Spraying appratus, printing appratus and spraying method

Abstract

The present invention relates to a spraying device, a printing device, and a spraying method comprising a moving part through which a solution mixed with a plurality of light-emitting elements moves, a nozzle for spraying the solution moved from the moving part, and a mixing part for mixing the solution, wherein the light-emitting elements mixed in the solution can be discharged in a spaced-apart state.

Description

Technology Field

[0001] The present invention relates to a spraying device, a printing device, and a spraying method. Background Technology

[0002] Printing technology is used for the fabrication of display devices. Inkjet printing devices, which are commonly used in the fabrication of display devices, are devices that print an image of a specific color on the surface of a printing paper by using an inkjet head to eject minute droplets of printing ink or solution onto a desired location on a printing medium, such as printing paper. Recently, the application scope of such inkjet printing devices has expanded to various fields, including flat panel displays such as Liquid Crystal Displays (LCDs) and Organic Light Emitting Devices (OLEDs), flexible displays such as E-Paper, printed electronics such as metal wiring, and Organic Thin Film Transistors (OTFTs). One of the most critical technical challenges in process technology for applying these inkjet printing devices to the aforementioned display and printed electronics fields is high-resolution and ultra-precision printing. Accordingly, there is a growing need for printing devices capable of high-resolution and ultra-precision printing.

[0003] The inkjet nozzle of a printing device sprays ink mixed with light-emitting elements. When ink mixed with light-emitting elements is continuously applied through the inkjet nozzle, clumping of the light-emitting elements may occur inside the nozzle or around the part where the ink is ejected, and this may result in manufacturing losses due to nozzle clogging or a reduction in the lifespan of the printing device.

[0004] Korean Patent Publication No. 10-2012-0022403, etc. discloses a method for ensuring printing uniformity by adjusting the ink ejection interval of defective nozzles; however, this has the disadvantage that it does not prevent the occurrence of defective nozzles but is merely a reactive measure for defective nozzles that have already occurred. Prior art literature

[0005] Republic of Korea Published Patent No. 10-2012-0022403 (Published on March 12, 2012) The problem to be solved

[0006] The purpose of the present invention is to provide a spraying device, a printing device, and a spraying method for preventing nozzle clogging and improving process precision by discharging a plurality of light-emitting elements mixed in a solution in a spaced-apart state. means of solving the problem

[0007] In order to achieve the above objective,

[0008] The present invention provides a spraying device for spraying a solution mixed with a plurality of light-emitting elements, comprising: a moving part through which the solution moves; a nozzle for spraying the solution moved from the moving part; and a mixing part for mixing the solution so that the light-emitting elements mixed in the solution can be discharged in a spaced-apart state.

[0009] In addition, the present invention provides a printing device comprising: a stage on which an electrode substrate is disposed; and a spraying device for spraying a solution in which a plurality of light-emitting elements are mixed onto the electrode substrate disposed on the stage, wherein the spraying device is a spraying device according to the present invention.

[0010] In addition, the present invention provides a spraying method comprising the steps of: introducing a solution mixed with a plurality of light-emitting elements into a nozzle; mixing the solution so that the light-emitting elements are discharged in a spaced-apart state; and spraying the solution from the nozzle. Effects of the invention

[0011] When using the spraying device, printing device, and spraying method according to the present invention, the light-emitting elements are coated on the electrode substrate in a spaced-apart state, thereby improving process precision, preventing nozzle clogging in advance to improve processability, and extending the lifespan of the nozzle. Brief explanation of the drawing

[0012] FIG. 1 is a figure showing a light-emitting element according to one embodiment of the present invention. FIG. 2a is a drawing showing an injection device according to one embodiment of the present invention. FIG. 2b is a diagram illustrating a mixing unit according to one embodiment of the present invention in more detail. FIG. 3 is a perspective view of a nozzle according to one embodiment of the present invention. FIG. 4 is a block diagram showing a mixing unit according to one embodiment of the present invention. FIG. 5a is a cross-sectional view showing an example of the present invention in which the mixing part is located in the nozzle. FIG. 5b is a cross-sectional view showing another example of the present invention in which the mixing part is located in the nozzle. Figure 6 is a figure showing another example of a nozzle. FIGS. 7a and 7b are cross-sectional views showing another example of the present invention in which the mixing part is located in the nozzle. FIG. 8 is a drawing illustrating an inkjet printing device according to one embodiment of the present invention. FIG. 9 is a flowchart showing a spraying method according to one embodiment of the present invention. Specific details for implementing the invention

[0013] The present invention relates to a spraying device, a printing device, and a spraying method.

[0015] The present invention will be described in detail below.

[0016] Throughout this specification, when a component is described as being located "on" another component, this includes not only cases where a component is in contact with another component, but also cases where another component exists between the two components.

[0017] Throughout this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0019] Hereinafter, the present invention will be described in detail with reference to examples in order to specifically explain the invention. However, the embodiments according to the present invention may be modified in various different forms, and the scope of the present invention should not be interpreted as being limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the invention to those with average knowledge in the art.

[0021] Light-emitting element

[0022] FIG. 1 is a figure showing a light-emitting element (100) according to one embodiment of the present invention. The light-emitting element (Light Emitting Diode) (100) according to the present embodiment may be an inorganic light-emitting diode (inorganic LED) made of inorganic material, having a size in the micrometer or nanometer range, but is not limited thereto.

[0023] When an electric field is formed in a specific direction between two electrodes facing each other, polarity is formed between the two electrodes, and an inorganic light-emitting diode can be aligned between the two electrodes in which polarity is formed. That is, a nano-device or an inorganic light-emitting diode corresponding to the light-emitting element (100) according to the present embodiment can be aligned between two electrodes existing on a substrate.

[0024] To explain the light-emitting element (100) in more detail, the light-emitting element (100) may be a rod-shaped dipole LED. For example, the light-emitting element (100) may include a first electrode layer (110), a first semiconductor layer (120), an active layer (130), a second semiconductor layer (140), and a second electrode layer (150), but is not limited thereto. At this time, the first electrode layer (110), the first semiconductor layer (120), the active layer (130), the second semiconductor layer (140), and the second electrode layer (150) included in the light-emitting element (100) may be arranged sequentially along one direction or have a stacked structure.

[0025] As the first electrode layer (110) and the second electrode layer (150) of the light-emitting element (100) each come into contact with the first electrode portion and the second electrode portion of the electrode substrate simultaneously, the light-emitting element (100) and the electrode substrate can be electrically connected through the first electrode portion and the second electrode portion. At this time, the first end portion (102) and the second end portion (104) according to the present embodiment may represent the portions where the light-emitting element (100) comes into contact with the first electrode portion and the second electrode portion of the electrode substrate.

[0026] The light-emitting element (100) according to the present embodiment may be cylindrical having a length L (105) as shown in FIG. 1, but is not limited thereto. At this time, the length L (105) of the light-emitting element (100) may be 10 μm, but is not limited thereto, and preferably may be 1.5 μm or more and 7 μm or less.

[0027] The light-emitting element (100) may have a polygonal prism shape such as a rod, a rectangle, or a hexagonal prism shape, having a shape that extends in one direction with a length L (105). In addition, the shape of the light-emitting element (100) according to the present embodiment is not limited thereto and may have a shape such as a cube, a tube, or a wire, or may have various shapes such as a shape that extends in one direction and has a partially inclined outer surface.

[0028] The first semiconductor layer (120), active layer (130), and second semiconductor layer (140) of the light-emitting element (100) can emit light of a specific wavelength range when an electrical signal is applied. For example, the first semiconductor layer (120) may include an n-type semiconductor layer, and the second semiconductor layer (140) may include a p-type semiconductor layer. Accordingly, when an electrical signal is applied to the light-emitting element (100) from an external power source, the active layer (130) transitions to a lower energy level as electrons and holes recombine, and can generate and emit light having a corresponding wavelength.

[0029] An electrical signal must be applied to the light-emitting element (100) so that the light-emitting element (100) according to the present embodiment can generate light. In order to apply the electrical signal to the light-emitting element (100) stably and efficiently, an electrode substrate including two electrode portions may be used, and as the light-emitting element (100) is electrically connected to the electrode substrate, it can generate light of a predetermined wavelength.

[0030] In order for the light-emitting elements (100) to be electrically connected to the electrode substrate according to the present embodiment, the light-emitting elements (100) must be applied to the electrode substrate. For example, the light-emitting elements (100) may be provided to the electrode substrate in a state mixed with a predetermined solution, and for this purpose, a spraying device is required to spray the solution mixed with the light-emitting elements (100).

[0032] <Spraying device>

[0033] FIG. 2a is a drawing showing a spraying device (200) according to an embodiment of the present invention. FIG. 2a is a cross-sectional view of the spraying device (200), and the spraying device (200) according to the present embodiment may include a moving part (210), a nozzle (220), and a mixing part (230). FIG. 2a shows only one nozzle (220) and two mixing parts (230), but is not limited thereto, and the spraying device (200) may further include a plurality of nozzles (220) and a plurality of mixing parts (230).

[0034] The spraying device (200) according to the present embodiment may be an inkjet head of an inkjet printing device, but is not limited thereto. For example, an inkjet printing device may use an inkjet head to discharge a fine droplet of a solution mixed with light-emitting elements (100), i.e., printing ink, to a desired location on an electrode substrate, thereby printing an image of a predetermined color on the surface of a printing paper. At this time, the solution mixed with light-emitting elements (100) may be provided in a colloidal state. To this end, the solvent may be methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, isopropyl alcohol, isobutyl alcohol, isoamyl alcohol, distilled water, hexamethyl phosphate triamide, acetonitrile, diethyl ether, diisopropyl ether, methyl-t-butyl ether, etc., but is not limited thereto. That is, a plurality of light-emitting elements (100) are included in a dispersed state within a solvent and supplied to a spraying device (200), after which they can be discharged.

[0035] The spraying device (200) generally converts an electrical signal into a physical force to cause a solution to be discharged in the form of a droplet through a small nozzle (220). For this operation, the spraying device (200) includes a moving part (210) which is a path through which a solution injected from a solution storage device (not shown) can move to the nozzle (220), and a nozzle (220) that sprays the solution flowing through the moving part (210) to the outside. The spraying device (200) according to the present embodiment may further include a mixing part (230) to prevent nozzle clogging due to uneven control during the process of the nozzle (220) discharging the solution.

[0037] Moving part (210)

[0038] The solution mixed with the light-emitting elements (100) according to the present embodiment moves through the moving unit (210). For example, the moving unit (210) receives the solution mixed with the light-emitting elements (100) through the solution supply unit (212). Referring to FIG. 2a, the solution supplied through the solution supply unit (212) can move along the direction of the arrow.

[0040] Nozzle (220)

[0041] The nozzle (220) according to the present embodiment sprays a solution moving from the moving part (210). The nozzle (220) may be connected to the moving part (210), and the solution flowing along the moving part (210) may be discharged through the nozzle (220) and provided to the upper surface of the electrode substrate. The spraying speed (m / s) of the solution discharged from the nozzle (220) according to the present embodiment may be adjusted according to the voltage applied to the nozzle (220). For example, the spraying speed (m / s) of the solution discharged from the nozzle (220) may be 10 m / s or less, preferably 5 m / s to 10 m / s, but is not limited thereto.

[0042] The nozzle (220) according to the present embodiment may have a shape capable of spraying a solution mixed with light-emitting elements (100). For example, the nozzle (220) may be cylindrical, rectangular, or cylindrical in shape with a diameter that narrows from top to bottom, but is not limited thereto. The nozzle (220) will be described in more detail below with reference to FIG. 3.

[0043] FIG. 3 is a perspective view of a nozzle (220) according to the present embodiment. Referring to FIG. 3, the nozzle (220) may include a solution inlet (222), a solution discharge (224), and a connecting part (226). The solution inlet (222) is connected to a moving part (210), and a solution moving from the moving part (210) may be introduced into the nozzle (220) through the solution inlet (222).

[0044] The solution discharge section (224) is located on the opposite side of the solution inlet section (222), and the solution introduced through the solution inlet section (222) can be discharged. For example, the diameter of the solution inlet section (222) has a larger value than the diameter of the solution discharge section (224). The solution discharged from the nozzle (220) having this shape is easy to spray in a desired direction, and accordingly, the light-emitting elements (100) mixed in the solution can be provided at a desired location, so the precision of the process can be improved.

[0045] The connecting portion (226) connects the solution inlet portion (222) and the solution discharge portion (224), allowing the solution introduced from the solution inlet portion (222) to be discharged through the solution discharge portion (224). Referring to FIG. 3, the diameter of the connecting portion (226) is shown to gradually decrease in order to connect the solution inlet portion (222) and the solution discharge portion (224) having different diameters, but it is not limited thereto, and the connecting portion (226) can have various shapes through which the solution can move.

[0047] Mixing section (230)

[0048] Referring again to FIG. 2a, the mixing unit (230) according to the present embodiment mixes the solution so that the light-emitting elements mixed in the solution can be discharged in a spaced-apart state. For example, the mixing unit (230) may include all methods of mixing or stirring the solution so as not to hinder the flow of the solution mixed with the light-emitting elements (100) and to minimize clumping or contact between the light-emitting elements (100).

[0049] FIG. 2b is a more detailed illustration of a mixing unit (230) according to the present embodiment. Referring to FIG. 2b, the mixing unit (230) may include a rotating unit (232) that rotates around a rotation axis to mix a solution, and a supporting unit (234) that supports the rotation axis of the rotating unit (232). The supporting unit (234) according to the present embodiment serves as a support for fixing the rotating unit (232) to a spraying device and may be used as the rotation axis of the rotating unit (232), but is not limited thereto; it may also be used to support the rotation axis by being connected to the rotation axis of the rotating unit (232). At this time, the rotation axis may be formed in the direction from the moving unit (210) to the nozzle (220), but is not limited thereto; it may be formed in various shapes and directions to rotate the rotating unit (232).

[0050] To explain the mixing section (230) in more detail, the mixing section (230) may have a rotating section (232) rotate around a rotation axis so that the solutions are mixed uniformly by a physical method, but is not limited thereto, and may include various methods that do not interfere with the flow of the solution and minimize clumping or contact of the light-emitting elements (100) mixed in the solution.

[0051] The rotating part (232) can be implemented as a propeller type. At this time, the shape and size of the propeller can be varied depending on the position of the rotating part (232), for example, a disc turbine type, a cross type, an anchor type, a spiral ribbon type, etc., can be used. In addition, in order to effectively separate the light-emitting elements (100), it is preferable for the rotating part (232) to have a symmetrical shape with respect to the rotation axis.

[0052] In this way, as the solution is mixed in the mixing unit (230), the light-emitting elements (100) mixed in the solution introduced into the nozzle (220) can be separated from each other. That is, the light-emitting elements (100) may be mixed in the solution in a clumped state, and if the light-emitting elements (100) in the clumped state exist within the nozzle (220), a problem may occur in which the solution cannot be discharged due to nozzle clogging. In addition, if the solution mixed with the light-emitting elements (100) in a clumped state is discharged, it is not easy for the light-emitting elements (100) to be electrically connected to the electrode substrate, and thus the light-emitting efficiency may be reduced. Therefore, the mixing unit (230) mixes the solution so that the light-emitting elements (100) mixed in the solution are separated from each other.

[0053] To this end, the mixing unit (230) according to the present embodiment may vary the rotational speed of the rotating unit (232) applied according to the flow rate (m / s) of the solution discharged from the nozzle (220). For example, as the flow rate (m / s) of the solution discharged from the nozzle (220) increases, the rotational speed of the rotating unit (232) may become faster. The mixing unit (230) will be described in more detail below with reference to FIG. 4.

[0054] FIG. 4 is a block diagram showing a mixing unit (230) according to the present embodiment. Referring to FIG. 4, the mixing unit (230) may include a sensing unit (231), a rotation speed selection unit (233), a rotation unit (232), and a support unit (234).

[0055] The sensing unit (231) senses the flow rate (m / s) of the solution to be discharged from the nozzle (220). For example, it may sense the flow rate (m / s) of the solution flowing into the nozzle (220) or sense the voltage value applied to the nozzle (220), but is not limited thereto.

[0056] The rotation speed selection unit (233) selects the rotation speed of the rotation unit (232) based on the amount of change of the solution sensed by the sensing unit (231).

[0057] The rotating part (232) rotates according to the rotational speed selected by the rotational speed selection part (233) to mix the solution. In this way, the mixing part (230) can effectively separate the light-emitting elements (100) by adjusting the rotational speed according to the flow rate (m / s) of the discharged solution.

[0058] In addition, the mixing unit (230) according to the present embodiment can appropriately adjust the mixing time for mixing the solution. Although FIG. 4 shows and describes the sensing unit (231) and the rotation speed selection unit (233) as being located inside the mixing unit (230), it is not limited thereto, and the sensing unit (231) and the rotation speed selection unit (233) may be located in the control unit (not shown) of the spraying device (200) rather than inside the mixing unit (230).

[0059] In this case, the rotational speed selected by the sensing unit (231) and the rotational speed selection unit (233) can be transmitted to the rotational unit (232) of the mixing unit (230). Accordingly, when the spraying device (200) includes a plurality of mixing units (230), the rotational unit (232) included in each mixing unit (230) may all rotate at the same rotational speed, or they may rotate at different rotational speeds depending on the flow rate (m / s) of the solution discharged from each nozzle (220).

[0060] The mixing unit (230) according to the present embodiment may continuously mix the solution, but is not limited thereto, and may select an appropriate mixing time depending on the position of the rotating unit (232).

[0061] For example, when the rotating part (232) is located inside the moving part (210), the rotating part (232) can rotate continuously.

[0062] To explain with other examples, when the rotating part (232) is located inside the nozzle (220), the rotating part (232) can rotate when spraying a solution from the nozzle (220) or when the nozzle (220) is clogged.

[0063] In this way, as the rotation intensity and rotation timing are controlled in the mixing section (230), the light-emitting elements (100) are spaced apart in the solution, so the positional precision for precisely dropping the light-emitting elements (100) at a location desired by the user can be improved, and this can ultimately improve process precision.

[0064] Referring again to FIG. 2a, the mixing unit (230) is located inside the moving unit (210) and, accordingly, mixes the solution moving from the moving unit (210). The mixing unit (230) according to the present embodiment is not limited thereto and may be located in various places inside the spraying device (200).

[0065] FIGS. 5A and 5B illustrate an example in which a mixing unit (230) according to the present embodiment is located inside a nozzle (220). FIGS. 5A and FIGS. 5B each show a cross-sectional view in which a mixing unit (230) is located inside a nozzle (220). As shown in FIGS. 5A and 5B, the mixing unit (230) is located inside the nozzle (220) so as not to interfere with the flow of the solution (510) in which the light-emitting elements (100) are mixed.

[0066] FIGS. 5A and 5B illustrate an example in which a solution (510) mixed with light-emitting elements (100) according to the present embodiment is discharged through a nozzle (220). Referring to FIGS. 5A and 5B, a mixing unit (230) is present inside the nozzle (220), and when a solution (510) mixed with a plurality of light-emitting elements (100) flows into the nozzle (220) through a moving unit (210), the mixing unit (230) can mix the solution (510) passing through the nozzle (220) according to a predetermined method.

[0067] Referring to FIG. 5a, the rotating part (232) mixes the solution inside the nozzle (220) to separate the light-emitting elements (100). Accordingly, as shown in FIG. 5a, a plurality of light-emitting elements (100) are clustered and mixed into the solution (510) between the solution inlet part (222) and the mixing part (230). However, as the solution is mixed by the rotating part (232) present inside the nozzle, a plurality of light-emitting elements (100) are separated from each other and mixed into the solution (510) between the rotating part (232) and the solution discharge part (224) where the solution (510) is discharged. Accordingly, the light-emitting elements (100) can exist separated from each other in the solution droplet (520) discharged from the nozzle (220), thereby improving the precision of the process.

[0068] Referring to FIG. 5b, the rotating part (232) may be located at the solution inlet (222) of the nozzle part (220) connected to the moving part (210). Accordingly, in the moving part (210), a plurality of light-emitting elements (100) are clustered together and mixed in the solution (510), but as the solution is mixed by the rotating part (232), the plurality of light-emitting elements (100) are mixed in the solution (510) in a spaced-apart state between the rotating part (232) and the solution discharge part (224) where the solution (510) is discharged. Accordingly, as the light-emitting elements (100) can exist in a spaced-apart state in the solution droplet (520) discharged from the nozzle (220), the precision of the process can be improved.

[0070] FIG. 6 shows a cross-sectional view illustrating another example of a nozzle (220). Referring to FIG. 6, the connecting portion (226) of the nozzle (220) according to the present embodiment includes a maximum diameter point (228) having a diameter larger than the diameter of the solution inlet portion (222) and the diameter of the solution outlet portion (224). That is, the nozzle (220) can be implemented such that the connecting portion (226) has a jar shape.

[0071] As the diameter of the connecting part (226) narrows again after passing through the maximum diameter point (228), when the solution mixed with the light-emitting elements (100) passes through the maximum diameter point (228) of the nozzle (220), a clumping phenomenon of the light-emitting elements (100) in the solution occurs. That is, as the nozzle (220) is implemented to have a maximum diameter point (228), the location where the light-emitting elements (100) clump together can be artificially controlled. As the mixing part (230) according to the present embodiment is placed at an appropriate location considering the location of the maximum diameter point (228), the light-emitting elements (100) can be efficiently separated.

[0073] Referring to FIGS. 7a and 7b, another example of a mixing section (230) present in a nozzle (220) according to the present embodiment is shown. As illustrated in FIG. 7a, the rotating section (232) may be located at the maximum diameter point (228). Accordingly, for example, if the rotating section (232) is implemented as a propeller, the size of the propeller may be larger, and thus the rotational force may be stronger, thereby allowing the clumping phenomenon of the light-emitting elements (100) to be resolved more effectively.

[0074] Referring to FIG. 7b for a more detailed explanation, between the solution inlet (222) and the rotating part (232), a plurality of light-emitting elements (100) are clustered together and mixed into the solution (510). However, as the solution is mixed by the rotating part (232), between the rotating part (232) and the solution discharge part (224) where the solution (510) is discharged, a plurality of light-emitting elements (100) are mixed into the solution (510) in a spaced-apart state. Accordingly, as the light-emitting elements (100) can exist in a spaced-apart state in the solution droplet (520) discharged from the nozzle (220), the precision of the process and the light-emitting efficiency can be improved.

[0075] In this way, as the rotating part (232) is located at various positions, the light-emitting elements (100) mixed in the solution can be effectively separated.

[0076] For example, since the rotating part (232) is located inside the moving part (210), the light-emitting elements (100) in the solution can be introduced into the nozzle (220) in a spaced-away state. Additionally, since the rotating part (232) exists separately from the nozzle (220), it may not affect the spraying accuracy of the nozzle (220).

[0077] To explain another example, the rotating part (232) may be located inside the nozzle (220) or in the solution inlet (222) connecting the moving part (210) and the nozzle (220). In this way, the closer the rotating part (232) is to the nozzle (220) or the more it is located inside the nozzle (220), the more effectively the nozzle (220) can be prevented from clogging.

[0078] In this way, by positioning the mixing unit (230) at various locations according to the usage environment of the spraying device (200), the light-emitting elements (100) mixed in the solution can be efficiently separated.

[0080] Printing device

[0081] FIG. 8 is a drawing illustrating an inkjet printing device (800) according to the present embodiment. FIG. 8 is a cross-sectional view of the inkjet printing device (800), and the inkjet printing device (800) includes a spraying device (200) and a stage (810). Since the ink of the inkjet printing device (800) according to the present embodiment may represent a solution in which the light-emitting elements (100) described in FIG. 1 to 7b are mixed, the description described in relation to FIG. 1 to 7b may also be applied to the ink of FIG. 8. Hereinafter, ink and solution may be used interchangeably.

[0082] The inkjet printing device (800) may employ various ink ejection methods, such as a piezoelectric method or an electrostatic method. The piezoelectric method is a method of ejecting ink by the deformation of a piezoelectric material, and the electrostatic method is a method of ejecting ink by electrostatic force. The electrostatic method can be divided into a method of ejecting ink by electrostatic induction and a method of accumulating charged pigments by electrostatic force and then ejecting them as ink droplets.

[0083] An inkjet printer (800) according to the present embodiment may include a stage (810) on which an electrode substrate (820) can be placed, and an inkjet head, i.e., an inkjet device (200) for spraying ink. With respect to the inkjet device (200) shown in FIG. 8, the description described in relation to FIG. 1 to FIG. 7b is applicable to the inkjet device (200) of FIG. 8, so redundant descriptions are omitted. Referring to FIG. 8, the inkjet device (200) includes four nozzles (220), but is not limited thereto, and the inkjet device (200) may include at least two nozzles (220).

[0084] An electrode substrate (820) may be placed on top of a stage (810). That is, the stage (810) may provide an area for applying ink where the electrode substrate (820) is placed and an area where an electric field generating unit (not shown) is placed. Additionally, the stage (810) may be placed on a movable rail (not shown). In this case, the rail may include a first rail and a second rail that move in different directions. The stage (810) may move on the rail through a separate moving member. Additionally, the electric field generating unit may move together with the stage, and ink sprayed from the nozzle (220) may be oriented through the electric field formed on top of the stage (810) and applied onto the electrode substrate (820). Since the nozzle (220) must apply ink mixed with light-emitting elements (100) onto the electrode substrate (820), the diameter of the nozzle (220) may narrow or widen from the moving part (210) toward the electrode substrate (820), but it is preferable to implement it with a shape that narrows in diameter as shown in FIG. 3 in order to improve the positional accuracy of the applied light-emitting elements (100).

[0085] Additionally, the sensing unit (231) and the rotation speed selection unit (233) of the nozzle (220) according to the present embodiment may exist in each of the plurality of nozzles (220), but are not limited thereto, and may exist in the control unit (not shown) of the inkjet printing device (800). For example, the sensing unit (231) and the rotation speed selection unit (233) transmit the selected rotation speed to each of the plurality of rotation units (232) so that the rotation units (232) can rotate at the same speed.

[0087] <Spraying Method>

[0088] In addition, the present invention provides a spraying method in which a solution in which a plurality of light-emitting elements are mixed is sprayed while the plurality of light-emitting elements are spaced apart.

[0089] In the above spraying method, the contents regarding the light-emitting element, moving part, nozzle, mixing part, etc., may be applied as described in FIGS. 1 to 8.

[0090] In the spraying method of the present invention, the structure and components such as the light-emitting element, moving part, nozzle, mixing part, etc., and the method of manufacturing the same are not particularly limited as long as they do not interfere with the technical features described above, and those known in the field may be employed without limitation.

[0091] FIG. 9 is a flowchart of a spraying method according to the present embodiment. The method described in FIG. 9 can be implemented using the components shown in FIG. 1 to 8, and the sequence described in FIG. 9 is based on one embodiment, and steps 901 to 903 can be implemented simultaneously or regardless of the order.

[0092] The spraying method according to the present embodiment includes the step (901) of introducing a solution mixed with a plurality of light-emitting elements into a nozzle, the step (902) of mixing the solution so that the light-emitting elements are discharged in a spaced-apart state, and the step (903) of spraying the solution from the nozzle.

[0093] Accordingly, since the solution discharged from the spraying device allows multiple light-emitting elements to exist spaced apart from each other, the precision of the process and the uniformity of the printing can be improved.

Claims

Claim 1 A spraying device for spraying a solution mixed with a plurality of light-emitting elements, comprising: a moving part through which the solution moves; a nozzle for spraying the solution moved from the moving part; and a mixing part for mixing the solution so that the light-emitting elements mixed in the solution can be discharged in a spaced-apart state; wherein the mixing part further comprises: a rotating part that rotates around a rotation axis to mix the solution; a supporting part that supports the rotation axis of the rotating part; a sensing part that senses the flow rate (m / s) of the solution to be discharged from the nozzle; and a rotation speed selection part that selects the rotation speed of the rotating part based on the sensed flow rate (m / s) of the solution; wherein the rotating part rotates according to the selected rotation speed to mix the solution. Claim 2 A spraying device according to claim 1, wherein the mixing part mixes the solution moved from the moving part. Claim 3 A spraying device according to claim 1, wherein the mixing unit mixes the solution passing through the nozzle. Claim 4 delete Claim 5 A spraying device according to claim 1, wherein the nozzle comprises: a solution inlet connected to the moving part; a solution discharge part located opposite the solution inlet and through which the solution is discharged; and a connecting part connecting the solution inlet and the solution discharge part, wherein the connecting part includes a maximum diameter point having a diameter greater than the diameter of the solution inlet and the diameter of the solution discharge part. Claim 6 A spraying device according to claim 5, characterized in that the rotating part is located at the maximum diameter point. Claim 7 A spraying device according to claim 1, wherein the nozzle comprises: a solution inlet connected to the moving part; a solution discharge part located opposite the solution inlet and through which the solution is discharged; and a connecting part connecting the solution inlet and the solution discharge part, and wherein the rotating part is located at the solution inlet. Claim 8 A spraying device according to claim 1, characterized in that the rotational speed of the rotating part varies depending on the amount of solution discharged from the nozzle. Claim 9 delete Claim 10 A spraying device according to claim 1, characterized in that the length of each of the plurality of light-emitting elements is 10 μm or less. Claim 11 A printing device comprising: a stage on which an electrode substrate is disposed; and a spraying device for spraying a solution in which a plurality of light-emitting elements are mixed onto the electrode substrate disposed on the stage; wherein the spraying device is a spraying device according to claim 1. Claim 12 A spraying method comprising: a step of introducing a solution mixed with a plurality of light-emitting elements into a nozzle; a step of mixing the solution so that the light-emitting elements are discharged in a spaced-apart state; and a step of spraying the solution from the nozzle; wherein the spraying is performed using a spraying device according to claim 1.

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