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 that sprays the solution moving from the moving part, and a vibrating part that applies vibration to the nozzle, so that 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 cause nozzle clogging, resulting in manufacturing losses 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 vibrating part attached to the nozzle for applying vibration to the nozzle.

[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: a step of introducing a solution mixed with a plurality of light-emitting elements into a nozzle; a step of applying vibration to the nozzle so that the light-emitting elements are discharged in a spaced-apart state; and a step of 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. 2 is a diagram showing an injection device according to one embodiment of the present invention. 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 vibration unit according to one embodiment of the present invention. Figure 5 is a cross-sectional view showing an example in which a vibrating part is attached to a nozzle. FIG. 6 is a figure showing an example in which a solution mixed with light-emitting elements according to one embodiment of the present invention is discharged through a nozzle. Figure 7 is a cross-sectional view showing another example in which a vibrating part is attached to a nozzle. FIG. 8 is a figure showing another example in which a solution mixed with light-emitting elements according to one embodiment of the present invention is discharged through a nozzle. FIG. 9 is a drawing illustrating an inkjet printing device according to one embodiment of the present invention. FIG. 10 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] <Injection device>

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

[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 vibration 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. 2, 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] Vibration part (230)

[0048] Referring again to FIG. 2, the vibration unit (230) according to the present embodiment is attached to the nozzle (220) and applies vibration to the nozzle (220). For example, the vibration unit (230) may apply vibration to the nozzle (220) by using physical methods such as ultrasonic waves, pressure, thermal expansion, etc., mechanical methods such as elastic bodies such as springs, mechanical friction, vibration motors, etc., and electrical and magnetic methods such as electromagnets, permanent magnets, etc., but is not limited thereto. It may include all methods of applying vibration that do not interfere with the flow of the solution mixed with the light-emitting elements (100) and minimize clumping or contact between the light-emitting elements (100).

[0049] As the vibration unit (230) applies vibration to the nozzle (220), 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 may not be 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 vibration unit (230) applies vibration to the nozzle (220) to separate the light-emitting elements (100) mixed in the solution from each other.

[0050] To this end, the vibration unit (230) can adjust the intensity of the vibration applied to the nozzle (220) differently according to the flow rate (m / s) of the solution discharged from the nozzle (220). For example, if the flow rate (m / s) of the solution discharged from the nozzle (220) decreases due to nozzle blockage, the intensity of the vibration applied by the vibration unit (230) can be increased to clear the nozzle blockage.

[0051] The vibration unit (230) can apply vibration to the nozzle (220) using various methods. For example, the vibration unit (230) can apply vibration to the nozzle (220) using ultrasonic waves or a vibration motor, but is not limited thereto. At this time, the vibration unit (230) can apply vibration to the nozzle (220) with a vibration frequency range of 20 kHz or more and 50 kHz or less, and preferably, can apply vibration with a vibration frequency of 24 kHz or 40 kHz.

[0052] The vibration part (230) will be described in more detail below with reference to FIG. 4.

[0053] FIG. 4 is a block diagram showing a vibration unit (230) according to an embodiment of the present invention. Referring to FIG. 4, the vibration unit (230) may include a sensing unit (232), a frequency selection unit (234), and an ultrasonic transmission unit (236).

[0054] The sensing unit (232) senses the amount of change 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.

[0055] The frequency selection unit (234) selects the vibration frequency of the ultrasound based on the flow rate (m / s) of the solution sensed by the sensing unit (232).

[0056] For example, the frequency selection unit (234) can select an appropriate vibration frequency in the range of 20 kHz or more and 50 kHz or less based on the flow rate (m / s) of the sensed solution.

[0057] To explain another example, the frequency selection unit (234) can select a first vibration frequency when the flow rate (m / s) of the sensed solution is below a first threshold value, assuming that nozzle clogging has occurred within the nozzle (220), and can select a second vibration frequency when the flow rate is below a second threshold value, assuming that the degree of nozzle clogging within the nozzle (220) is severe. At this time, the first threshold value may be 10 m / s and the second threshold value may be 5 m / s, but is not limited thereto. The first vibration frequency may be 20 kHz or more and less than 35 kHz, preferably 20 kHz or more and less than 30 kHz, and more preferably 24 kHz. In addition, the second vibration frequency may be 35 kHz or more and less than 50 kHz, preferably 35 kHz or more and less than 45 kHz, and more preferably 40 Hz. Meanwhile, if the flow rate (m / s) of the solution sensed by the sensing unit (232) is greater than or equal to the first threshold value, it is assumed that no nozzle clogging has occurred in the nozzle (220), so vibration may not be applied to the nozzle (220).

[0058] The ultrasonic transmitter (236) can transmit ultrasonic waves according to the vibration frequency selected by the frequency selector (234) in order to apply vibration to the nozzle (220). For example, if the vibration frequency of the ultrasonic waves selected by the frequency selector (234) is 24 kHz, the ultrasonic transmitter (236) can transmit ultrasonic waves of 24 kHz to apply vibration to the nozzle (220), and if the vibration frequency of the ultrasonic waves selected by the frequency selector (234) is 40 kHz, the ultrasonic transmitter (236) can transmit ultrasonic waves of 40 kHz to apply vibration to the nozzle (220).

[0059] In this way, the vibration unit (230) can adjust the intensity of the vibration, and additionally, the vibration unit (230) can also adjust the timing of the vibration.

[0060] For example, the vibrating unit (230) can apply vibration to the nozzle (220) just before spraying the solution from the nozzle (220). For another example, the vibrating unit (230) can apply vibration to the nozzle (220) when the nozzle (220) is clogged. For yet another example, the vibrating unit (230) can continuously apply vibration to the nozzle (220) without adjusting the timing of the vibration.

[0061] In this way, by adjusting the vibration intensity and vibration timing in the vibration unit (230), positional precision for precisely loading light-emitting elements (100) at a location desired by the user can be improved, and this can ultimately improve process precision.

[0063] FIG. 5 shows an example in which a vibrating member (230) is attached to a nozzle (220), and shows a cross-sectional view of the vibrating member (230) attached to the nozzle (220). As shown in FIG. 5, the vibrating member (230) is attached to the outside of the nozzle (220) so as not to interfere with the flow of the solution mixed with the light-emitting elements (100).

[0065] FIG. 6 is a diagram showing an example in which a solution (610) mixed with light-emitting elements (100) according to the present embodiment is discharged through a nozzle (220). Referring to FIG. 6, a vibrating member (230) is attached to the nozzle (220), and when a solution (610) mixed with a plurality of light-emitting elements (100) flows into the nozzle (220) through a moving member (210), the vibrating member (230) can apply vibration to the nozzle (220) according to a predetermined method.

[0066] As illustrated in FIG. 6, between the solution inlet (222) and the vibrating section (230), a plurality of light-emitting elements (100) are clustered together and mixed into the solution (610). However, as vibration is applied from the vibrating section (230), between the vibrating section (230) and the solution discharge section (224) where the solution (610) is discharged, the plurality of light-emitting elements (100) are separated from each other and mixed into the solution (610). Accordingly, as the light-emitting elements (100) can exist separated from each other in the solution droplet (620) discharged from the nozzle (220), the precision of the process can be improved.

[0068] FIG. 7 shows another example in which a vibrating part (230) is attached to a nozzle (220), and shows a cross-sectional view of the nozzle (220) with the vibrating part (230) attached. Referring to FIG. 7, the connecting part (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 part (222) and the diameter of the solution discharge part (224). That is, the nozzle (220) can be implemented so that the connecting part (226) has a jar shape.

[0069] As the diameter of the connecting part (226) narrows again after passing through the maximum diameter point (228), when the solution mixed with 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 may occur. 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 vibrating 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.

[0070] For example, the vibrating part (230) may be located between the maximum diameter point (228) and the solution discharge part (224). Additionally, since the spraying precision may be affected if the vibrating part (230) is close to the solution discharge part (224) of the nozzle (220), the vibrating part (230) may be located closer to the maximum diameter point (228) than to the solution discharge part (224). For example, the vibrating part (230) may be attached directly below the maximum diameter point (228), but is not limited thereto.

[0072] FIG. 8 is a diagram showing another example in which a solution (610) mixed with light-emitting elements (100) according to the present embodiment is discharged through a nozzle (220). Referring to FIG. 8, the nozzle (220) has a maximum diameter point (228), and a vibrating part (230) is attached below the maximum diameter point (228) of the nozzle (220). When a solution (610) mixed with a plurality of light-emitting elements (100) flows into the nozzle (220) through a moving part (210), the vibrating part (230) can apply vibration to the nozzle (220) according to a predetermined method.

[0073] As shown in FIG. 8, between the solution inlet (222) and the vibrating part (230), a plurality of light-emitting elements (100) are clustered together and mixed in the solution (610), and when the diameter of the nozzle (220) narrows again after the solution (610) passes through the maximum diameter point (228), the clustering phenomenon of the light-emitting elements (100) occurs more severely.

[0074] At this time, as vibration is applied from the vibration unit (230), a plurality of light-emitting elements (100) are mixed into the solution while spaced apart from each other between the vibration unit (230) and the solution discharge unit (224). Accordingly, as the light-emitting elements (100) can exist in a spaced-apart state in the solution droplet (620) discharged from the nozzle (220), the precision and light-emitting efficiency of the process can be improved.

[0076] Printing device

[0077] FIG. 9 is a drawing illustrating an inkjet printing device (900) according to the present embodiment. FIG. 9 is a cross-sectional view of the inkjet printing device (900), and the inkjet printing device (900) includes a spraying device (200) and a stage (910). Since the ink of the inkjet printing device (900) according to the present embodiment may represent a solution in which the light-emitting elements (100) described in FIG. 1 to 8 are mixed, the description described in relation to FIG. 1 to 8 may also be applied to the ink of FIG. 9. Hereinafter, ink and solution may be used interchangeably.

[0078] The inkjet printing device (900) 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.

[0079] An inkjet printer (900) according to the present embodiment may include a stage (910) on which an electrode substrate (920) can be placed, and an inkjet head, i.e., an inkjet head, for spraying ink. With respect to the inkjet device (200) shown in FIG. 9, the description described in relation to FIG. 1 to FIG. 8 may be applied to the inkjet device (200) of FIG. 9, so redundant descriptions are omitted. Referring to FIG. 9, 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).

[0080] The electrode substrate (920) may be placed on the upper part of the stage (910). That is, the stage (910) may provide an area for applying ink where the electrode substrate (920) is placed and an area where an electric field generating unit (not shown) is placed. Additionally, the stage (910) 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 (910) 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 the upper part of the stage (910) and applied onto the electrode substrate (920).

[0082] <Spraying Method>

[0083] 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.

[0084] In the above spraying method, the details regarding the light-emitting element, moving part, nozzle, vibrating part, etc., may be applied as described in FIGS. 1 to 9.

[0085] In the spraying method of the present invention, the structure and components such as the light-emitting element, moving part, nozzle, and vibrating part, 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.

[0086] FIG. 10 is a flowchart of a spraying method according to the present embodiment. The method described in FIG. 10 can be implemented using the components shown in FIG. 1 to 9, and the sequence described in FIG. 10 is based on one embodiment, and steps 1001 to 1003 can be implemented simultaneously or regardless of the order.

[0087] The spraying method according to the present embodiment includes a step (1001) in which a solution mixed with a plurality of light-emitting elements is introduced into a nozzle, a step (1002) in which vibration is applied to the nozzle so that the light-emitting elements are discharged in a spaced-apart state, and a step (1003) in which the solution is sprayed from the nozzle. At this time, the step (1002) in which vibration is applied may apply vibration to the nozzle using ultrasound.

[0088] 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 moving from the moving part; and a vibrating part attached to the nozzle for applying vibration to the nozzle; wherein the vibrating part comprises: a sensing part for sensing the flow rate (m / s) of the solution to be discharged from the nozzle; a frequency selection part for selecting the vibration frequency of an ultrasound based on the sensed flow rate (m / s) of the solution; and an ultrasound transmitting part for transmitting an ultrasound according to the selected vibration frequency to apply vibration to the nozzle. Claim 2 A spraying device according to claim 1, wherein the intensity of the vibration applied by the vibrating part varies according to the flow rate (m / s) of the solution discharged from the nozzle. Claim 3 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 4 A spraying device according to claim 3, characterized in that the vibrating part is located between the maximum diameter point and the solution discharge part. Claim 5 A spraying device according to claim 4, characterized in that the vibrating part is located closer to the maximum diameter point than the solution discharge part. Claim 6 A spraying device according to claim 1, characterized in that the vibration part applies vibration to the nozzle using ultrasound. Claim 7 A spraying device according to claim 6, characterized in that the vibration part applies vibration to the nozzle using ultrasonic waves having a vibration frequency of 20 kHz or more and 50 kHz or less. Claim 8 delete Claim 9 A spraying device according to claim 1, characterized in that when the flow rate (m / s) of the solution sensed by the sensing unit is greater than or equal to a first threshold value, vibration is not applied to the nozzle. Claim 10 A spraying device according to claim 1, wherein the frequency selection unit selects a first vibration frequency when the flow rate (m / s) of the solution sensed by the sensing unit is less than a first threshold value, and the ultrasonic transmitter transmits an ultrasonic wave of the first vibration frequency to apply vibration to the nozzle. Claim 11 A spraying device according to claim 10, wherein the frequency selection unit selects a second vibration frequency when the flow rate (m / s) of the solution sensed by the sensing unit is less than a second threshold value, and the ultrasonic transmitter transmits an ultrasonic wave of the second vibration frequency to apply vibration to the nozzle. Claim 12 A spraying device according to claim 1, wherein the vibrating part applies vibration to the nozzle immediately before spraying the solution from the nozzle. Claim 13 A spraying device according to claim 1, wherein the vibration part applies vibration to the nozzle when the nozzle is clogged. Claim 14 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 15 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 16 A spraying method comprising: a step of introducing a solution mixed with a plurality of light-emitting elements into a nozzle; a step of applying vibration to the nozzle 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. Claim 17 In claim 16, the step of applying vibration is characterized by applying vibration to the nozzle using ultrasound.

Images