KR20210111422A - Apparatus for cleaning inkjet head and system for treating substrate with the apparatus - Google Patents

Abstract

Provided are an inkjet head cleaning device for removing ink agglomerated in a nozzle by using microbubbles, and a substrate treatment system with the same. The inkjet head cleaning device includes an ink storage unit for storing ink, an inkjet head unit for discharging ink onto a substrate using a nozzle, and a microbubble generating unit for generating and providing microbubbles to the nozzle; and cleans the nozzle using the microbubbles.

Description

Inkjet head cleaning apparatus and substrate processing system having the same

The present invention relates to a substrate processing system for printing a substrate using an inkjet head. More particularly, it relates to a substrate processing system having an apparatus for cleaning an inkjet head.

When a printing process is performed on a transparent substrate to manufacture a display device such as a liquid crystal display (LCD), printing equipment including an inkjet head may be used.

Korean Patent Publication No. 10-2019-0118008 (published date: 2019.10.17.)

The inkjet head may eject ink onto the substrate to print the substrate. However, nanoparticles contained in the ink may cause ink agglomeration in the nozzle of the inkjet head. Such agglomeration of ink may clog the nozzles, may cause ink non-ejection and/or erroneous contact, and may act as a cause of poor pixel printing. Therefore, cleaning the nozzle of the inkjet head may act as a very important factor in pixel printing.

In the case of cleaning the nozzles of the inkjet head, conventionally, ink that has accumulated in the nozzles is removed by discharging the ink with a strong pressure. However, this method has problems in that the cleaning effect is insufficient and the consumption of ink is large.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inkjet head cleaning apparatus for removing ink agglomerated in a nozzle by using microbubbles.

Another object of the present invention is to provide a substrate processing system including an inkjet head cleaning apparatus for removing ink agglomerated in a nozzle by using microbubbles.

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 head cleaning apparatus of the present invention for achieving the above object includes an ink storage unit for storing ink; an inkjet head unit for discharging the ink onto a substrate using a nozzle; and a microbubble generator that generates microbubbles and provides them to the nozzle, wherein the nozzle is cleaned using the microbubbles.

The microbubble generating unit may generate the microbubbles and provide the microbubbles to the nozzle when the ink is not discharged on the substrate or the discharge amount of the ink is less than or equal to a reference amount.

The microbubble generating unit is connected to a first flow path providing a path for the ink moving from the ink storage unit to the inkjet head unit, or providing a path for the ink moving from the inkjet head unit to the ink storage unit. The second flow path and the first flow path may be respectively connected to each other.

The inkjet head cleaning apparatus may further include an ultrasonic wave generator for cleaning the nozzle.

The microbubble generator may be connected to one end of the nozzle, and the ultrasonic generator may be connected to the other end of the nozzle.

The inkjet head cleaning apparatus may include: a first pipe having one end connected to the ink storage unit; a second pipe having one end connected to the inkjet head unit and the other end coupled to the first pipe; and a third pipe having one end connected to the microbubble generator and the other end connected to any one of the first pipe and the second pipe, wherein the first pipe, the second pipe, and the second pipe 3 The pipe may be formed in a Y-shape or a T-shape.

The inkjet head cleaning apparatus may include a first valve installed on the first pipe; a second valve installed on the third pipe; and a first valve control unit for controlling opening and closing of the first valve and the second valve, wherein the first valve control unit controls opening and closing of the first valve and the second valve when the microbubble generator operates can be controlled

The microbubble generating unit may generate the microbubbles using a cleaning solution containing a solvent.

The ink storage unit may remove the microbubbles that move together with the ink when the ink returns from the inkjet head unit.

One aspect of the substrate processing system of the present invention for achieving the above object, the base; a substrate support unit installed on the base and supporting a substrate; An ink storage unit for storing ink, an inkjet head unit for discharging the ink onto a substrate by using a nozzle, and a fine bubble generating unit for generating fine bubbles and providing them to the nozzles, wherein the nozzles are used to generate fine bubbles. an inkjet head cleaning device for cleaning; and a pumping unit that applies pressure to the ink reservoir so that the ink moves to or returns from the inkjet head unit.

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

1 is a perspective view showing a schematic structure of a printing equipment according to an embodiment.
2 is a plan view showing a schematic structure of a printing equipment according to an embodiment.
3 is a diagram schematically showing the structure of an inkjet head cleaning apparatus according to a first embodiment of the present invention.
FIG. 4 is an exemplary view for explaining the role of the microbubble generating unit constituting the inkjet head cleaning apparatus of FIG. 3 .
5 is a diagram schematically showing the structure of an inkjet head cleaning apparatus according to a second embodiment of the present invention.
6 is a diagram schematically showing the structure of an inkjet head cleaning apparatus according to a third embodiment of the present invention.
7 is a diagram schematically showing the structure of an inkjet head cleaning apparatus according to a fourth embodiment of the present invention.
8 is a diagram schematically showing the structure of an inkjet head cleaning apparatus according to a fifth embodiment of the present invention.
9 is a first exemplary view for explaining a method of operating an inkjet head cleaning apparatus according to a fifth embodiment of the present invention.
10 is a second exemplary view for explaining a method of operating an inkjet head cleaning apparatus according to a fifth embodiment of the present invention.
11 is a diagram schematically showing the structure of an inkjet head cleaning apparatus according to a sixth embodiment 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 for 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, only these embodiments make the publication of the present invention 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 elements. include all On the other hand, reference to an element "directly on" or "immediately 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. 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, if 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.

The present invention relates to an inkjet head cleaning apparatus for removing ink agglomerated in a nozzle of an inkjet head using microbubbles (eg, microbubbles), and a substrate processing system having the same. Hereinafter, the present invention will be described in detail with reference to drawings and the like.

1 is a perspective view showing a schematic structure of a printing equipment according to an embodiment. And FIG. 2 is a plan view showing a schematic structure of a printing equipment according to an embodiment.

1 and 2, the printing equipment 100 includes a base 110, a substrate support unit 120, a gantry unit 130, a gantry movement unit 140, an inkjet head unit 150, a head movement unit ( 160 ), a droplet discharge amount measurement unit 170 , and a nozzle inspection unit 180 .

The base 110 may be provided in a rectangular parallelepiped shape having a constant thickness. A substrate support unit 120 is disposed on the upper surface of the base 110 .

The substrate support unit 120 has a support plate 121 on which the substrate S is placed. The support plate 121 may be a plate having a rectangular shape. A rotation driving member 122 is connected to the lower surface of the support plate 121 . The rotation driving member 122 may be a rotation motor. The rotation driving member 122 rotates the support plate 121 about a central axis of rotation perpendicular to the support plate 121 .

When the support plate 121 is rotated by the rotation driving member 122 , the substrate S may be rotated by the rotation of the support plate 121 . When the long side direction of the cell formed on the substrate S to which the droplet is applied faces the second direction 20 , the rotation driving member 122 rotates the substrate so that the long side direction of the cell faces the first direction 10 . can

The support plate 121 and the rotation driving member 122 may be linearly moved in the first direction 10 by the linear driving member 123 . The linear driving member 123 includes a slider 124 and a guide member 125 . The rotation driving member 122 is installed on the upper surface of the slider 124 .

The guide member 125 extends long in the first direction 10 in the center of the upper surface of the base 110 . A linear motor (not shown) may be built in the slider 124 , and the slider 124 is linearly moved in the first direction 10 along the guide member 125 by the linear motor (not shown).

The gantry unit 130 is provided on the path along which the support plate 121 moves. The gantry unit 130 is disposed to be spaced apart from the upper surface of the base 110 in the upper direction, and the gantry unit 130 is disposed such that the longitudinal direction faces the second direction 20 .

The gantry moving unit 140 linearly moves the gantry unit 130 in the first direction 10 . The gantry moving unit 140 includes a first moving unit 141 and a second moving unit 142 .

The first moving unit 141 is provided at one end of the gantry unit 130 , and the second moving unit 142 is provided at the other end of the gantry unit 130 . The first moving unit 141 slides along the guide rail 221 provided on one side of the base 110 , and the second moving unit 142 moves along the guide rail 222 provided on the other side of the base 110 . The sliding movement moves the gantry unit 130 in a straight line in the first direction 10 .

The inkjet head unit 150 is coupled to the gantry unit 130 by the head moving unit 160 . The inkjet head unit 150 may move linearly in the longitudinal direction of the gantry unit 130 , that is, in the second direction 20 , or in the third direction 30 by the head moving unit 160 . Also, the inkjet head unit 150 may rotate about an axis parallel to the third direction 30 with respect to the head moving unit 160 .

The inkjet head unit 150 discharges droplets to the substrate S. A plurality of inkjet head units 150 may be provided. For example, three inkjet head units 150 such as a first head unit 151 , a second head unit 152 , and a third head unit 153 may be provided. The plurality of inkjet head units 150 are coupled to the gantry unit 130 in parallel in a line in the second direction 20 .

The inkjet head unit 150 may include a plurality of nozzles (not shown) for discharging droplets and a nozzle plate (not shown) on which the plurality of nozzles are formed. The inkjet head unit 150 may be provided with, for example, 128 nozzles or 256 nozzles.

The number of piezoelectric elements corresponding to the plurality of nozzles may be provided in the inkjet head unit 150 . A droplet discharge amount of the plurality of nozzles may be independently adjusted by controlling a voltage applied to the piezoelectric element.

The head moving unit 160 may be provided in each of the inkjet head units 150 . In the present embodiment, since three inkjet head units 151, 152, and 153 are provided as an example, three head moving units 160 may also be provided to correspond to the number of heads. Alternatively, a single head moving unit 160 may be provided, and in this case, the inkjet head unit 150 may be moved integrally rather than individually.

The droplet discharge amount measuring unit 170 measures the droplet discharge amount of the inkjet head unit 150 . The droplet discharge amount measuring unit 170 may be disposed on one side of the substrate support unit 120 on the base 110 .

The droplet discharge amount measurement unit 170 measures the droplet amount discharged from all nozzles for each inkjet head unit 150 . By measuring the droplet discharge amount of the inkjet head unit 150 , it is possible to macroscopically check whether all nozzles of the inkjet head unit 150 are abnormal. That is, when the droplet discharge amount of the inkjet head unit 150 deviates from the reference value, it may be recognized that at least one of the inkjet head units 150 is abnormal.

The inkjet head unit 150 is moved in the first direction 10 and the second direction 20 by the gantry moving unit 140 and the head moving unit 160 to be positioned above the droplet discharge amount measuring unit 170 . can The head moving unit 160 may move the inkjet head unit 150 in the third direction 30 to adjust a vertical distance between the inkjet head unit 150 and the droplet discharge amount measuring unit 170 .

The nozzle inspection unit 180 checks whether individual nozzles provided in the inkjet head unit 150 are abnormal through an optical inspection. As a result of checking whether the macroscopic nozzle is abnormal in the droplet discharge amount measuring unit 170, if it is determined that there is an abnormality in the unspecified nozzle, the nozzle inspection unit 180 performs a complete inspection of the nozzle while checking whether the individual nozzle is abnormal can proceed.

The nozzle inspection unit 180 may be disposed on one side of the substrate support unit 120 on the base 110 . The inkjet head unit 150 may be moved in the first direction 10 and the second direction 20 by the gantry moving unit 140 and the head moving unit 160 to be positioned above the nozzle inspection unit 180 . have. The head moving unit 160 may move the inkjet head unit 150 in the third direction 30 to adjust a vertical distance between the inkjet head unit 150 and the nozzle inspection unit 180 .

Meanwhile, the printing equipment 100 may further include a droplet supply device 210 .

The droplet supply device 210 may be installed on the upper and side portions of the gantry unit 130 . The droplet supply device 210 includes a droplet supply module 211 and a pressure control module 212 .

The droplet supply module 211 and the pressure control module 212 may be coupled to the gantry unit 130 . The droplet supply module 211 receives droplets from the droplet supply device 210 and supplies the droplets to the inkjet head unit 150 . The pressure control module 212 regulates the pressure of the droplet supply module 211 by providing positive or negative pressure to the droplet supply module 211 .

Next, an inkjet head cleaning apparatus for removing ink accumulated in a plurality of nozzles of the inkjet head unit 150 will be described. The inkjet head cleaning apparatus may use microbubbles (eg, microbubbles) to remove ink accumulated in a plurality of nozzles.

3 is a diagram schematically showing the structure of an inkjet head cleaning apparatus according to a first embodiment of the present invention.

Referring to FIG. 3 , the inkjet head cleaning apparatus 300 may include an inkjet head unit 150 , an ink storage unit 310 , a pumping unit 320 , and a microbubble generating unit 330 .

The ink storage unit 310 stores ink discharged onto the substrate. The ink storage unit 310 may be connected to the inkjet head unit 150 through a first pipe 341 and a second pipe 342 that are coupled to each other. In this embodiment, the droplet supply module 211 of FIG. 2 may be implemented as the ink storage unit 310 .

The pumping unit 320 applies pressure to the ink storage unit 310 to move the ink stored in the ink storage unit 310 to the inkjet head unit 150 . In this embodiment, the pressure control module 212 of FIG. 2 may be implemented as the pumping unit 320 .

The microbubble generator 330 generates microbubbles and provides them to the inkjet head unit 150 . FIG. 4 is an exemplary view for explaining the role of the microbubble generating unit constituting the inkjet head cleaning apparatus of FIG. 3 . The following description refers to FIG. 4 .

When the ink stored in the ink storage unit 310 moves to the inkjet head unit 150 , some nanoparticles 410 included in the ink are agglomerated and the nozzles 430 of the inkjet head unit 150 are agglomerated. ) can be moved to Nanoparticles 410 moved to the nozzle 430 in the agglomerated state may cause a problem of closing the nozzle 430 to make it difficult to eject the ink.

In the present embodiment, the microbubble generating unit 330 may generate the microbubble 420 and provide it to the inkjet head unit 150 . After the microbubbles 420 are adsorbed to the nanoparticles 410 aggregated in the nozzle 430 , they are decomposed to solve the problem that the nozzle 430 is closed.

It will be described again with reference to FIG. 3 .

The micro-bubble generating unit 330 may generate micro-bubbles, that is, micro bubbles, of micro-bubbles, and supply them to the nozzles 430 of the inkjet head unit 150 . In this case, the microbubble generator 330 may be implemented as a microbubble generator. However, the present embodiment is not limited thereto. The micro-bubble generating unit 330 may generate nano-bubbles having a size of nanometers (nm) as micro-bubbles and supply them to the nozzle 430 of the inkjet head unit 150 .

The microbubble generating unit 330 may generate microbubbles using a cleaning solution. A cleaning solution used to generate microbubbles may be prepared based on a solvent.

The microbubble generator 330 may be connected to the inkjet head unit 150 through a second pipe 342 and a third pipe 343 that are coupled to each other to provide microbubbles to the inkjet head unit 150 . have. In this case, the first pipe 341 , the second pipe 342 , and the third pipe 343 may be coupled to each other in a Y-shape.

The microbubble generating unit 330 is connected to a Y-shaped pipe in which the first pipe 341 , the second pipe 342 , and the third pipe 343 are combined into one to directly discharge the microbubbles to the inkjet head unit 150 . can do. At this time, the microbubbles supplied from the microbubble generating unit 330 may move into the inkjet head unit 150 to decompose the agglomerated nanoparticles.

However, the present embodiment is not limited thereto. The first pipe 341 , the second pipe 342 , and the third pipe 343 may be coupled to each other in a T-shape as shown in FIG. 5 . 5 is a diagram schematically showing the structure of an inkjet head cleaning apparatus according to a second embodiment of the present invention.

It will be described again with reference to FIG. 3 .

The microbubble generator 330 may be connected to the upper portion of the inkjet head unit 150 through the second pipe 342 and the third pipe 343 . However, the present embodiment is not limited thereto. The microbubble generating unit 330 may be connected to a lower portion of the inkjet head unit 150 to which the nozzle is exposed to the outside.

The microbubble generator 330 may operate when the nozzles of the inkjet head unit 150 are clogged. In the present embodiment, after ink is discharged onto the test substrate by using the inkjet head unit 150 , a nozzle from which ink is not discharged is determined as a defective nozzle, and the corresponding nozzle is formed using the microbubble generator 330 . can be cleaned.

On the other hand, when the amount of the ejected ink is less than the reference value, the microbubble generator 330 may determine that the nozzle is a defective nozzle and use the microbubble generator 330 to clean the nozzle. Also, the microbubble generator 330 may periodically clean the inkjet head unit 150 even if the nozzle clogging problem does not occur.

In order to supply microbubbles to the inkjet head unit 150 at a necessary time (eg, when the nozzle 430 of the inkjet head unit 150 is clogged), the ink storage unit 310 and the microbubble generation unit 330 ) and a valve may be installed on a pipe connecting the inkjet head unit 150 .

6 is a diagram schematically showing the structure of an inkjet head cleaning apparatus according to a third embodiment of the present invention. The following description refers to FIG. 6 .

The first valve 351 is installed on a pipe connecting the ink storage unit 310 and the inkjet head unit 150 . Specifically, the first valve 351 may be installed on the first pipe 341 interconnecting the ink storage unit 310 and the second pipe 342 . The first valve 351 may be installed in this way to open and close the first pipe 341 .

The second valve 352 is installed on a pipe connecting the microbubble generator 330 and the inkjet head unit 150 . Specifically, the second valve 352 may be installed on the third pipe 343 interconnecting the microbubble generator 330 and the second pipe 342 . The second valve 352 may be installed in this way to open and close the third pipe 343 .

The first valve control unit 353 controls opening and closing of the first valve 351 and the second valve 352 . The first valve control unit 353 may be implemented in the form of an ON/OFF switch.

The first valve controller 353 may control opening and closing of at least one of the first valve 351 and the second valve 352 according to whether the inkjet head unit 150 is operated. For example, when the inkjet head unit 150 is used to discharge droplets on the substrate, the first valve control unit 353 opens (ON) the first valve 351 and closes the second valve 352 . Can be closed (OFF). On the other hand, when cleaning the inkjet head unit 150 , the first valve control unit 353 may close the first valve 351 (OFF) and open the second valve 352 (ON).

Meanwhile, different inks may be used when printing a substrate using the inkjet head unit 150 and when cleaning the inkjet head unit 150 . The first valve control unit 353 may open both the first valve 351 and the second valve 352 when the inkjet head unit 150 is cleaned using a different ink than when printing the substrate.

Meanwhile, in the present embodiment, only the second valve 352 is installed, and the first valve control unit 353 may control the opening and closing of the second valve 352 .

Ink stored in the ink storage unit 310 may be moved from the ink storage unit 310 to the inkjet head unit 150 to be discharged as droplets on the substrate. In this case, a portion of the ink may be discharged as droplets on the substrate through the inkjet head unit 150 , and the remainder may be moved back to the ink storage unit 310 . The inkjet head unit 150 may include an injection end and an exhaust end for this purpose.

The injection end and the discharge end of the inkjet head unit 150 may have different flow paths formed inside the inkjet head unit 150 . Therefore, in this embodiment, in order to maximize the cleaning effect of the inkjet head unit 150, the microbubble generating unit 330 may be installed to be respectively connected to the injection end and the discharge end.

7 is a diagram schematically showing the structure of an inkjet head cleaning apparatus according to a fourth embodiment of the present invention. The following description refers to FIG. 7 .

In the following description, the fine bubble generating unit 330 connected to the injection end 361 of the inkjet head unit 150 is defined as the first fine bubble generating unit 331 , and the discharge end of the inkjet head unit 150 ( The fine bubble generating unit 330 connected to 362 is defined as a second fine bubble generating unit 332 .

The first microbubble generating unit 331 is connected to a pipe that provides a path so that ink can move from the ink storage unit 310 to the inkjet head unit 150 , and is connected to the injection end 361 of the inkjet head unit 150 . ) can be connected to Specifically, the first microbubble generator 331 may be connected to the injection end 361 of the inkjet head unit 150 through the second pipe 342 and the third pipe 343 that are interconnected. The first microbubble generator 331 may be configured as described above, and may supply microbubbles to the injection end 361 of the inkjet head unit 150 to clean the nozzles formed in the inkjet head unit 150 . .

The second microbubble generating unit 332 is connected to a pipe providing a path so that ink can move from the inkjet head unit 150 to the ink storage unit 310 , and the discharge end 362 of the inkjet head unit 150 . ) can be connected to Specifically, the second microbubble generator 332 may be connected to the discharge end 362 of the inkjet head unit 150 through the fifth pipe 345 and the sixth pipe 346 that are interconnected. The second microbubble generating unit 332 may be configured as described above to supply microbubbles to the discharge end 362 of the inkjet head unit 150 to clean the nozzles formed in the inkjet head unit 150 . .

When the ink storage unit 310 , the first microbubble generator 331 , and the inkjet head unit 150 are connected by a Y-shaped pipe (or T-shaped pipe), the ink storage unit 310 is connected to the inkjet head unit 150 . ) may be connected to the second pipe 342 through the first pipe 341 to supply the ink. In addition, when the ink storage unit 310 , the second microbubble generator 332 , and the inkjet head unit 150 are connected by a Y-shaped pipe (or T-shaped pipe), the ink storage unit 310 is connected to the inkjet head unit. In order to collect the ink discharged from the 150 , it may be connected to the fifth pipe 345 through the fourth pipe 344 .

In this case, in order to control the flow of ink or microbubbles, as shown in FIG. 8 , on the first pipe 341 , the third pipe 343 , the fourth pipe 344 , and the sixth pipe 346 . A first valve 351 , a second valve 352 , a third valve 354 , and a fourth valve 355 may be installed, respectively.

8 is a diagram schematically showing the structure of an inkjet head cleaning apparatus according to a fifth embodiment of the present invention. The following description refers to FIG. 8 .

The first valve 351 is installed on the first pipe 341 connecting the ink storage unit 310 and the second pipe 342 , and the ink jet is discharged from the ink storage unit 310 through the first pipe 341 . The flow of ink moving to the head unit 150 is controlled.

The second valve 352 is installed on the third pipe 343 connecting the first microbubble generator 331 and the second pipe 342 , and generates the first microbubbles through the third pipe 343 . The flow of microbubbles moving from the unit 331 to the inkjet head unit 150 is controlled.

The third valve 354 is installed on the fourth pipe 344 connecting the ink storage unit 310 and the fifth pipe 345 , and the ink is discharged from the inkjet head unit 150 through the fourth pipe 344 . The flow of ink moving to the storage unit 310 is controlled.

The fourth valve 355 is installed on the sixth pipe 346 connecting the second microbubble generator 332 and the fifth pipe 345 to generate second microbubbles through the sixth pipe 346 . The flow of microbubbles moving from the unit 332 to the inkjet head unit 150 is controlled.

The first valve control unit 353 controls opening and closing of the first valve 351 and the second valve 352 . The first valve control unit 353 may be installed on a point where the first pipe 341 , the second pipe 342 , and the third pipe 343 meet. However, the present embodiment is not limited thereto. The first valve control unit 353 may be installed anywhere as long as it can control the opening and closing of the first valve 351 and the second valve 352 in this embodiment.

The second valve control unit 356 controls opening and closing of the third valve 354 and the fourth valve 355 . The second valve control unit 356 may be installed on a point where the fourth pipe 344 , the fifth pipe 345 , and the sixth pipe 346 meet. However, the present embodiment is not limited thereto. The second valve control unit 356 may be installed anywhere as long as it can control the opening and closing of the third valve 354 and the fourth valve 355 in this embodiment.

On the other hand, in the present embodiment, only one of the first valve control unit 353 and the second valve control unit 356 is provided, and the valve control unit includes the first valve 351 , the second valve 352 , and the second valve control unit. It is also possible to control the opening and closing of the third valve 354 and the fourth valve 355 .

Next, an operation method of the inkjet head cleaning apparatus 300 will be described.

9 is a first exemplary view for explaining a method of operating an inkjet head cleaning apparatus according to a fifth embodiment of the present invention, and FIG. It is a second exemplary diagram for The following description refers to FIGS. 9 and 10 .

First, referring to FIG. 9 , when printing a substrate, the first valve control unit 353 opens the first valve 351 to discharge the ink stored in the ink storage unit 310 onto the substrate, and , to close the second valve 352 . Then, the ink moves from the ink storage unit 310 to the injection end 361 of the inkjet head unit 150 , and the inkjet head unit 150 discharges the ink onto the substrate.

The ink that has moved to the inkjet head unit 150 is not all discharged on the substrate, and accordingly, the ink may remain on the inkjet head unit 150 . The pumping unit 320 provides pressure to collect ink that has been moved to the inkjet head unit 150 but is not discharged onto the substrate to the ink storage unit 310 . At this time, the second valve control unit 356 opens the third valve 354 and closes the fourth valve 355 so that ink is discharged from the discharge end 362 of the inkjet head unit 150 to the ink storage unit 310 . to be able to move to

Next, referring to FIG. 10 , when printing on the substrate is finished or ink is not normally discharged on the substrate, the first valve control unit 353 closes the first valve 351 and the second valve 352 ) is opened. Then, the microbubbles generated by the first microbubble generator 331 may be moved to the inkjet head unit 150 to clean the nozzles in the inkjet head unit 150 .

Similarly, the second valve control unit 356 closes the third valve 354 and opens the fourth valve 355 . Then, the microbubbles generated by the second microbubble generator 332 may be moved to the inkjet head unit 150 to clean the nozzles in the inkjet head unit 150 .

Meanwhile, in the present embodiment, it is also possible to operate only one of the first microbubble generating unit 331 and the second microbubble generating unit 332 in consideration of the position of the nozzle from which ink is not normally discharged. do.

Meanwhile, when the ink remaining in the inkjet head unit 150 moves to the ink storage unit 310 by the pumping unit 320 , the microbubbles may also move to the ink storage unit 310 together with the ink. In the present embodiment, it is also possible to provide a microbubble removal unit in the ink storage unit 310 so that the microbubbles can be removed from the ink storage unit 310 .

Meanwhile, the inkjet head cleaning apparatus 300 may further include an ultrasonic wave generator in addition to the microbubble generator 330 . Hereinafter, this will be described.

11 is a diagram schematically showing the structure of an inkjet head cleaning apparatus according to a sixth embodiment of the present invention. The following description refers to FIG. 11 .

The ultrasonic generator 370 cleans the nozzles of the inkjet head unit 150 together with the microbubble generator 330 . The ultrasonic generator 370 may generate a short pulse to clean the nozzle of the inkjet head unit 150 .

The ultrasonic generator 370 may be disposed to be close to one end of the nozzle under the inkjet head unit 150 to which the nozzle is exposed to the outside. In this case, the microbubble generator 330 may be connected to the other end of the nozzle at the top of the inkjet head unit 150 . In this embodiment, as described above, the ultrasonic generating unit 370 and the fine bubble generating unit 330 are connected to both ends of the nozzle and operate at the same time, thereby maximizing the cleaning effect.

Meanwhile, the ultrasonic generator 370 has an excellent cleaning effect, but may damage the nozzle. Therefore, in the present embodiment, after cleaning the inkjet head unit 150 using the microbubble generator 330 , if ink is still not discharged on the substrate, the inkjet head unit 150 is used using the ultrasonic generator 370 . ) can also be cleaned.

In addition, when the microbubble generator 330 and the ultrasonic generator 370 are used at the same time, the ultrasonic generator 370 is operated for a shorter time than the microbubble generator 330 to clean the inkjet head unit 150 . It is also possible

The inkjet head cleaning apparatus 300 according to various embodiments of the present invention has been described above with reference to FIGS. 3 to 11 .

In this embodiment, microbubbles, particularly microbubbles, are applied to maximize the cleaning effect. Microbubbles have proven to have excellent cleaning power due to their minute vibrations, increased cleaning surface area, and radicals on the bubble surface. As described above, if the microbubbles are used, nanoparticles trapped in the nozzles of the inkjet head unit 150 can be effectively removed.

The inkjet head unit 150 has an injection end 361 and a discharge end 362 . Since the injection end 361 and the discharge end 362 have different flow paths formed inside the inkjet head unit 150 , the microbubble generating unit 330 may be installed to maximize the cleaning effect.

In addition, the Y-shaped pipe connecting the ink storage unit 310, the microbubble generation unit 330, and the inkjet head unit 150 automatically turns ON/OFF because different inks are used for printing and cleaning. Possible devices can be applied.

In addition, the microbubble generating unit 330 is not limited to the bubble size, and may be coupled to the injection/discharge or the lower end (nozzle) of the inkjet head unit 150 . In addition, it is coupled to the ink storage unit 310 to maximize the effect of movement of the particles.

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 the technical spirit or essential features. You can understand that there is Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

100: printing equipment 150: inkjet head unit
300: inkjet head cleaning device 310: ink storage unit
320: pumping unit 330, 331, 332: micro-bubble generating unit
341, 342, 343, 344, 345, 346: piping
351, 352, 354, 355: valves 353, 356: valve control
361: inlet end 362: outlet end
370: ultrasonic generator 410: nanoparticles
420: microbubbles 430: nozzle

Claims (10)

an ink storage unit for storing ink;
an inkjet head unit for discharging the ink onto a substrate using a nozzle; and
and a microbubble generating unit that generates microbubbles and provides them to the nozzle,
An inkjet head cleaning apparatus for cleaning the nozzle using the microbubbles. The method of claim 1,
The micro-bubble generating unit generates the micro-bubbles and provides the micro-bubbles to the nozzle when the ink is not discharged on the substrate or the discharge amount of the ink is less than or equal to a reference amount. The method of claim 1,
The microbubble generating unit is connected to a first flow path providing a path for the ink moving from the ink storage unit to the inkjet head unit, or providing a path for the ink moving from the inkjet head unit to the ink storage unit. 2 and an inkjet head cleaning apparatus respectively connected to the first flow passage. The method of claim 1,
The inkjet head cleaning apparatus further comprising an ultrasonic generator for cleaning the nozzle. 5. The method of claim 4,
The microbubble generating unit is connected to one end of the nozzle,
The ultrasonic generator is connected to the other end of the inkjet head cleaning apparatus. The method of claim 1,
a first pipe having one end connected to the ink storage unit;
a second pipe having one end connected to the inkjet head unit and the other end coupled to the first pipe; and
It further comprises a third pipe having one end connected to the microbubble generator and the other end connected to any one of the first pipe and the second pipe,
The first pipe, the second pipe, and the third pipe are formed in a Y-shape or a T-shape. 7. The method of claim 6,
a first valve installed on the first pipe;
a second valve installed on the third pipe; and
Further comprising a first valve control unit for controlling the opening and closing of the first valve and the second valve,
The first valve control unit controls the opening and closing of the first valve and the second valve when the microbubble generator operates. The method of claim 1,
The micro-bubble generating unit is an inkjet head cleaning apparatus for generating the micro-bubbles by using a cleaning solution containing a solvent. The method of claim 1,
The ink storage unit removes the microbubbles moving together with the ink when the ink returns from the inkjet head unit. Base;
a substrate support unit installed on the base and supporting a substrate;
An ink storage unit for storing ink, an inkjet head unit for discharging the ink onto a substrate using a nozzle, and a fine bubble generating unit for generating fine bubbles and providing them to the nozzles, wherein the nozzles are used to generate fine bubbles. an inkjet head cleaning device for cleaning; and
and a pumping unit that applies pressure to the ink reservoir so that the ink moves to or returns from the inkjet head unit.

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