Inkjet recording apparatus and recording apparatus

Abstract

The present invention provides an inkjet recording device and recording device capable of automatically cleaning the front end of a head, comprising: a print head having a nozzle that atomizes and ejects supplied ink particles, a charging electrode that charges the ink particles ejected from the nozzle, a deflection electrode that deflects the ink particles charged by the charging electrode, and a tank that recovers unused ink not used in printing; a main body having an ink supply path that supplies ink in an ink container to the print head, an ink recovery path that recovers ink not used in printing into the ink container, and a solvent supply path that supplies a solvent in a solvent container to the ink container; a main body control unit that controls the operation of the print head; and a head mounting unit having a head mounting portion for mounting the print head and a recovery container that stores a liquid used in cleaning, the head mounting unit having a cleaning base portion that stores the front end of the print head and into which the liquid used to clean the front end of the print head flows.

Description

[0001] This application is a divisional application of PCT application No. PCT / JP2020 / 045911 filed on December 9, 2020, which entered the Chinese national phase on August 10, 2022, and has application No. 202080096299.9. Technical Field

[0002] This invention relates to an inkjet recording device and a method for cleaning the inkjet recording device. Background Technology

[0003] Inkjet printing devices are widely used in industry for printing products on production lines. During printing, the printhead of an inkjet printing device can become contaminated with ink particles ejected from the nozzles, potentially leading to contamination of the printhead's interior and front surface. Continuing to print in this state can degrade print quality. Furthermore, prolonged periods without printing can cause dirt to accumulate on the printhead nozzles and near the opening at the printhead's front end, preventing proper ink particle ejection and further reducing print quality. Therefore, proper printhead cleaning is necessary. However, manual cleaning of the printhead is cumbersome, and the cleaning time, solvent usage, and degree of ink and dirt removal vary depending on the operator's skill level. To address these technical problems, the technology disclosed in WO2019 / 234965A1 (Patent Document 1) is known.

[0004] Patent document 1 discloses an inkjet recording apparatus including a cleaning unit that automatically cleans the entire printhead. The cleaning unit includes: a cleaning tank for receiving the printhead; a cleaning nozzle for spraying cleaning fluid onto the printhead inserted (received) in the cleaning tank; an air nozzle for drying; and a recovery container for recovering the cleaning fluid after cleaning.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: WO2019 / 234965A1 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] In the technology of Patent Document 1, high-pressure cleaning fluid is sprayed from the cleaning nozzle onto the printhead while the entire printhead is inserted inside the cleaning unit. Therefore, it is possible to automatically clean the components inside the printhead (nozzles, charged electrodes, deflection electrodes, slots, etc.).

[0010] However, while the technology in Patent Document 1 is suitable for automatically cleaning primarily the internal components of the printhead, it is insufficient for cleaning the opening at the front of the printhead cover where ink particles are ejected from the printed material. Therefore, cleaning the front of the printhead requires manual operation by the operator, presenting a technical challenge in achieving full automation of the cleaning process.

[0011] Therefore, the present invention provides an inkjet recording device capable of automatically cleaning the front end of the printhead and a cleaning method for the inkjet recording device.

[0012] Technical means for solving technical problems

[0013] To achieve the above objectives, one example of the present invention is an inkjet recording device comprising: a printhead that receives ink and performs printing; a body that supplies the ink to the printhead; and a cleaning unit having a cleaning tank into which the printhead is inserted, wherein cleaning fluid is sprayed from a cleaning nozzle onto the printhead for cleaning, and a cleaning base portion having a receiving portion is provided in the cleaning tank, the receiving portion being able to receive the front end of the printhead, and the cleaning fluid flowing into the receiving portion.

[0014] Furthermore, another example of the present invention is a cleaning method for an inkjet recording device, the inkjet recording device comprising: a printhead that receives ink and performs printing; a body that supplies the ink to the printhead; and a cleaning unit having a cleaning tank for receiving the printhead, wherein cleaning fluid is sprayed from a cleaning nozzle onto the printhead for cleaning, the cleaning method being characterized in that: a cleaning base portion having a receiving portion for receiving the front end of the printhead and into which the cleaning fluid can flow, the front end of the printhead being received in the receiving portion, and the front end of the printhead being cleaned using the cleaning fluid.

[0015] The effects of the invention

[0016] According to the present invention, an inkjet recording apparatus capable of automatically cleaning the front end of the head and a cleaning method for the inkjet recording apparatus can be provided. Attached Figure Description

[0017] Figure 1 This is a diagram illustrating the usage of the inkjet recording device in an embodiment of the present invention.

[0018] Figure 2 This is a diagram showing the overall path structure of the inkjet recording device in the embodiment.

[0019] Figure 3 This is a structural diagram of the printhead in the embodiment.

[0020] Figure 4 This is a structural diagram of the cleaning unit in the embodiment.

[0021] Figure 5 This is a cross-sectional view of the cleaning unit with the printhead installed.

[0022] Figure 6 This is a diagram showing an example of the structure of the cleaning base section.

[0023] Figure 7 This is a diagram showing the structure of the cleaning base portion in the embodiment.

[0024] Figure 8 This is a diagram showing other structural examples of the cleaning base section.

[0025] Figure 9 This is a diagram showing other structural examples of the cleaning base section.

[0026] Figure 10 This is a flowchart of the printhead cleaning function. Detailed Implementation

[0027] Next, use Figures 1-10 Specific embodiments of the present invention will be described below. However, the present invention is not limited to the embodiments described below. Furthermore, in the following figures, the same numbers (reference numerals) are assigned to the same devices (components), and descriptions of devices already described are generally omitted.

[0028] (Usage status of the inkjet recording device in the embodiment)

[0029] First, the basic structure and usage of the inkjet recording device 100 in the embodiments of the present invention will be described. Figure 1 This is a diagram showing the usage state of the inkjet recording device 100 in this embodiment.

[0030] First, such as Figure 1 As shown, the inkjet recording apparatus 100 of this embodiment includes: a main body 1; a printhead 2 connected to the main body 1 via a conduit 5 (for the printhead); and a cleaning unit 3 connected to the main body 1 via a conduit 6 for the cleaning unit.

[0031] The inkjet recording device 100 is installed, for example, on a production line in a factory producing food, beverages, etc. The main body 1 has the function of supplying ink for printing to the printhead 2 and recovering unused ink from the printhead 2. Furthermore, the main body 1 includes an ink container for holding ink, and an auxiliary ink container for replenishing ink to the ink container when the ink in the ink container has decreased due to printing. It also includes built-in paths for supplying and recovering ink and solvent, and on / off valve assemblies (solenoid valve assemblies) and pump assemblies along these paths. Further, the main body 1 includes a control unit (not shown) for controlling the printhead to perform printing, controlling the supply and recovery of ink and solvent, etc.; and an operation display unit 8 for displaying various states of the inkjet recording device when control commands are given to the control unit. Specifically, the control unit can be implemented using a conventional computer, as is generally known. That is, the control unit (computer) consists of an MPU (microprocessor unit) that executes control actions through a program, a ROM (read-only memory) that stores the program used to make the MPU operate, and RAM (random access memory) that stores data required for executing control. Since the structure of a computer is generally well-known, further explanation of the control unit is omitted here. The main body 1 is located in a space sufficient to ensure regular maintenance operations.

[0032] The printhead 2 is fixed to the printhead fixing metal part 13 located near the belt conveyor 11, and is positioned close to the belt conveyor 11 for printing the printing objects 12A and 12B conveyed in the direction of arrow X. Here, printing object 12A refers to the object to be printed before printing, and printing object 12B refers to the object to be printed after printing. Furthermore, the printhead 2 has a nozzle, charged electrode, deflection electrode, etc., mounted on the printhead base 16. Figure 1 (The part is not shown in the diagram). In addition, the printhead 2 is fitted with a cover 17 to protect these parts.

[0033] The cleaning unit 3, provided for cleaning the printhead 2, is installed near the conveyor 11 via a fixing clamp 92 and a fitting part 93 for engaging with the fixing clamp 92. The cleaning unit 3 includes: a cleaning tank 71; and cleaning nozzles (in...) for cleaning the printhead 2 installed in the cleaning tank. Figure 1 (Not shown in the figure); and a recovery container 4 for recovering cleaning fluid, etc. The conduit 6 is a conduit used to supply cleaning fluid from the main body 1 to the cleaning unit 3.

[0034] (Overall path structure)

[0035] Next, the path structure of the inkjet recording device 100 in the embodiments of the present invention will be described. Figure 2This is a diagram showing the overall path structure of the inkjet recording device in this embodiment.

[0036] exist Figure 2 In this inkjet recording device 100, there are a main body 1, a printhead 2, a cleaning unit 3, and conduits 5 and 6 connecting them. The main body 1 is connected to the printhead 2 via conduit 5. The main body 1 is connected to the cleaning unit 3 via conduit 6.

[0037] [Ink supply to the printhead]

[0038] First, the ink supply path (paths 801-803) for supplying ink from the main body 1 to the printhead 2 will be explained. Figure 2 In the main body 1, an ink container 31 is provided for pre-filling (storing) ink 68A for circulation.

[0039] The portion of ink container 31 immersed in ink 68A is connected to path 801. A viscosity meter 45 and a solenoid valve 49 for opening and closing the path for ink supply are located along path 801. The viscosity meter 45 is provided for measuring the viscosity of the ink.

[0040] Furthermore, path 801 is connected to pump 34, which is installed in path 802, via confluence path 901. Pump 34 is used to draw and pressurize ink 68A. Moreover, the output side of pump 34 is connected to filter 39 (for ink supply) for removing foreign matter mixed in ink 68A.

[0041] Filter 39 is connected to pressure regulating valve 46, which adjusts the pressure of ink 68A pumped from pump 34 to an appropriate level for printing. Pressure regulating valve 46 is connected to pressure sensor 47, which measures the pressure of ink 68A supplied to nozzle 21. Path 802, through which pressure sensor 47 is configured, is connected to printhead 2 via conduit 5. Specifically, it is connected to switching valve 26, which controls whether ink 68A is supplied to nozzle 21.

[0042] The switching valve 26 is connected via path 803 to a nozzle 21 having an outlet for discharging ink 68A. The switching valve 26 is a three-way solenoid valve. The switching valve 26 is connected to path 802 for ink supply and path 812 for nozzle cleaning, and can switch the supply of ink 68A and solvent 69A to the nozzle 21. In the straight-line direction of the nozzle 21's outlet, there is a charged electrode 23 for applying a predetermined amount of charge (the amount of charge applied corresponds to the printing content) to the ink particles 68B atomized by the nozzle 21; a deflection electrode 24 for deflecting the ink particles 68B corresponding to their charge; and a groove 25 for capturing ink particles 68B that are not being printed and are therefore not charged, traveling straight ahead without deflection. Printing is performed by having the ink particles 68B, deflected by the deflection electrode 24, strike the printed object.

[0043] [Ink recovery from the printhead]

[0044] Next, the ink return path (path 804) of the inkjet recording device 100 in this embodiment will be described. Figure 2 In this configuration, tank 25 is connected to path 804. Path 804, through conduit 5, is connected to filter 40 (for ink recycling), disposed within the main body 1, for removing foreign matter mixed into the ink. Filter 40 is connected to solenoid valve 50 (for ink recycling), which opens and closes path 804. Furthermore, solenoid valve 50 is connected to pump 35 (for ink recycling), which draws ink particles 68B captured by tank 25. Pump 35 is connected to ink container 31. In this configuration, ink particles 68B captured by tank 25 are recycled from ink container 31 by opening solenoid valve 50 and driving pump 35. Additionally, ink container 31, in its upper space not in contact with ink 68A, is connected to path 805, which communicates with the outside of the main body 1. Gas within ink container 31 can be released to the outside via path 805.

[0045] [Solvent supply route]

[0046] Next, the solvent supply path (paths 809 to 810) of the inkjet recording apparatus 100 in this embodiment will be described. Figure 2In the main body 1, a solvent container 33 is provided. This solvent container 33 is used to supply solvent 69A to the ink container 31 and to store (collect) solvent 69A for nozzle cleaning and head cleaning. The portion of the solvent container 33 immersed in solvent 69A is connected to a path 809, in which a pump 37 for suction and pressure delivery of solvent is arranged. The pump 37 is connected to a branch path 903 to change the destination of solvent 69A supply as needed. The branch path 903 is connected in the solvent supply path to a solenoid valve 53 arranged in path 810 for opening and closing the flow path. The solenoid valve 53 is connected to the ink container 31 via path 809.

[0047] In this structure, to supply solvent 69A to ink container 31, solenoid valve 53 is opened, driving pump 37. If the ink viscosity detected by viscosity meter 45 is higher than a specified value, solvent is supplied (replenished) to ink container 31 to bring the ink viscosity back to within the specified range.

[0048] [Ink supply path]

[0049] Next, the ink supply path of the inkjet recording device 100 in this embodiment will be described. Figure 2 In the main body 1, an auxiliary ink container 32 for maintaining replenished ink 68C is provided. The portion of the auxiliary ink container 32 immersed in ink 68C is connected to a path 811 for ink replenishment. Path 811 is connected to a solenoid valve 54 for opening and closing the path. The solenoid valve 54 is connected via a confluence path 901 to a pump 34 located in path 802 for drawing and pressing ink 68C. The ink 68C in the auxiliary ink container 32 is conveyed and supplied to the print head 2, passing through the nozzle 21 and slot 25, and flowing into the ink container 31 through the ink return path formed by path 804, solenoid valve 50, and pump 35. In this way, replenished ink 68C can be added to the ink container 31.

[0050] The timing for replenishing ink from the auxiliary ink container 32 to the ink container 31 is determined using the level detection value of a level detection device 31A that detects the ink level in the ink container 31. That is, a level detection device 31A is installed in the ink container 31, which detects whether the ink level in the ink container 31 has reached a reference level as an appropriate amount. The detection signal from the level detection device 31A is sent to a control unit (not shown), and the control unit performs ink replenishment control upon detecting the detection signal.

[0051] [Nozzle Cleaning]

[0052] Next, the nozzle cleaning paths (paths 809 and 812) will be explained. Figure 2 In this configuration, pump 37, located in path 809, is connected to path 812 via branch path 903. Path 812 is connected to solenoid valve 55 (for nozzle cleaning) for opening and closing the flow path. Solenoid valve 55 is connected to filter 41 (for nozzle cleaning) for removing foreign matter mixed into solvent 69A. Filter 41 is positioned along path 812 within conduit 5 and connected to switching valve 26, which controls whether solvent 69A for cleaning is supplied to nozzle 21. In this configuration, by opening solenoid valve 55, pump 37 is driven, and solvent from solvent container 33 is supplied to the nozzle to clean nozzle 21.

[0053] [Cleaning Unit]

[0054] Next, the basic structure of the cleaning unit 3 of the inkjet recording device 100 in this embodiment will be described.

[0055] exist Figure 2 The cleaning unit 3 for cleaning the printhead 2 includes: a cleaning tank 71 with an opening on its upper surface and a storage space therein for inserting (installing) the printhead 2; a cleaning nozzle 72 for spraying cleaning fluid to clean the printhead 2 installed in the cleaning tank 71; and an air nozzle 73 for spraying dry air to dry the cleaned printhead 2. It also includes: a cleaning base 600 with a storage portion for the front end of the printhead into which the cleaning fluid sprayed from the cleaning nozzle 72 can flow; and a recovery container 4 installed at the bottom of the cleaning tank 71 for recovering the cleaning fluid 69B flowing out from the opening at the bottom of the cleaning tank.

[0056] In this embodiment, the cleaning fluid used in the cleaning unit 3 is solvent 69A stored in solvent container 33. For this purpose, the solvent 69A in solvent container 33 is connected to path 809 at the immersion point, and a pump 37 disposed along path 809 is connected to path 821 via branch path 903. Path 821 is connected to the cleaning nozzle 72 of cleaning unit 3. A solenoid valve 56 for opening and closing the flow path is disposed along path 821. With this structure, by opening the solenoid valve 56 to control the pump 37, the solvent 69A in solvent container 33 can be supplied as "cleaning fluid" to the cleaning nozzle 72 within cleaning unit 3. Alternatively, the cleaning fluid can be supplied from a cleaning fluid supply device disposed outside the solvent container of the main body 1.

[0057] In addition, after the printhead is cleaned, air is ejected from the air nozzle 73 to dry the printhead 2. The air nozzle 73 is connected to the path 825, and by driving the pump 38 located in the path 825, air can be ejected from the air nozzle 73 into the cleaning tank 71. Furthermore, the main body 1 and the cleaning unit 3 are connected by a conduit 6. The recovery container 4 is provided to collect the cleaning fluid 69B after cleaning. When the cleaning fluid 69B in the container is above a certain level, the recovery container 4 is removed to drain the cleaning fluid 69B. The empty recovery container 4, after draining the cleaning fluid 69B, is reinstalled at the bottom of the cleaning tank 71 to collect the cleaning fluid 69B. After the printing operation is completed, the operator uses the operation display unit 8 (see reference 8). Figure 1 The system operates by instructing the control unit (not shown) to perform a cleaning process, thereby cleaning printhead 2. Alternatively, the cleaning of printhead 2 can be performed automatically by the control unit after the printing operation is completed. The process control of the series of cleaning actions will be described later.

[0058] Furthermore, a liquid level detection device 4A is provided in the recovery container 4 of the cleaning unit 3. The liquid level detection device 4A includes a floating member 74 that can move up and down in response to the liquid level within the recovery container 4; and a holding member 75 that holds the floating member 74. Additionally, a sensor 76 is provided on the outside of the recovery container 4, which outputs a liquid level detection signal when the floating member 74 moves closer due to its up-and-down movement. The detection signal from the sensor 76 is sent to a control unit (not shown). Here, because the sensor 76 is located outside the recovery container 4, it does not obstruct the disassembly or installation of the recovery container 4. When the cleaning fluid 69B in the recovery container 4 accumulates to the amount that should be drained, the control unit (not shown) inputs the liquid level detection signal from the sensor 76, and... Figure 1 The operation display unit 8 shown presents a warning. This warning display allows the operator to determine the timing for draining the recovery container 4. Alternatively, the cleaning fluid can be drained from the cleaning tank 71 without disassembly by installing a check valve or similar device at the bottom of the recovery container 4.

[0059] (Structure of the print head)

[0060] Next, use Figure 3 The structure of the printhead 2 of the inkjet recording device 100 in this embodiment will be described. Figure 3 This is a perspective view of the printhead in this embodiment. Figure 3 (A) shows a perspective view of the printhead 2 with the cover 17 installed, and (B) shows a perspective view of the printhead 2 with the cover 17 removed.

[0061] exist Figure 3In (A), the printhead 2 includes: a printhead base 16; a conduit (for the printhead) 5 connecting the main body 1 and the printhead 2; a protective cover 18 installed to protect the switching valve 26 (not shown) provided on the printhead base 16; a printhead cover 17 installed on the protective cover 18 via a fixing button 19; and a printhead tip 28, on which a printing opening 28A for through-holes for ink particles is formed. When the printhead cover 17 is installed, the space surrounded by the printhead base 16, the printhead cover 17, and the printhead tip 28 is protected from impacts during maintenance. The components surrounded by the printhead cover 17 become the space for maintenance by operators performing routine work. Furthermore, the internal area surrounded by the printhead base 16 and the protective cover 18 becomes the area for maintenance by service personnel.

[0062] Next, regarding Figure 3 (B) The printhead 2 is described with the head cover 17 removed. A nozzle 21, a charged electrode 23, a deflection electrode 24, a groove 25, and a front end 28 are mounted on the head base 16. In addition, a tube (for supply) 802A and a tube (for cleaning) made of solvent-resistant material are connected to the nozzle 21.

[0063] Furthermore, in the printhead 2, a spacer 20 is installed between the printhead base and the protective cover 18 so that the inside of the protective cover 18 is not exposed even when the printhead cover 17 is removed. Additionally, a sensor 27 is installed in the spacer 20, which can detect whether the printhead cover 17 is installed and whether the printhead 2 is installed in the cleaning unit 3.

[0064] In addition, to improve the ease of maintenance of the nozzle 21, the front end 28 can also be a detachable structure.

[0065] (The specific structure of the cleaning unit)

[0066] Next, use Figure 4 The specific structure of cleaning unit 3 will be described.

[0067] exist Figure 4 In the cleaning tank 71, a cover assembly 81 is provided at the upper part. The cover assembly 81 has a printhead insertion part 81A, which allows the printhead 2 to be inserted into the cleaning tank 71. A cover member 83 is provided on the lower surface of the insertion part 81A, which is normally closed due to the spring force of the cover hinge 82. This structure is used to prevent debris and other contaminants from entering the cleaning tank 71. 85 indicates a cover for protecting the piping section.

[0068] When cleaning the printhead 2, the operator inserts the printhead 2 into the cleaning tank 71 through the insertion part 81A. At this time, the cover part 83, which is closed by the spring force of the cover hinge 82, rotates, and the printhead 2 is installed in the cleaning tank 71. At this time, a proximity sensor 86 located near the insertion part 81A can detect whether the printhead 2 has been inserted into the cleaning unit 3. Its detection signal is sent to the control unit (not shown). The cleaning fluid sent to the cleaning unit 3 through the path 822 flows into the cleaning nozzle 72 through the liquid delivery connector 84. A filter 43 is provided along the path 822 to remove debris from the cleaning fluid. The cleaning nozzle 72 sprays cleaning fluid corresponding to the cleaning part of the printhead 2 that has been inserted (received) for cleaning. In this embodiment, the cleaning nozzle 72 has two liquid discharge holes 72A and 72B. In addition, the air nozzle 73, which is provided to dry the cleaned printhead 2, also has two air discharge holes 73A and 73B. The recycling container 4 is mounted on the lower part of the cleaning tank 71 via a threaded mounting part 71A, allowing for installation and removal of the recycling container 4. Inside the recycling container 4, a liquid level detection device 4A is installed to detect the liquid level. This liquid level detection device 4A includes: a floating member 74 disposed within a holding member 75; a magnet disposed within the floating member 74; and a sensor 76 that detects the position of the floating member 74 by detecting the magnetic force of the magnet. The sensor 76 is mounted outside the container, and the position detection signal detected by the sensor 76 is transmitted to a control unit (not shown) via a wire 76A.

[0069] In addition, Figure 4 In this text, 600 represents the cleaning base section. The cleaning base section 600 is disposed within the cleaning tank 71. The front end of the printhead 2 is cleaned using this cleaning base section 600. In this example, the cleaning base section 600 is suspended by a support rod 78, which serves as a support member. Since the cleaning base section 600 can be installed within the cleaning tank 71, the support structure can be of any type. The cleaning base section 600 has a receiving section 602 that houses the front end of the printhead 2 and into which cleaning fluid can flow. Furthermore, the bottom of the receiving section 602 is an inclined surface, and a fluid passage hole 604 is formed at the lowest point of the bottom surface. The cleaning fluid ejected from the cleaning nozzle 72, after cleaning the internal components of the printhead 2, flows down and into the receiving section 602. The front end of the printhead 2 is cleaned by the cleaning fluid flowing into the receiving section 602. Moreover, the cleaning fluid accumulated in the receiving section 602 flows downward through the fluid passage hole 604. Details regarding the specific structure of the cleaning base section 600 will follow later. Figure 7 Please provide an explanation.

[0070] (Cleaning actions in the cleaning unit)

[0071] Next, use Figure 5 right Figure 4The cleaning action performed by the cleaning unit 3 on the printhead 2 will be explained. Figure 5 This is a cross-sectional view of the cleaning unit with the printhead 2 installed in the cleaning unit 3. The printhead 2 is installed (inserted) into the cleaning unit 3 during cleaning. The printhead cover 17 is removed during installation.

[0072] After the printhead 2 is installed in the cleaning tank 71 of the cleaning unit 3, cleaning begins by spraying cleaning fluid from the cleaning nozzle 72. The cleaning nozzle 72 sprays cleaning fluid toward the printhead 2 as indicated by arrows J and K. While cleaning the nozzle 21, charged electrode 23, deflection electrode 24, and tank 25 installed on the printhead 2, the cleaning fluid flows downwards due to gravity as indicated by arrow L. Afterwards, the cleaning fluid flows into and accumulates in the receiving section 602 of the cleaning base section 600. The cleaning fluid accumulated in the receiving section 602 remains in the receiving section 602 and cleans the front end 28 of the printhead 2. Then, the cleaning fluid flows through the inner surface of the receiving section 602 and flows out from the liquid passage 604 provided on the bottom surface, at which time the cleaning fluid also cleans the front end 28 of the printhead 2. The cleaning fluid, after cleaning the front end face of the printhead, flows from the receiving section 602 to the recovery container 4 as indicated by arrow M, and is collected (accumulated) inside the recovery container 4. When the cleaning of printhead 2 is finished, the cleaning nozzle 72 stops spraying cleaning fluid. At this stop, air begins to spray from the air nozzle 73, drying printhead 2.

[0073] In this way, the cleaning of the cleaning unit, including the front end of the printhead, is carried out automatically.

[0074] (Cleaning the base)

[0075] Next, the specific structure and function of the cleaning base 600 used for cleaning the front end of the printhead 2 will be explained. Here, four examples of the structure of the cleaning base 600 will be described, but the cleaning base of the present invention is not limited to the manner described herein.

[0076] [First cleaning step: base section]

[0077] First, use Figure 6 The structure of the first cleaning base section will be explained. Figure 6 (A) is a top view of the liquid-flow cleaning base 600 viewed from above the cleaning unit 3, and (B) is a cross-sectional view of (A) along the X-X axis.

[0078] exist Figure 6In the design, two holes 601 are for mounting support rods 78. By mounting the support rods 78 through these holes, the cleaning base 600 is supported within the cleaning tank. A receiving portion 602 of a predetermined depth is provided in the central part of the cleaning base 600. This receiving portion 602 receives the front end of the printhead 2, and the accumulated cleaning fluid is stored inside. The front end 28 of the printhead is cleaned using the accumulated cleaning fluid. Furthermore, to enhance the cleaning effect, a vibrator is installed in the cleaning base 600 to vibrate the cleaning fluid for effective cleaning.

[0079] In this configuration, when the cleaning process of printhead 2 ends, the front end 28 remains immersed in the cleaning solution and cannot be dried. Therefore, in the cleaning base portion 600 of this structure, after cleaning, the support rod 78 is moved downwards to remove the front end of printhead 2 from the cleaning solution for drying. Specifically, the support rod 78 is moved downwards by a drive unit (not shown) to remove the front end 28 from the cleaning solution surface within the receiving portion 602. After this movement, air is ejected from the air nozzle 73 to dry the printhead 2. Figure 6 The storage section 602 shown adopts a structure in which the central part of the cleaning base section 600 is removed to form a recessed space for accumulating liquid. However, as with the cleaning base section described later, the storage section 602 can also be formed by providing wall sections on all four sides of the central part of the cleaning base section 600.

[0080] [Second cleaning base section]

[0081] Next, use Figure 7 The structure of the second cleaning base section 600 will be described. Figure 7 The cleaning base portion 600 shown is the one described above. Figure 4 The detailed structure of the cleaning base section 600 is shown. Figure 7 (A) is a top view of the cleaning base 600 with a liquid passage in the storage section 602, and (B) is a cross-sectional view of (A) along the X-X axis.

[0082] exist Figure 7 In the middle, the three holes 601 are the locations for mounting the support rods 78. By mounting the support rods 78 in the holes 601, the cleaning base part 600 is supported. Figure 7 The storage section 602 is formed by walls 602A to 602D provided on four sides. Alternatively, the storage section 602 may not be formed by walls, but rather... Figure 6This is achieved by removing a portion of the base portion. The space 603 inside the receiving portion 602 houses the front end of the printhead 2, and cleaning fluid, used to clean the internal components of the printhead 2 (nozzles, charged electrodes, deflection electrodes, grooves, etc.), flows into and accumulates therein. The cleaning fluid accumulates in this space 603 such that the front end 28 of the printhead is immersed in it. Using this cleaning fluid, ink and other contaminants adhering to the front end of the printhead can be cleaned.

[0083] The front end 28 of the head is cleaned by accumulating cleaning fluid, and... Figure 6 The situation is the same, but Figure 7 The cleaning base portion 600 has a flow hole 604 formed at the bottom 605 of the storage portion 602 for allowing the cleaning fluid to flow out. 622 indicates a filter installed above the flow hole 604 at the bottom 605. This filter 622 removes impurities such as debris from the cleaning fluid. Furthermore, the lower part of the storage portion 602, according to... Figure 7 As shown in (B), an inclined surface is formed on the bottom surface facing the liquid passage 604. With this structure, the temporarily accumulated cleaning fluid cleans the front end 28 of the head and flows out through the liquid passage 604. The cleaning fluid flowing out cleans the front end 28 of the head through its flow action. Therefore, with... Figure 6 Compared to the previous case, the cleaning performance is improved.

[0084] so, Figure 7 The liquid passage 604 allows for the accumulation of cleaning fluid for a limited time when the cleaning nozzle sprays the cleaning fluid, enabling cleaning through the accumulated fluid. Furthermore, the cleaning fluid experiences active flow as it exits the liquid passage 604 from the bottom surface, resulting in improved cleaning performance. Additionally, its inclined design further enhances fluidity, making it preferable for improved cleaning performance. To achieve this effect, the size of the liquid passage 604 is configured such that the flow rate entering the space 603 is greater than the flow rate of the cleaning fluid exiting the liquid passage 604.

[0085] When the cleaning process ends and the cleaning fluid stops spraying from the cleaning nozzle 72, the cleaning fluid accumulated in the collection section 602 naturally falls and flows through the fluid passage 604 into the recovery container 4. Furthermore, because the bottom 605 is inclined, the cleaning fluid can flow completely into the recovery container 4 without remaining in the space 603. Once the cleaning fluid has drained, air is ejected from the air nozzle 73 to dry the printhead 2.

[0086] Furthermore, the method for allowing the cleaning fluid to accumulate for a specified time is not limited to providing the fluid passage 604. For example, a cap that opens and closes when a certain amount of fluid has accumulated can also be provided. Additionally, a solenoid valve can be provided to electrically control the outflow of the cleaning fluid. Furthermore, by spraying the cleaning fluid in multiple stages, the cleaning performance can be improved.

[0087] [Third cleaning unit: base section]

[0088] Next, use Figure 8 The structure of the third cleaning base section 600 will be described. Figure 8 (A) is a top view of the cleaning base 600 with a liquid passage in the storage section 602, and (B) is a cross-sectional view of (A) along the X-X axis.

[0089] Figure 8 The cleaning base section 600 shown is basically the same as Figure 7 The structure of the cleaning base 600 shown is similar. The difference lies in the size of the liquid inlet 604. That is, Figure 8 The size of the liquid inlet 604 is such that the cleaning fluid flowing into the receiving section 602 does not accumulate in the receiving section 602, but flows directly toward the liquid inlet 604. The front end 28 of the head is cleaned through the flow of this cleaning fluid. That is, in Figure 7 In this case, the structure employs both cleaning methods utilizing accumulated cleaning fluid and cleaning methods utilizing liquid flow, but... Figure 8 In this case, the cleaning method mainly relies on liquid flow for cleaning, with almost no use of accumulated cleaning fluid. Because the cleaning base 600 of this structure hardly accumulates cleaning fluid in the storage section 602, the drying process via air nozzles can begin immediately after the cleaning unit 3 finishes cleaning.

[0090] [4th cleaning base section]

[0091] Next, use Figure 9 The structure of the fourth cleaning base section 600 will be explained. Figure 9 (A) is a top view of the cleaning base 600, which is divided into two parts: the first base part and the second base part. (B) is a cross-sectional view of (A) along the X-X axis.

[0092] Figure 9 The cleaning base section 600 is basically the same as Figure 7 The cleaning base shown is the same. However, Figure 9 The cleaning base 600 is a dual-component structure having a liquid storage section 610 as a first base and a liquid passage section 620 as a second base. The liquid storage section 610 and the liquid passage section 620 are connected by a structure that is easy to assemble and disassemble.

[0093] The liquid storage section 610 has a protrusion 611 for positioning the printhead 2 within the hole 601 and the receiving section 602 (composed of walls 602A to 602D). It is further configured by the upper part 621 of the liquid passage section 620 and the hole 612 through which the filter 622 can enter. The upper part of the protrusion 611 is sloped. Therefore, when the printhead 2 is inserted into the cleaning base section 600, the cleaning liquid installed in the receiving section 602 is sprayed to the appropriate position at the most suitable location. Furthermore, because the protrusion 611 contacts the front end 28 of the printhead, after cleaning, some of the cleaning liquid remaining on the front end 28 can be circulated using capillary action. This shortens the drying time of the printhead 2.

[0094] The fluid passage 620 includes a fluid passage hole 604, a filter 622, and an O-ring 623. External dust and other contaminants are highly likely to adhere to the front end 28 of the head, and these contaminants may be washed away by the cleaning fluid, clogging the fluid passage hole 604. Therefore, to reduce the frequency of clogging of the fluid passage hole 604, a filter 622 is provided at the upper part 621 of the fluid passage 620.

[0095] Here, the filter 622 is an integral part of the liquid passage section 620, so the filter 622 can be replaced simultaneously by replacing the liquid passage section. However, it is not limited to an integral structure; for example, the filter 622 can also be a structure in which the filter 622 is fixed to the upper part by a protrusion. In this case, after removing the liquid passage section 620, only the filter 622 can be replaced. At this time, the liquid passage hole 604 and the like are cleaned, a new filter 622 is installed, and the liquid passage section 620 is reinstalled in the liquid storage section 610.

[0096] A gap is generated between the hole 612 of the liquid storage section 610 and the upper part 621 of the liquid passage section 620 and the filter 622. Here, by providing an O-ring 623 in the gap (connection) between the hole 612 and the upper part 621, cleaning fluid can be stored in the space 603.

[0097] Furthermore, it is also possible to consider the scenario where the fluid passage 604 and filter 622 are clogged, and liquid remains in the space 603 when the fluid passage 620 is replaced. In this case, there is a concern that the accumulated cleaning fluid may flow to the operator's side when the fluid passage 620 is disassembled. Therefore, a bag-shaped portion 624 is provided to receive the flowing cleaning fluid. The volume of this bag-shaped portion 624 is larger than the volume of the space 603. In addition, in order to make it possible to visually confirm the flow of cleaning fluid, it is preferable that the bag-shaped portion 624 is made of a transparent or semi-transparent material. Furthermore, since there is a possibility that the fluid passage may be disassembled without noticing the flow of cleaning fluid, for example, the connection between the liquid storage portion 610 and the fluid passage 620 can be made into a threaded structure, with a greater number of threads and engagement length.

[0098] Furthermore, in the cleaning described above, a cleaning fluid was used to clean the internal components of the printhead 2, but the method for cleaning the front end 28 of the printhead is not limited to this method. For example, a cleaning nozzle capable of directly spraying cleaning fluid to the front end 28 of the printhead can be provided in addition to the cleaning nozzle used for internal cleaning.

[0099] (Cleaning control procedure)

[0100] Next, use Figure 10 The cleaning control procedure is explained. After the printing operation is completed, the printhead 2 is cleaned under the control of the control unit (not shown).

[0101] First, since the printing job is finished, ink ejection from the nozzle stops. This state is step S01. Due to step S01, the printhead 2 can be cleaned. In step S02, the operator removes the printhead cover 17 from the printhead 2 and checks whether the internal components and the front end 28 of the printhead are dirty due to ink or other contaminants. If it is determined that cleaning is necessary, the operator inserts the printhead 2 into the cleaning unit 3.

[0102] Next, in step S03, the operation display unit 8 (see reference 8) provided in the inkjet recording device 100 is used. Figure 1 The control unit is instructed to start the head cleaning function of cleaning unit 3.

[0103] In step S04, when the printhead cleaning function begins, the sensor 27 installed in the cleaning unit 3 detects whether the printhead 2 is installed in the cleaning unit. Here, if the printhead 2 is detected to be inserted (yes), proceed to step S08. If the printhead 2 is not detected to be inserted (no), proceed to step S05.

[0104] In step S05, the automatic cleaning process is paused. Next, in step S06, an alarm is displayed on the operation display unit 8 (e.g., "No head inserted"). The operator may also be notified by a buzzer or similar means. Then, in step S07, the head cleaning process is stopped. This prevents the unnecessary use of cleaning fluid in cases of operator error.

[0105] In step S08, a process control is performed to spray cleaning fluid from the cleaning nozzle 72 to clean the internal components of the head and the front end 28 of the head. Since details of this process control have already been explained, they are omitted here. During this cleaning process, intermittent spraying of the cleaning fluid improves cleaning performance by using a small amount of cleaning fluid. When cleaning is complete, proceed to step S09.

[0106] Next, in step S09, a process control is performed to discharge dry air from the air nozzle 73 to dry the print head 2. At this time, the dry air is branched, with one portion sprayed towards the internal components and the other towards areas prone to solvent gas leakage. This suppresses the concentration of solvent gas discharged to the outside during drying. Furthermore, as a method to suppress solvent gas concentration, a suction pump is provided to draw the generated solvent gas back to the main body 1.

[0107] Step S09 can also begin when the cleaning fluid sprayed in step S08 is stored in the receiving section 602. Furthermore, the operation can be configured such that the actions of steps S08 and S09 can be confirmed by the operation display section 8, allowing the operator to pause the head cleaning process at a desired time.

[0108] When the cleaning process is completed, proceed to step S10 to stop the printhead cleaning. After stopping, the end screen of printhead cleaning is displayed on the operation display unit 8.

[0109] In step S11, the operator removes the printhead 2 from the cleaning unit 3 and installs the printhead cover 17 on the printhead 2. Then, by installing the printhead 2 on the printhead fixing metal part 13, printing can be started again.

[0110] Furthermore, even when the inkjet recording device 100 is stopped, the printhead 2 can remain mounted on the cleaning unit 3. Subsequently, if the printhead cleaning process is performed when the inkjet recording device 100 is started, it also has the effect of reducing problems such as ink particles turning and being drawn back into the inkwell during startup.

[0111] Alternatively, in steps S08 and S09, the operator can select different times for the cleaning fluid to be sprayed and the drying air to be sprayed. Furthermore, the system may also include a function allowing the operator to set the timing of each step.

[0112] Furthermore, the inkjet recording device 100 can be configured to save records of head cleaning processes. By configuring this function, the amount of solvent used can be calculated. Therefore, for example, if the cleaning fluid accumulated in the recovery container reaches the recommended waste liquid level, information about the cleaning fluid accumulated in the waste recovery container can be displayed after step S10. Moreover, when the sensor 76 detects that the recovery container has been removed, the liquid level in the recovery container is reset. Thus, even if the liquid level detection device malfunctions, the operator can be notified to perform waste liquid timing before the recovery container is filled with cleaning fluid.

[0113] Other embodiments of the present invention

[0114] This invention is not limited to the embodiments described above, but includes modifications that alter the structure without departing from the technical concept and intent of the invention. Furthermore, the embodiments described above have been detailed to facilitate understanding of the invention, and the invention is not limited to all described structures. Moreover, it is possible to add, delete, or replace other structures within a portion of the structure of the embodiments.

[0115] Explanation of reference numerals in the attached figures

[0116] 1…Main body, 2…Print head, 3…Cleaning unit, 4…Recovery container, 4A…Level detection device, 5…Conduit, 6…Conduit, 8…Operation display, 11…Belt conveyor, 12A…Printing object, 12B…Printing object, 13…Metal part for fixing print head, 16…Print head base, 17…Print head cover, 18…Protective cover, 21…Nozzle, 23…Electrically charged electrode, 24…Deflection electrode, 25…Groove, 26…Switching valve, 27…Sensor, 28…Print head tip, 28A…Printing opening, 31…Ink container, 31 A… Liquid level detection device, 32… Auxiliary ink container, 33… Solvent container, 34… Pump, 35… Pump, 37… Pump, 38… Pump, 39… Filter, 40… Filter, 41… Filter, 43… Filter, 45… Viscometer, 46… Pressure regulating valve, 47… Pressure sensor, 49… Solenoid valve, 50… Solenoid valve, 53… Solenoid valve, 54… Solenoid valve, 55… Solenoid valve, 56… Solenoid valve, 68A… Ink, 68B… Ink particles, 68C… Ink, 69A… Solvent, 69B… Cleaning fluid, 71… Cleaning tank 71A… Mounting part, 72… Cleaning nozzle, 72A… Liquid discharge port, 72B… Liquid discharge port, 73… Air nozzle, 73A… Air discharge port, 73B… Air discharge port, 74… Floating part, 75… Holding part, 76… Sensor, 76A… Wire, 78… Support rod, 81… Cover assembly, 81A… Insertion part, 82… Cover hinge, 83… Cover part, 84… Liquid delivery connector, 85… Cover, 86… Proximity sensor, 91… Fixing clamp (for main body), 92… Fixing clamp, 93… Fitting part, 100… Inkjet recording device, 600…cleaning base section, 601…hole, 602…receiving section, 602A~602D…wall, 603…space, 604…liquid passage hole, 605…bottom, 610…liquid accumulation section, 611…protrusion, 612…hole, 620…liquid passage section, 621…upper section, 622…filter, 623…O-ring, 624…bag-shaped section, 801~805…path, 809~811…path, 821…path, 822…path, 825…path, 901…merging path, 903…branching path.

Claims

1. An inkjet recording device, characterized in that, include: The printhead has a nozzle that atomizes and ejects supplied ink, an electrode that charges the ink particles ejected from the nozzle, a deflection electrode that deflects the charged ink particles passing through the electrode, and a tank for recycling unused ink during printing. The main body has an ink supply path for supplying ink from the ink container to the printhead, an ink recovery path for recovering unused ink during printing back to the ink container, and a solvent supply path for supplying solvent from the solvent container to the ink container. The main control unit that controls the movement of the print head; and The printhead mounting unit includes a printhead mounting section for mounting the printhead and a recovery container for collecting solvents used during cleaning. The printhead mounting unit has a cleaning base portion for receiving the front end of the printhead and for cleaning solvent inflow into the front end of the printhead. The printhead is cleaned by the solvent while it is mounted in the printhead mounting unit. The cleaning base has a receiving portion that houses the front end of the printhead and allows the solvent to flow in. After cleaning the nozzles, charged electrodes, deflection electrodes, and grooves of the printhead, the solvent flows downwards into the receiving section. The front end of the printhead is cleaned by the solvent flowing into the receiving section. The cleaning base portion has a liquid passage hole for allowing solvent that has cleaned the front end of the printhead to flow out from below, and an inclined surface formed toward the liquid passage hole. The liquid passage is sized to allow the solvent flowing into the receiving part to accumulate within the receiving part for a specified time. The front end of the printhead is cleaned by the solvent flowing into the receiving part through a first process of cleaning by the solvent that has accumulated in the receiving part for the specified time, and a second process of cleaning by the solvent that flows out from the liquid passage along the inclined surface.

2. The inkjet recording device as claimed in claim 1, characterized in that: The cleaning base portion has a side wall portion, which is configured to cover the front end of the print head when the print head is mounted in the head mounting unit.

3. The inkjet recording device as described in claim 1, characterized in that: In the second process, as the solvent flows out of the liquid passage, the front end of the printhead is cleaned by the flow of the generated solvent.

4. The inkjet recording device as claimed in claim 1, characterized in that: The size of the liquid inlet is set such that the flow rate of the solvent flowing into the receiving part is greater than the flow rate flowing out of the liquid inlet, thereby allowing the solvent to accumulate in the receiving part for a specified time.

5. The inkjet recording apparatus according to any one of claims 1 to 4, characterized in that: The head mounting unit has a cleaning nozzle, to which solvent is supplied to clean the printhead.

6. The inkjet recording apparatus according to any one of claims 1 to 4, characterized in that: The head mounting unit has an air nozzle for supplying air, and the main body is provided with an air supply section for supplying air to the air nozzle.

7. A recording device, characterized in that, include: Main body, print head, and head mounting unit on which the print head is mounted. The main body has an ink container for storing ink used for printing on the object being printed and for supplying ink to the print head. The printhead has a nozzle connected to the ink container and discharging pressurized ink, a charged electrode for charging ink particles discharged from the nozzle, a deflecting electrode for deflecting the charged ink particles passing through the charged electrode, and a tank for recycling unused ink during printing. The printhead mounting unit includes a printhead mounting section for mounting the printhead, a recovery container for collecting solvent used in cleaning, and a cleaning base section for collecting the front end of the printhead and for receiving solvent flowing into the front end of the printhead during cleaning. The printhead is cleaned by the solvent while it is mounted in the printhead mounting unit. The cleaning base has a receiving portion that houses the front end of the printhead and allows the solvent to flow in. After cleaning the nozzles, charged electrodes, deflection electrodes, and grooves of the printhead, the solvent flows downwards into the receiving section. The front end of the printhead is cleaned by the solvent flowing into the receiving section. The cleaning base portion has a liquid passage hole for allowing solvent that has cleaned the front end of the printhead to flow out from below, and an inclined surface formed toward the liquid passage hole. The liquid passage is sized to allow the solvent flowing into the receiving part to accumulate within the receiving part for a specified time. The front end of the printhead is cleaned by the solvent flowing into the receiving part through a first process of cleaning by the solvent that has accumulated in the receiving part for the specified time, and a second process of cleaning by the solvent that flows out from the liquid passage along the inclined surface.

8. The recording apparatus as claimed in claim 7, characterized in that: The cleaning base portion has a side wall portion, which is configured to cover the front end of the print head when the print head is mounted in the head mounting unit.

9. The recording apparatus as claimed in claim 7, characterized in that: In the second process, as the solvent flows out of the liquid passage, the front end of the printhead is cleaned by the flow of the generated solvent.

10. The recording apparatus as claimed in claim 7, characterized in that: The size of the liquid inlet is set such that the flow rate of the solvent flowing into the receiving part is greater than the flow rate flowing out of the liquid inlet, thereby allowing the solvent to accumulate in the receiving part for a specified time.

11. The recording apparatus according to any one of claims 7 to 10, characterized in that: The head mounting unit has a cleaning nozzle, to which solvent is supplied to clean the printhead.

12. The recording apparatus according to any one of claims 7 to 10, characterized in that: The head mounting unit has an air nozzle for supplying air, and the main body is provided with an air supply section for supplying air to the air nozzle.

Images