JP6679174B2 - Inkjet device - Google Patents

Description

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

  An inkjet printer is known in which a resist film for patterning a conductor formed on the surface of a substrate is formed by ejecting ink from an inkjet head (Patent Document 1).

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

JP, 2005-133453, A

  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 the 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 clean (co-wash) the supply system with ink when the operation is restarted. Therefore, waste ink is generated.

An object of the present invention is to provide an ink jet equipment that can be can be washed with an inkjet head efficiently, and to suppress the generation of waste ink.

According to one aspect of the invention,
An inkjet head that has an ink inlet and an ink outlet and discharges ink;
An ink tank for storing the ink,
A forward path for transporting the ink from the ink tank to the ink inlet of the inkjet head,
A return path for transporting the ink from the ink outlet of the inkjet head to the ink tank,
A first flow path switching valve inserted in the forward path,
A second flow path switching valve introduced into the return path,
A bypass flow passage connecting the first flow passage switching valve and the second flow passage switching valve ;
A first cleaning channel connected to the first channel switching valve and sending a cleaning liquid to the first channel switching valve ;
A second cleaning flow path connected to the second flow path switching valve;
Have
The first flow path switching valve and the second flow path switching valve can switch between two states of a circulating state and a cleaning state,
In the circulation state, the first flow path switching valve connects the forward path upstream of the first flow path switching valve and the forward path downstream of the first flow path switching valve, and connects the first cleaning flow path and the first cleaning flow path. The bypass flow path is shut off from the forward path, and the second flow path switching valve connects the return path upstream of the second flow path switching valve and the return path downstream of the second flow path switching valve to conduct the second cleaning. Disconnecting the flow path and the bypass flow path from the return path,
In the cleaning state, the first flow path switching valve connects the forward path upstream of the first flow path switching valve to the bypass flow path and connects the first cleaning flow path to the first flow path. The forward path downstream of the flow path switching valve, and the second flow path switching valve connects the bypass flow path to the return path downstream of the second flow path switching valve, An inkjet device is provided in which the return path upstream of the second flow path switching valve is connected to the second cleaning flow path .

  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 flowing the cleaning liquid only in a part of the ink flow path, the inside of the inkjet head can be efficiently cleaned and the generation of waste ink can be suppressed.

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

  An inkjet apparatus and a cleaning method thereof according to an embodiment will be described with reference to FIGS. 1, 2A, and 2B.

  FIG. 1 is a schematic diagram of an inkjet device according to an embodiment. The inkjet head 10 and the ink tank 11 are connected by a forward path 12 and a 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 outward path 12 transports the 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 outward 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 outward path 12 between the supply pump 20 and the inkjet head 10. The 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 passage 18 connects the first flow passage switching valve 31 and the second flow passage switching valve 32.

  The 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 flow passage 16 connects the second flow passage switching valve 32 and the waste liquid tank 17. The cleaning liquid supply pump 22 is inserted in the first cleaning liquid flow path 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. The cleaning liquid discharge pump 23 is inserted in the second cleaning liquid flow path 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 cleaning liquid dedicated to the ink can be used. Besides, a volatile solvent such as acetone, isopropyl alcohol, or ethanol can be used. The heating device 41 heats the cleaning liquid in the cleaning liquid tank 14.

  The 1st flow-path switching valve 31 and the 2nd flow-path switching valve 32 function as the switching part 30 which switches two states, a circulation state and a washing state, as demonstrated below.

  When the switching unit 30 is in the circulation state, the first flow path switching valve 31 brings the upstream path 12 and the downstream path 12 upstream of the first flow path switching valve 31 into conduction, and the first cleaning liquid flow path 15 and the bypass passage 18 are shut off from the outward passage 12. The second flow path switching valve 32 connects the return path 13 upstream of the second flow path switching valve 32 and the return path 13 downstream of 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 the circulating state, it is possible to eject the 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 connects the outward path 12 on the upstream side of the first flow path switching valve 31 to the bypass flow path 18 to connect the first cleaning liquid flow path 15 to the first cleaning liquid flow path 15. The first passage switching valve 31 is electrically connected to the outward passage 12 on the downstream side. The second flow path switching valve 32 connects the bypass flow path 18 to the return path 13 downstream of the second flow path switching valve 32, and connects the bypass path 18 upstream of the second flow path switching valve 32 to the second return path 13. To the cleaning liquid flow path 16. The first cleaning liquid flow channel 15 and the second cleaning liquid flow channel 16 function as a cleaning flow 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 in the cleaning state, it is possible to circulate the ink in the circulation path including the ink tank 11, the forward path 12, the bypass flow path 18, and the return path 13. In this way, the bypass flow path 18 can transport ink from the outward path 12 to the return path 13 without passing through the inkjet head 10. Further, the cleaning of the inkjet head 10 is performed by supplying the cleaning liquid to the inkjet head 10 through the first cleaning liquid channel 15 and collecting the cleaning liquid from the inkjet head 10 through the second cleaning liquid channel 16. You can

  A stage 45 that supports the substrate is arranged below the inkjet head 10. The stage 45 can move a substrate supported on the stage 45 in a horizontal two-dimensional direction. The 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 controller 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, the tray 46 is arranged below the inkjet head 10 instead 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 inkjet device when ink is ejected from the inkjet head 10 to form a film on a substrate. Prior to the film formation, the substrate 50 is conveyed to above the stage 45 and supported by the stage 45. By setting the first flow path switching valve 31 and the second flow path switching valve 32 in the circulation state and operating the supply pump 20 and the recovery pump 21, the ink tank 11, the outward path 12, the inkjet head 10, and the return path 13 are removed. Ink is circulated in 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 inkjet device when the inkjet head 10 is being cleaned. The first flow path switching valve 31 and the second flow path switching valve 32 are put into a cleaning state. By operating the supply pump 20 and the recovery pump 21, the ink is circulated in the 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 arranged 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 effects of the inkjet device according to the above-described 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 the washing state to wash the inkjet head 10 (FIG. 2B). At this time, the cleaning liquid does not flow in the ink tank 11, the outward 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. In the ink circulation path, the cleaning liquid flows only in the outward 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. It is possible to reduce the amount of the cleaning liquid remaining in the circulation path through which the ink flows, as compared with the case where the entire circulation path through which the ink flows is cleaned with the cleaning liquid.

  Further, if the cleaning liquid for exclusive use of the ink is used and then the cleaning liquid is washed with a volatile solvent, the cleaning liquid remaining in the ink circulation path is almost evaporated by the time the operation of the apparatus is restarted. Even if a part of the cleaning liquid remains in the ink circulation path, the remaining cleaning liquid contacts the heated ink and evaporates in a short time. Therefore, it is not necessary to wash the ink circulation path together with the ink when the operation of the apparatus is restarted. As a result, almost no waste ink is generated.

  In order to reduce the cleaning liquid remaining in the ink circulation path, it is preferable that the insertion positions of the first flow path switching valve 31 and the second flow path switching valve 32 be 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 passage lengths of the outward passage 12 on the downstream side of the first passage switching valve 31 and the return passage 13 on the upstream side of the second passage switching valve 32 become substantially zero.

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

  If the circulation of the ink is stopped during the cleaning of the inkjet head 10, the temperature of the ink remaining in the forward path 12 and the return path 13 is lowered and the viscosity becomes high. When the circulation of the ink to the inkjet head 10 is restarted in the state where the high-viscosity ink remains on the forward path 12 and the return path 13, the high-viscosity ink flows into the inkjet head 10 and the fine flow path in the inkjet head 10 is clogged. There is a risk that In this embodiment, before the ink flowing from the ink tank 11 to 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 are provided. The cleaning liquid can be flowed to the inkjet head 10 for cleaning while being folded back and circulated without passing through the inkjet head 10. Since the 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. Therefore, the time from the end of cleaning the inkjet head 10 to the start of ink ejection can be shortened.

  During the cleaning of the inkjet head 10, by stopping the outflow of the ink from the ink tank 11 to the outward path 12 and operating the recovery pump 21, the ink in the outward path 12 is passed through the bypass flow path 18 and the ink tank 11 is discharged. Can be collected.

After the cleaning of the inkjet head 10, when the circulation of the ink via the bypass flow path 18 is also stopped, the high-viscosity ink may remain in the circulation path. When the operation is restarted, the switching unit 30 is put into a cleaning state, the ink is circulated through the bypass passage 18, and the high-viscosity ink remaining in the circulation passage can be heated. After the high-viscosity ink is heated to have a low viscosity, the switching unit 30 is switched to the circulation state, so that the high-viscosity ink can be prevented from flowing into the inkjet head 10. As a result, it is possible to suppress clogging of fine flow paths in the inkjet head 10.
.

If the cleaning liquid can flow to the waste liquid tank 17 only by 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 discharge amount of the cleaning liquid from the inkjet head 10 can be adjusted by adjusting the discharge pressure of both.

  After cleaning the inkjet head 10, it is possible to supply ink to the inkjet head 10 while keeping only the first flow path switching valve 31 in the circulating state and leaving the second flow path switching valve 32 in the cleaning 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 in the inkjet head 10 by also setting the second flow path switching valve 32 in the circulation 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 FIGS. 1, 2A and 2B will be described, and description of common configurations will be omitted.

  3A and 3B are schematic views of the inkjet device in a circulating state and a cleaning state, respectively. In this embodiment, the function of the first flow path switching valve 31 of the inkjet device shown in FIG. 1 is realized by the two three-way valves 33a and 33b, and the function of the second flow path switching valve 32 is two three-way valves. It is realized by the valves 34a and 34b.

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

  As shown in FIG. 3A, when the switching unit 30 is in the circulation state, the three-way valves 33a and 33b connect the outward path 12 from the ink tank 11 to the inkjet head 10 to connect the bypass flow path 18 and the first cleaning liquid flow path 15 to each other. Shut off from the outward route 12. Furthermore, the three-way valves 34 a and 34 b connect the return path 13 from the inkjet head 10 to the ink tank 11, and shut off 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 outward path 12 upstream of the three-way valve 33a to the bypass flow path 18, and the three-way valve 33b operates 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 of 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.

  The inkjet device according to the embodiment shown in FIGS. 3A and 3B can also obtain the same effect as the inkjet device according to the embodiment shown in FIG.

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

  FIG. 4 is a schematic view of the inkjet device 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 10A includes an ink inlet 36 and an ink outlet 37.

  The distribution unit 61 inserted in the outward path 12 branches one outward path 12 into a plurality of outward paths 12A. The plurality of outward paths 12A after branching are respectively connected to the ink introduction ports 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.

  The plurality of return paths 13A respectively connect the ink discharge ports 37 of the head block 10A to the merging portion 62. The merging unit 62 has a function of merging the ink flowing out from the ink discharge ports 37 of the plurality of head blocks 10A into one return path 13 and returning it to the ink tank 11.

  The first flow path switching valve 31 is inserted in the outward path 12 on the upstream side of the distributor 61. The second flow path switching valve 32 is inserted in the return path 13 on the downstream side of the confluence portion 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 the cleaning state, the cleaning liquid that has flowed from the first cleaning liquid flow path 15 into the outward path 12 is distributed to a plurality of distribution units 61. The cleaning liquids distributed to the head block 10A and discharged from the plurality of head blocks 10A join at the joining portion 62. The cleaning liquid merged in the merging portion 62 flows out to the second cleaning liquid flow passage 16 via the second flow passage switching valve 32.

  In the present 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, with reference to FIG. 5, an inkjet apparatus according to another embodiment will be described. Hereinafter, differences from the embodiment shown in FIG. 4 will be described, and description of common configurations will be omitted.

  FIG. 5 is a schematic view of the inkjet device according to the present embodiment. In the embodiment shown in FIG. 4, the first passage switching valve 31 is inserted in the outward passage 12 upstream of the distributor 61, and the second passage switching valve 31 is inserted in the return passage 13 downstream of the confluence portion 62. 32 was inserted. In the present embodiment, the first flow path switching valve 31A is inserted into each of the plurality of outward paths 12A after being branched by the distributor 61. Further, the second flow path switching valve 32A is inserted in each of the plurality of return paths 13A before being joined at the joining portion 62.

  The bypass flow passage 18A connects the first flow passage switching valve 31A and the second flow passage 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 branched first cleaning liquid flow paths 15A are respectively connected to the first flow path switching valve 31A. The second cleaning liquid flow passages 16A are connected to the plurality of second cleaning liquid flow passages 32A, respectively, and the plurality of second cleaning liquid flow passages 16A join the one second cleaning liquid flow passage 16. . The plurality of first opening / closing valves 66 are inserted in the plurality of first cleaning liquid flow paths 15A, respectively. The plurality of second opening / closing valves 67 are inserted in the plurality of second cleaning liquid flow paths 16A, respectively.

  The cleaning liquid supply pump 22 is inserted in the one first cleaning liquid passage 15 before branching, and the cleaning liquid discharge pump 23 is inserted in the one second cleaning liquid passage 16 after the merging.

  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.

  A plurality of head blocks 10A can be cleaned by putting the switching unit 30 in the cleaning state.

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

  One of the plurality of head blocks 10A is cleaned by selectively bringing one of the first on-off valves 66 into conduction and the corresponding one of the second on-off valves 67 of selectively conducting. be able to. As a result, it is possible to efficiently clean the clogged head block 10A. The first opening / closing valve 66 and the second opening / closing valve 67 function as a head block selection unit that selects one from the plurality of head blocks 10A and causes the cleaning liquid to flow to the selected head block 10A.

Next, an inkjet 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 view of the inkjet device according to the present embodiment. When the switching unit 30 is in the circulation state, the plurality of head blocks 10A are connected to the distribution unit 61 and the confluence unit 62 in parallel. When the switching unit 30 is in the cleaning state, the plurality of head blocks 10A are inserted in series in 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 31A corresponding to the first-stage head block 10A is connected to the cleaning liquid tank 14 via the first cleaning liquid flow path 15. The second flow path switching valve 32A corresponding to one head block 10A is connected to the first flow path switching valve 31A of the subsequent head block 10A via the series connection flow path 19. A second flow passage 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 passage 16.

  When the switching unit 30 is in the cleaning state, the cleaning liquid flowing 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 the present embodiment, when the number of head blocks 10A is increased, the number of pipes for the cleaning liquid can be reduced as compared with the embodiment shown in FIG.

  Next, an inkjet 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 view of the inkjet device according to the present embodiment. In the present embodiment, for each head block 10A of the inkjet head 10, the state of the switching unit 30 corresponding to the head block 10A can be switched between the circulating state and the cleaning state.

  When the switching unit 30 is switched to the circulation state, as in the case of the embodiment shown in FIG. 6, the first flow path switching valve 31A has a forward path 12A upstream of the first flow path switching valve 31A. And the downstream outward path 12A are electrically connected, and the second flow path switching valve 32A electrically connects 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 connect the first cleaning liquid flow path 15 or the preceding series connection flow path 19 to each other. The bypass flow passage 18A is connected to the subsequent serial connection flow passage 19 or the second cleaning liquid flow passage 16.

  By setting the switching unit 30 corresponding to a specific part of the head block 10A in the cleaning state, the cleaning liquid can be flowed only to the head block 10A for cleaning. The head block 10A corresponding to the other switching unit 30 in the circulating state can keep the ink circulated. The bypass flow passage 18A of the switching unit 30 in the circulating state functions as a flow passage for transporting the cleaning liquid to the switching unit 30 in the subsequent stage without causing the cleaning liquid to flow 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 cleaned, and the other head blocks 10A can be maintained in a state in which high-temperature ink is circulated. It is also possible to wash the plurality of head blocks 10A by setting the switching unit 30 corresponding to the plurality of head blocks 10A in the washing state.

  In the embodiment shown in FIG. 7, only one or some specific head blocks 10A can be cleaned. The high-temperature ink circulates in the other head blocks 10A, and even in the head block 10A to be cleaned, the high-temperature ink is supplied to the corresponding bypass passage 18A, so that the temperature of the ink supply path becomes high. Maintained. Therefore, after cleaning the specific head block 10A, the film formation can be restarted in a short time.

  Needless to say, each of the above-described embodiments is merely an example, and partial replacement or combination of the configurations shown in different embodiments is possible. The same effects by the same configurations of the plurality of embodiments will not be sequentially described for each embodiment. Furthermore, the invention is not limited to the embodiments described above. For example, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

10 Inkjet head 10A Head block 11 Ink tank 12 Outgoing path 12A Outgoing path after branching 13 Returning path 13A Returning path before merging 14 Cleaning solution tank 15 First cleaning solution flow path 15A First cleaning solution flow path 16 After branching Second cleaning solution flow path 16A Second cleaning liquid channel before merging 17 Waste liquid tank 18, 18A Bypass channel 19 Series connection channel 20 Supply pump 21 Recovery pump 22 Cleaning solution supply pump 23 Cleaning solution discharge pump 30 Switching section 31, 31A First channel switching Valves 32, 32A Second flow path switching valves 33a, 33b Three-way valves 34a, 34b Three-way valve 36 Ink inlet 37 Ink outlets 40, 41 Warming device 45 Stage 46 Tray 50 Substrate 55 Control device 61 Distributor 62 Joining part 66 First on-off valve 67 Second on-off valve

Claims (4)

An inkjet head that has an ink inlet and an ink outlet and discharges ink;
An ink tank for storing the ink,
A forward path for transporting the ink from the ink tank to the ink inlet of the inkjet head,
A return path for transporting the ink from the ink outlet of the inkjet head to the ink tank,
A first flow path switching valve inserted in the forward path,
A second flow path switching valve introduced into the return path,
A bypass flow passage connecting the first flow passage switching valve and the second flow passage switching valve ;
A first cleaning channel connected to the first channel switching valve and sending a cleaning liquid to the first channel switching valve ;
A second cleaning flow path connected to the second flow path switching valve;
Have
The first flow path switching valve and the second flow path switching valve can switch between two states of a circulating state and a cleaning state,
In the circulation state, the first flow path switching valve connects the forward path upstream of the first flow path switching valve and the forward path downstream of the first flow path switching valve, and connects the first cleaning flow path and the first cleaning flow path. The bypass flow path is shut off from the forward path, and the second flow path switching valve connects the return path upstream of the second flow path switching valve and the return path downstream of the second flow path switching valve to conduct the second cleaning. Disconnecting the flow path and the bypass flow path from the return path,
In the cleaning state, the first flow path switching valve connects the forward path upstream of the first flow path switching valve to the bypass flow path and connects the first cleaning flow path to the first flow path. The forward path downstream of the flow path switching valve, and the second flow path switching valve connects the bypass flow path to the return path downstream of the second flow path switching valve, An inkjet device that connects the return path upstream of the second flow path switching valve to the second cleaning flow path .   The inkjet device according to claim 1, wherein the inkjet head has a structure for circulating ink. further,
A cleaning liquid tank that stores the cleaning liquid and causes the cleaning liquid to flow out to the first cleaning flow path;
The inkjet device according to claim 1, further comprising a waste liquid tank that stores the cleaning liquid recovered from the inkjet head through the second cleaning flow path . A plurality of the inkjet heads are provided,
Corresponding to each of the plurality of inkjet heads, the forward path, the return path, the first flow path switching valve, the second flow path switching valve, the bypass flow path, the first cleaning flow path, and The second cleaning channel is provided,
When the plurality of inkjet heads are ordered, the second cleaning flow path corresponding to the preceding inkjet head and the first cleaning flow path corresponding to the subsequent inkjet head constitute a common series connection flow path. The inkjet device according to claim 1, wherein the inkjet device is provided.

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