JP2018030047A - Ink jet device, and ink jet device cleansing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet device capable of cleaning the inside of an ink jet head efficiently and suppressing the production of waste ink.SOLUTION: An approach route transports ink from an ink tank to an ink jet head, and a return route transports the ink in a reverse direction. A bypass passage transports the ink from the approach route to a return route not through the ink jet tank. The washing route feeds a washing liquid to the ink jet head and recovers the washing liquid from the ink jet head. A changeover part switches a circulation state, in which the ink is circulated in a circulation passage including the approach route, the ink jet head, the return route and an ink tank, and a cleaning state, in which the ink is circulated in a circuit containing the approach route, the ink jet head, the return route and the ink tank, and in the cleaning state, in which the ink is circulated in the circuit containing the approach route, the bypass passage, the return passage and the ink tank, and a cleaning state, in which the ink is circulated in a circulation passage containing the approach route, the bypass route, the return route and the ink tank, and the cleaning state, in which the ink jet head is rinsed by performing the feed of the cleaning fluid via the cleaning route, and in which the feed of the cleaning liquid via the rinsing passage to the ink jet head, and the recovery of the washing liquid via the washing liquid from the ink jet head.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inkjet device and a method for cleaning an inkjet device.

  An ink jet printer that forms a resist film for patterning a conductor formed on the surface of a substrate by discharging ink from an ink jet head is known (Patent Document 1).

  When ink having a high viscosity at room temperature is used, the ink must be heated in order to reduce the viscosity to such an extent that it can be ejected from the inkjet head. When the operation of the apparatus is stopped after film formation by the ink jet printer, the viscosity of the ink remaining in the ink jet head increases. A number of fine ink flow paths are formed in the inkjet head. The high-viscosity ink remaining in the ink-jet head causes clogging of the fine ink flow path.

Japanese Patent Laying-Open No. 2015-133453

  Before the operation of the apparatus is stopped, the ink remaining in the inkjet head can be sucked to reduce the residual amount of ink. However, it is difficult to completely discharge ink from the inkjet head by this method. By cleaning the ink supply system from the ink tank to the inkjet head with the cleaning liquid, the ink in the inkjet head can be discharged. However, in this method, since the cleaning liquid remains in the ink supply system, it is necessary to wash (co-wash) the supply system with ink when the operation is resumed. For this reason, waste ink is generated.

  An object of the present invention is to provide an inkjet apparatus and an inkjet apparatus cleaning method that can efficiently clean the inside of the inkjet head and suppress the generation of waste ink.

According to one aspect of the invention,
An inkjet head that ejects ink;
An ink tank for storing the ink;
A forward path for transporting the ink from the ink tank to the inkjet head;
A return path for transporting the ink from the inkjet head to the ink tank;
A bypass flow path for transporting the ink from the forward path to the return path without passing through the inkjet head;
A cleaning flow path for supplying a cleaning liquid to the inkjet head and collecting the cleaning liquid from the inkjet head;
A circulation state in which the ink is circulated through the circulation path including the forward path, the inkjet head, the return path, and the ink tank, and the ink in the circulation path including the forward path, the bypass flow path, the return path, and the ink tank. And the cleaning state in which the inkjet head is cleaned can be switched by supplying the cleaning liquid to the inkjet head through the cleaning flow path and collecting the cleaning liquid from the inkjet head. An ink jet device having a switching unit is provided.

According to another aspect of the invention,
A method of cleaning an ink jet apparatus that discharges the ink from the ink jet head while circulating ink between the ink tank and the ink jet head,
A method for cleaning an ink jet apparatus, wherein the ink heading from the ink tank toward the ink jet head is turned back before flowing into the ink jet head and circulated without passing through the ink jet head, and a cleaning liquid is supplied to the ink jet head for cleaning. Is provided.

  Since the cleaning liquid does not flow in the flow path in which the ink is circulated during the cleaning, the cleaning liquid does not remain after the cleaning. By allowing the cleaning liquid to flow only in part of the ink flow path, the inside of the inkjet head can be cleaned efficiently and the generation of waste ink can be suppressed.

FIG. 1 is a schematic diagram of an inkjet apparatus according to an embodiment. FIG. 2A is a schematic view of an ink jet apparatus when a film is formed on a substrate by ejecting ink from the ink jet head, and FIG. 2B is a schematic view of the ink jet apparatus when the ink jet head is washed. . 3A and 3B are schematic views of a circulation state and a cleaning state of an ink jet apparatus according to another embodiment, respectively. FIG. 4 is a schematic view of an inkjet apparatus according to still another embodiment. FIG. 5 is a schematic view of an inkjet apparatus according to still another embodiment. FIG. 6 is a schematic view of an inkjet apparatus according to still another embodiment. FIG. 7 is a schematic view of an inkjet apparatus according to still another embodiment.

  With reference to FIG. 1, FIG. 2A, and FIG. 2B, the inkjet apparatus by the Example and its washing | cleaning method are demonstrated.

  FIG. 1 is a schematic diagram of an inkjet apparatus according to an embodiment. The inkjet head 10 and the ink tank 11 are connected by the forward path 12 and the return path 13. The inkjet head 10 has a plurality of nozzle holes, and ejects ink droplets from the nozzle holes. The ink tank 11 stores ink. The forward path 12 transports ink from the ink tank 11 to the inkjet head 10. The return path 13 transports ink from the inkjet head 10 to the ink tank 11. A circulation path for circulating ink is formed by the ink tank 11, the forward path 12, the inkjet head 10, and the return path 13. The heating device 40 heats the ink in the ink tank 11. As the ink, for example, a resist solution for forming a resist film for etching, a resist solution for forming a solder resist film, or the like can be used.

  A supply pump 20 and a recovery pump 21 are inserted in the forward path 12 and the return path 13, respectively. The supply pump 20 sends ink from the ink tank 11 to the inkjet head 10. The recovery pump 21 sends ink from the inkjet head 10 to the ink tank 11.

  A first flow path switching valve 31 is inserted in the forward path 12 between the supply pump 20 and the inkjet head 10. A second flow path switching valve 32 is inserted in the return path 13 between the inkjet head 10 and the recovery pump 21. The bypass flow path 18 connects the first flow path switching valve 31 and the second flow path switching valve 32.

  A first cleaning liquid flow path 15 connects the cleaning liquid tank 14 and the first flow path switching valve 31. The cleaning liquid tank 14 stores the cleaning liquid. The second cleaning liquid channel 16 connects the second channel switching valve 32 and the waste liquid tank 17. A cleaning liquid supply pump 22 is inserted into the first cleaning liquid channel 15. The cleaning liquid supply pump 22 sends the cleaning liquid from the cleaning liquid tank 14 to the first flow path switching valve 31. A cleaning liquid discharge pump 23 is inserted into the second cleaning liquid channel 16. The cleaning liquid discharge pump 23 sends the cleaning liquid from the second flow path switching valve 32 to the waste liquid tank 17. As the cleaning liquid, a dedicated cleaning liquid for ink can be used. In addition, for example, volatile solvents such as acetone, isopropyl alcohol, and ethanol can be used. The warming device 41 warms the cleaning liquid in the cleaning liquid tank 14.

  As will be described below, the first flow path switching valve 31 and the second flow path switching valve 32 function as a switching unit 30 that switches between two states of a circulation state and a cleaning state.

  When the switching unit 30 is in a circulating state, the first flow path switching valve 31 causes the upstream path 12 and the downstream path 12 to be connected to the first flow path switching valve 31 so as to be electrically connected to each other. 15 and the bypass flow path 18 are blocked from the forward path 12. The second flow path switching valve 32 connects the upstream return path 13 and the downstream return path 13 with respect to the second flow path switching valve 32, and connects the second cleaning liquid flow path 16 and the bypass flow path 18 to the return path 13. Shut off from. By setting the switching unit 30 in a circulating state, it is possible to eject ink from the inkjet head 10 while circulating the ink.

  When the switching unit 30 is in the cleaning state, the first flow path switching valve 31 allows the forward path 12 upstream of the first flow path switching valve 31 to be connected to the bypass flow path 18, and the first cleaning liquid flow path 15 is changed. The first flow path switching valve 31 is connected to the forward path 12 on the downstream side. The second flow path switching valve 32 allows the bypass flow path 18 to be connected to the return path 13 downstream of the second flow path switching valve 32, and the return path 13 upstream of the second flow path switching valve 32 is connected to the second flow path 13. To the cleaning liquid flow path 16. The first cleaning liquid channel 15 and the second cleaning liquid channel 16 function as a cleaning channel that supplies the cleaning liquid to the inkjet head 10 and collects the cleaning liquid from the inkjet head 10.

  By setting the switching unit 30 to the cleaning state, the ink can be circulated through the circulation path including the ink tank 11, the forward path 12, the bypass flow path 18, and the return path 13. Thus, the bypass flow path 18 can transport ink from the forward path 12 to the return path 13 without going through the inkjet head 10. Further, the inkjet head 10 is cleaned by supplying the cleaning liquid to the inkjet head 10 through the first cleaning liquid flow path 15 and collecting the cleaning liquid from the inkjet head 10 through the second cleaning liquid flow path 16. Can do.

  A stage 45 that supports the substrate is disposed below the inkjet head 10. The stage 45 can move the substrate supported thereon in a horizontal two-dimensional direction. Ink droplets ejected from the inkjet head 10 adhere to the substrate supported by the stage 45. A film can be formed on the substrate by curing the ink attached to the substrate.

  The control device 55 controls the movement of the substrate by the stage 45 and the ejection of ink from the nozzle holes of the inkjet head 10. The control device 55 forms a film having a desired pattern on the substrate by controlling the movement of the stage 45 and the timing of ejecting ink from each nozzle hole based on the image data defining the pattern of the film to be formed. be able to.

  When cleaning the inkjet head 10, a tray 46 is disposed below the inkjet head 10 in place of the stage 45. The tray 46 receives the cleaning liquid dropped from the nozzle holes of the inkjet head 10 during cleaning.

  FIG. 2A is a schematic diagram of an ink jet apparatus when ink is ejected from the ink jet head 10 to form a film on a substrate. Prior to film formation, the substrate 50 is transferred onto the stage 45 and supported by the stage 45. By bringing the first flow path switching valve 31 and the second flow path switching valve 32 into a circulation state and operating the supply pump 20 and the recovery pump 21, the ink tank 11, the forward path 12, the inkjet head 10, and the return path 13 are Ink is circulated through the circulation path. The cleaning liquid supply pump 22 and the cleaning liquid discharge pump 23 are stopped.

  In this state, a film can be formed on the substrate 50 by ejecting ink from each nozzle hole of the inkjet head 10 while moving the substrate 50 by the stage 45.

  FIG. 2B is a schematic view of the ink jet apparatus when the ink jet head 10 is being cleaned. The first flow path switching valve 31 and the second flow path switching valve 32 are brought into a cleaning state. By operating the supply pump 20 and the recovery pump 21, the ink is circulated through a circulation path including the ink tank 11, the forward path 12, the bypass flow path 18, and the return path 13. The tray 46 is disposed below the inkjet head 10.

  Further, the cleaning liquid supply pump 22 and the cleaning liquid discharge pump 23 are operated. As a result, the cleaning liquid flows out from the cleaning liquid tank 14 and is collected in the waste liquid tank 17 via the first cleaning liquid flow path 15, the inkjet head 10, and the second cleaning liquid flow path 16. The cleaning liquid dropped from the nozzle holes of the inkjet head 10 is collected in the tray 46.

  Next, the excellent effect of the ink jet apparatus according to the above embodiment will be described.

  Before the operation of the apparatus is stopped and the power is turned off, the switching unit 30 can be put into a cleaning state to clean the inkjet head 10 (FIG. 2B). At this time, the cleaning liquid does not flow in the ink tank 11, the forward path 12 upstream of the first flow path switching valve 31, and the return path 13 downstream of the second flow path switching valve 32. Of the ink circulation path, the cleaning liquid flows only in the forward path 12 downstream of the first flow path switching valve 31, the inkjet head 10, and the return path 13 upstream of the second flow path switching valve 32. The cleaning liquid remaining in the circulation path through which the ink flows can be reduced as compared with the case where the entire circulation path through which the ink flows is washed with the cleaning liquid.

  Further, when cleaning is performed with a volatile solvent after cleaning with a cleaning liquid dedicated to ink, the cleaning liquid remaining in the ink circulation path is substantially evaporated by the time when the operation of the apparatus is resumed. Even if a part of the cleaning liquid remains in the ink circulation path, the remaining cleaning liquid evaporates in a short time by contacting the heated ink. For this reason, it is not necessary to wash the ink circulation path with ink when the operation of the apparatus is resumed. As a result, almost no waste ink is generated.

  In order to reduce the amount of cleaning liquid remaining in the ink circulation path, the insertion positions of the first flow path switching valve 31 and the second flow path switching valve 32 are preferably close to the inkjet head 10. The first flow path switching valve 31 and the second flow path switching valve 32 may be directly connected to the ink inlet and the ink outlet of the inkjet head 10, respectively. At this time, the flow path lengths of the forward path 12 downstream of the first flow path switching valve 31 and the return path 13 upstream of the second flow path switching valve 32 are substantially zero.

  By heating the cleaning liquid with the heating device 41 (FIG. 2B), the cleaning effect can be enhanced.

  If the circulation of the ink is stopped during the cleaning of the ink jet head 10, the temperature of the ink remaining in the forward path 12 and the backward path 13 is lowered and the viscosity becomes high. When the ink circulation to the ink jet head 10 is resumed with the high viscosity ink remaining in the forward path 12 and the return path 13, the high viscosity ink flows into the ink jet head 10 and the fine flow path in the ink jet head 10 is clogged. There is a risk that In the present embodiment, before the ink heading from the ink tank 11 toward the inkjet head 10 flows into the inkjet head 10, the first flow path switching valve 31, the bypass flow path 18, and the second flow path switching valve 32. It is possible to clean the ink jet head 10 by flowing a cleaning liquid while turning back and circulating without going through the ink jet head 10. Since ink circulates in this circulation path even during cleaning, it is possible to prevent high viscosity ink from remaining in the ink circulation path.

  When the cleaning of the inkjet head 10 is completed, the heated ink can be immediately supplied to the inkjet head 10 by switching the switching unit 30 to the circulation state. For this reason, the time from the end of cleaning of the inkjet head 10 to the start of ink ejection can be shortened.

  During the cleaning of the ink jet head 10, the recovery pump 21 is operated by stopping the outflow of ink from the ink tank 11 to the forward path 12, whereby the ink in the forward path 12 is passed through the bypass flow path 18 to the ink tank 11. Can be recovered.

When the ink circulation via the bypass flow path 18 is also stopped after the inkjet head 10 is cleaned, high viscosity ink may remain in the circulation path. When the operation is resumed, the switching unit 30 is brought into a cleaning state, and the ink is circulated through the bypass flow path 18 so that the high viscosity ink remaining in the circulation path can be heated. By switching the switching unit 30 to the circulating state after the high-viscosity ink has been heated to a low viscosity, the high-viscosity ink can be prevented from flowing into the inkjet head 10. Thereby, clogging of the fine flow path in the inkjet head 10 can be suppressed.
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If the cleaning liquid can flow to the waste liquid tank 17 only with the discharge pressure of the cleaning liquid supply pump 22, the cleaning liquid discharge pump 23 may be omitted. When both the cleaning liquid supply pump 22 and the cleaning liquid discharge pump 23 are arranged, the amount of cleaning liquid dropped from the inkjet head 10 can be adjusted by adjusting the discharge pressure of both.

  After the inkjet head 10 is washed, only the first flow path switching valve 31 may be circulated, and the ink may be supplied to the inkjet head 10 while the second flow path switching valve 32 is in the washed state. At this time, the cleaning liquid remaining in the inkjet head 10 is pushed out by the ink and collected in the waste liquid tank 17 together with the ink.

  After the cleaning liquid is pushed out from the inkjet head 10, the ink can be circulated through the inkjet head 10 by setting the second flow path switching valve 32 in a circulating state.

  Next, an inkjet apparatus according to another embodiment will be described with reference to FIGS. 3A and 3B. Hereinafter, differences from the embodiment shown in FIG. 1, FIG. 2A and FIG. 2B will be described, and description of common configurations will be omitted.

  3A and 3B are schematic views of the ink jet apparatus in a circulation state and a cleaning state, respectively. In the present embodiment, the function of the first flow path switching valve 31 of the ink jet apparatus shown in FIG. 1 is realized by two three-way valves 33a and 33b, and the function of the second flow path switching valve 32 is two three-way. This is realized by the valves 34a and 34b.

  Two three-way valves 33 a and 33 b are inserted in series in the forward path 12, and two three-way valves 34 a and 34 b are inserted in series in the return path 13. A three-way valve 33 a on the upstream side of the forward path 12 and a three-way valve 34 a on the downstream side of the return path 13 are connected by a bypass flow path 18. The first cleaning liquid flow path 15 is connected to the three-way valve 33 b on the downstream side of the forward path 12, and the second cleaning liquid flow path 16 is connected to the three-way valve 34 b on the upstream side of the return path 13. The four three-way valves 33a, 33b, 34a, and 34b have a function as the switching unit 30.

  As shown in FIG. 3A, when the switching unit 30 is in a circulating state, the three-way valves 33a and 33b connect the forward path 12 from the ink tank 11 to the inkjet head 10, and connect the bypass flow path 18 and the first cleaning liquid flow path 15 to each other. Shut off from forward path 12. Further, the three-way valves 34 a and 34 b conduct the return path 13 from the inkjet head 10 to the ink tank 11, and block the bypass flow path 18 and the second cleaning liquid flow path 16 from the return path 13.

  As shown in FIG. 3B, when the switching unit 30 is in the cleaning state, the three-way valve 33a connects the forward path 12 upstream of the three-way valve 33a to the bypass flow path 18, and the three-way valve 33b is the first cleaning liquid flow path. 15 is connected to the inkjet head 10. Further, the three-way valve 34 a connects the bypass flow path 18 to the return path 13 downstream from the three-way valve 34 a, and the three-way valve 34 b connects the inkjet head 10 to the second cleaning liquid flow path 16.

  Also in the ink jet apparatus according to the embodiment shown in FIGS. 3A and 3B, the same effect as that of the ink jet apparatus according to the embodiment shown in FIG. 1 can be obtained.

  Next, an ink jet apparatus according to another embodiment will be described with reference to FIG. Hereinafter, differences from the embodiment shown in FIG. 1, FIG. 2A and FIG. 2B will be described, and description of common configurations will be omitted.

  FIG. 4 is a schematic view of the ink jet apparatus according to the present embodiment. In this embodiment, the inkjet head 10 is composed of a plurality of head blocks 10A. Each of the plurality of head blocks 10 </ b> A includes an ink introduction port 36 and an ink discharge port 37.

  The distribution unit 61 inserted in the forward path 12 branches one forward path 12 into a plurality of forward paths 12A. The plurality of forward paths 12A after branching are respectively connected to the ink inlets 36 of the head block 10A. The distribution unit 61 has a function of distributing the ink to the ink introduction ports 36 of the plurality of head blocks 10A.

  A plurality of return paths 13 </ b> A connect the ink discharge ports 37 of the head block 10 </ b> A to the junction 62. The merging unit 62 has a function of merging ink that has flowed out from the ink discharge ports 37 of the plurality of head blocks 10 </ b> A into one return path 13 and returning it to the ink tank 11.

  The first flow path switching valve 31 is inserted in the forward path 12 upstream of the distribution unit 61. The second flow path switching valve 32 is inserted into the return path 13 on the downstream side of the junction 62. The tray 46 collects the cleaning liquid dropped from the plurality of head blocks 10A.

  When the switching unit 30 including the first flow path switching valve 31 and the second flow path switching valve 32 is in a cleaning state, the cleaning liquid that has flowed into the forward path 12 from the first cleaning liquid flow path 15 is divided into a plurality of parts in the distribution section 61. The cleaning liquid distributed to the head block 10 </ b> A and discharged from the plurality of head blocks 10 </ b> A merges at the merge unit 62. The cleaning liquid merged in the merging portion 62 flows out to the second cleaning liquid flow path 16 via the second flow path switching valve 32.

  In this embodiment, the inkjet head 10 is composed of a plurality of head blocks 10A, so that the film material can be applied to a wider area of the substrate by one scanning of the stage 45. Further, the plurality of head blocks 10A can be cleaned at the same time.

  Next, an ink jet apparatus according to still another embodiment will be described with reference to FIG. Hereinafter, differences from the embodiment shown in FIG. 4 will be described, and description of common configurations will be omitted.

  FIG. 5 shows a schematic view of the ink jet apparatus according to the present embodiment. In the embodiment shown in FIG. 4, the first flow path switching valve 31 is inserted into the forward path 12 upstream of the distribution section 61, and the second flow path switching valve is connected to the return path 13 downstream of the junction section 62. 32 was inserted. In the present embodiment, the first flow path switching valve 31A is inserted into each of the plurality of forward paths 12A after being branched by the distributor 61. Further, the second flow path switching valve 32A is inserted into each of the plurality of return paths 13A before being merged at the merge section 62.

  The bypass flow path 18A connects the first flow path switching valve 31A and the second flow path switching valve 32A corresponding to one head block 10A.

  The first cleaning liquid flow path 15 branches into a plurality of first cleaning liquid flow paths 15A, and the plurality of first cleaning liquid flow paths 15A after branching are respectively connected to the first flow path switching valve 31A. The second cleaning liquid flow path 16A is connected to each of the plurality of second flow path switching valves 32A, and the plurality of second cleaning liquid flow paths 16A merge into one second cleaning liquid flow path 16. . A plurality of first on-off valves 66 are inserted into the plurality of first cleaning liquid flow paths 15A, respectively. A plurality of second on-off valves 67 are inserted into the plurality of second cleaning liquid flow paths 16A, respectively.

  The cleaning liquid supply pump 22 is inserted into one first cleaning liquid flow path 15 before branching, and the cleaning liquid discharge pump 23 is inserted into one second cleaning liquid flow path 16 after joining.

  In the present embodiment, the plurality of first flow path switching valves 31A and the plurality of second flow path switching valves 32A have a function as the switching unit 30 shown in FIG.

  The plurality of head blocks 10A can be cleaned by setting the switching unit 30 to the cleaning state.

  When cleaning is performed with all of the plurality of first on-off valves 66 turned on and all of the plurality of second on-off valves 67 turned on, the cleaning liquid flows preferentially to the head block 10A where no clogging has occurred. Further, even when all the head blocks 10A are clogged, the cleaning liquid flows preferentially to the head block 10A first clogged by cleaning. For this reason, it becomes difficult to proceed with cleaning of the head block 10A in which clogging has occurred.

  One of the plurality of head blocks 10A is washed by selectively conducting one of the first on-off valves 66 and selectively conducting one of the second on-off valves 67. be able to. Thereby, the head block 10A in which clogging has occurred can be efficiently cleaned. The first on-off valve 66 and the second on-off valve 67 function as a head block selection unit that selects one of the plurality of head blocks 10A and allows the cleaning liquid to flow through the selected head block 10A.

Next, an ink jet apparatus according to another embodiment will be described with reference to FIG. Hereinafter, differences from the embodiment shown in FIG. 5 will be described, and description of common configurations will be omitted.
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FIG. 6 is a schematic diagram of the ink jet apparatus according to the present embodiment. When the switching unit 30 is in a circulating state, the plurality of head blocks 10 </ b> A are connected in parallel to the distribution unit 61 and the junction unit 62. When the switching unit 30 is in the cleaning state, the plurality of head blocks 10 </ b> A are inserted in series into the cleaning liquid flow path from the cleaning liquid tank 14 to the waste liquid tank 17. For example, the first flow path switching valve 31 </ b> A corresponding to the first-stage head block 10 </ b> A is connected to the cleaning liquid tank 14 via the first cleaning liquid flow path 15. A second flow path switching valve 32A corresponding to one head block 10A is connected to the first flow path switching valve 31A of the head block 10A in the subsequent stage via a serial connection flow path 19. A second flow path switching valve 32A corresponding to the final-stage head block 10A is connected to the waste liquid tank 17 via the second cleaning liquid flow path 16.

  When the switching unit 30 is in the cleaning state, the cleaning liquid that has flowed out of the cleaning liquid tank 14 sequentially flows through the plurality of head blocks 10A and is collected in the waste liquid tank 17.

  In this embodiment, when the number of head blocks 10A increases, the number of pipes for cleaning liquid can be reduced as compared with the embodiment shown in FIG.

  Next, an ink jet apparatus according to another embodiment will be described with reference to FIG. Hereinafter, differences from the embodiment shown in FIG. 6 will be described, and description of common configurations will be omitted.

  FIG. 7 is a schematic diagram of the ink jet apparatus according to the present embodiment. In the present embodiment, the state of the switching unit 30 corresponding to the head block 10A can be switched between the circulation state and the cleaning state for each head block 10A of the inkjet head 10.

  When the switching unit 30 is switched to the circulating state, the first flow path switching valve 31A is upstream of the first flow path switching valve 31A, as in the embodiment shown in FIG. The second flow path switching valve 32A conducts the return path 13A upstream of the second flow path switching valve 32A and the downstream return path 13A. Further, when the switching unit 30 is set to the circulation state, the first flow path switching valve 31A and the second flow path switching valve 32A are connected to the first cleaning liquid flow path 15 or the preceding series connection flow path 19. The bypass channel 18A is connected to the bypass channel 18A, and the bypass channel 18A is connected to the subsequent serial connection channel 19 or the second cleaning liquid channel 16.

  By setting the switching unit 30 corresponding to a specific part of the head blocks 10A to the cleaning state, it is possible to perform cleaning by flowing the cleaning liquid only to the head blocks 10A. The head block 10A corresponding to the other switching unit 30 in the circulation state can keep the ink circulated. The bypass flow path 18A of the switching section 30 that is in a circulating state functions as a flow path for transporting the cleaning liquid to the subsequent switching section 30 without flowing the cleaning liquid into the head block 10A.

  FIG. 7 shows an example in which the switching unit 30 corresponding to the second head block 10A from the left is in the cleaning state and the other switching units 30 are in the circulation state. In the example shown in FIG. 7, only the second head block 10A from the left can be washed, and the other head block 10A can be maintained in a state where high-temperature ink is circulated. In addition, it is also possible to wash | clean several head block 10A by making the switching part 30 corresponding to several head block 10A into a washing | cleaning state.

  In the embodiment shown in FIG. 7, only a specific one or a part of the head block 10 </ b> A can be cleaned. The high temperature ink circulates in the other head block 10A, and the high temperature ink is supplied to the corresponding bypass flow path 18A also in the head block 10A to be cleaned, so the temperature of the ink supply path becomes high. Maintained. For this reason, after the specific head block 10A is washed, the film formation can be resumed in a short time.

  Each of the above embodiments is an exemplification, and needless to say, partial replacement or combination of the configurations shown in the different embodiments is possible. About the same effect by the same composition of a plurality of examples, it does not refer to every example one by one. Furthermore, the present invention is not limited to the embodiments described above. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

DESCRIPTION OF SYMBOLS 10 Inkjet head 10A Head block 11 Ink tank 12 Outbound path 12A Outbound path 13 after branching Return path 13A Inbound path 14 before joining Cleaning liquid tank 15 First cleaning liquid path 15A First cleaning liquid path 16 after branching Second cleaning liquid path 16A Second cleaning liquid flow path 17 before merging Waste liquid tanks 18 and 18A Bypass flow path 19 Serial connection flow path 20 Supply pump 21 Recovery pump 22 Cleaning liquid supply pump 23 Cleaning liquid discharge pump 30 Switching unit 31, 31A First flow path switching Valves 32 and 32A Second flow path switching valves 33a and 33b Three-way valves 34a and 34b Three-way valve 36 Ink introduction port 37 Ink discharge ports 40 and 41 Heating device 45 Stage 46 Tray 50 Substrate 55 Control device 61 Distribution unit 62 Merge unit 66 First on-off valve 67 Second on-off valve

Claims (4)

An inkjet head that ejects ink;
An ink tank for storing the ink;
A forward path for transporting the ink from the ink tank to the inkjet head;
A return path for transporting the ink from the inkjet head to the ink tank;
A bypass flow path for transporting the ink from the forward path to the return path without passing through the inkjet head;
A cleaning flow path for supplying a cleaning liquid to the inkjet head and collecting the cleaning liquid from the inkjet head;
A circulation state in which the ink is circulated through the circulation path including the forward path, the inkjet head, the return path, and the ink tank, and the ink in the circulation path including the forward path, the bypass flow path, the return path, and the ink tank. And the cleaning state in which the inkjet head is cleaned can be switched by supplying the cleaning liquid to the inkjet head through the cleaning flow path and collecting the cleaning liquid from the inkjet head. Inkjet apparatus having a switching unit. The inkjet head is composed of a plurality of head blocks each including an ink inlet and an ink outlet,
The forward path includes a distribution unit that distributes the ink to the ink introduction ports of the plurality of head blocks,
The return path includes a merge portion that merges the ink that has flowed out of the ink discharge ports of the plurality of head blocks and returns the ink to the ink tank,
The bypass flow path connects the forward path for transporting the ink after being distributed at the distribution section and the return path for transporting the ink before being merged at the merge section,
2. The ink jet apparatus according to claim 1, wherein the cleaning flow path includes a head block selection unit that selects one of the plurality of head blocks and allows the cleaning liquid to flow through the selected head block. further,
A cleaning liquid tank for storing the cleaning liquid and causing the cleaning liquid to flow into the cleaning flow path;
The inkjet apparatus according to claim 1, further comprising a heating device that heats the cleaning liquid stored in the cleaning liquid tank. A method of cleaning an ink jet apparatus that discharges the ink from the ink jet head while circulating ink between the ink tank and the ink jet head,
A method for cleaning an ink jet apparatus, wherein the ink heading from the ink tank toward the ink jet head is turned back before flowing into the ink jet head and circulated without passing through the ink jet head, and a cleaning liquid is supplied to the ink jet head for cleaning. .

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