Inkjet printing device

Abstract

An inkjet printing apparatus includes a head module for ejecting ink onto a surface of a substrate, and including an inflow connection portion and an outflow connection portion; a storage container for storing the ink, and connected to the head module and supplying the ink to the head module, the storage container including a first flow inlet, a second flow inlet, a first flow outlet, and a second flow outlet separated from each other; a first transfer conduit connecting the first flow outlet and the inflow connection portion; a second transfer conduit connecting the first flow inlet and the outflow connection portion; a pump connected to the first transfer conduit or the second transfer conduit; and a circulation conduit connecting the second flow outlet and the second flow inlet.

Description

Technical Field

[0001] This utility model relates to an inkjet printing apparatus. More specifically, this utility model relates to an inkjet printing apparatus used in an inkjet printing process and a method for ink recycling using the same. Background Technology

[0002] With the development of information technology, the importance of display devices, as the connection medium between users and information, is becoming increasingly prominent. As a result, the use of display devices such as liquid crystal display devices, organic light-emitting display devices, and plasma display devices is increasing.

[0003] In thin film manufacturing processes such as the formation of light-emitting layers, optical patterns, or color filters in display devices, inkjet printing, a process that sprays ink onto the surface of an object to form a thin film of a desired shape, can be used. An inkjet printing apparatus can print a thin film with a desired pattern on the surface of a substrate by generating ink droplets in a nozzle of a head module and ejecting those droplets to a predetermined position on the substrate. Utility Model Content

[0004] One object of this invention is to provide an inkjet printing apparatus that prevents the sedimentation of particles contained in the ink located inside a storage container.

[0005] Another objective of this invention is to provide an ink recycling method using the inkjet printing apparatus.

[0006] However, the purpose of this utility model is not limited to this purpose, and it can be extended to various purposes without departing from the idea and field of this utility model.

[0007] To achieve the aforementioned objective of this utility model, an inkjet printing apparatus according to an embodiment of this utility model may include: a head module for spraying ink onto the surface of a substrate, and including an inflow connection and an outflow connection; a storage container for storing the ink, and connected to the head module to supply the ink to the head module, the storage container including a first inlet, a second inlet, a first outlet, and a second outlet, which are separated from each other; a first transfer pipe connecting the first outlet and the inflow connection; a second transfer pipe connecting the first inlet and the outflow connection; a pump connected to the first transfer pipe or the second transfer pipe; and a circulation pipe connecting the second outlet and the second inlet.

[0008] In one embodiment, while the pump is operating and the ink flows from the storage container into the first delivery pipe through the first outlet, the ink can also flow from the storage container into the circulation pipe through the second outlet.

[0009] In one embodiment, the second inlet may be disposed adjacent to the first outlet.

[0010] In one embodiment, the second inlet may be located on a first side of the storage container, the first inlet may be located on a second side of the storage container opposite to the first side, and the first outlet and the second outlet may be located on the bottom surface of the storage container opposite to the head module.

[0011] In one embodiment, the pump's revolutions per minute (RPM) may be proportional to the speed and flow rate of the ink circulating inside the circulation pipe.

[0012] In one embodiment, the inkjet printing apparatus may further include: a bypass conduit connecting the first transfer conduit and the second transfer conduit.

[0013] In one embodiment, the inkjet printing apparatus may further include a valve connected to the bypass pipe and used to regulate the supply of ink.

[0014] In one embodiment, the inkjet printing apparatus may further include a filter connected to the circulation pipe and used to filter impurities in the ink moving inside the circulation pipe.

[0015] In one embodiment, the inkjet printing apparatus may further include a degasser connected to the circulation pipe and used to remove air bubbles from the ink moving inside the circulation pipe.

[0016] In one embodiment, the inkjet printing apparatus may further include: a filter connected to the circulation pipe and used to filter impurities in the ink moving inside the circulation pipe; and a degasser connected to the circulation pipe and used to remove air bubbles in the ink moving inside the circulation pipe.

[0017] In one embodiment, the inkjet printing apparatus may have an ink channel and a plurality of nozzles formed inside the head module, wherein the ink channel includes the inflow connection and the outflow connection, and the plurality of nozzles are connected to the ink channel and are used to spray the ink delivered from the first delivery pipe.

[0018] To achieve another objective of the present invention as described above, an ink circulation method according to an embodiment of the present invention may include the following steps: allowing the ink to flow into a first transfer pipe through a first outlet of a storage container for storing ink, wherein the first transfer pipe is connected to a head module for spraying the ink onto the surface of a substrate; and while the ink is flowing into the first transfer pipe, the ink flows from the storage container into a circulation pipe through a second outlet of the storage container, thereby circulating the ink within the circulation pipe.

[0019] In one embodiment, the step of circulating the ink within the circulation pipe may include the following steps: generating a negative pressure at a second inlet of the storage container when the ink flows into the first transfer pipe; using the negative pressure, the ink flows from the storage container into the circulation pipe through a second outlet; and the ink flowing into the circulation pipe using the negative pressure flows into the storage container through the second inlet.

[0020] In one embodiment, during the step of allowing the ink to flow into the first transfer pipe, the ink can be allowed to flow into the first transfer pipe through the first outlet by operating a pump connected to the first transfer pipe.

[0021] In one embodiment, the pump's RPM may be proportional to the speed and flow rate of the ink circulating inside the circulation pipe.

[0022] In one embodiment, after the step of allowing the ink to flow into the first transfer pipe, the ink circulation method may further include the following steps: the ink flowing into the first transfer pipe flows into the ink channel of the head module; the ink flowing into the ink channel that is not sprayed onto the substrate flows into a second transfer pipe connected to the ink channel; and the ink flowing into the second transfer pipe flows into the storage container through a first inlet of the storage container.

[0023] In one embodiment, the ink recycling method may further include the following steps: the ink flowing into the first transfer pipe moves from the first transfer pipe to the second transfer pipe through a bypass pipe connecting the first transfer pipe and the second transfer pipe.

[0024] The inkjet printing apparatus of this invention may include: a head module for spraying ink onto a substrate; a storage container for storing ink and connected to the head module to supply ink to the head module; a first transfer pipe connecting a first outlet and the head module; a second transfer pipe connecting a first inlet and the head module; a pump connected to either the first or second transfer pipe; and a circulation pipe connecting the second outlet and the second inlet. When the pump operates and ink flows into the first transfer pipe through the first outlet, a negative pressure may be generated at the second inlet, and due to the negative pressure, ink can flow from the storage container into the circulation pipe through the second outlet.

[0025] This prevents the sedimentation of particles contained in the ink located inside the storage container. Furthermore, since no additional pumps (e.g., pumps connected to the circulation pipeline) are required besides the pump connected to the head module, the structure of the inkjet printing unit is simplified, and maintenance costs are reduced.

[0026] However, the effects of this utility model are not limited to the above-mentioned effects, and can be extended to various effects without departing from the concept and field of this utility model. Attached Figure Description

[0027] Figure 1 This is a diagram illustrating an inkjet printing apparatus according to an embodiment of the present invention.

[0028] Figure 2 It is Figure 1 The diagram shows an enlarged view of the head module, the first transfer pipe, and the second transfer pipe.

[0029] Figure 3 It is used to illustrate the use Figure 1 A diagram illustrating the ink circulation method of an inkjet printing device.

[0030] Figure 4 This is a diagram illustrating an inkjet printing apparatus according to another embodiment of the present invention.

[0031] Figure 5 This is a diagram illustrating an inkjet printing apparatus according to another embodiment of the present invention.

[0032] Figure 6 This is a diagram illustrating an inkjet printing apparatus according to another embodiment of the present invention.

[0033] Figure 7 This is a diagram illustrating an inkjet printing apparatus according to another embodiment of the present invention.

[0034] Figure 8 This is a diagram illustrating an inkjet printing apparatus according to another embodiment of the present invention.

[0035] Explanation of reference numerals in the attached figures

[0036] 100, 101, 102, 103, 104, 105: Inkjet printing equipment

[0037] ST: Storage container OT1: First outlet

[0038] OT2: Second-tier exit; IT1: First-tier entry

[0039] IT2: Second Stream Entry HM: Header Module

[0040] TP1: First transfer conduit; TP2: Second transfer conduit

[0041] P: Pump; CP: Circulation Pipe

[0042] IK: Ink; BP: Bypass Pipe

[0043] VL: Valve; DG: Degasser

[0044] FT: Filter Detailed Implementation

[0045] The inkjet printing apparatus and ink circulation method using the same embodiment of the present invention will now be described in more detail with reference to the accompanying drawings. The same reference numerals are used for the same structural elements in the drawings, and repeated descriptions of the same structural elements are omitted.

[0046] Figure 1 This is a diagram illustrating an inkjet printing apparatus according to an embodiment of the present invention. Figure 2 It is Figure 1 The diagram shows an enlarged view of the head module, the first transfer pipe, and the second transfer pipe.

[0047] Reference Figure 1 and Figure 2 An embodiment of the inkjet printing apparatus 100 of this utility model may include a storage container ST, a head module HM, a first transfer pipe TP1, a second transfer pipe TP2, a first valve VL1, a second valve VL2, a circulation pipe CP, a pump P, a bypass pipe BP, and a valve VL.

[0048] An externally located ink supply unit can be connected to the storage container ST and supply and discharge ink IK to the storage container ST. The ink supply unit can be positioned higher than the storage container ST. The storage container ST can store (or contain) the ink IK. The storage container ST can be connected to the head module HM and supply the ink IK into the head module HM. The storage container ST can be positioned higher than the head module HM.

[0049] The storage container ST may include a first side SS1, a second side SS2, and a bottom surface BS. The first side SS1 may be opposite to the second side SS2. Specifically, the first side SS1 may be opposite to the second side SS2 in a first direction DR1. The bottom surface BS may be opposite to the head module HM.

[0050] In one embodiment, the storage container ST may include a first inlet IT1, a second inlet IT2, a first outlet OT1, and a second outlet OT2, which are separate from each other. The ink IK can flow into the storage container ST through the first inlet IT1 and the second inlet IT2, and the ink IK can flow out of the storage container ST from the outside of the storage container ST through the first outlet OT1 and the second outlet OT2.

[0051] In one embodiment, the second inlet IT2 may be disposed adjacent to the first outlet OT1. For example, the first outlet OT1 may be located on the bottom surface BS, and the second inlet IT2 may be located on the first side surface SS1. Specifically, the second inlet IT2 may be located on the lower end of the first side surface SS1 near the head module HM. However, embodiments of the present invention are not necessarily limited to this.

[0052] For example, the first inlet IT1 may be located on the second side SS2, and the second outlet OT2 may be located on the bottom surface BS. However, embodiments of this invention are not necessarily limited to this.

[0053] The first transfer pipe TP1 and the second transfer pipe TP2 can connect the head module HM and the storage container ST. Specifically, the first transfer pipe TP1 can connect the inflow connection ICP of the head module HM and the first outflow outlet OT1 of the storage container ST, and the second transfer pipe TP2 can connect the outflow connection OCP of the head module HM and the first inflow inlet IT1 of the storage container ST.

[0054] In one embodiment, the pump P may be connected to the first transfer conduit TP1. For example, when the pump P is operating, the ink IK can flow from the storage container ST into the first transfer conduit TP1 through the first outlet OT1. The ink IK flowing into the first transfer conduit TP1 can be transferred to the head module HM.

[0055] A first valve VL1 for regulating the supply of ink IK can be connected to the first transfer pipe TP1, and a second valve VL2 for regulating the supply of ink IK can be connected to the second transfer pipe TP2. For example, the first valve VL1 can be connected to the portion of the first transfer pipe TP1 adjacent to the inflow connection ICP, and the second valve VL2 can be connected to the portion of the second transfer pipe TP2 adjacent to the outflow connection OCP.

[0056] The first valve VL1 and the second valve VL2 can be opened or closed. For example, when the first valve VL1 and the second valve VL2 are open, the ink IK flowing into the first transfer pipe TP1 can be transferred to the head module HM, and a portion of the ink IK flowing into the head module HM can flow into the second transfer pipe TP2. Conversely, when the first valve VL1 and the second valve VL2 are closed, the supply of ink IK through the first transfer pipe TP1 and the second transfer pipe TP2 can be blocked.

[0057] The head module HM can receive the ink IK from the storage container ST and the first transfer conduit TP1. The head module HM can eject the ink IK onto the substrate. For example, the inkjet printing apparatus 100 can be used in an inkjet printing process that forms a thin film of a desired shape by ejecting the ink IK onto the surface of an object (e.g., the substrate). In this case, the head module HM can form a light-emitting layer, optical pattern, or color filter of a display device by ejecting the ink IK onto the substrate. However, embodiments of the present invention are not necessarily limited to this.

[0058] Inside the head module HM, an ink flow channel IFP and multiple nozzles NZ can be formed. The ink flow channel IFP includes an inflow connection ICP and an outflow connection OCP. The multiple nozzles NZ are connected to the ink flow channel IFP and are used to spray the ink IK delivered from the first transfer pipe TP1. That is, the ink IK can be sprayed onto the surface of the substrate through the multiple nozzles NZ.

[0059] The inflow connector ICP may be located at the first end of the ink flow channel IFP, and the outflow connector OCP may be located at the second end of the ink flow channel IFP opposite to the first end. The plurality of nozzles NZ may be configured to be spaced apart along the first direction DR1, and may spray the ink IK into a second direction DR2 that intersects the first direction DR1.

[0060] As described above, the head module HM can eject the ink IK onto the substrate. Ink IK that is not ejected to the outside of the head module HM (e.g., the substrate) can move within the ink flow channel IFP and the second transfer channel TP2 and be recycled back to the storage container ST through the first inlet IT1, thus allowing the ink IK to circulate. That is, the ink IK can circulate within the first transfer channel TP1, the head module HM, and the second transfer channel TP2.

[0061] In one embodiment, the circulation pipe CP can be connected to the second inlet IT2 and the second outlet OT2 of the storage container ST. Therefore, the circulation pipe CP does not share inlet and outlet with the first transfer pipe TP1 and the second transfer pipe TP2. That is, the circulation pipe CP can be separated from the first transfer pipe TP1 and the second transfer pipe TP2. No additional pump may be connected to the circulation pipe CP.

[0062] In one embodiment, the bypass pipe BP can connect the first transfer pipe TP1 and the second transfer pipe TP2. Furthermore, a valve VL for regulating the supply of ink IK can be connected to the bypass pipe BP. The valve VL can be opened or closed. For example, when the valve VL is closed, the supply of ink IK through the bypass pipe BP can be blocked. In this case, the first valve VL1 and the second valve VL2 can be opened. Conversely, when the valve VL is open, at least a portion of the ink IK flowing into the first transfer pipe TP1 can move through the bypass pipe BP from the first transfer pipe TP1 to the second transfer pipe TP2. In this case, the first valve VL1 and the second valve VL2 can be opened or closed. However, when the first valve VL1 and the second valve VL2 are closed, the valve VL must be opened.

[0063] Figure 3 It is used to illustrate the use Figure 1 A diagram illustrating the ink circulation method of an inkjet printing device.

[0064] Reference Figure 3 To prevent particles included in the ink IK from settling inside the storage container ST, the ink IK in the inkjet printing apparatus 100 can be circulated through two paths.

[0065] First, the ink IK can flow from the storage container ST into the first transfer pipe TP1 through the first outlet OT1 of the storage container ST. For example, when the pump P connected to the first transfer pipe TP1 is working, the ink IK can flow from the storage container ST into the first transfer pipe TP1 through the first outlet OT1 of the storage container ST.

[0066] The ink IK flowing into the first transfer pipe TP1 can move inside the first transfer pipe TP1 and flow into the ink channel of the head module HM (e.g., Figure 2 The ink IK flowing into the ink flow channel IFP (in the ink flow channel IFP) can move inside the ink flow channel IFP and flow into the second transfer channel TP2. At this time, the first valve VL1 and the second valve VL2 can be opened, and the valve VL can be opened or closed.

[0067] Optionally, the ink IK flowing into the first transfer pipe TP1 can also move inside the first transfer pipe TP1 and flow into the bypass pipe BP. In this case, the ink IK can move from the first transfer pipe TP1 to the second transfer pipe TP2 through the bypass pipe BP. That is, the ink IK flowing into the bypass pipe BP can move inside the bypass pipe BP and flow into the second transfer pipe TP2. At this time, the valve VL can be opened, and the first valve VL1 and the second valve VL2 can be opened or closed.

[0068] The ink IK flowing into the second transfer pipe TP2 can move inside the second transfer pipe TP2 and flow into the storage container ST through the first inlet IT1 of the storage container ST.

[0069] As a result, the ink IK stored in the storage container ST can circulate within the first transfer pipe TP1, the head module HM, and the second transfer pipe TP2.

[0070] In one embodiment, when the ink IK flows into the first transfer pipe TP1, the ink IK can flow from the storage container ST into the circulation pipe CP through the second outlet OT2 of the storage container ST, and the ink IK can circulate inside the circulation pipe CP.

[0071] Specifically, when the ink IK flows into the first transfer pipe TP1, a negative pressure is generated at the second inlet IT2 of the storage container ST. Using this negative pressure, the ink IK flows from the storage container ST into the circulation pipe CP through the second outlet OT2 of the storage container ST. The ink IK flowing into the circulation pipe CP under this negative pressure moves within the circulation pipe CP and flows back into the storage container ST through the second inlet IT2. As a result, the ink IK stored in the storage container ST can also circulate within the circulation pipe CP.

[0072] In one embodiment, the RPM of the pump P may be proportional to the speed and flow rate of the ink IK circulating inside the circulation pipe CP. For example, when the RPM of the pump P increases, the speed and flow rate of the ink IK circulating inside the circulation pipe CP may increase, and when the RPM of the pump P decreases, the speed and flow rate of the ink IK circulating inside the circulation pipe CP may decrease.

[0073] In one embodiment, as described above, when the second inlet IT2 is arranged adjacent to the first outlet OT1, the speed and flow rate of the ink IK circulating inside the circulation pipe CP can be increased.

[0074] In one embodiment, the outer diameter of the circulation pipe CP may be inversely proportional to the speed and flow rate of the ink IK circulating inside the circulation pipe CP. For example, when the outer diameter of the circulation pipe CP is small, the speed and flow rate of the ink IK circulating inside the circulation pipe CP may be increased, and when the outer diameter of the circulation pipe CP is large, the speed and flow rate of the ink IK circulating inside the circulation pipe CP may be decreased.

[0075] Figure 4 This is a diagram illustrating an inkjet printing apparatus according to another embodiment of the present invention.

[0076] Reference Figure 4 Another embodiment of the inkjet printing apparatus 101 of this utility model may include the storage container ST, the head module HM, the first transfer pipe TP1, the second transfer pipe TP2, the first valve VL1, the second valve VL2, the circulation pipe CP, the pump P, the bypass pipe BP, and the valve VL. However, referring to... Figure 4 The inkjet printing apparatus 101 described herein, except for the position of the pump P, can be referenced. Figure 1 The inkjet printing apparatus 100 described herein is substantially the same as or similar to that described herein. Therefore, omissions or simplifications are made in accordance with the references. Figure 1The description of the inkjet printing apparatus 100 is repeated.

[0077] In one embodiment, the pump P may be connected to the second transfer conduit TP2. For example, when the pump P is operating, the ink IK can flow from the storage container ST into the first transfer conduit TP1 through the first outlet OT1. The ink IK flowing into the first transfer conduit TP1 can move inside the first transfer conduit TP1 and be transferred to the head module HM. A portion of the ink IK flowing into the head module HM can flow into the second transfer conduit TP2. The ink IK flowing into the second transfer conduit TP2 can move inside the second transfer conduit TP2 and flow into the storage container ST through the first inlet IT1 of the storage container ST.

[0078] Figure 5 This is a diagram illustrating an inkjet printing apparatus according to another embodiment of the present invention.

[0079] Reference Figure 5 Another embodiment of the inkjet printing apparatus 102 of this utility model may include the storage container ST, the head module HM, the first transfer pipe TP1, the second transfer pipe TP2, the circulation pipe CP, and the pump P. However, referring to... Figure 5 The inkjet printing apparatus 102 described herein, except for omitting the bypass pipe BP and the valve VL, can be compared with the referenced... Figure 1 The inkjet printing apparatus 100 described herein is substantially the same as or similar to that described herein. Therefore, omissions or simplifications are made in accordance with the references. Figure 1 The description of the inkjet printing apparatus 100 is repeated.

[0080] In one embodiment, it can be obtained from Figure 1 The inkjet printing apparatus 100 omits the bypass pipe BP and the valve VL. That is, Figure 5 The inkjet printing apparatus 102 may not include the bypass pipe BP and the valve VL. In this case, the ink IK flowing into the first transfer pipe TP1 may move to the second transfer pipe TP2 via the head module HM instead of the bypass pipe BP.

[0081] Figure 6 This is a diagram illustrating an inkjet printing apparatus according to another embodiment of the present invention.

[0082] Reference Figure 6Another embodiment of the inkjet printing apparatus 103 of this utility model may include the storage container ST, the head module HM, the first transfer pipe TP1, the second transfer pipe TP2, the first valve VL1, the second valve VL2, the circulation pipe CP, the pump P, and the degasser DG. However, referring to Figure 6 The inkjet printing apparatus 103 described herein, in addition to further including the degassing unit DG, can be compared with the referenced... Figure 1 The inkjet printing apparatus 100 described herein is substantially the same as or similar to that described herein. Therefore, omissions or simplifications are made in accordance with the references. Figure 1 The description of the inkjet printing apparatus 100 is repeated.

[0083] In one embodiment, the degasser DG may be connected to the circulation pipe CP. The degasser DG removes air bubbles from the ink IK moving inside the circulation pipe CP. For example, the degasser DG may be connected to any part of the circulation pipe CP.

[0084] Figure 7 This is a diagram illustrating an inkjet printing apparatus according to another embodiment of the present invention.

[0085] Reference Figure 7 Another embodiment of the inkjet printing apparatus 104 of this utility model may include the storage container ST, the head module HM, the first transfer pipe TP1, the second transfer pipe TP2, the first valve VL1, the second valve VL2, the circulation pipe CP, the pump P, and the filter FT. However, referring to... Figure 7 The inkjet printing apparatus 104 described herein, in addition to further including the filter FT, can be compared with the referenced Figure 1 The inkjet printing apparatus 100 described herein is substantially the same as or similar to that described herein. Therefore, omissions or simplifications are made in accordance with the references. Figure 1 The description of the inkjet printing apparatus 100 is repeated.

[0086] In one embodiment, the filter FT may be connected to the circulation pipe CP. The filter FT can filter impurities in the ink IK moving inside the circulation pipe CP. For example, the filter FT may be connected to any part of the circulation pipe CP.

[0087] Figure 8 This is a diagram illustrating an inkjet printing apparatus according to another embodiment of the present invention.

[0088] Reference Figure 8Another embodiment of the inkjet printing apparatus 105 of this utility model may include the storage container ST, the head module HM, the first transfer pipe TP1, the second transfer pipe TP2, the first valve VL1, the second valve VL2, the circulation pipe CP, the pump P, the degasser DG, and the filter FT. However, referring to... Figure 8 The inkjet printing apparatus 105 described herein, in addition to further including the degasser DG and the filter FT, can be compared with the referenced Figure 1 The inkjet printing apparatus 100 described herein is substantially the same as or similar to that described herein. Therefore, omissions or simplifications are made in accordance with the references. Figure 1 The description of the inkjet printing apparatus 100 is repeated.

[0089] In one embodiment, the degasser DG and the filter FT may be connected to the circulation pipe CP. The degasser DG removes air bubbles from the ink IK moving inside the circulation pipe CP. The filter FT filters out impurities from the ink IK moving inside the circulation pipe CP.

[0090] The degasser DG and the filter FT can be connected to any part of the circulation pipe CP. For example, the filter FT can be connected adjacent to the degasser DG in the first direction DR1. However, the embodiments of this utility model are not necessarily limited to this.

[0091] Refer again Figures 1 to 8 The inkjet printing apparatus 100, 101, 102, 103, 104, and 105 of this utility model embodiment may include: a head module HM for spraying ink IK onto the substrate; a storage container ST for storing ink IK and connected to the head module HM to supply ink IK to the head module HM; a first transfer pipe TP1 connecting the first outlet OT1 and the head module HM; a second transfer pipe TP2 connecting the first inlet IT1 and the head module HM; a pump P connected to the first transfer pipe TP1 or the second transfer pipe TP2; and a circulation pipe CP connecting the second outlet OT2 and the second inlet IT2. When the pump P is operating and the ink IK flows into the first transfer pipe TP1 through the first outlet OT1, a negative pressure can be generated at the second inlet IT2, and due to the negative pressure, the ink IK flows from the storage container ST into the circulation pipe CP through the second outlet OT2.

[0092] This prevents the precipitation of particles included in the ink IK located inside the storage container ST. Furthermore, since no additional pumps (e.g., pumps connected to the circulation pipe CP) are provided except for the pump P connected to the head module HM, the structure of the inkjet printing apparatuses 100, 101, 102, 103, 104, and 105 can be simplified, and maintenance costs can be reduced.

[0093] Although the present invention has been described above with reference to exemplary embodiments thereof, those skilled in the art will understand that the present invention can be modified and altered in various ways without departing from the spirit and scope of the invention as set forth in the claims.

[0094] This invention can be applied to the manufacturing processes of various display devices, which may include a display unit. For example, this invention can be applied to the manufacturing processes of high-resolution smartphones, cellular phones, smart panels, smartwatches, tablet PCs, in-vehicle navigation systems, televisions, computer monitors, laptops, etc.

Claims

1. An inkjet printing apparatus, characterized in that, include: The head module is used to spray ink onto the surface of a substrate, and includes an inflow connector and an outflow connector. A storage container for storing the ink and connected to the head module to supply the ink to the head module, the storage container including a first inlet, a second inlet, a first outlet, and a second outlet that are separate from each other; A first transmission conduit connects the first outlet and the inflow connection. The second transmission conduit connects the first inlet and the outlet connection. A pump is connected to either the first or the second transmission conduit; and A circulation pipe connects the second flow outlet and the second flow inlet.

2. The inkjet printing apparatus according to claim 1, characterized in that, While the pump is operating and the ink flows from the storage container into the first transfer pipe through the first outlet, the ink also flows from the storage container into the circulation pipe through the second outlet.

3. The inkjet printing apparatus according to claim 1, characterized in that, The second flow inlet is located adjacent to the first flow outlet.

4. The inkjet printing apparatus according to claim 1, characterized in that, The second inlet is located on the first side of the storage container. The first inlet is located on a second side of the storage container opposite to the first side. The first outlet and the second outlet are located on the bottom surface of the storage container opposite the head module.

5. The inkjet printing apparatus according to claim 1, characterized in that, The pump's revolutions per minute are proportional to the speed and flow rate of the ink circulating inside the circulation pipe.

6. The inkjet printing apparatus according to claim 1, characterized in that, Further includes: A bypass pipe connects the first transmission pipe and the second transmission pipe.

7. The inkjet printing apparatus according to claim 6, characterized in that, Further includes: A valve, connected to the bypass pipe, is used to regulate the supply of the ink.

8. The inkjet printing apparatus according to claim 1, characterized in that, Further includes: A filter, connected to the circulation pipe, is used to filter impurities in the ink moving inside the circulation pipe.

9. The inkjet printing apparatus according to claim 1 or 8, characterized in that, Further includes: A degasser, connected to the circulation pipe, is used to remove air bubbles from the ink moving inside the circulation pipe.

10. The inkjet printing apparatus according to claim 1, characterized in that, Inside the head module, an ink flow channel and a plurality of nozzles are formed, wherein the ink flow channel includes the inflow connection and the outflow connection, and the plurality of nozzles are connected to the ink flow channel and are used to spray the ink delivered from the first delivery pipe.

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