KR20220145493A - Inkjet printing equipment - Google Patents

Abstract

Provided is inkjet printing equipment capable of maintaining a meniscus state of ink injected into an inkjet head. The inkjet printing equipment includes: an inkjet head having a plurality of nozzles for discharging ink; an ink storage device for storing the ink to supply the ink to the inkjet head; a pressure control unit connected to the ink storage device, and regulating pressure in the ink storage device; a first supply flow path for supplying the ink from the ink storage device to the inkjet head; a first recovery flow path for recovering the ink from the inkjet head to the ink storage device; a filter device separated from the ink storage device, and filtering the ink in the ink storage device; a second supply flow path for supplying the ink from the ink storage device to the filter device; and a second recovery flow path for recovering the ink from the filter device to the ink storage device.

Description

Inkjet printing equipment

The present invention relates to an inkjet printing facility.

In general, the inkjet method of spraying liquid ink on the surface of a medium in the form of droplets according to a shape signal is used not only as printing for creating documents or flyers, but also in solution processes in semiconductor or display fields.

The application range of inkjet printing, which can form a pattern of a complex shape on a substrate or precisely eject ink only at a specific location, is expanding. Small-sized inkjet printers for document creation have a form of storing ink in an inkjet head that ejects ink droplets, but large-sized document printers or industrial inkjet printers use a large amount of ink. A structure in which the storage unit and the inkjet head are separated is applied.

In order to eject an accurate amount of ink in the inkjet printing process, the ink in the ejection ready state in the inkjet head must maintain a meniscus state, which is a curved state in which the ink is indented inwardly by capillary action with respect to the nozzle inlet. For this purpose, it is common to position the ink storage device higher than the inkjet head, and instead generate a negative pressure inside the ink storage device to prevent the ink from flowing down from the inkjet head to maintain the meniscus state. .

An object of the present invention is to provide an inkjet printing facility capable of maintaining a meniscus state of ink injected into an inkjet head.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

One aspect of the inkjet printing equipment of the present invention for achieving the above object is an inkjet head having a plurality of nozzles for discharging ink; an ink storage device for storing ink to supply ink to the inkjet head; a pressure control unit connected to the ink storage device and controlling the pressure inside the ink storage device; a first supply passage for supplying the ink from the ink storage device to the inkjet head; a first recovery passage for recovering the ink from the inkjet head to the ink storage device; a filter device that is separated from the ink storage device and filters the ink of the ink storage device; a second supply passage for supplying the ink from the ink storage device to the filter device; and a second recovery passage for recovering the ink from the filter device to the ink storage device.

The filter device may include a filter unit for removing foreign substances from the ink supplied from the ink storage device, and a degasser for removing bubbles of the ink supplied from the ink storage device.

The filter unit may include a porous membrane.

The ink storage device is located above the inkjet head, so that the ink stored in the ink storage device is provided to the inkjet head along the first supply passage by gravity, and a first circulation pump is provided in the first recovery passage. is installed to transfer ink from the inkjet head to the ink storage device by the operation of the first circulation pump.

A buffer storage device connected to the ink storage device and replenishing the ink of the ink storage device by the amount of ink consumed through the inkjet head based on the amount of ink in the ink storage device may be further included.

The inner wall of the ink storage device may include Teflon.

Another aspect of the inkjet printing equipment of the present invention for achieving the above object includes an ink storage device physically separated from each other, an inkjet head and a filter unit, and the ink stored in the ink storage device is the inkjet head. It circulates along a first circulation path passing through, and circulates along a second circulation path passing through the filter unit, but at least a portion of the first circulation path and the second circulation path may not overlap.

The first circulation path may be a path returning from the ink storage device to the ink storage device through the inkjet head, the first circulation pump, and the first gas remover in sequence.

The ink storage device is located above the inkjet head, so that the ink stored in the ink storage device is supplied to the inkjet head along a part of the first circulation path by gravity, and the ink remaining in the inkjet head is By the operation of the first circulation pump, it is possible to return to the ink storage device along another part of the first circulation path.

The second circulation path may be a path returning from the ink storage device to the ink storage device through the second circulation pump, the filter unit, and the second gas remover in sequence.

The details of other embodiments are included in the detailed description and drawings.

1 and 2 are schematic diagrams illustrating an ink circulation structure of an inkjet printing facility according to some embodiments of the present invention.
3 is a perspective view illustrating an inkjet printing facility according to some embodiments of the present invention.
4 is an enlarged view of an inkjet head in an inkjet printing facility according to some embodiments of the present invention.
5A to 5C are exemplary views for explaining a meniscus state of an inkjet head in an inkjet printing facility according to some embodiments of the present invention.
6 is a schematic diagram illustrating an ink circulation structure of an inkjet printing facility according to some embodiments of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments published below, but may be implemented in various different forms, and only these embodiments allow the publication of the present invention to be complete, and common knowledge in the technical field to which the present invention pertains. It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Reference to an element or layer “on” or “on” another element or layer includes not only directly on the other element or layer, but also with intervening other layers or other elements. include all On the other hand, reference to an element "directly on" or "directly on" indicates that no intervening element or layer is interposed.

Spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe a correlation between an element or components and other elements or components. The spatially relative terms should be understood as terms including different orientations of the device during use or operation in addition to the orientation shown in the drawings. For example, when an element shown in the figures is turned over, an element described as "beneath" or "beneath" another element may be placed "above" the other element. Accordingly, the exemplary term “below” may include both directions below and above. The device may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

Although first, second, etc. are used to describe various elements, components, and/or sections, it should be understood that these elements, components, and/or sections are not limited by these terms. These terms are only used to distinguish one element, component, or sections from another. Accordingly, it goes without saying that the first element, the first element, or the first section mentioned below may be the second element, the second element, or the second section within the spirit of the present invention.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural, unless specifically stated otherwise in the phrase. As used herein, “comprises” and/or “comprising” refers to the presence of one or more other components, steps, operations and/or elements mentioned. or addition is not excluded.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. A description will be omitted.

1 and 2 are schematic diagrams illustrating an ink circulation structure of an inkjet printing facility according to some embodiments of the present invention. 3 is a perspective view illustrating an inkjet printing facility according to some embodiments of the present invention.

1 to 3 , the inkjet printing equipment 100 includes an inkjet head 110 , a first supply passage 210 , a first recovery passage 220 , an ink storage device 120 , and a pressure controller 130 . , a filter device 140 , a second supply passage 310 , and a second recovery passage 320 .

The inkjet head 110 may include a plurality of nozzles 111 . The inkjet head 110 may discharge ink in the first direction (X). The inkjet printing facility 100 of this embodiment is configured for industrial use, and the inkjet head 110 and the ink storage device 120 may be separated.

Except for the fact that the inkjet head 110 and the ink storage device 120 are separated, the technical configuration of the conventional inkjet head may be variously modified within a range that does not impair the characteristics of the present invention.

One end of the first supply passage 210 and one end of the first recovery passage 220 may be connected to the inkjet head 110 .

The inkjet head 110 may receive ink through the first supply passage 210 . The inkjet head 110 may perform inkjet printing through a nozzle using the supplied ink. Ink remaining in the inkjet head 110 may be discharged through the first recovery passage 220 .

The ink storage device 120 may store ink. The ink storage device 120 may provide the stored ink to the inkjet head 110 .

The inner wall of the ink storage device 120 may include Teflon.

The other end of the first supply passage 210 and the other end of the first recovery passage 220 may be connected to the ink storage device 120 .

The ink storage device 120 may supply ink to the inkjet head 110 through the first supply passage 210 . The ink remaining in the inkjet head 110 may be recovered to the ink storage device 120 through the first recovery passage 220 .

As shown in FIG. 3 , the ink storage device 120 may be positioned above the inkjet head 110 . Accordingly, the ink stored in the ink storage device 120 may be provided to the inkjet head 110 along the first supply passage 210 by gravity.

In the inkjet printing facility 100 according to some embodiments of the present invention, a first circulation pump 221 and a first gas remover 222 may be installed on the first recovery passage 220 . Ink may be transferred from the inkjet head 110 to the ink storage device 120 by the operation of the first circulation pump 221 . The first gas remover 222 may remove bubbles of ink recovered from the inkjet head 110 .

The ink storage device 120 can be applied without limitation to the technology of the ink storage device 120 that has been conventionally used in the range that does not impair the characteristics of the present invention. For example, by dividing the inner space of the ink storage device 120 into two or more, the ink supplied to the inkjet head 110 through the first supply passage 210 and the ink recovered through the first recovery passage 220 are divided into two or more. A technique of storing ink in different spaces and configuring the ink to move between these spaces only under specific conditions may be applied without limitation.

The ink storage device 120 may be connected to the pressure controller 130 . The pressure controller 130 may adjust the pressure inside the ink storage device 120 . The pressure controller 130 controls the ink inside the inkjet head 110 to maintain a meniscus state. The meniscus state will be described in detail with reference to FIGS. 5A to 5C .

One end of the second supply passage 310 and one end of the second recovery passage 320 may be connected to the ink storage device 120 .

The ink storage device 120 may supply ink to the filter device 140 through the second supply passage 310 . Ink filtered in the filter device 140 may be recovered to the ink storage device 120 through the second recovery passage 320 . The filter device 140 may be separated from the ink storage device 120 .

The filter device 140 may be connected to one end of the second supply passage 310 and one end of the second recovery passage 320 .

The filter device 140 may receive ink through the second supply passage 310 . The filter device 140 may perform inkjet printing through a nozzle using the supplied ink. Ink remaining in the inkjet head 110 may be discharged through the first recovery passage 220 .

In FIG. 3 , the second supply passage 310 is connected to the upper surface of the ink storage device 120 , and the second recovery passage 320 is illustrated as being connected to the side surface of the ink storage device 120 , but this is an example. However, the technical spirit of the present invention is not limited thereto.

For reference, FIG. 2 is a schematic diagram showing a detailed configuration of the filter device 140 .

Specifically, the filter device 140 may include a second circulation pump 141 , a filter unit 142 , a second gas remover 143 , and a flow meter 144 .

Ink may be transferred from the ink storage device 120 to the filter device 140 by the operation of the second circulation pump 141 .

The filter unit 142 may receive ink from the ink storage device 120 . The filter unit 142 may remove foreign substances from the supplied ink. For example, the filter unit may include a porous membrane. Accordingly, the filter unit 142 may filter out foreign substances from the ink. However, this is only an example, and the technical spirit of the present invention is not limited thereto.

The second degasser may receive ink from the ink storage device 120 . The second gas remover 143 may remove bubbles of the supplied ink.

In FIG. 2 , it is illustrated that the ink supplied from the ink storage device 120 is transferred to the second gas remover 143 after passing through the filter unit 142 , but this is only an example, and the technical spirit of the present invention is limited thereto doesn't happen For example, the ink supplied from the ink storage device 120 may be transferred to the filter unit 142 after passing through the second gas remover 143 .

The flow meter 144 may measure the amount of flowing ink. Accordingly, it is possible to measure the total amount of ink filtered in the filter device 140 .

In the inkjet printing facility 100 according to some embodiments, the ink storage device 120 , the inkjet head 110 , and the filter unit 142 may be physically separated from each other.

The ink stored in the ink storage device 120 may circulate along the first circulation path L1 passing through the inkjet head 110 . The first circulation path L1 may be a path from the ink storage device 120 to the inkjet head 110 and the first circulation pump 221 sequentially to return to the ink storage device 120 . That is, the first circulation path L1 may form an endless loop by connecting the ink storage device 120 and the inkjet head 110 .

The configuration of the first circulation path L1 is only an example, and the technical spirit of the present invention is not limited thereto. For example, the first gas remover 222 may be further included on the first circulation path L1. Accordingly, the first circulation path L1 passes from the ink storage device 120 through the inkjet head 110 , the first circulation pump 221 , and the first gas remover 222 sequentially and back to the ink storage device 120 . It may be a return path.

The ink storage device 120 may be located above the inkjet head 110 . Accordingly, the ink stored in the ink storage device 120 may be provided to the inkjet head 110 along a part of the first circulation path L1 by gravity. The ink remaining in the inkjet head 110 may return to the ink storage device 120 along another part of the first circulation path L1 by the operation of the first circulation pump 221 .

The ink stored in the ink storage device 120 may circulate along the second circulation path L2 passing through the filter unit 142 . The second circulation path L2 sequentially passes from the ink storage device 120 through the second circulation pump 141 , the filter unit 142 and the second gas remover 143 to return to the ink storage device 120 . It can be a path. That is, the second circulation path L2 may form an endless loop by connecting the ink storage device 120 and the filter unit 142 .

At least a portion of the first circulation path L1 and the second circulation path L2 may not overlap. That is, the first circulation path L1 and the second circulation path L2 may be separate circulation paths.

4 is an enlarged view of an inkjet head in an inkjet printing facility according to some embodiments of the present invention. 5A to 5C are exemplary views for explaining a meniscus state of an inkjet head in an inkjet printing facility according to some embodiments of the present invention.

1 and 4 , the inkjet head 110 may include a plurality of nozzles 111 . The number of nozzles 111 is only an example, and the technical spirit of the present invention is not limited thereto. For example, as shown in FIG. 1 , the inkjet head 110 may include six nozzles 111 . Additionally, only three nozzles 111 are shown in FIG. 4 for ease of viewing, but the technical spirit of the present invention is not limited thereto.

The injection direction of the nozzle 111 may be the first direction (X). The first direction X may be a direction toward the ground. However, this is only an example, and the technical spirit of the present invention is not limited thereto.

For reference, FIGS. 5A to 5C are views illustrating a state in which ink is formed on the nozzle 111 by enlarging area A of FIG. 4 .

5A to 5C , the ink formed on the nozzle 111 of the inkjet head 110 should maintain an appropriate meniscus state. The meniscus state may help the inkjet head 110 accurately eject an appropriate amount of ink in a desired direction.

The ink storage device 120 may be located above the inkjet head 110 . Accordingly, ink may be supplied from the ink storage device 120 to the inkjet head 110 by gravity. In the nozzle 111 of the inkjet head 110, ink may flow out by gravity.

Accordingly, by controlling the pressure inside the ink storage device 120 by the pressure controller 130 , it is possible to prevent the ink from leaking out. The pressure controller 130 applies a negative pressure to the inside of the ink storage device 120 so that the ink inside the inkjet head 110 maintains a meniscus state.

For reference, FIG. 5A illustrates the nozzle 111 of the inkjet head 110 before the pressure controller 130 adjusts the pressure. FIG. 5B illustrates the nozzle 111 of the inkjet head 110 when the pressure controller 130 applies a negative pressure to the inside of the ink storage device 120 . FIG. 5C illustrates the nozzle 111 of the inkjet head 110 when the pressure controller 130 applies excessively negative pressure to the inside of the ink storage device 120 .

Referring to FIG. 5A , the ink in the nozzle 111 of the inkjet head 110 may form a convex ink surface 10a outside the nozzle 111 . In this case, ink may spill out or be over-ejected.

Referring to FIG. 5B , the ink in the nozzle 111 of the inkjet head 110 may form a convex ink surface 10b outside the nozzle 111 . However, in this case, the degree of convexity may be smaller than that shown in FIG. 5A . An appropriate level of convexity may help the inkjet head 110 accurately eject ink.

Referring to FIG. 5C , the ink in the nozzle 111 of the inkjet head 110 may be positioned inside the nozzle 111 to form a concave ink surface 10c. In this case, the ink may not be ejected in a desired direction and time.

6 is a schematic diagram illustrating an ink circulation structure of an inkjet printing facility according to some embodiments of the present invention.

Referring to FIG. 6 , the inkjet printing facility 100 according to some embodiments may further include a stirring device and a buffer storage device 150 .

Although not shown, the stirring device may be installed inside the ink storage device 120 . The stirring device may agitate the ink in the ink storage device 120 . For example, a magnetic rotating agitator may be installed.

In order to maintain fluidity and dispersibility of ink only by stirring the ink using a stirring device, excessive stirring of the ink is required. Therefore, it is difficult to maintain the meniscus when the fluidity and dispersibility are improved only by the stirring device.

That is, whether or not the stirring device is installed is only an example, and the technical idea of the present invention is not limited thereto. For example, the stirring device may not be installed.

Meanwhile, in order to supplement the ink consumed by performing printing, new ink must be additionally supplied to the ink storage device 120 . Since a loss occurs when printing is stopped for adding ink, it is preferable that ink is additionally supplied even while printing is performed. However, since the meniscus state may be damaged when ink is directly refilled in the ink storage device, the buffer storage device 150 may be additionally disposed.

The buffer storage device 150 may be connected to the ink storage device 120 . The buffer storage device 150 may replenish the ink of the ink storage device 120 by the amount of ink consumed through the inkjet head 110 based on the amount of ink in the ink storage device 120 .

Although the embodiments of the present invention have been described with reference to the above and the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can practice the present invention in other specific forms without changing its technical spirit or essential features. You will understand that there is Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

100: inkjet printing equipment 110: inkjet head
111: nozzle 120: ink storage device
130: pressure control unit 140: filter device
210: first supply passage 220: first recovery passage
310: second supply passage 320: second recovery passage
510: first circulation path 520: second circulation path

Claims (10)

an inkjet head having a plurality of nozzles for discharging ink;
an ink storage device for storing ink to supply ink to the inkjet head;
a pressure control unit connected to the ink storage device and controlling the pressure inside the ink storage device;
a first supply passage for supplying the ink from the ink storage device to the inkjet head;
a first recovery passage for recovering the ink from the inkjet head to the ink storage device;
a filter device that is separated from the ink storage device and filters the ink of the ink storage device;
a second supply passage for supplying the ink from the ink storage device to the filter device; and
and a second recovery passage for recovering the ink from the filter device to the ink storage device. The method of claim 1,
The filter device is
a filter unit for removing foreign substances from the ink supplied from the ink storage device;
and a degasser for removing bubbles of the ink supplied from the ink storage device. 3. The method of claim 2,
The filter unit inkjet printing equipment including a porous membrane. The method of claim 1,
The ink storage device is located above the inkjet head,
The ink stored in the ink storage device is provided to the inkjet head along the first supply passage by gravity,
A first circulation pump is installed in the first recovery passage, and the ink is transferred from the inkjet head to the ink storage device by the operation of the first circulation pump. The method of claim 1,
Connected to the ink storage device, based on the amount of ink in the ink storage device, the amount of ink consumed through the inkjet head
Inkjet printing equipment further comprising a buffer storage device for replenishing the ink of the ink storage device. The method of claim 1,
Inkjet printing equipment comprising the inner wall of the ink storage device Teflon (Teflon). Including an ink storage device, an inkjet head and a filter unit physically separated from each other,
Ink stored in the ink storage device,
circulate along a first circulation path through the inkjet head;
It circulates along the second circulation path passing through the filter unit,
and at least a portion of the first circulation path and the second circulation path do not overlap. 8. The method of claim 7,
and the first circulation path is a path returning from the ink storage device to the ink storage device through the inkjet head, the first circulation pump, and the first gas eliminator sequentially. 9. The method of claim 8,
The ink storage device is located above the inkjet head,
The ink stored in the ink storage device is provided to the inkjet head along a part of the first circulation path by gravity,
The ink remaining in the inkjet head is returned to the ink storage device along another part of the first circulation path by the operation of the first circulation pump. 8. The method of claim 7,
The second circulation path is a path returning from the ink storage device to the ink storage device through the second circulation pump, the filter unit, and the second gas remover in sequence.

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