogging by drawing external air into the nozzles, a suction path is connected between the nozzle inlet and the ink container. Finally, a solvent supply path is connected between the solvent container and the nozzles to clean the nozzles and the aforementioned paths.

[0004] The inkjet recording device also has a main body with an ink container and a solvent container installed, and a printhead is connected to the main body by a conduit with tubing such as hoses that form various paths.

[0005] As an existing inkjet recording device, Patent Document 1 discloses "an inkjet recording device comprising an ink container for storing ink for printing on an object, a nozzle connected to the ink container for ejecting pressurized ink, a charged electrode for charging ink particles ejected from the nozzle, a deflection electrode for deflecting the ink particles charged by the charged electrode, a flow channel for collecting ink not used for printing, a solvent container for storing solvent, and a liquid nozzle connected to the solvent container for ejecting pressurized solvent, wherein the liquid nozzle has a liquid flow path extending from the nozzle toward the flow channel and a liquid ejection orifice formed at an angle through which the pressurized solvent reaches the nozzle."

[0006] Furthermore, Patent Document 2 discloses "an inkjet recording apparatus comprising an ink container for storing ink for printing on an object, a nozzle connected to the ink container for ejecting pressurized ink, an electrode for charging ink particles ejected from the nozzle, an electrode for generating an electrode signal that charges the electrode, a deflection electrode for deflecting the charged ink particles, a flow channel for collecting ink not used for printing, and a control unit for controlling the operation of the entire apparatus, wherein a first charge detection unit is provided for detecting the amount of charge on the ink particles between the electrode and the deflection electrode, and a second charge detection unit is provided for detecting the amount of charge on the ink particles flowing in the flow channel."

[0007] Furthermore, Patent Document 3 discloses "an inkjet recording apparatus comprising a nozzle for ejecting generated ink particles, a charged electrode for charging the ejected ink particles to form a signal of text or image, a deflection electrode for deflecting the charged ink particles, a flow channel for capturing ink particles not used to form text or image, a main ink container into which the ink particles captured by the flow channel return to be used again to form text or image, an ink replenishment unit for replenishing the main ink container with the amount of replenishing ink consumed in forming text or image, and a replenishing fluid replenishment unit for replenishing the main ink container with the amount of replenishing fluid evaporated, wherein a liquid volume detection unit is included to detect the amount of ink accumulated in the main ink container, the liquid volume detection unit being capable of detecting multiple liquid level levels including upper, middle, and lower, and selecting the liquid level to be detected in accordance with the ambient temperature."

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2020-49786

[0011] Patent Document 2: Japanese Patent Application Publication No. 2019-123117

[0012] Patent Document 3: Japanese Patent Application Publication No. 2007-62071 Summary of the Invention

[0013] The problem that the invention aims to solve

[0014] When the inkjet recording device is stopped, and the ink and solvent remain in a state of no flow for an extended period, the ink accumulated in the circulation path may solidify, and there is a possibility that even when the device is started, the circulating ink may not flow normally.

[0015] In addition, when the inkjet recording device is used for a long time due to repeated printing and head cleaning, the viscosity of the ink in the main ink container may change, deviating from the appropriate viscosity range, or becoming higher or lower.

[0016] Patent documents 1 to 3 do not describe measures to prevent ink from solidifying when such a device remains in a stopped state for an extended period, nor do they describe measures to adjust the viscosity of the ink in the main ink container to a suitable range when the viscosity deviates from the appropriate viscosity range.

[0017] The present invention addresses the problems of the prior art by providing an inkjet recording device and a management method for the inkjet recording device, configured to prevent ink from solidifying when the device is not in use, and to adjust the viscosity of the ink in the main ink container to a suitable range when the viscosity deviates from a suitable range.

[0018] Technical solutions for solving the problem

[0019] To address the aforementioned issues, the present invention provides an inkjet recording apparatus comprising: a printhead for printing an object, having nozzles for discharging ink; a main body comprising: an ink container for storing ink supplied to the printhead, a solvent container for storing solvent, a supply path for supplying ink from the ink container to the printhead, a circulation path having a circulation pump for returning a portion of the ink supplied to the printhead to the ink container, a recovery path having a recovery pump for attracting ink ejected from the nozzles of the printhead and recovering the ink to the ink container, and a viscosity measuring unit for measuring the viscosity of the ink stored in the ink container; a printhead mounting unit for mounting the printhead; and a control unit for controlling the printhead and the main body, the control unit being configured to control the printhead and the main body when the viscosity of the ink measured by the viscosity measuring unit deviates from a predetermined range, thereby causing the viscosity of the ink to converge to the predetermined range. In addition, to solve the above-mentioned problems, the present invention is configured as an inkjet recording device, comprising: a printhead for printing on a printing object, having nozzles for discharging ink; a main body comprising: an ink container for storing ink supplied to the printhead, a solvent container for storing solvent, a supply path for supplying ink from the ink container to the printhead, a circulation path for returning a portion of the ink supplied to the printhead to the ink container, and a recovery path for attracting ink ejected from the nozzles of the printhead and recovering the ink to the ink container; and a control unit for controlling the printhead and the main body, the control unit controlling the printhead and the main body during a period when printing on the printing object is stopped, such that at regular intervals during the period when printing is stopped, the operation of supplying solvent stored in the solvent container to the printhead and returning the solvent to the ink container via the circulation path and the recovery path is repeatedly performed.

[0020] The effects of the invention

[0021] According to the present invention, by supplying solvent to the printhead and spraying solvent from the nozzle, the liquid can be made to circulate through a circulation path, thereby improving the effect of preventing solidification.

[0022] Furthermore, according to the present invention, in an inkjet recording apparatus, the viscosity of the ink in the main ink container can be automatically adjusted, including cases with high viscosity and cases with low viscosity. Attached Figure Description

[0023] Figure 1 This is a perspective view showing the use of the inkjet recording device in the embodiment.

[0024] Figure 2 This is a path diagram illustrating the path structure of the flowing ink or solvent in the inkjet recording device of the embodiment.

[0025] Figure 3 This is a block diagram showing the structure of the control unit of the inkjet recording device in the embodiment.

[0026] Figure 4 This is a flowchart of the process for preventing ink from solidifying in the inkjet recording device of the embodiment.

[0027] Figure 5 This is a path diagram illustrating the path of the flowing ink during the measurement of ink viscosity in the process of preventing ink caking in the inkjet recording device of the embodiment.

[0028] Figure 6 This is a path diagram illustrating the path of supplying solvent to the printhead and recovering it during the process of preventing ink from solidifying in the inkjet recording device of the embodiment.

[0029] Figure 7 This is a path diagram illustrating the path taken during the process of preventing ink from solidifying in the inkjet recording device of the embodiment, when measuring the viscosity of the ink while circulating the ink within the main body.

[0030] Figure 8 This is a flowchart illustrating the process of adjusting the viscosity of the ink in the inkjet recording device of the embodiment to bring the viscosity of the ink within a certain range.

[0031] Figure 9 This is a path diagram illustrating the path structure of the inkjet recording device in the embodiment, showing the state of measuring the viscosity of the ink.

[0032] Figure 10 This is a path diagram illustrating the path structure of the inkjet recording device in the embodiment, which adjusts the viscosity of the ink to a certain range when the ink viscosity is high, and circulates the ink through the printhead.

[0033] Figure 11 This is a path diagram illustrating the path structure of the inkjet recording device in the embodiment, in the process of adjusting the viscosity of the ink to a certain range when the ink viscosity is high, so that the ink is discharged from the printhead.

[0034] Figure 12 This is a path diagram illustrating the path structure of the inkjet recording device in the embodiment, which adjusts the viscosity of the ink to a certain range when the ink viscosity is high, and supplies solvent to the main ink container while circulating the ink.

[0035] Figure 13 This is a path diagram illustrating the path structure of the inkjet recording device in the embodiment, which adjusts the viscosity of the ink to a certain range when the ink viscosity is high, and measures the viscosity of the ink in the main ink container while circulating the ink.

[0036] Figure 14 This is a path diagram showing the path structure of the ink circulation path, including the printhead, in the inkjet recording device of the embodiment, in the state of cleaning the ink circulation path.

[0037] Figure 15 This is a path diagram showing the path structure of the inkjet recording device in the embodiment, in the state of fine cleaning of the printhead.

[0038] Figure 16 This is a path diagram illustrating the process of adjusting the viscosity of the ink to a certain range when the ink viscosity is low in the inkjet recording device of the embodiment, and measuring the viscosity of the ink in the main ink container while replenishing ink from the auxiliary ink container to the main ink container via the printhead.

[0039] Figure 17 This is a front view of the operation display section in the embodiment, which shows the initial and adjusted values ​​of the ink viscosity display area. Detailed Implementation

[0040] In this invention, when the inkjet recording device is stopped, solvent is supplied to the printhead and ejected from the nozzle at regular intervals, thereby enabling the liquid to flow through the circulation path.

[0041] Furthermore, in this invention, the inkjet recording device can automatically adjust the viscosity according to the conditions of higher and lower viscosity when the viscosity of the ink deviates from a predetermined range.

[0042] Furthermore, in this invention, when the viscosity of the ink in the inkjet recording device becomes higher than a predetermined range, the viscosity of the ink can be adjusted to an appropriate range simply by discarding a portion of the ink contained in the main ink container in accordance with the viscosity of the ink. Therefore, it is not necessary to discard all the ink in the main ink container and replace it with new ink, which can reduce the amount of ink wasted and increase the effective amount of ink used.

[0043] Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. In all the drawings used to illustrate these embodiments, the same reference numerals are used for parts with the same function, and repeated descriptions are generally omitted.

[0044] However, this invention is not limited to the description of the embodiments shown below. It will be readily understood by those skilled in the art that the specific structure can be modified without departing from the spirit or essence of this invention.

[0045] Example 1

[0046] <Usage Status>

[0047] First, regarding the usage state of the inkjet recording device in Embodiment 1 of the present invention, using... Figure 1 Please provide an explanation. Figure 1 This is a perspective view showing the use of the inkjet recording device in Embodiment 1 of the present invention.

[0048] Figure 1 In the inkjet recording devices 600A and 600B, the structure is identical, comprising a main body 1, a printhead 2 connected to the main body 1 via a cable (for the printhead) 5, and a printhead mounting unit 3 connected to the main body 1 via a cable (for the printhead mounting unit) 6. Here, the printhead mounting unit 3 primarily functions to house the printhead, but it can also be used to clean the printhead by spraying cleaning fluid.

[0049] The head mounting unit 3 described below has a structure that adds a function for cleaning the printhead. For the inkjet recording device 600A, the state in which the printhead 2 is set in the production line is shown. In addition, for the inkjet recording device 600B, the state in which the printhead 2 is removed from the production line and installed (set) in the head mounting unit 3 is shown.

[0050] In addition, the recycling container 4 installed at the bottom of the head mounting unit 3 is provided to collect the liquid (cleaning fluid) after the printhead is cleaned by the head mounting unit 3.

[0051] The inkjet recording device 600A is installed, for example, in a production line within a factory producing food, beverages, etc., with the main body 1 positioned in a location with sufficient space to ensure regular maintenance. The printhead 2 is fixed to a printhead mounting member 13 located near the conveyor belt 11, and is positioned close to it for printing objects 12A and 12B that are being conveyed along the production line in the direction of arrow X, such as the conveyor belt 11. Furthermore, a protective cover 17 is installed on the printhead 2 to protect the internal components. The image shows the object 12B after printing with the printhead 2 has finished and is being conveyed along the conveyor belt 11.

[0052] in addition, Figure 1 In this design, the main body 1 stores (holds) the ink for printing, and the drive unit (pump and solenoid valve) inside the main body supplies ink to the print head 2 via cable (for the print head) 5. Details regarding the internal path structure and control unit of the main body 1 will be described later. An operation display unit 8 is located on the top surface of the main body 1; this is a touch-input display panel. The operator can touch the operation display unit 8 to start or stop the control unit's indicator device, set the content to be printed on the object 12A, or display information about the ink viscosity before and after adjustment. Furthermore... Figure 1 In the text, 16 in printhead 2 represents the printhead base.

[0053] The printhead mounting unit 3 is disposed around the printhead 2. The printhead mounting unit 3 in the inkjet recording apparatus 600A is fixed by combining the fitting portion 93 mounted on the printhead mounting unit 3 with the fixing clamp 92 mounted on the conveyor belt 11. Furthermore, the printhead mounting unit 3 has a printhead mounting portion 81A for mounting the printhead 2. Additionally, the printhead mounting unit 3 has a start button 18 for initiating the cleaning process of the printhead 2, a stop button 19 for stopping the cleaning process of the printhead 2, and a display unit 15 for the operator to identify confirmation messages, alarms, abnormalities, and other alerts. This display unit 15 can, for example, allow the operator to identify the operating status or any abnormalities by whether a light is illuminating or by a difference in color.

[0054] In this embodiment of the inkjet recording apparatus 600A, the head mounting unit 3 is fixed near the conveyor belt 11, but the head mounting unit 3 can be freely moved to a location easily accessible to the user. Furthermore, regarding the length of the cable 6 (for the head mounting unit) connecting the main body 1 to the head mounting unit 3, it is preferably the same as or longer than the cable 5 connecting the main body 1 of the inkjet recording apparatus 600 to the printhead 2. This is to ensure flexibility in the configuration of the head mounting unit.

[0055] Furthermore, the main body 1 has a fixing part 91 for fixing the head mounting unit 3, and the head mounting unit 3 can also be removed from the fixing clamp (for conveyor belt) 92 and replaced with the fixing part 91 for use. This state is shown for the inkjet recording device 600B.

[0056] In the inkjet recording apparatus 600B, the head mounting unit 3 is shown to be fixed to the main body 1 by combining the fitting part 93 with the fixing part 91 mounted on the main body 1. This allows the head mounting unit 3 to be fixed to the main body 1, enabling it to be installed even when there is no space for installation near the conveyor belt 11 or elsewhere.

[0057] Next, the state in which the printhead 2 is mounted on the head mounting unit 3 in the inkjet recording apparatus 600B will be described. The printhead 2 is mounted on the head mounting portion 81A of the head mounting unit 3, starting from the front end of the printhead 2. In this embodiment, by mounting the printhead 2 on the head mounting unit 3 in this way, the inkjet recording apparatus 600B can clean the printhead 2 with solvent 69A supplied from the main body 1 via the cable (for the head mounting unit) 6.

[0058] In the inkjet recording apparatus 600A, the printhead 2 can also be cleaned when the printhead 2 is mounted on the head mounting unit 3, which is fixed by combining the fitting part 93 with the fixing clamp 92 mounted on the conveyor belt 11.

[0059] <Path Structure>

[0060] Next, regarding the inkjet recording device 600 in Embodiment 1 (which will... Figure 1 The inkjet recording devices 600A and 600B shown are collectively referred to as inkjet recording device 600), and their path structure is described using... Figure 2 Please provide an explanation. Figure 2 This is a diagram showing the overall path structure of the inkjet recording device 600 in this embodiment.

[0061] First, the ink supply path (paths 801 to 803) of the inkjet recording device 600 in Example 1 will be described. Figure 2 In the main body 1, there is a main ink container 31 for storing ink 68A for printing. The main ink container 31 has a liquid level sensor 31A (sensor 1) for detecting that the liquid (ink 68A) in the main ink container 31 exceeds the appropriate amount, i.e., the reference liquid level, for maintaining it inside; a liquid level sensor 31B (sensor 2) for detecting whether the appropriate amount, i.e., the reference liquid level, has been reached; and a liquid level sensor 31C (sensor 3) for detecting the endpoint of the amount of ink discarded when ink is discarded from the main ink container 31.

[0062] The portion of the main ink container 31 immersed in ink 68A is connected to a path (supply) 801, along which a solenoid valve (supply) 49 for opening and closing the path is installed. Furthermore, path 801 is connected via a manifold 901 to a pump (supply) 34, located in path 802, for drawing and pumping ink 68A. Then, at the output side of the pump (supply) 34, a filter (supply) 39 is connected to remove foreign matter mixed into the ink 68A.

[0063] The filter (supply) 39 is connected to a pressure regulating valve 46 that adjusts the pressure of the ink 68A pumped from the pump (supply) 34 to a pressure suitable for printing. The pressure regulating valve 46 is connected to a pressure sensor 38 that measures the pressure of the ink 68A supplied to the nozzle 21. The path 802 in which the pressure regulating valve 46 is located is connected via a branch path 921 to a path 803 within the cable (printhead) 5. The path 803 is connected to a solenoid valve 26 located within the printhead 2 for controlling whether to supply ink 68A to the nozzle 21.

[0064] A heater 20 is provided in front of the solenoid valve (for switching) 26 to heat the ink 68A supplied to the nozzle 21 to an optimal temperature. The heater 20 has a temperature sensor for heating control inside (not shown).

[0065] The solenoid valve (switching) 26 is connected to the nozzle 21 that ejects ink 68A via the filter 27. Furthermore, the solenoid valve (switching) 26 is a three-way solenoid valve, connecting the ink supply path 803 and the nozzle cleaning path 825, enabling switching between the supply of ink 68A and solvent 69A to the nozzle 21. In the straight-line direction of the ink particles 68B ejected from the nozzle 21, a charged electrode 23 is provided for applying a predetermined amount of charge to the ink particles 68B, a deflection electrode 24 is provided for deflecting the ink particles 68B used in printing, and a flow channel 25 is provided for capturing ink particles 68B that are not charged and deflected because they are not used for printing, and which are flying in a straight line.

[0066] Next, the ink recovery paths 811 and 812 of the inkjet recording device 600 will be described. Figure 2 In the middle, the flow channel 25 is connected to the path 811, in which a charge sensor 48 is configured to detect whether ink particles 68B with an added charge by the charged electrode 23 have been recovered. Then, the path 811 passes through the cable (for the printhead) 5 and is connected to the filter (for recovery) 40 configured in the main body 1 to remove foreign matter mixed in with the ink. The filter (for recovery) 40 is connected to the solenoid valve (for recovery) 50 that opens and closes the path.

[0067] A solenoid valve (for recovery) 50 is configured in path 812, connected via manifold 902, and is connected to a pump (for recovery) 35 that draws ink particles 68B captured by flow channel 25. Pump (for recovery) 35 is connected to the main ink container 31. By opening the solenoid valve 50, the pump (for recovery) 35 is driven, and the ink particles 68B captured by flow channel 25 are recovered from path 811 through path 812 to the main ink container 31.

[0068] Next, the exhaust path (path 814) of the inkjet recording device 600 in this embodiment will be described. The main ink container 31 is connected to the path 814 in the upper space where it is not in contact with the ink 68A. The path 814 adopts a structure that is connected to the exhaust duct connection 62 which communicates with the outside of the main body 1.

[0069] Next, the ink circulation paths (paths 821 and 822) of the inkjet recording apparatus 600 in this embodiment will be described. The nozzle 21, located within the printhead 2, is connected not only to the path through which ink 68A is supplied via the filter 27, but also to path 821 within the cable (for the printhead) 5. A solenoid valve (for circulation) 59, located within the main body 1, is disposed in path 821 to open and close the path (flow path). The solenoid valve (for circulation) 59 is connected to path 822 via a manifold 903, and a pump (for circulation) 36, which draws ink from the nozzle 21, is disposed in path 822. Furthermore, the pump (for circulation) 36 is connected to the main ink container 31 via path 822.

[0070] Next, the paths (824 and 822) for viscosity measurement in the inkjet recording device 600 of this embodiment will be described. Figure 2 In the middle, the portion of the main ink container 31 immersed in ink 68A is connected to the path (for viscosity measurement) 824.

[0071] The path (for viscosity measurement) 824 is connected to the filter (for viscosity measurement) 42 for removing foreign matter mixed in with the ink 68A supplied from the main ink container 31, and then connected to the viscosity meter 45 in order to know the viscosity of the ink 68A in the main ink container 31.

[0072] The viscosity meter 45 is connected to a solenoid valve 57 for opening and closing the path. The solenoid valve 57 is connected to a pump 36 (for circulation) arranged in path 822 via a manifold 903.

[0073] This allows the ink 68A within the main ink container 31 to circulate in the viscosity measurement path, and the viscosity of the ink 68A is measured using a viscosity meter 45. Information about the measured viscosity is input to the control unit 7 for viscosity control of the ink 68A within the main ink container 31.

[0074] Next, the solvent replenishment paths (paths 831 and 833) of the inkjet recording device 600 in this embodiment will be described. Figure 2 In the main body 1, there is a solvent container 33 that stores solvent 69A used for replenishing solvent to ink container 31, cleaning nozzles, and cleaning head. A solvent box 69B containing the solvent for replenishment is installed in the solvent container 33.

[0075] The portion of solvent container 33 immersed in solvent 69A is connected to path 831, in which a pump (solvent) 37 for drawing and pressurizing solvent is arranged. The pump (solvent) 37 is connected to branch path 922 to change the destination of solvent 69A according to the purpose.

[0076] Branch path 922 is connected to solenoid valve (solvent replenishment) 53 in the solvent replenishment path for opening and closing the path configured in path 833. Solenoid valve (solvent replenishment) 53 is connected to the main ink container 31 via path 833. Using paths 831 to 833, the viscosity of ink 68A in the main ink container 31 is controlled by control unit 7.

[0077] Furthermore, inside the solvent container 33, as the solvent 69A evaporates and the pressure inside the solvent container 33 increases, in order to discharge the evaporated solvent to the outside, the solvent container 33 is connected to the exhaust pipe connection 62 by the exhaust path 816.

[0078] Next, the ink replenishment path 806 of the inkjet recording device 600 in this embodiment will be described. Figure 2 In the main body 1, there is an auxiliary ink container 32 for holding replenished ink 68C. An ink cartridge 68D for holding replenished ink is installed on the auxiliary ink container 32.

[0079] The portion of the auxiliary ink container 32 immersed in ink 68C is connected to path 806. In path 806, a solenoid valve (for ink replenishment) 54, which controls the opening and closing of the path, is connected. The solenoid valve (for ink replenishment) 54 is connected via a manifold path 901 to a pump (for supply) 34 located in path 802, which draws and pressurizes the ink 68C. Then, with the solenoid valve (for ink replenishment) 54 open and the solenoid valve (for supply) 49 closed, the ink 68C in the auxiliary ink container 32 is ejected from nozzle 21 through paths 802-803, and replenishes the main ink container 31 via flow channel 25, path 811, solenoid valve 50, and pump 35.

[0080] Furthermore, inside the auxiliary ink container 32, when the solvent in the ink 68C evaporates and the pressure inside the auxiliary ink container 32 increases, the auxiliary ink container 32 is connected to the exhaust pipe connection 62 via the exhaust path 815 in order to discharge the evaporated solvent to the outside.

[0081] Next, the nozzle cleaning paths (paths 831 and 825) of the inkjet recording device 600 in this embodiment will be described. Figure 2 In this configuration, the pump (solvent) 37, configured in path 831, is connected to path 825 via branch path 922. Path 825 is connected to a solenoid valve (nozzle cleaning) 55 for opening and closing the path. The solenoid valve (nozzle cleaning) 55 is connected to a filter (nozzle cleaning) 41 for removing foreign matter mixed into the solvent 69A. The filter (nozzle cleaning) 41 is connected via path 821 within the cable (printhead) 5 to a solenoid valve (switching) 26 located within the printhead 2 for controlling whether to deliver cleaning solvent 69A to the nozzles 21.

[0082] Next, the main circulation paths (paths 808 and 812) of the inkjet recording apparatus 600 in this embodiment will be described. Path 802 is connected to path 808 via branch path 921. In path 808, a solenoid valve (for main circulation) 58 is connected to open and close the path, and the solenoid valve (for main circulation) 58 is connected to a pump (for circulation) 35 provided in path 812 via a busbar path 902.

[0083] Next, the head cleaning paths (paths 831 and 837) of the inkjet recording device 600 in this embodiment will be described. Figure 2 In the middle, the pump (solvent) 37 is connected to the path 837 via the branch path 922. The path 837 is equipped with a solenoid valve (head cleaning) 56 for opening and closing the path. The solenoid valve (head cleaning) 56 is connected to the filter (head cleaning) 43 for removing foreign matter mixed in the solvent 69A.

[0084] The recovery container 4 installed in the head-mounting unit 3 is designed to collect the solvent remaining after cleaning with the cleaning fluid (solvent) sprayed from the cleaning nozzle 72 installed in the cleaning tank 71 of the head-mounting unit 3. Inside the recovery container 4, a float 74 with a built-in magnet is installed to detect the level of the solvent after cleaning. On the outside of the recovery container 4, magnetic sensors 76A and 76B, and a magnet 75 are installed to detect the amount of solvent accumulated inside the recovery container 4. When the float 74 with the built-in magnet 75 reaches the specified level, the magnetic sensor A76 detects the magnetic field of the built-in magnet 75 in the float 74 and outputs a message to the control unit 7 indicating that the cleaning fluid in the recovery container 4 has reached the specified level.

[0085] Next, the air supply path (path 841) of the inkjet recording device 600 in this embodiment will be described. Figure 2 The main body 1 includes a pump (for drying) 60 for drawing and compressing air, and an air intake port communicating with the interior of the main body 1 is formed in the pump (for drying) 60. The pump (for drying) 60 is connected to the head mounting unit 3 via a path 841 through a cable (for head mounting unit) 6.

[0086] Next, the air suction path (path 843) of the inkjet recording apparatus 600 in this embodiment will be described. In the cleaning tank 71 provided within the head mounting unit 3, air is drawn and compressed via path 843 through the cable (for the head mounting unit) 6 to a pump (suction pump) 61 provided within the main body 1. The pump (suction pump) 61 is connected to an exhaust duct connection 62 that communicates with the outside of the main body 1.

[0087] <Structure of the Control Unit>

[0088] Next, the structure of the control unit 7 of the inkjet recording device 600 in this embodiment will be described. Figure 3 This is a diagram showing the schematic structure of the control unit 7 and the printing mechanism (main body 1 and print head 2) of the inkjet recording device 600 in this embodiment. Figure 3 In this context, 301 is the control unit, or microprocessor unit (hereinafter referred to as MPU), that controls the entire inkjet recording device 600.

[0089] 302 is a bus that functions to transmit data and control signals between the various devices that make up the control unit. For example, bus 302 is used to input data and detection signals required for the operation of MPU 301 from each machine, and to transmit data signals, address signals and control signals to each device.

[0090] 306 is a read-only memory (ROM) that stores the control program and data required for the operation of MPU301. 307 is a rewritable memory (RAM) that temporarily stores data required when MPU301 executes a program. 8 is an operation display unit for inputting print content and settings, or displaying input data and print content. This operation display unit 8 uses a touch input display panel with a transparent touch switch superimposed on the surface of the liquid crystal display screen.

[0091] Furthermore, the head-mounted unit 3 can be controlled from the operation display unit 8 of the control unit 7. The operation unit (start button 18 and stop button 19) is used when operating the head-mounted unit 3 near the head-mounted unit 3, not on the operation display unit 8. The display unit 15 is used to check the operating status of the head-mounted unit 3 and any abnormal messages near the head-mounted unit 3, not on the operation display unit 8.

[0092] The printhead 2 of the inkjet recording device 600 has a nozzle 21 that atomizes and discharges ink 68A supplied under pressure from the main ink container 31. The nozzle 21 ejects the ink in a columnar shape, with the leading edge separating to discharge as ink particles 68B. In addition, the printhead 2 has charged electrodes 23 surrounding the ink particles 68B, so that the ink particles 68B are charged accordingly with respect to the printed content.

[0093] Furthermore, the printhead 2 deflects the ink particles 68B, which are charged and flying due to the charged electrode 23, in accordance with their charge, and directs them toward the object to be printed (not shown). The flying ink particles then hit the object to be printed, thus performing printing. The deflection electrode 24 of the printhead 2 consists of a ground electrode 24B and a positive electrode 24A. Additionally, the printhead 2 has a flow channel 25 for capturing ink particles 68B that are not used for printing (unused ink), and a charge sensor 48 for generating a phase detection signal corresponding to the charge of the ink particles 68B1 with trace charges captured by the flow channel 25. Moreover, on the main body 1 side, there is a pump (for recovery) 35 for recovering the ink (ink particles) captured by the flow channel 25 to the main ink container 31, and ink recovery paths 811-812 connecting the flow channel 25 and the main ink container 31.

[0094] Furthermore, the control unit 7 has an excitation voltage generating circuit 331 that excites the electrodeformation element (not shown) built into the nozzle 21 to make the timing of the separation of the ink column ejected from the nozzle 21 into ink particles 68B regular.

[0095] Furthermore, the control unit 7 includes a printing charge signal generation circuit 342 and a phase search charge signal generation circuit 341, a D / A converter 343 that converts the charge signal in digital form output from them into an analog voltage signal, and an amplification circuit 344 that amplifies the analog voltage signal output from the D / A converter 343 to generate a charge voltage applied to the charge electrode 23. Alternatively, instead of providing both the printing charge signal generation circuit 342 and the phase search charge signal generation circuit 341, charge control can be achieved solely using the printing charge signal generation circuit 342 through the control unit. Additionally, the inkjet recording apparatus 600 includes a deflection voltage generation circuit 332 that generates a deflection voltage applied to the deflection electrode 24.

[0096] In addition, the inkjet recording device 600 includes an amplification circuit 353 that amplifies the phase detection signal in the form of an analog signal output from the charge sensor 48, a phase judgment circuit 351 that inputs the amplified phase detection signal to determine whether the charge is good, and an A / D converter 352 that inputs the amplified phase detection signal and performs A / D conversion.

[0097] then, Figure 3 In the control unit 7, the MPU301 is connected via bus 302 to: a liquid level detection circuit 313 for managing the liquid level of the main ink container 31; a pressure detection circuit 312 for detecting whether the pressure of the ink supplied to the nozzle 21 is appropriate; a viscosity measurement circuit 311 for measuring whether the viscosity of the ink 68A supplied to the nozzle 21 is appropriate for printing using a viscosity meter 45; a pump control circuit 314 for controlling the suction and delivery of ink 68A and solvent 69A installed in the main body 1; and a solenoid valve drive circuit 315 for controlling the opening and closing of solenoid valves 49-50 and 53-59 in each path, thereby controlling each part.

[0098] In addition, the MPU301 is connected via bus 302 to a pump control circuit 321 for controlling pumps 60 and 61, a recycling container sensor detection circuit 322 for detecting that the liquid 70 in the recycling container 4 is not more than a specified amount when the recycling container 4 is installed on the head mounting unit 3 using a magnetic sensor 76A and a magnet 75, a printhead detection circuit 323 for detecting that the printhead 2 is installed on the head mounting unit 3, and a head mounting unit detection circuit 324 for detecting that the printhead 2 is installed on the head mounting unit 3, thereby controlling each part.

[0099] Furthermore, the control unit 7 can use a computer. Specifically, the control unit 7 can be composed of an MPU 301, memory (306 and 307) storing the program for operating the MPU 301 and the data and information required for the operation, and a drive unit that operates the print head 2, the print head mounting unit 3, and the main body 1 according to the instructions of the MPU 301. Detailed description of the control unit 7 is omitted here.

[0100] <Actions to prevent consolidation during the stop>

[0101] For actions to prevent ink from solidifying during printing stoppages while the printhead 2 is mounted on the head mounting unit 3, the following applies: Figures 4 to 7 Please provide an explanation.

[0102] exist Figure 4 The process for preventing ink caking is shown. First, with printing stopped by the printhead 2, the MPU 301 of the control unit 7 checks the amount of solvent 69A used for cleaning the printhead 2 inside the solvent container 33 based on the stored control program and the signals from the level sensors 33A and 33B, and checks whether the solvent cartridge 69B used to supply solvent 69A to the solvent container 33 can be replaced (S401).

[0103] If the liquid level sensor 33B does not detect solvent 69A inside the solvent container 33, in MPU 301, it is determined that the amount of solvent 69A inside the solvent container 33 is low and the solvent cartridge 69B can be replaced (Yes in S401), and the process proceeds to S402. On the other hand, if the liquid level sensor 33A detects solvent 69A inside the solvent container 33, in MPU 301, it is determined that the amount of solvent 69A inside the solvent container 33 is sufficient and the solvent cartridge 69B cannot be replaced (No in S401), and the process proceeds to the anti-solidification step (S404).

[0104] If it is determined in S401 that the solvent cartridge 69B can be replaced (yes in S401), proceed to S402, and according to the instructions from MPU301, guidance suggesting the replacement of the solvent cartridge 69B is displayed on the display unit 15 and the operation display unit 8. If the solvent cartridge 69B has been replaced according to the guidance, and the interrupt button (not shown) marked on the display unit 15 and the operation display unit 8 is touched in S403, the anti-caking operation is interrupted. On the other hand, if the execute button (not shown) marked on the display unit 15 and the operation display unit 8 is touched in S403, proceed to the anti-caking step (S404).

[0105] In the anti-caking step S404, firstly, the solenoid valve drive circuit 315 is controlled by MPU301 to repeatedly open and close the solenoid valves (for ink replenishment) 54, 26 (for switching) and 56 (for head cleaning) (S4041) to prevent the ink adhering to the solenoid valves 54, 26 and 56 from caking and hindering the opening and closing of the solenoid valves 54, 26 and 56.

[0106] Next, during the solvent evaporation process (S4042), the pump control circuit 314 is controlled by MPU301, such as... Figure 5 As shown, with the pump (recovery) 35 operating, the solenoid valve (recovery) 50 is opened, and air is drawn in from the flow channel 25 via paths (recovery) 811 and 812, supplying air to the interior of the main ink container 31. The air supplied to the interior of the main ink container 31 is connected to the exhaust duct connection 62 via path (exhaust) 814, and exhausted using an exhaust unit (not shown). In this way, the air drawn in from the flow channel 25 passes through the interior of the main ink container 31 and connects to the exhaust duct connection 62, causing the solvent inside the main ink container 31 to evaporate.

[0107] The process continues, drawing air from the flow channel 25 through the interior of the main ink container 31 and connecting it to the exhaust duct connection 62 to cause the solvent inside the main ink container 31 to evaporate until the liquid level of the ink 68A inside the main ink container 31 decreases, the liquid level sensor 31B no longer detects ink 68A, and the liquid level of ink 68A reaches the initial level (the level of the liquid level sensor 31B switching from OFF to ON, or vice versa, the level of ink 68A) (S4043).

[0108] Therefore, it is possible to prevent the ink volume 68A inside the main ink container 31 from increasing excessively and exceeding the allowable level during printing with printhead 2, because the ink recovered from the flow channel 25 through paths (for recycling) 811 and 812 to the main ink container 31 and the solvent 69A supplied from the solvent container 33.

[0109] The pump (for recovery) 35 is operated to draw air from the flow channel 25, and the drawn air is temporarily stored inside the main ink container 31 and discharged through the exhaust pipe connection 62 via the path (for exhaust) 814. This process is continued for 5 to 10 minutes, during which the back pressure of the pump (for recovery) 35 increases and the suction capacity of the pump (for recovery) 35 decreases.

[0110] At this time, by closing solenoid valve 50 and opening solenoid valves 49 and 58 while pumps 34 and 35 are in operation, the ink 68A inside the main ink container 31 is circulated through path 801, 808, and 812 for 1 minute, thereby restoring the amount of air drawn into pump (for recovery) 35 from flow channel 25.

[0111] When the liquid level of ink 68A inside the main ink container 31 returns to its initial level (the case in S4043), the viscosity of ink 68A inside the main ink container 31 after solvent evaporation is measured (S4044). To measure the viscosity of ink 68A, the pump (circulation) 36 is operated with the solenoid valve (for recovery) 50 closed and the solenoid valve (for viscosity measurement) 57 open. In this state, ink 68A inside the main ink container 31 passes through the filter (for viscosity measurement) 42 and then through the viscometer 45 via the path (for viscosity measurement) 824, thereby measuring the viscosity. The ink whose viscosity has been measured by the viscometer 45 passes through the solenoid valve (for viscosity measurement) 57, through the path (for head circulation) 822, and returns to the inside of the main ink container 31.

[0112] After the viscosity measurement performed by the viscosity meter 45 is completed, the solenoid valve (for viscosity measurement) 57 is closed and the ink supply to the viscosity meter 45 is stopped. Next, with the pump (for circulation) 36 operating, the pump (for solvent) 37 and the pump (for recovery) 35 are then operated, opening the solenoid valves (for nozzle cleaning) 55, (for recovery) 50, and (for circulation) 59, causing solvent to be ejected from the printhead 2 (S4045). By opening the solenoid valves 55, 50, and 59, as... Figure 6 As shown, the solvent path (represented by thick lines) connecting the solvent container 33 to the solenoid valve (switching) 26 of the printhead 2, consisting of path (solvent supply) 831 and path (nozzle cleaning) 825, the circulation path (represented by thick lines) connecting the nozzle 21 of the printhead 2 to the main ink container 31, the circulation path (represented by thick lines) connecting the nozzle 21 of the printhead 2 to the main ink container 31, and the recovery path (represented by thick lines) connecting the flow channel 25 of the printhead 2 to the main ink container 31, the circulation path (represented by thick lines) connecting the flow channel 25 of the printhead 2 to the main ink container 31, are respectively connected.

[0113] In this state, the solvent 69A contained inside the solvent container 33 is drawn by the pump (solvent) 37, passes through the solenoid valve (nozzle cleaning) 55, through the path (solvent supply) 831 and the path (nozzle cleaning) 825 that constitute the solvent path, and is supplied to the nozzle 21 through the solenoid valve (switching) 26 and the filter 27.

[0114] Of the solvent supplied to nozzle 21, a portion passes through path 821 (for head circulation) which is connected to nozzle 21 and forms a circulation path, then through solenoid valve 59 and is collected in main ink container 31 via path 822 (for head circulation). On the other hand, solvent ejected forward from nozzle 21 enters flow channel 25, passes through path 811 (for recovery) which forms a recovery path, then through solenoid valve 50 and is collected in main ink container 31 via path 812 (for recovery).

[0115] In this way, by employing a structure that supplies solvent 69A stored inside the solvent container 33 to the printhead 2 via a solvent path and recovers it to the main ink container 31 via a circulation path and a recovery path, solvent can be passed through the interiors of solenoid valves 50 (for recovery) and 59 (for circulation) during inkjet recording device 600A or 600B shutdown. This allows the solvent to dissolve and recover any residual ink inside solenoid valves 50 and 59. Consequently, malfunctions of solenoid valves 50 and 59 due to hardening of residual ink can be prevented during inkjet recording device 600A or 600B shutdown.

[0116] Furthermore, since the solvent is emitted from the nozzle 21, the solvent stream bends and leaves the flow channel 25 and splashes to the surroundings. Unlike the case of ink, the splashed solvent does not contaminate the surroundings but evaporates. Therefore, for example, it is possible to prevent ink from solidifying by simply covering the area around the printhead 2 with a beaker or similar object. However, if the printhead 2 is mounted on the head mounting unit 3 as described in this embodiment, it can be carried out without preparing items such as the aforementioned beaker.

[0117] In addition, unlike ink, there is no need to worry about contaminating the surrounding area even if the solvent splashes around, so the solvent spraying process can be carried out unattended.

[0118] Next, in order to uniformly dissolve the recovered solvent into the ink 68A inside the main ink container 31, the ink 68A inside the main ink container 31 is circulated (S4046). The path for ink circulation is as follows: Figure 7 The thick lines in the middle show the paths from path (for supply) 801 through path (for main circulation) 808 to path (for recovery) 812, and from path (for viscosity measurement) 824 to path (for head circulation) 822.

[0119] By energizing solenoid valves 49 (for supply) and 58 (for main circulation), the path is opened, causing pumps 34 (for supply) and 35 (for recovery) to operate. This allows ink 68A collected in the main ink container 31 to flow along the path from path 801 through path 808 to path 812 (for recovery). Thus, ink 68A flowing out of the main ink container 31 circulates through solenoid valve 49, pump 34, filter 39, pressure regulating valve 46, solenoid valve 58, pump 35, and back to the main ink container 31.

[0120] Furthermore, in the main body 1, the path is opened by energizing the solenoid valve (for viscosity measurement) 57, causing the pump (for circulation) 36 to operate. The ink 68A contained in the main ink container 31 flows from the path (for viscosity measurement) 824 along the path (for head circulation) 822, passing through the viscometer 45, the solenoid valve (for viscosity measurement) 57, and the pump (for circulation) 36, returning to the main ink container 31, thereby circulating the ink 68A. In this way, if the viscosity of the ink 68A is measured in advance using the viscometer 45 during the ink circulation within the main body 1, the state of the ink 68A can be easily determined for the next use.

[0121] After the ink circulation continues for a specified time, the anti-caking action stops (S4047), and the anti-caking step ends (S404).

[0122] Next, the device remains in a stopped state (S405). While the operation display unit 8 displays a waiting state screen, it checks whether the stop was interrupted (S406). If the stop was interrupted (Yes in S406), the process ends. Figure 4 The process shown is an anti-solidification treatment performed during equipment shutdown.

[0123] On the other hand, if the stop is not interrupted and the stop state continues (No in S406), in S4047, it is checked whether a certain time has passed since entering the stop state (S407). If a certain time has not passed (No in S407), it returns to S405.

[0124] On the other hand, if a certain amount of time has passed since entering the stop state in S4047 (e.g., 24 hours or 48 hours in S407), the process returns to S404 and repeats the series of actions from S4041 to S4047.

[0125] As explained above, during the period when the printing action using printhead 2 is in a stopped state, the operation is automatically performed at certain time intervals. Figure 4 This describes a series of operations to prevent ink from solidifying. Therefore, even if the printing operation is stopped for an extended period, ink solidification in the solenoid valve inside the main body 1 or inside the printhead 2 can be prevented, and the printing operation can begin smoothly even after the printhead 2 has been idle for a considerable time.

[0126] <Vitality Adjustment of Ink in the Main Ink Container>

[0127] Next, the viscosity of the ink in the main ink container is adjusted while the printhead 2 is mounted on the printhead mounting unit 3. Figures 8 to 16 Please provide an explanation.

[0128] During prolonged printing with printhead 2, the ink recovered from flow channel 25 accumulates in the main ink container 31, causing viscosity changes in the ink 68A inside the main ink container 31. Additionally, there is a possibility of... Figure 4 In flowchart S4045, the solvent is ejected from the printhead 2 and recycled to the main ink container 31, or ink 68C is replenished to the main ink container 31 from the auxiliary ink container 32. This causes the viscosity of the ink 68A stored in the main ink container 31 to change and deviate from the appropriate range. Furthermore, if the printhead is not used for an extended period, the solvent will evaporate during this time, causing a change in the viscosity of the ink 68A inside the main ink container 31. Therefore, the viscosity of the ink 68A stored in the main ink container 31 is measured. If the viscosity of the ink 68A deviates from the appropriate range, it is necessary to adjust the viscosity of the ink 68A to bring it within the appropriate range.

[0129] exist Figure 8 The process of adjusting the viscosity of ink 68A stored in the main ink container 31 is shown. First, instructions on viscosity adjustment are displayed on the operation display unit 8 (illustration omitted) (S801).

[0130] Next, the output of the magnetic sensor 76A and the magnet 75 is used to determine whether the liquid inside the recovery container 4 mounted on the head mounting unit 3 does not exceed a predetermined amount (S802). If the amount of liquid inside the recovery container 4 exceeds the predetermined amount, the liquid inside the recovery container 4 is discarded and the determination is performed again.

[0131] After confirming that the liquid contained inside the recycling container 4 does not exceed the prescribed amount, such as Figure 9 As shown, pumps (supply) 34 and (recovery) 35 are operated, and solenoid valves (supply) 49 and (main body circulation) 58 are opened, thereby opening paths (supply) 801, (main body circulation) 808, and (recovery) 812, allowing the ink 68A in the main ink container 31 to circulate. Additionally, pump (circulation) 36 is operated, and solenoid valve (viscosity measurement) 57 is opened, thereby opening paths (viscosity measurement) 824 and (head circulation) 822, thereby allowing the ink 68A contained inside the main ink container 31 to pass through the viscosity meter 45 for viscosity measurement (S803).

[0132] The viscosity of ink 68A was measured according to... Figure 4 The same process is described in step S4044 of the processing flowchart.

[0133] In S803, the result of the viscosity measurement is judged (S8031). If it is determined that the viscosity of ink 68A is within an appropriate range (Yes in S8031), the ink viscosity adjustment step ends.

[0134] In contrast, in S8031, if it is determined that the viscosity of ink 68A is higher than an appropriate range ("high" in S8031), the process proceeds to step S810. On the other hand, if it is determined that the viscosity of ink 68A is lower than an appropriate range ("low" in S8031), the process proceeds to step S830.

[0135] <<Adjusting Ink Viscosity When It's High>>

[0136] exist Figure 8 If, in step S8031, it is determined that the viscosity of the ink 68A contained in the main ink container 31 is higher than an appropriate range, the steps following step S810 are executed to adjust the ink viscosity so that the higher ink viscosity is within an appropriate range.

[0137] First, in step S810, in order to start the ink ejection from printhead 2, from... Figure 9 The state is switched to Figure 10 The state is as follows: that is, the solenoid valve (for viscosity measurement) 57 is closed and the pump (for circulation) 36 is stopped, thus stopping the ink 68A from passing through the viscosity meter 45.

[0138] Additionally, the circulation of ink 68A in the main ink container 31 is stopped by closing the solenoid valve 58. Next, with the pump (supply) 34 and the pump (recovery) 35 in operation, the solenoid valve (switching) 26 is opened to open the paths (supply) 801, 802, and 803, supplying ink 68A from the main ink container 31 to the print head 2 and ejecting ink from the nozzle 21 (S810). The solenoid valve (recovery) 50 is opened to open the ink recovery path formed by the paths (recovery) 811 and 812, and the flow channel 25 captures the ink 68A supplied to the print head 2 and ejected from the nozzle 21 and recovers it to the main ink container 31.

[0139] Next, as Figure 11 As shown, closing the solenoid valve 50 (S811) cuts off the ink recovery path formed by path 811 (for recovery) and path 812 (for recovery). As a result, the ink 68A supplied to the printhead 2 and ejected from the nozzle 21 overflows from the flow channel 25 and is recovered into the recovery container 4 mounted on the printhead mounting unit 3. Consequently, the level of ink 68A collected inside the main ink container 31 continuously decreases.

[0140] Because the level of ink 68A stored inside the main ink container 31 continuously decreases, the detection signal of ink 68A by the level sensor 31B (sensor 2) installed in the main ink container 31 becomes OFF (not detected) (Yes in S812). This state is maintained from the time the detection signal of the level sensor 31B (sensor 2) becomes OFF (not detected) until a predetermined time has elapsed. As a result, the level of ink 68A stored inside the main ink container 31 is lower than the level detected by the level sensor 31B (sensor 2).

[0141] Here, the predetermined time from when the detection signal of ink 68A by the liquid level sensor 31B (sensor 2) becomes OFF (not detected) (Yes in S812) is determined in MPU301 using a pre-set conditional formula, corresponding to the viscosity of the ink measured in S803 and the temperature of the ink measured by a temperature sensor (not shown). If the detected viscosity of the ink deviates significantly from the appropriate range, the predetermined time is set to be longer; if the detected viscosity of the ink deviates relatively little from the appropriate range, the predetermined time is set to be shorter.

[0142] In this way, by adjusting the amount of ink 68A discarded from the main ink container 31 in accordance with the viscosity of the ink, even if the viscosity of the ink is higher than the appropriate range, it is not necessary to discard all the ink 68A in the main ink container 31 and replace it with new ink, thereby reducing the amount of ink wasted and making efficient use of the ink.

[0143] On the other hand, even if the ink overflows from the flow channel 25 and after a certain period of time the detection signal of the liquid level sensor 31B (sensor 2) installed in the main ink container 31 for the ink 68A is not OFF (not detected) (if the 'no' state in S812 continues and the preset time is reached: 'yes' in S8121), an abnormal message is output on the operation display unit 8 (S8122), and the solenoid valve 49 is closed to stop the supply of ink to the print head 2.

[0144] After a predetermined time has elapsed since the detection signal of ink 68A from liquid level sensor 31B (sensor 2) becomes OFF (not detected) (Yes in S812), such as Figure 12 As shown, the solenoid valve 50 is opened to open the ink recovery path consisting of path (for recovery) 811 and path (for recovery) 812 (S813), and the ink ejected from the nozzle 21 of the printhead 2 and captured by the flow channel 25 is recovered to the main ink container 31.

[0145] In this state, Figure 12As shown by the thick dashed line, with the solenoid valve (for solvent replenishment) 53 open, thus opening paths (for solvent supply) 831 and 833 connecting the solvent container 33 to the main ink container 31, the pump (for solvent) 37 operates. This replenishes the main ink container 31 with solvent 69A stored in the solvent container 33 via paths 831 and 833 (S814). The replenishment of solvent 69A to the main ink container 31 continues until the liquid level sensor 31B (sensor 2) detects that the level of ink 68A stored in the main ink container 31 has reached the initial level (until S815).

[0146] When the liquid level sensor 31B (sensor 2) detects that the liquid level of the ink 68A contained in the main ink container 31 has reached the initial level (Yes in S815), the solenoid valve (for solvent replenishment) 53 is closed, and the supply of solvent 69A from the solvent container 33 to the main ink container 31 is stopped. Figure 13 The pump (for circulation) 36 is operated as shown, and the solenoid valve (for viscosity measurement) 57 is opened, thereby opening the path (for viscosity measurement) 824 and the path (for head circulation) 822, so that the ink 68A contained inside the main ink container 31 passes through the viscosity measuring device 45 to measure the viscosity of the ink 68A (S816).

[0147] The viscosity measurement method for ink 68A is the same as the procedure in S803. Figure 4 The process flow chart S4044 is different. Ink 68A is supplied to the printhead 2 from the main ink container 31 and captured by the flow channel 25, and then recycled back to the main ink container 31 through paths (for recycling) 811 and 812, while the ink 68A is being circulated.

[0148] On the other hand, even if a certain period of time has passed after the main ink container 31 is replenished with solvent 69A, and the liquid level sensor 31B (sensor 2) does not detect that the liquid level of the ink 68A contained in the main ink container 31 has reached the initial level (the state of "No" in S815 has reached the preset time: "Yes" in S8151), an abnormal message is output on the operation display unit 8 (S8122), and the solenoid valve (for solvent replenishment) 53 is closed to stop the replenishment of solvent 69A inside the main ink container 31.

[0149] Next, the viscosity value measured in S816 is judged (S817). If the measured viscosity value is higher than the preset value of "high ink viscosity" stored in ROM306 (No in S817), the process returns to S811 and repeats the process of reducing the viscosity of the ink.

[0150] On the other hand, if the measured viscosity value is below a preset value stored in ROM306 that indicates "high ink viscosity" (as in S817), it is determined that the ink viscosity is within an appropriate range and the circuit is closed according to the instruction from CPU301. Figure 13 The solenoid valve (for supply) 49 in the middle is turned off and the pump (for supply) 34 is stopped, thereby stopping the supply of ink 68A to the print head 2 and stopping the ink from being ejected from the nozzle 21 of the print head 2 (S818), and the solenoid valve (for viscosity measurement) 57 is turned off, stopping the supply of ink to the viscosity meter 45.

[0151] Next, as Figure 14 As shown, by opening the solenoid valve (for nozzle cleaning) 55 and activating the pump (for solvent) 37, solvent 69A is supplied from the solvent container 33 to the nozzle 21 of the printhead 2 via the solvent path (for solvent supply) 831 and the path (for nozzle cleaning) 825, which connects to the printhead 2. At this time, the solenoid valves (for recovery) 50 and (for circulation) 59 are opened, so that the paths (for printhead circulation) 821 and (for recovery) 811 are connected from the printhead 2 to the main ink container 31. As a result, the solvent 69A supplied to the printhead 2 is recovered to the main ink container 31 via the paths (for printhead circulation) 821 and (for recovery) 811. Thus, the ink 68A remaining in the paths (for printhead circulation) 821 and (for recovery) 811, as well as in the nozzle 21 and the flow channel 25, is flushed, and the circulation path is cleaned (S819).

[0152] After cleaning the circulation path for the specified time in S819, close solenoid valves 50 (for recovery), 55 (for nozzle cleaning), and 59, and stop pumps 35 (for recovery) and 36, while keeping pump 37 operational as described above. Figure 15 The solenoid valve (for head cleaning) 56 is opened as shown, and solvent is sprayed from the cleaning nozzle 72 onto the head mounting unit 3 on which the printhead 2 is mounted, spraying solvent from the outside of the printhead 2. This performs a more time-consuming and more solvent-intensive head cleaning (S820) on the printhead 2 compared to normal cleaning. This removes the dirt from the printhead 2 that overflowed from the ink channel 25 in S811.

[0153] After the solvent spraying stops, the pump (drying) 60 is activated to spray air onto the printhead 2 from the supply nozzle 73 with an air outlet, and the pump (suction) 61 is activated to expel the air from inside the head mounting unit 3, thereby drying the printhead 2 wetted by the solvent 69A and ending the fine head cleaning process.

[0154] After performing fine head cleaning, the process enters a stop state (S821), ending the ink viscosity normalization process. Figure 17 As shown, the ink viscosity display area 80 of the operation display unit 8 displays the initial value of the ink viscosity (the value measured in S803) and the value after viscosity adjustment (the value measured in S816). However, the information displayed in the ink viscosity display area 80 may not be the ink viscosity value itself, but rather information about the ink viscosity (e.g., "Viscosity is high. Adjustment is needed," "Viscosity is within the appropriate range," etc.). Furthermore, Figure 17 Although not shown in the diagram, the date and time of the viscosity adjustment and the date and time of the last viscosity adjustment can also be displayed in the ink viscosity display area 80 of the operation display unit 8. Additionally, the fine head cleaning process in S820 can be omitted.

[0155] <<Adjusting the viscosity of ink when it is low>>

[0156] exist Figure 8 In S8031, if it is determined that the viscosity of the ink 68A contained in the main ink container 31 is lower than an appropriate range, the steps after S830 are executed to adjust the ink viscosity so that the lower ink viscosity is within an appropriate range.

[0157] First, in step S830, in order to start the ink ejection from printhead 2, from... Figure 9 The state is switched to Figure 10 The state is as follows: that is, the solenoid valve (for viscosity measurement) 57 is closed and the pump (for circulation) 36 is stopped, thus stopping the ink 68A from passing through the viscosity meter 45.

[0158] Additionally, closing the solenoid valve 58 stops the circulation of ink 68A within the main ink container 31.

[0159] Next, with the pump (supply) 34 and pump (recovery) 35 in operation, the solenoid valve (switching) 26 is opened to open the paths (supply) 801, 802, and 803, so that ink 68A is supplied from the main ink container 31 to the print head 2 and ink is ejected from the nozzle 21. The solenoid valve (recovery) 50 is opened to open the ink recovery path formed by the paths (recovery) 811 and 812, so that the flow channel 25 captures the ink 68A supplied to the print head 2 and ejected from the nozzle 21 and recovers it to the main ink container 31.

[0160] By making that Figure 10 The state shown is that ink 68A is supplied to the printhead 2 from the main ink container 31 and ejected from the nozzle 21, captured by the flow channel 25 and recovered to the main ink container 31 through the ink recovery path, while the solvent contained in the ink 68A evaporates and the ink is concentrated (S831).

[0161] Corresponding to the amount of solvent evaporation, the amount of ink 68A captured by the flow channel 25 and recovered to the main ink container 31 via the ink recovery path decreases relative to the amount of ink 68A supplied from the main ink container 31 to the printhead 2, and the liquid level of ink 68A stored inside the main ink container 31 continues to decrease.

[0162] The level of ink 68A inside the main ink container 31 continuously decreases, causing the detection signal of ink 68A by the level sensor 31B (sensor 2) installed in the main ink container 31 to become OFF (not detected) (Yes in S832). This state is maintained from the time the detection signal of the level sensor 31B (sensor 2) becomes OFF until a predetermined time has elapsed. As a result, the level of ink 68A contained inside the main ink container 31 is lower than the level detected by the level sensor 31B (sensor 2).

[0163] Here, the predetermined time from when the detection signal of ink 68A by the liquid level sensor 31B (sensor 2) becomes OFF (not detected) (Yes in S832) is determined in MPU301 using a pre-set conditional formula, corresponding to the viscosity of the ink measured in S803 and the temperature of the ink measured by a temperature sensor (not shown). If the detected viscosity of the ink deviates significantly from the appropriate range, the predetermined time is set to be longer; if the detected viscosity of the ink deviates relatively little from the appropriate range, the predetermined time is set to be shorter.

[0164] In this way, by adjusting the amount of solvent vaporized from ink 68A in accordance with the viscosity of the ink, even when the viscosity of the ink is below an appropriate range, it is not necessary to discard all the ink 68A in the main ink container 31 and replace it with new ink, thereby reducing the amount of ink wasted and making efficient use of the ink.

[0165] On the other hand, even if ink 68A is supplied from the main ink container 31 to the print head 2 and ejected from the nozzle 21, captured by the flow channel 25, and recovered to the main ink container 31 via the ink recovery path after a certain period of time, and the detection signal of the liquid level sensor 31B (sensor 2) installed on the main ink container 31 for ink 68A is not OFF (not detected) (the state of no in S832 continues and the preset time is reached: yes in S8321), an abnormal message is output on the operation display unit 8 (S8322), the solenoid valve 49 is closed, and the supply of ink to the print head 2 is stopped.

[0166] After a predetermined time has elapsed since the detection signal of ink 68A from liquid level sensor 31B (sensor 2) becomes OFF (not detected) (Yes in S832), such as Figure 16The solenoid valve (supply) 49 is closed and the solenoid valve (ink replenishment) 54 is opened. This stops the supply of ink 68A from the main ink container 31 to the print head 2, and supplies ink 68C from the auxiliary ink container 32 to the print head 2 via a path formed by path (replenishment) 806 and paths (supply) 802 and 803, and ejects it from the nozzle 21. The ink 68C ejected from the nozzle 21 is captured by the flow channel 25 and recovered to the main ink container 31 via the ink recovery path. This replenishes the main ink container 31 with ink 68C from the auxiliary ink container 32 (S833).

[0167] The ink 68C is continuously replenished from the auxiliary ink container 32 to the main ink container 31 until the liquid level sensor 31B (sensor 2) detects that the liquid level of the ink 68A contained in the main ink container 31 has reached the initial level (until it becomes yes in S834).

[0168] When the liquid level sensor 31B (sensor 2) detects that the level of the ink 68A contained in the main ink container 31 has reached the initial level (Yes in S834), such as Figure 16 The pump (for circulation) 36 is operated as shown, and the solenoid valve (for viscosity measurement) 57 is opened, thereby opening the path (for viscosity measurement) 824 and the path (for head circulation) 822, so that the ink 68A contained inside the main ink container 31 passes through the viscosity measuring device 45 to measure the viscosity of the ink 68A (S835).

[0169] The viscosity measurement method for ink 68A is the same as the procedure in S803. Figure 4 The process flow chart S4044 is different. Ink 68C is supplied to the printhead 2 from the auxiliary ink container 32 and captured by the flow channel 25. It is then recycled to the main ink container 31 through paths (for recycling) 811 and 812. This process is carried out simultaneously with the supply of ink 68C from the auxiliary ink container 32 to the main ink container 31.

[0170] On the other hand, even if a certain period of time has elapsed after the main ink container 31 is supplied with ink 68C, and the liquid level sensor 31B (sensor 2) does not detect that the liquid level of the ink 68A contained in the main ink container 31 has reached the initial level (the state of "No" in S834 indicates that the preset time has been reached; the state of "Yes" in S8341), an abnormal message is output on the operation display unit 8 (S8322), and the solenoid valve (for ink replenishment) 54 is closed to stop the replenishment of ink 68C from the auxiliary ink container 32 to the main ink container 31.

[0171] Next, the viscosity value measured in S835 is judged (S836). If the measured viscosity value is lower than the preset value of "low ink viscosity" stored in ROM306 (No in S836), the process returns to S831 and repeats the process of increasing the viscosity of the ink.

[0172] On the other hand, if the measured viscosity value is above a preset value stored in ROM306 indicating "low ink viscosity" (as in S836), it is determined that the ink viscosity is within an appropriate range and the circuit is closed according to the instruction from CPU301. Figure 16 The solenoid valve (for ink replenishment) 54 in the middle is stopped and the pump (for supply) 34 is stopped, thereby stopping the supply of ink 68C to the print head 2 and stopping the ink from being ejected from the nozzle 21 of the print head 2 (S837), and the solenoid valve (for viscosity measurement) 57 is closed, stopping the supply of ink to the viscosity meter 45.

[0173] Next, as Figure 14 As shown, by opening the solenoid valve (for nozzle cleaning) 55 and activating the pump (for solvent) 37, solvent 69A is supplied from the solvent container 33 to the nozzle 21 of the printhead 2 via the solvent path (for solvent supply) 831 and the path (for nozzle cleaning) 825, which connects to the printhead 2. At this time, the solenoid valves (for recovery) 50 and (for circulation) 59 are opened, so that the paths (for printhead circulation) 821 and (for recovery) 811 are connected from the printhead 2 to the main ink container 31. As a result, the solvent 69A supplied to the printhead 2 is recovered to the main ink container 31 via the paths (for printhead circulation) 821 and (for recovery) 811. Thus, the ink 68A remaining in the paths (for printhead circulation) 821 and (for recovery) 811, as well as in the nozzle 21 and the flow channel 25, is flushed, and the circulation path is cleaned (S838).

[0174] After cleaning the circulation path, the process enters a stop state (S839), ending the ink viscosity normalization process. Figure 17 As shown, the ink viscosity display area 80 of the operation display unit 8 displays the initial value of the ink viscosity (the value measured in S803) and the value after viscosity adjustment (the value measured in S835). However, the information displayed in the ink viscosity display area 80 may not be the ink viscosity value itself, but rather information about the ink viscosity (e.g., "Viscosity is low. Adjustment is needed," "Viscosity is within the appropriate range," etc.). Furthermore, Figure 17 Although not shown in the figure, the date and time information about the viscosity adjustment and the date and time information of the last viscosity adjustment can also be displayed in the ink viscosity display area 80 of the operation display unit 8.

[0175] <Effects of this embodiment>

[0176] According to this embodiment, when the inkjet recording device is in a continuous stopped state, solvent is ejected from the printhead and recovered from the flow channel at regular intervals from the start of the stop, and the ink is circulated inside the device body. Therefore, even if the inkjet recording device is in a stopped state for a long time, the ink can be prevented from solidifying on the solenoid valve and the like.

[0177] Furthermore, according to this embodiment, the viscosity of the ink is measured, and viscosity adjustment is automatically performed according to the conditions of higher and lower viscosity when the viscosity deviates from the predetermined range. Therefore, during printing, the ink can be supplied to the print head while keeping the viscosity of the ink within an appropriate range.

[0178] Especially when the ink viscosity is higher than a predetermined range, the viscosity can be adjusted to an appropriate range simply by discarding a portion of the ink contained in the main ink container. Therefore, it is not necessary to discard all the ink in the main ink container and replace it with new ink, which can reduce the amount of ink wasted and increase the effective amount of ink used.

[0179] Explanation of reference numerals in the attached figures

[0180] 1…Main body, 2…Print head, 3…Head mounting unit, 4…Recycle container, 5…Cable (for print head), 6…Cable (for head mounting unit), 7…Control unit, 8…Operation display unit, 11…Conveyor belt, 12A…Printing object, 12B…Printing object, 13…Print head fixing component, 15…Display unit, 16…Head base, 17…Protective cover, 18…Start button, 19…Stop button, 20…Heater, 21…Nozzle, 23…Electrically charged electrode, 24…Deflection electrode, 24A…Positive electrode, 24B…Ground electrode, 25…Flow channel, 26…Solenoid valve (for switching), 27…Filter, 31…Main ink container, 31A, B, C…Liquid level sensors, 32…Auxiliary ink container, 33… Solvent container, 34… Pump (supply), 35… Pump (recovery), 36… Pump (circulation), 37… Pump (solvent), 38… Pressure sensor, 39… Filter (supply), 40… Filter (recovery), 41… Filter (nozzle cleaning), 43… Filter (head cleaning), 45… Viscometer, 46… Pressure regulating valve, 48… Charge sensor, 49… Solenoid valve (supply), 50… Solenoid valve (recovery), 53… Solenoid valve (solvent replenishment), 54… Solenoid valve (ink replenishment), 55… Solenoid valve (nozzle cleaning), 56… Solenoid valve (head cleaning), 57… Solenoid valve (viscosity measurement), 58… Solenoid valve (main body circulation), 59… Solenoid valve (circulation). 60… Pump (for drying), 61… Pump (for suction), 62… Exhaust duct connection, 68A… Ink, 68B… Ink particles, 68B1… Ink particles, 68C… Ink, 69A… Solvent, 70… Liquid, 74… Float, 75… Magnet, 76A, B… Magnetic sensors, 81A… Head mounting, 91… Fixing part, 92… Fixing clamp (for conveyor belt), 93… Fitting part, 301… MPU, 302… Bus, 306… ROM, 307… RAM, 311… Viscosity measurement circuit, 312… Pressure detection circuit, 313… Liquid level detection circuit, 314… Pump control circuit, 315… Solenoid valve drive circuit, 321… Pump control circuit, 322… Recycling container sensor detection circuit 323…Printhead detection circuit, 324…Printhead mounting unit detection circuit, 331…Excitation voltage generating circuit, 332…Deflection voltage generating circuit, 341…Phase search charged signal generating circuit, 342…Printing charged signal generating circuit, 343…D / A converter, 344…Amplifier circuit, 351…Phase judgment circuit, 352…A / D converter, 353…Amplifier circuit, 600…Inkjet recording device, 801~803…Path (for supply), 806…Path (for replenishment), 808…Path (for main body circulation), 811, 812…Path (for recovery), 814…Path (for exhaust), 821, 822…Path (for head circulation), 824…Path (for viscosity measurement).825…path (for nozzle cleaning), 831…path (for solvent supply), 833…path (for solvent replenishment), 837…path (for head cleaning), 841…path (for air supply), 843…path (for air suction), 901-903…combination path, 921…branch path.

Claims

1. An inkjet recording device, comprising: A print head that prints on an object, having nozzles for discharging ink. The main body includes: an ink container for storing ink supplied to the printhead, an auxiliary ink container for supplying ink to the ink container, a solvent container for storing solvent, a supply path having a supply pump for supplying ink from the ink container to the printhead, a circulation path having a circulation pump for returning a portion of the ink supplied to the printhead to the ink container, a recycling path having a recycling pump for attracting ink ejected from the nozzle of the printhead and recycling the ink back to the ink container, and a viscosity measuring unit for measuring the viscosity of the ink stored in the ink container. A head mounting unit for mounting the print head; and The control unit that controls the print head and the main body The inkjet recording device is characterized in that: The control unit controls the printhead and the main body when the viscosity of the ink, as measured by the viscosity measuring unit, deviates from a preset range, so that the viscosity of the ink converges to the preset range. The control unit controls the printhead and the main body when the viscosity of the ink measured by the viscosity measuring unit is higher than the preset specified range. This causes a portion of the ink contained in the ink container to be discarded from the printhead into the interior of the printhead mounting unit via the supply path while the printhead is mounted in the printhead mounting unit, and the solvent contained in the solvent container to be supplied to the ink container, thereby reducing the viscosity of the ink contained inside the ink container.

2. The inkjet recording device as claimed in claim 1, characterized in that: When the viscosity of the ink measured by the viscosity measuring unit is higher than the preset specified range, and the ink collected in the ink container is discarded from the printhead, the control unit changes the amount by which the liquid level of the ink collected in the ink container decreases from the preset reference level of the ink container due to the ink being discarded from the printhead, in accordance with the viscosity of the ink measured by the viscosity measuring unit.

3. The inkjet recording device as described in claim 2, characterized in that: After the ink is discarded from the printhead, the printhead is cleaned with the solvent contained in the solvent container.

4. The inkjet recording device as claimed in claim 1, characterized in that: The control unit controls the printhead and the main body when the viscosity of the ink measured by the viscosity measuring unit is lower than the preset specified range, so that the ink is supplied from the auxiliary ink container to the ink container through the printhead, thereby increasing the viscosity of the ink contained inside the ink container.

5. The inkjet recording apparatus as claimed in claim 1, characterized in that: The main body also has an operation display unit, which displays information about the viscosity of the ink after the main body is controlled by the control unit to make the viscosity of the ink converge to the specified range.

6. The inkjet recording apparatus as described in claim 5, characterized in that: The information about the viscosity of the ink displayed on the operation display includes information about the viscosity of the ink when the viscosity deviates from the predetermined range before the control unit controls the main body to adjust the viscosity of the ink, and information about the viscosity of the ink after the control unit controls the main body to bring the viscosity of the ink to the predetermined range.

7. The inkjet recording apparatus as claimed in claim 1, characterized in that: The control unit controls the printhead and the main body when the viscosity of the ink measured by the viscosity measuring unit deviates from the preset specified range. While the ink is being discharged from the printhead, the control unit controls the printhead and the main body to bring the viscosity of the ink back to the specified range. After the viscosity of the ink has converged to the specified range, the control unit stops discharging the ink from the printhead and supplies solvent from the solvent container to clean the circulation path.

8. The inkjet recording apparatus as claimed in claim 1, characterized in that: The control unit controls the printhead and the body during the period when the printhead stops printing on the object to be printed, such that at regular intervals during the period when the printhead stops printing, it repeatedly supplies the printhead with the solvent contained in the solvent container and returns the solvent to the ink container through the circulation path and the recovery path.

9. The inkjet recording apparatus as claimed in claim 8, characterized in that: The recycling path includes a recycling solenoid valve and a recycling pump. During the period when the print head stops printing on the object being printed, the control unit activates the recycling pump at regular intervals while the recycling solenoid valve is energized and opened. This allows air to flow from the print head side through the recycling path into the ink container, causing the solvent contained in the ink in the ink container to evaporate.

10. A method for managing an inkjet recording device, wherein the inkjet recording device comprises: A print head that prints on an object, having nozzles for discharging ink. The main body includes: an ink container for storing ink supplied to the printhead, an auxiliary ink container for supplying ink to the ink container, a solvent container for storing solvent, a supply path for supplying ink from the ink container to the printhead, a circulation path for returning a portion of the ink supplied to the printhead to the ink container, a recycling path for attracting ink ejected from the nozzle of the printhead to recover the ink to the ink container, and a viscosity measuring unit for measuring the viscosity of the ink stored in the ink container. A head mounting unit for mounting the print head; and The control unit that controls the print head and the main body The management method of the inkjet recording device manages the viscosity of the ink contained in the ink container, characterized in that: If the viscosity of the ink measured by the viscosity measuring unit deviates from a preset range, the control unit controls the printhead and the main body to adjust the viscosity of the ink contained in the ink container. If the viscosity of the ink measured by the viscosity measuring unit is higher than a predetermined range, the control unit controls the printhead and the main body such that, with the printhead mounted on the printhead mounting unit, a portion of the ink contained in the ink container is discarded from the printhead to the interior of the printhead mounting unit via the supply path, and the solvent contained in the solvent container is supplied to the ink container, thereby reducing the viscosity of the ink contained inside the ink container.

11. The management method of the inkjet recording device as described in claim 10, characterized in that: When the viscosity of the ink measured by the viscosity measuring unit is higher than a predetermined range, and the ink collected in the ink container is discarded from the printhead, the amount by which the liquid level of the ink collected in the ink container decreases from the reference level of the ink container due to the ink being discarded from the printhead changes accordingly to the viscosity of the ink measured by the viscosity measuring unit.

12. The management method for the inkjet recording device as described in claim 10, characterized in that: If the viscosity of the ink measured by the viscosity measuring unit is lower than a predetermined range, the control unit controls the printhead and the main body to supply ink from the auxiliary ink container to the ink container via the printhead, thereby increasing the viscosity of the ink contained inside the ink container.

13. The management method for the inkjet recording device as described in claim 10, characterized in that: During each period of printing stoppage of the printhead, the control unit controls the printhead and the body to repeatedly supply the printhead with the solvent contained in the solvent container and return the solvent to the ink container through the circulation path and the recovery path during each period of printing stoppage of the printhead, so as to prevent the ink from solidifying.

14. The management method for the inkjet recording device as described in claim 13, characterized in that: The control unit controls the pump in the recycling path to operate at regular intervals during the period when the print head stops printing on the object being printed, while the recycling solenoid valve in the recycling path is energized and opened. This causes air to flow from the print head side through the recycling path into the ink container, thereby causing the solvent contained in the ink in the ink container to evaporate.

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