Storage device of light-emitting element, printing device and method for manufacturing display device

Abstract

Disclosed are a storage device for light-emitting elements, a printing device including the same, and a method for manufacturing a display device using the same. The storage device for the light-emitting element may include a storage container, a first electrode, a second electrode, and a power supply unit, wherein: the storage container contains contents including a solvent in which at least one light-emitting element is dispersed; the first electrode is arranged on a lower surface of the storage container; the second electrode is arranged on an upper surface of the storage container opposite the lower surface; and the power supply unit is electrically connected to each of the first and second electrodes to apply a signal corresponding to each of the first and second electrodes. Here, the first and second electrodes can form an electric field in the vertical direction. In addition, the light-emitting element may include a first end and a second end located at both ends in the longitudinal direction, and the longitudinal direction may be parallel to the vertical direction.

Description

Technical Field

[0001] The present invention relates to a storage device for a light-emitting element, a printing device including the storage device, and a method for manufacturing a display device using the storage device. Background Art

[0002] With the growing interest in information display and the increasing demand for portable information media, the demand for display devices and the commercialization of display devices are being focused on. Summary of the Invention

[0003] Technical problems solved

[0004] An object of the present invention is to provide a storage device for light-emitting elements capable of preventing supply defects of light-emitting elements, a printing device including the storage device, and a method for manufacturing a display device using the printing device.

[0005] Workaround

[0006] A storage device for a light-emitting element according to one embodiment of the present invention may include a storage container, a first electrode, a second electrode, and a power supply unit. The storage container contains a content including a solvent in which at least one light-emitting element is dispersed; the first electrode is disposed on a lower surface of the storage container; the second electrode is disposed on an upper surface of the storage container opposite the lower surface; and the power supply unit is electrically connected to each of the first and second electrodes to apply a signal corresponding to each of the first and second electrodes. The first and second electrodes may form an electric field in a vertical direction.

[0007] In one embodiment of the present invention, the light emitting element may include a first end portion and a second end portion located at both ends in a length direction, and the length direction may be parallel to the vertical direction.

[0008] In one embodiment of the present invention, the light-emitting element may include a first semiconductor layer, a second semiconductor layer and an active layer, wherein the first semiconductor layer corresponds to the first end and is doped with a first conductive dopant; the second semiconductor layer corresponds to the second end and is doped with a second conductive dopant different from the first conductive dopant; and the active layer is located between the first semiconductor layer and the second semiconductor layer.

[0009] In one embodiment of the present invention, the light emitting element may include a light emitting diode of nanometer to micrometer scale.

[0010] In one embodiment of the present invention, each of the first electrode and the second electrode may be applied with signals of different polarities from each other.

[0011] In one embodiment of the present invention, the first electrode and the second electrode may be arranged on an outer surface of the storage container.

[0012] In one embodiment of the present invention, the first electrode and the second electrode may have the same size and may include a conductive material.

[0013] According to one embodiment of the present invention, a printing device including a printing head unit may include a storage section, at least one storage unit and a supply unit, wherein: the storage section accommodates contents including a solvent in which at least one light-emitting element is dispersed; at least one storage unit receives the contents accommodated in the storage section through a first supply section to accommodate the contents; and the supply unit receives the contents accommodated in the storage unit through a second supply section to supply the contents to the printing head unit.

[0014] In one embodiment of the present invention, a storage unit may include a storage container, a first electrode, a second electrode, and a power supply unit, wherein: the storage container contains contents; the first electrode is provided on a lower surface of the storage container; the second electrode is provided on an upper surface of the storage container; and the power supply unit is electrically connected to each of the first and second electrodes to apply a signal corresponding to each of the first and second electrodes. Here, the first and second electrodes can form an electric field in a vertical direction.

[0015] In one embodiment of the present invention, the light emitting element may include a first end portion and a second end portion located at both ends in a length direction, and the length direction may be parallel to the vertical direction.

[0016] In one embodiment of the present invention, the light-emitting element may include a first semiconductor layer, a second semiconductor layer and an active layer, wherein the first semiconductor layer corresponds to the first end and is doped with a first conductive dopant; the second semiconductor layer corresponds to the second end and is doped with a second conductive dopant; and the active layer is located between the first semiconductor layer and the second semiconductor layer.

[0017] In one embodiment of the present invention, the light emitting element may include a light emitting diode of nanometer to micrometer scale.

[0018] In one embodiment of the present invention, the storage unit may include a first storage container, a first electrode, and a second electrode, wherein: the first storage container accommodates the contents in the storage portion delivered through the first supply portion; the first electrode is arranged on the lower surface of the first storage container; and the second electrode is arranged on the upper surface of the first storage container.

[0019] In one embodiment of the present invention, the supply unit may include a second storage container, a first electrode, and a second electrode, wherein: the second storage container accommodates the contents of the storage unit delivered through the second supply part; the first electrode is arranged on the lower surface of the second storage container; and the second electrode is arranged on the upper surface of the second storage container.

[0020] In one embodiment of the present invention, the supply unit may further include a stirring member for stirring the contents in the second storage container.

[0021] In one embodiment of the present invention, each of the first electrode and the second electrode may be applied with signals of different polarities from each other.

[0022] In one embodiment of the present invention, the first electrode and the second electrode may have the same size and may include a conductive material.

[0023] In one embodiment of the present invention, the print head unit may include a print head and a plurality of nozzles, wherein the plurality of nozzles are connected to the print head and eject the content.

[0024] In one embodiment of the present invention, a display device using a printing device including at least one storage unit (which receives contents including at least one light-emitting element contained in the storage unit through a first supply unit to contain the contents) and a supply unit (which receives the contents contained in the storage unit through a second supply unit to supply the contents to a printing head unit) can be manufactured by the following steps: a step of preparing a substrate including a first pixel electrode and a second pixel electrode spaced apart from each other; a step of ejecting the contents onto an upper portion of the substrate through the printing head unit; and a step of aligning the light-emitting elements of the contents between the first pixel electrode and the second pixel electrode.

[0025] In one embodiment of the present invention, the content may be ink including a fluid solvent and light-emitting elements dispersed in the solvent.

[0026] In one embodiment of the present invention, the storage unit can accommodate contents in a storage container, and apply signals to a first electrode arranged on the lower surface of the storage container and a second electrode arranged on the upper surface of the storage container to form a vertical electric field between the first electrode and the second electrode, thereby keeping the light-emitting element in a suspended state.

[0027] In one embodiment of the present invention, the first electrode and the second electrode may have the same size and may include a conductive material.

[0028] Beneficial effects

[0029] The present invention can form a vertical electric field by using two electrodes arranged opposite each other up / down outside a storage container containing contents (including a solvent in which multiple light-emitting elements are dispersed), thereby keeping the light-emitting elements in a suspended state within the storage container to prevent the light-emitting elements from sinking.

[0030] The effects according to one embodiment of the present invention are not limited to those exemplified above, and more various effects are included in this specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a perspective view schematically showing a light emitting element according to one embodiment.

[0032] Figure 2 yes Figure 1 Cross-sectional view of a light-emitting element.

[0033] Figure 3 FIG. 1 is a side cross-sectional view schematically showing a storage device including a light emitting element according to an embodiment.

[0034] Figure 4a It is a perspective view schematically showing a storage unit according to one embodiment.

[0035] Figure 4b It is schematically shown Figure 4a A side sectional view of a storage portion.

[0036] Figure 5a and Figure 5b It is schematically shown Figure 4a A side cross-sectional view of a storage portion before and after an electric field is formed.

[0037] Figure 6 This is a diagram schematically showing a printing device according to one embodiment.

[0038] Figure 7 is a side sectional view schematically showing part of a printing apparatus according to one embodiment.

[0039] Figure 8 is a schematic plan view of a display device manufactured by a method according to one embodiment.

[0040] Figure 9 is a circuit diagram illustrating an electrical connection relationship among constituent elements included in each pixel of a display device according to one embodiment.

[0041] Figure 10 FIG. 1 is a plan view schematically showing each pixel of a display device according to one embodiment.

[0042] Figure 11 It is along Figure 10Schematic cross-sectional view along line II'.

[0043] Figure 12 It is along Figure 10 Schematic cross-sectional view along line II-II'.

[0044] Figures 13 to 15 1 is a cross-sectional view schematically illustrating a method for manufacturing a display device according to one embodiment, in process steps. DETAILED DESCRIPTION

[0045] The present invention is susceptible to various modifications and may have various forms, and specific embodiments are illustrated in the drawings and will be described in detail herein. However, this is not intended to limit the present invention to the specific disclosed forms, but should be understood to include all modifications, equivalents, and alternatives encompassed by the concept and technical scope of the present invention.

[0046] When describing each figure, similar reference numerals are used for similar constituent elements. In the accompanying drawings, for the clarity of the present invention, the size of the structure is enlarged compared to the actual size. Although the terms "first", "second" and the like can be used to describe various constituent elements, the above constituent elements should not be limited by the above terms. The above terms are only used to distinguish one constituent element from another constituent element. For example, without departing from the scope of the present invention, the first constituent element can be referred to as the second constituent element, and similarly, the second constituent element can also be referred to as the first constituent element. Unless the context clearly indicates otherwise, the expression of the singular includes the expression of the plural number.

[0047] It should be understood that, in this application, terms such as "including" or "having" are intended to specify the presence of features, numbers, steps, operations, constituent elements, parts or combinations thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features or numbers, steps, operations, constituent elements, parts or combinations thereof. In addition, when a portion of a layer, film, region, plate, etc. is mentioned as being "on" another portion, it includes not only the case where it is "directly "on" another portion, but also the case where there is another portion between them. In addition, in this specification, when a portion of a layer, film, region, plate, etc. is mentioned as being formed on another portion, the above-mentioned formation direction is not limited to the upper direction, but also includes the case where it is formed in the lateral direction or the lower direction. On the contrary, when a portion of a layer, film, region, plate, etc. is mentioned as being "under" another portion, it includes not only the case where it is "directly "under" another portion, but also the case where there is another portion between them.

[0048] It should be understood that in this application, when it is mentioned that a certain component (for example, "a first component") is "(functionally or communicatively) coupled with / to" or "connected to" another component (for example, "a second component"), the above-mentioned certain component may be directly connected to the above-mentioned another component, or may be connected to the above-mentioned another component through another component (for example, "a third component"). Conversely, when it is mentioned that a certain component (for example, "a first component") is "directly connected to" or "directly coupled to" another component (for example, "a second component"), it can be understood that there is no other component (for example, "a third component") between the above-mentioned certain component and the above-mentioned another component.

[0049] Hereinafter, preferred embodiments of the present invention and matters necessary for making it easy for those skilled in the art to understand the contents of the present invention will be described in detail with reference to the accompanying drawings. In the following description, unless the context clearly indicates that only the singular is included, the expression in the singular also includes the expression in the plural.

[0050] Figure 1 is a perspective view schematically showing a light emitting element according to one embodiment, and Figure 2 yes Figure 1 Cross-sectional view of a light-emitting element.

[0051] In one embodiment of the present invention, the type and / or shape of the light emitting element is not limited to Figure 1 and Figure 2 The embodiment shown.

[0052] refer to Figure 1 and Figure 2 The light emitting element LD may include a first semiconductor layer 11, a second semiconductor layer 13, and an active layer 12, wherein the active layer 12 is interposed between the first semiconductor layer 11 and the second semiconductor layer 13. For example, the light emitting element LD may implement a light emitting stack in which the first semiconductor layer 11, the active layer 12, and the second semiconductor layer 13 are sequentially stacked.

[0053] The light emitting element LD may be provided in a shape extending in one direction. If the extending direction of the light emitting element LD is referred to as the length direction, the light emitting element LD may include one end (or lower end) and the other end (or upper end) along the extending direction. One end (or lower end) of the light emitting element LD may be arranged with one of the first semiconductor layer 11 and the second semiconductor layer 13, and the other end (or upper end) of the light emitting element LD may be arranged with the other of the first semiconductor layer 11 and the second semiconductor layer 13. For example, one end (or lower end) of the light emitting element LD may be arranged with the first semiconductor layer 11, and the other end (or upper end) of the light emitting element LD may be arranged with the second semiconductor layer 13.

[0054] The light emitting element LD may be provided in various shapes. For example, the light emitting element LD may have a rod-like shape or a bar-like shape that is elongated in the length direction (i.e., having an aspect ratio greater than 1). In one embodiment of the present invention, the length L of the light emitting element LD in the length direction may be greater than its diameter D (or the width of the cross section). For example, such a light emitting element LD may include a light emitting diode (LED) that is manufactured to be sufficiently ultra-small to have a diameter D and / or length L of nanoscale to microscale.

[0055] The diameter D of the light-emitting element LD may be about 0.5 μm to about 500 μm, and the length L of the light-emitting element LD may be about 1 μm to about 10 μm. However, the diameter D and the length L of the light-emitting element LD are not limited thereto, and the size of the light-emitting element LD may be changed to meet the requirements (or design conditions) of the lighting device or self-luminous display device to which the light-emitting element LD is applied.

[0056] For example, the first semiconductor layer 11 may include at least one n-type semiconductor layer. For example, the first semiconductor layer 11 includes any one of InAlGaN, GaN, AlGaN, InGaN, AlN and InN semiconductor materials, and may be an n-type semiconductor layer doped with a first conductive dopant (or n-type dopant) such as Si, Ge, Sn, etc. However, the substance constituting the first semiconductor layer 11 is not limited thereto, and the first semiconductor layer 11 may also be composed of various substances. In one embodiment of the present invention, the first semiconductor layer 11 may include a gallium nitride (GaN) semiconductor material doped with a first conductive dopant (or n-type dopant). The first semiconductor layer 11 may include an upper surface in contact with the active layer 12 along the length L direction of the light-emitting element LD and a lower surface exposed to the outside. The lower surface of the first semiconductor layer 11 may be one end (or lower end) of the light-emitting element LD.

[0057] The active layer 12 can be arranged on the first semiconductor layer 11 and formed into a single or multiple quantum well structure. For example, in the case where the active layer 12 is formed into a multiple quantum well structure, in the above-mentioned active layer 12, the barrier layer (not shown), the strain reinforcing layer (strain reinforcing layer) and the well layer (well layer) can be periodically stacked repeatedly as a unit. The strain reinforcing layer has a smaller lattice constant than the barrier layer, thereby further strengthening the strain (e.g., compressive strain) applied to the well layer. However, the structure of the active layer 12 is not limited to the above-mentioned embodiment.

[0058] The active layer 12 can emit light with a wavelength of 400nm to 900nm, and a double heterostructure can be used. In one embodiment of the present invention, a clad layer (not shown) doped with a conductive dopant can also be formed on the upper and / or lower part of the active layer 12 along the length L direction of the light-emitting element LD. For example, the clad layer can be formed by an AlGaN layer or an InAlGaN layer. According to the embodiment, substances such as AlGaN, InAlGaN, etc. can be used to form the active layer 12, and various substances can also constitute the active layer 12 in addition. The active layer 12 may include a first surface and a second surface, wherein the first surface is in contact with the first semiconductor layer 11, and the second surface is in contact with the second semiconductor layer 13.

[0059] When an electric field exceeding a predetermined voltage is applied to both ends of the light-emitting element LD, electron-hole pairs combine in the active layer 12, causing the light-emitting element LD to emit light. By utilizing this principle to control the light emission of the light-emitting element LD, the light-emitting element LD can be used as a light source (or light emission source) in various light-emitting devices, including pixels in display devices.

[0060] The second semiconductor layer 13 may be arranged on the second surface of the active layer 12 and include a semiconductor layer of a different type from the first semiconductor layer 11. For example, the second semiconductor layer 13 may include at least one p-type semiconductor layer. For example, the second semiconductor layer 13 may include at least one semiconductor material selected from the group consisting of InAlGaN, GaN, AlGaN, InGaN, AlN, and InN, and may include a p-type semiconductor layer doped with a second conductive dopant (or p-type dopant) such as Mg. However, the material constituting the second semiconductor layer 13 is not limited thereto, and various other materials may also constitute the second semiconductor layer 13. In one embodiment of the present invention, the second semiconductor layer 13 may include a gallium nitride (GaN) semiconductor material doped with a second conductive dopant (or p-type dopant). The second semiconductor layer 13 may include a lower surface that contacts the second surface of the active layer 12 along the length L of the light-emitting element LD and an upper surface that is exposed to the outside. Here, the upper surface of the second semiconductor layer 13 may be the other end (or upper end) of the light-emitting element LD.

[0061] In one embodiment of the present invention, the first semiconductor layer 11 and the second semiconductor layer 13 may have different thicknesses along the length L of the light-emitting element LD. For example, along the length L of the light-emitting element LD, the first semiconductor layer 11 may be relatively thicker than the second semiconductor layer 13. Therefore, the active layer 12 of the light-emitting element LD may be positioned closer to the upper surface of the second semiconductor layer 13 than to the lower surface of the first semiconductor layer 11.

[0062] In addition, although the first semiconductor layer 11 and the second semiconductor layer 13 are shown as being composed of one layer respectively, the present invention is not limited to this. In one embodiment of the present invention, each of the first semiconductor layer 11 and the second semiconductor layer 13 may also include at least one layer (e.g., a capping layer and / or a TSBR (tensile strain barrier reducing) layer) depending on the material of the active layer 12. The TSBR layer may be a strain relief layer, which is arranged between semiconductor layers with different lattice structures to act as a buffer for reducing the difference in lattice constants. The TSBR layer may be composed of a p-type semiconductor layer such as p-GaInP, p-AlInP, p-AlGaInP, etc., but the present invention is not limited to this.

[0063] According to an embodiment, in addition to the first semiconductor layer 11, the active layer 12, and the second semiconductor layer 13, the light-emitting element LD may further include an additional electrode (not shown, hereinafter referred to as the "first additional electrode") disposed on top of the second semiconductor layer 13. Furthermore, according to another embodiment, another additional electrode (not shown, hereinafter referred to as the "second additional electrode") disposed below the first semiconductor layer 11 may also be included.

[0064] Each of the first additional electrode and the second additional electrode may be an ohmic contact electrode, but the present invention is not limited thereto. According to an embodiment, the first additional electrode and the second additional electrode may be Schottky contact electrodes. The first additional electrode and the second additional electrode may include a conductive substance (or material). For example, the first additional electrode and the second additional electrode may include an opaque metal such as chromium (Cr), titanium (Ti), aluminum (Al), gold (Au), nickel (Ni), and their oxides or alloys, used alone or in combination, but the present invention is not limited thereto. According to an embodiment, the first additional electrode and the second additional electrode may also include a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium gallium zinc oxide (IGZO), or indium tin zinc oxide (ITZO).

[0065] The materials contained in the first and second additional electrodes may be the same or different. The first and second additional electrodes may be substantially transparent or translucent. Therefore, light generated by the light-emitting element LD can pass through each of the first and second additional electrodes and be emitted outside the light-emitting element LD. Depending on the embodiment, if light generated by the light-emitting element LD is emitted outside the light-emitting element LD through regions other than the two end portions of the light-emitting element LD without passing through the first and second additional electrodes, the first and second additional electrodes may also be made of an opaque metal.

[0066] In one embodiment of the present invention, the light emitting element LD may further include an insulating film 14. However, depending on the embodiment, the insulating film 14 may be omitted and may be provided to cover only a portion of the first semiconductor layer 11, the active layer 12, and the second semiconductor layer 13.

[0067] The insulating film 14 prevents electrical short circuits that could occur due to contact between the active layer 12 and conductive materials other than the first semiconductor layer 11 and the second semiconductor layer 13. Furthermore, the insulating film 14 minimizes surface defects in the light-emitting element LD, thereby improving the lifespan and luminous efficiency of the light-emitting element LD. Furthermore, when multiple light-emitting elements LD are closely arranged, the insulating film 14 prevents undesirable short circuits between the light-emitting elements LD. The presence or absence of the insulating film 14 is not critical as long as it can prevent short circuits between the active layer 12 and external conductive materials.

[0068] The insulating film 14 may be provided in a form that entirely surrounds the outer peripheral surface of the light emitting stack including the first semiconductor layer 11, the active layer 12, and the second semiconductor layer 13. The outer peripheral surface of the insulating film 14 is surface-treated so that an element coupler can be coupled to at least a portion of the surface. When manufacturing a device (e.g., a display device) using the light emitting element LD, the element coupler can stably secure the light emitting element LD to a desired area.

[0069] In the above embodiment, the insulating film 14 is described as entirely surrounding the outer peripheral surface of each of the first semiconductor layer 11, the active layer 12, and the second semiconductor layer 13. However, the present invention is not limited thereto. Depending on the embodiment, when the light-emitting element LD includes a first additional electrode, the insulating film 14 may entirely surround the outer peripheral surface of each of the first semiconductor layer 11, the active layer 12, the second semiconductor layer 13, and the first additional electrode. Furthermore, according to another embodiment, the insulating film 14 may not completely surround the outer peripheral surface of the first additional electrode, or may only surround a portion of the outer peripheral surface of the first additional electrode and not surround the remaining portion of the outer peripheral surface of the first additional electrode. Furthermore, depending on the embodiment, when the first additional electrode is disposed at the other end (or upper end) of the light-emitting element LD and the second additional electrode is disposed at one end (or lower end) of the light-emitting element LD, the insulating film 14 may expose at least one region of each of the first and second additional electrodes.

[0070] The insulating film 14 may include a transparent insulating material. For example, the insulating film 14 may include a material selected from silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (SiO x N y ), aluminum oxide (AlO x ) and titanium oxide (TiO 2 ) and the like, but the present invention is not limited thereto, and various materials having insulating properties can be used as the material of the insulating film 14.

[0071] According to an embodiment, the light-emitting element LD may also be implemented as a light-emitting pattern having a core-shell structure. In this case, the above-mentioned first semiconductor layer 11 may be located at the core (core, i.e., the center (or center)) of the light-emitting element LD, the active layer 12 may be provided and / or formed into a form surrounding the outer peripheral surface of the above-mentioned first semiconductor layer 11, and the second semiconductor layer 13 may be provided and / or formed into a form surrounding the above-mentioned active layer 12. In addition, the light-emitting element LD may also include an additional electrode (not shown) surrounding at least one side of the above-mentioned second semiconductor layer 13. In addition, according to an embodiment, the light-emitting element LD may further include an insulating film 14 provided on the outer peripheral surface of the light-emitting pattern of the core-shell structure and comprising a transparent insulating substance. The light-emitting element LD implemented as a light-emitting pattern of a core-shell structure may be manufactured by a growth method.

[0072] The above-mentioned light-emitting element LD can be used as a light source for various display devices. The light-emitting element LD can be manufactured through a surface treatment process. For example, when a plurality of light-emitting elements LD are mixed with a fluid solution (or solvent) to be supplied to each pixel area (for example, the light-emitting area of ​​each pixel or the light-emitting area of ​​each sub-pixel), each light-emitting element LD can be surface-treated so that the light-emitting element LD can be uniformly sprayed into the solution rather than unevenly agglomerated in the solution.

[0073] The light-emitting unit (or light-emitting device) including the above-described light-emitting element LD can be used in various types of electronic devices requiring a light source, including display devices. For example, when multiple light-emitting elements LD are arranged within the pixel region of each pixel of a display panel, the above-described light-emitting element LD can serve as the light source for each of the pixels. However, the application areas of the light-emitting element LD are not limited to the above-described examples. For example, the light-emitting element LD can also be used in other types of electronic devices requiring a light source, such as lighting devices.

[0074] Figure 3 is a side sectional view schematically showing a storage device of a light emitting element according to one embodiment, Figure 4a It is a perspective view schematically showing a storage unit according to one embodiment. Figure 4b It is schematically shown Figure 4a A side sectional view of the storage portion, and Figure 5a and Figure 5b It is schematically shown Figure 4a A side cross-sectional view of a storage portion before and after an electric field is formed.

[0075] exist Figure 3 、 Figure 4a 、 Figure 4b 、 Figure 5a and Figure 5b, for convenience of description, the light emitting element LD is shown as a cylindrical shape.

[0076] refer to Figures 1 to 5b The storage device 100 of a light emitting element according to one embodiment may include a storage unit 110 and a power supply unit 120 .

[0077] The storage unit 110 may include a storage container 110 a and an electric field forming device, wherein the storage container 110 a contains (or stores) the content INK (or mixture), and the electric field forming device forms an electric field E (electric field) in the content INK.

[0078] The content INK may be provided in a solution state. The content INK may be ink including a fluid solvent SLV and a plurality of light emitting elements LD contained (or dispersed) in the solvent SLV.

[0079] The solvent SLV is liquid or fluid, and may have a viscosity sufficient to enable the light-emitting element LD, which corresponds to a dispersoid, to move within the solvent SLV. The solvent SLV may include a substance that enables the light-emitting element LD to easily move within the solvent SLV due to the electric field formed by the electric field forming device. For example, the solvent SLV may include acetone, water, ethanol, toluene, etc., but the present invention is not limited thereto. Depending on the embodiment, the solvent SLV may include at least one substance that evaporates or volatilizes at room temperature or upon heating. Depending on the embodiment, the solvent SLV may also include an organic resin. For example, the organic resin may be a thermoplastic resin, a thermosetting resin, a photocurable resin, etc., alone, or a mixture of two or more of the plastic resin, the thermosetting resin, the photocurable resin, etc.

[0080] The light emitting element LD may be a solid substance that finally remains on the object (eg, substrate) after the solvent SLV is removed. Figure 1 and Figure 2 As described, the above-mentioned light-emitting element LD can be an ultra-small light-emitting diode with a size ranging from nanometer to micrometer. Each of the light-emitting elements LD can include a first end EP1 and a second end EP2 along the length L direction. The first end EP1 can be arranged with one of the first semiconductor layer 11 and the second semiconductor layer 13, and the second end EP2 can be arranged with the other of the first semiconductor layer 11 and the second semiconductor layer 13. Therefore, the first end EP1 and the second end EP2 can have different polarities from each other. In the case where an electric field is formed outside the storage container 110a, each of the light-emitting elements LD whose first end EP1 and second end EP2 have different polarities can receive electric power (for example, attraction and repulsion), thereby maintaining a suspended state in the solvent SLV without sinking.

[0081] The storage container 110a may be a storage space for accommodating the aforementioned content INK. Although the storage container 110a is shown as having a quadrilateral cross-section, the present invention is not limited thereto, but may be changed to various shapes as long as the storage container 110a can accommodate the content INK and the electric field forming device can be stably arranged on the outer surface of the storage container 110a.

[0082] The storage container 110a may be made of a non-conductive substance (or material), for example, an insulating substance. According to an embodiment, the storage container 110a may selectively use at least one of a transparent insulating substance and / or an opaque insulating substance.

[0083] The storage container 110a may include an inflow portion 110b and a discharge portion 110c, wherein the above-mentioned content INK flows in from the inflow portion 110b, and the discharge portion 110c discharges the above-mentioned content INK. The above-mentioned inflow portion 110b and the above-mentioned discharge portion 110c may be in direct fluid communication with corresponding conduits (not shown). Each of the inflow portion 110b and the discharge portion 110c may be located at a side surface of the storage container 110a. For example, the inflow portion 110b may be located at the first side surface S3 of the storage container 110a, and the discharge portion 110c may be located at the second side surface S4 of the above-mentioned storage container 110a. Here, when viewing Figure 4a and Figure 4b In the present invention, the first side surface S3 may be a left side surface of the storage container 110 a , and the second side surface S4 may be a right side surface of the storage container 110 a , but the present invention is not limited thereto.

[0084] The storage unit 110 may further include a check valve (not shown) located between the inflow portion 110b and a conduit corresponding to the inflow portion 110b. The check valve can be selectively opened or closed to prevent the contents INK above a certain level from flowing into the storage container 110a. In addition, the storage unit 110 may further include a supply valve (not shown) located between the discharge portion 110c and a conduit corresponding to the discharge portion 110c. The supply valve can be selectively opened or closed to supply the contents INK contained in the storage container 110a to an object (e.g., a printing device, etc.).

[0085] The electric field forming device may include a first electrode EL1 and a second electrode EL2 facing each other in a vertical direction. A length L of each of the light emitting elements LD included in the content INK may be parallel to the vertical direction.

[0086] The first electrode EL1 and the second electrode EL2 may include a conductive substance (or material). The width W1 of the first electrode EL1 and the width W2 of the second electrode EL2 may be the same as each other. The first electrode EL1 and the second electrode EL2 may have the same planar shape. For example, Figure 4a As shown, the second electrode EL2 and the first electrode EL1 located below the second electrode EL2 have the same planar shape, wherein the second electrode EL2 and the first electrode EL1 are sandwiched between the storage container 110a and can completely overlap when viewed on a plane.

[0087] The first electrode EL1 and the second electrode EL2 may be located outside the storage container 110a to prevent the contents INK contained within the storage container 110a from degenerating and to minimize any effects caused by the contents INK (e.g., contamination and corrosion of the first and second electrodes EL1 and EL2). Furthermore, to prevent the light-emitting element LD included in the contents INK contained within the storage container 110a from sinking due to gravity, the first and second electrodes EL1 and EL2 may be arranged on the upper and lower surfaces of the storage container 110a, respectively, to form an electric field parallel to gravity. Specifically, the first and second electrodes EL1 and EL2 may be located on the outer surfaces of the storage container 110a, facing each other in a direction parallel to gravity, to prevent the light-emitting element LD included in the contents INK from sinking due to gravity. For example, the first electrode EL1 may be arranged on one surface S1 (or lower surface) of the storage container 110a, and the second electrode EL2 may be arranged on the other surface S2 (or upper surface) of the storage container 110a.

[0088] The power supply part 120 may include a signal applying part 120 a and a signal amplifying part 120 b .

[0089] The signal applying part 120 a may be a structure that applies a signal corresponding to each of the first electrode EL1 and the second electrode EL2 so as to form an electric field between the first electrode EL1 and the second electrode EL2 .

[0090] The signal amplifier 120b can amplify the predetermined signal supplied from the signal application unit 120a to a certain level or higher, and transmit the signal to the first electrode EL1 and the second electrode EL2 through the first wiring CL1 and the second wiring CL2. The signal amplifier 120b can transmit the amplified predetermined signal to the first electrode EL1 through the first wiring CL1, and can transmit the amplified predetermined signal to the second electrode EL2 through the second wiring CL2.

[0091] The prescribed signal applied to the first electrode EL1 and the prescribed signal applied to the second electrode EL2 may be signals having a voltage difference and / or phase difference sufficient to form an electric field between the first electrode EL1 and the second electrode EL2. For example, the prescribed signal applied to each of the first electrode EL1 and the second electrode EL2 may be a voltage in the range of 1V to 100V. The prescribed signal applied to each of the first electrode EL1 and the second electrode EL2 may be a DC voltage and / or an AC voltage in the form of a sine wave, a sawtooth wave, a square wave, or a triangle wave. When the prescribed signal applied to each of the first electrode EL1 and the second electrode EL2 is an AC voltage, the frequency of the signal may be in the range of 1Hz to 100kHz. However, the present invention is not limited thereto, and the intensity and frequency of the prescribed signal applied to each of the first electrode EL1 and the second electrode EL2 may be determined based on the material and thickness of the storage container 110a, the viscosity of the contents INK containing the light-emitting element LD, and the concentration of the light-emitting element LD.

[0092] The intensity and frequency of the prescribed signal applied to each of the first and second electrodes EL1 and EL2 may be timely and continuously changed according to the amount of the content INK remaining in the storage container 110a after being discharged from the discharge portion 110c of the storage portion 110 to the object through the corresponding conduit.

[0093] In the storage container 110a containing the contents INK, the light emitting element LD has a random orientation direction when no external force acts, and as shown in FIG. Figure 5a As shown, the contents INK may sink toward the bottom surface of the storage container 110a due to gravity. If the contents INK is stored in the storage portion 110 for a long time, the light-emitting elements LD may sink and condense on the bottom surface of the storage container 110a. In this case, when the contents INK is discharged to the target object through the discharge portion 110c and the corresponding conduit, the light-emitting elements LD may aggregate in a specific area based on the concentration gradient of the particles (e.g., the light-emitting elements LD) in the contents INK, resulting in an uneven flow of the contents INK. As a result, the appropriate amount of contents INK may not be discharged in the desired area, or the discharge accuracy may be reduced.

[0094] Therefore, the present invention can arrange the first electrode EL1 and the second electrode EL2 that are opposite to each other in the vertical direction with the storage container 110a interposed therebetween on the outer surface of the storage container 110a, and apply a corresponding prescribed signal to each of the first electrode EL1 and the second electrode EL2 through the power supply unit 120, so as to Figure 5bAs shown, an electric field E is formed vertically between the first electrode EL1 and the second electrode EL2. The intensity of the electric field E can be set to be approximately several mV to several kV depending on the size of the light-emitting element LD in the contents INK, the viscosity of the solvent SLV in the contents INK, the temperature of the storage container 110a, etc., but the present invention is not limited thereto.

[0095] While the contents INK are contained within the storage container 110a, the storage device 100 for the light-emitting element LD may apply a corresponding prescribed signal to each of the first electrode EL1 and the second electrode EL2, thereby continuously forming the electric field E between the first electrode EL1 and the second electrode EL2 in the vertical direction. However, the present invention is not limited to the above-described embodiment, and depending on the embodiment, the storage device 100 for the light-emitting element may also periodically change the polarity of the prescribed signal applied to the first electrode EL1 and the polarity of the prescribed signal applied to the second electrode EL2, thereby guiding the light-emitting element LD within the contents INK to flow vertically with a small amplitude without sinking.

[0096] Since each of the light-emitting elements LD included in the content INK is provided in a dipole form with a first end EP1 and a second end EP2 having different polarities from each other, each of the light-emitting elements LD can be affected by the above-mentioned electric field E and flow in the solvent SLV along the direction of the above-mentioned electric field E. In other words, the above-mentioned light-emitting element LD can remain in a suspended (e.g., floating) state in the above-mentioned solvent SLV. For example, each of the light-emitting elements LD can flow in the solvent SLV so that the length L direction of the light-emitting element LD is parallel to the direction of formation of the above-mentioned electric field E, thereby preventing it from sinking toward the bottom surface of the storage container 110a.

[0097] In the above-mentioned embodiment, by applying a corresponding signal to each of the first electrode EL1 and the second electrode EL2 arranged on the outer surface of the storage container 110a opposite to each other in the vertical direction to continuously form a vertical electric field E in the above-mentioned storage container 110a, the above-mentioned light-emitting element LD can remain in a suspended state without sinking, wherein the storage container 110a contains the contents INK including the light-emitting element LD.

[0098] As the light-emitting element LD remains suspended, the contents INK are not blocked or aggregated in a specific area when being discharged from the storage unit 110 and moved to the target object. As a result, the contents INK can be smoothly transferred to the target object and an appropriate amount of contents INK can be discharged in the desired area, thereby improving the discharge accuracy of the target object.

[0099] In addition, according to the above-mentioned embodiment, by forming the first electrode EL1 and the second electrode EL2 as the electric field forming device on the outer surface of the above-mentioned storage container 110a containing the above-mentioned content INK, the above-mentioned content INK is separated from the above-mentioned first electrode EL1 and the above-mentioned second electrode EL2, thereby preventing the physical properties of the above-mentioned content INK itself from changing, and preventing contamination or corrosion of the above-mentioned first electrode EL1 and the above-mentioned second electrode EL2.

[0100] Figure 6 is a diagram schematically showing a printing apparatus according to one embodiment, and Figure 7 is a side sectional view schematically showing part of a printing apparatus according to one embodiment.

[0101] refer to Figure 6 and Figure 7 , a printing apparatus 1 according to one embodiment may include a first unit 200 , a second unit 300 , and a third unit 400 , and a printing head unit 500 .

[0102] The first unit 200 can be in fluid communication with the storage container 110a of the external ink supply unit 100 via a first conduit SPL1 to receive the content INK contained in the storage container 110a. The content INK can be ink including a solvent SLV and a plurality of light emitting elements LD dispersed in the solvent SLV.

[0103] Since the external ink supply unit 100 corresponds to the reference Figures 3 to 5b The light emitting element storage device 100 described above has the same structure, and thus a detailed description thereof will be omitted.

[0104] The external ink supply unit 100 may include a storage container 110a, a first electrode EL1, and a second electrode EL2, wherein the storage container 110a contains the contents INK including the light emitting element LD and the solvent SLV, the first electrode EL1 is arranged on the lower surface S1 of the storage container 110a, and the second electrode EL2 is arranged on the upper surface S2 of the storage container 110a. Although not directly shown in the drawings, the external ink supply unit 100 may include a power supply unit (refer to FIG. 1 ) that applies a corresponding signal to each of the first electrode EL1 and the second electrode EL2. Figure 3"120"). The power supply unit 120 can apply a signal corresponding to each of the first electrode EL1 and the second electrode EL2, thereby forming an electric field in the vertical direction between the first electrode EL1 and the second electrode EL2. Due to the electric field, the light-emitting element LD of the content INK contained in the storage container 110a can be aligned so that its length L direction is parallel to the direction of formation of the electric field. For example, the light-emitting element LD of the content INK contained in the external ink supply unit 100 can be aligned so that its length L direction is parallel to the direction of formation of the electric field. Therefore, the light-emitting element LD of the content INK contained in the storage container 110a of the external ink supply unit 100 will not sink to the bottom surface of the storage container 110a due to the electric field, but can flow in the solvent SLV of the content INK and maintain a suspended state.

[0105] The contents INK, including the light-emitting element LD suspended in the solvent SLV, can be moved to a target object (e.g., the first unit 200 of the printing apparatus 1) via the first conduit SPL1. Since the light-emitting element LD remains suspended, the contents INK are prevented from agglomerating or becoming blocked in specific areas when moving from the external ink supply unit 100 to the first unit 200. Consequently, the contents INK can be smoothly moved from the external ink supply unit 100 to the first unit 200.

[0106] The first conduit SPL1 may be an umbilical formed with a flexible tube having a single channel configured to supply the contents INK of the external ink supply unit 100 to an inflow portion (not shown) of the first unit 200, but the present invention is not limited thereto. According to embodiments, the first conduit SPL1 may be provided in various structures as long as the contents INK of the external ink supply unit 100 can be stably supplied to the first unit 200.

[0107] The first unit 200 may include a storage container (hereinafter referred to as the "first storage container") 210, a first electrode (hereinafter referred to as the "1-1 electrode") EL1, and a second electrode (hereinafter referred to as the "2-1 electrode") EL2. The first storage container 210 holds the contents INK of the external ink supply unit 100 supplied via a first conduit SPL1. The 1-1 electrode EL1 is arranged on a lower surface S1 of the first storage container 210, and the 2-1 electrode EL2 is arranged on an upper surface S2 of the first storage container 210. Furthermore, the first unit 200 may include a power supply unit (not shown) that applies a corresponding signal to each of the 1-1 electrode EL1 and the 2-1 electrode EL2. The power supply unit may apply a signal corresponding to each of the 1-1 electrode EL1 and the 2-1 electrode EL2, thereby forming an electric field in a vertical direction between the 1-1 electrode EL1 and the 2-1 electrode EL2. Due to the electric field, the light emitting elements LD of the contents INK contained in the first storage container 210 can be aligned so that their length L is parallel to the direction of the electric field. Therefore, the light emitting elements LD of the contents INK contained in the first storage container 210 of the first unit 200 do not sink to the bottom surface of the first storage container 210 due to the electric field, but can flow in the solvent SLV of the contents INK and remain suspended.

[0108] The contents INK, including the light-emitting element LD maintained in a suspended state, can be moved to a target object (e.g., the second unit 300 of the printing apparatus 1) via the second conduit SPL2. Since the light-emitting element LD remains suspended, the contents INK are prevented from agglomerating or becoming obstructed in specific areas when moving from the first unit 200 to the second unit 300. Therefore, the contents INK can be moved smoothly from the first unit 200 to the second unit 300.

[0109] In one embodiment of the present invention, the first unit 200 receiving the content INK from the external ink supply portion 100 through the first pipe SPL1 may be an ink tank of the printing apparatus 1 .

[0110] The second conduit SPL2 may be an umbilical formed with a flexible pipe having a single channel configured to be capable of supplying the content INK of the first storage container 210 of the first unit 200 to an inflow portion (not shown) of the second unit 300 .

[0111] The second unit 300 may be fluidically connected to the first storage container 210 of the first unit 200 via a second conduit SPL2 to receive the content INK contained in the first storage container 210 .

[0112] The second unit 300 may include a storage container (hereinafter referred to as the "second storage container") 310, a first electrode (hereinafter referred to as the "1-2 electrode") EL1, and a second electrode (hereinafter referred to as the "2-2 electrode") EL2. The second storage container 310 holds the contents INK of the first storage container 210 supplied via a second conduit SPL2. The 1-2 electrode EL1 is disposed on a lower surface S1 of the second storage container 310, and the 2-2 electrode EL2 is disposed on an upper surface S2 of the second storage container 310. Furthermore, the second unit 300 may include a power supply unit (not shown) that applies a corresponding signal to each of the 1-2 electrode EL1 and the 2-2 electrode EL2. The power supply unit may apply a signal corresponding to each of the 1-2 electrode EL1 and the 2-2 electrode EL2, thereby forming an electric field in a vertical direction between the 1-2 electrode EL1 and the 2-2 electrode EL2. Due to the electric field, the light emitting elements LD of the contents INK contained in the second storage container 310 can be aligned so that their length L is parallel to the direction of the electric field. Therefore, the light emitting elements LD of the contents INK contained in the second storage container 310 of the second unit 300 do not sink to the bottom surface of the second storage container 310 due to the electric field, but can flow in the solvent SLV of the contents INK and remain suspended.

[0113] The contents INK, while remaining suspended, can be moved to a target object (e.g., the third unit 400 of the printing apparatus 1) via the third conduit SPL3. Since the light-emitting element LD remains suspended, the contents INK are prevented from agglomerating or becoming obstructed in specific areas when moving from the second unit 300 to the third unit 400. Consequently, the contents INK can move smoothly from the second unit 300 to the third unit 400.

[0114] In one embodiment of the present invention, the second unit 300 that receives the content INK from the first unit 200 through the second conduit SPL2 may be one of the storage units of the printing device 1 described above.

[0115] The third conduit SPL3 may be an umbilical formed with a flexible pipe having a single channel configured to be capable of supplying the content INK of the second storage container 310 of the second unit 300 to an inflow portion (not shown) of the third unit 400 .

[0116] The third unit 400 may include a storage container (hereinafter referred to as the "third storage container") 410, a first electrode (hereinafter referred to as the "first-third electrodes") EL1, and a second electrode (hereinafter referred to as the "second-third electrodes") EL2. The third storage container 410 holds the contents INK of the second unit 300 supplied via a third conduit SPL3. The first-third electrodes EL1 are arranged on a lower surface S1 of the third storage container 410, and the second-third electrodes EL2 are arranged on an upper surface S2 of the third storage container 410. Furthermore, the third unit 400 may include a power supply (not shown) that applies a corresponding signal to each of the first-third electrodes EL1 and the second-third electrodes EL2. The power supply may apply a signal corresponding to each of the first-third electrodes EL1 and the second-third electrodes EL2, thereby forming an electric field in a vertical direction between the first-third electrodes EL1 and the second-third electrodes EL2. Due to the electric field, the light emitting elements LD of the contents INK contained in the third storage container 410 can be aligned so that their length L is parallel to the direction of the electric field. Therefore, the light emitting elements LD of the contents INK contained in the third storage container 410 of the third unit 400 do not sink to the bottom surface of the third storage container 410 due to the electric field, but can flow in the solvent SLV of the contents INK and remain suspended.

[0117] The contents INK, while remaining suspended, can be moved to a target object (e.g., the print head unit 500 of the printing apparatus 1) via the fourth conduit SPL4. Since the light-emitting element LD remains suspended, the contents INK are prevented from agglomerating or becoming obstructed in specific areas when moving from the third unit 400 to the print head unit 500. Consequently, the contents INK can be moved smoothly from the third unit 400 to the print head unit 500.

[0118] In one embodiment of the present invention, the third unit 400 that receives the content INK from the second unit 300 through the third conduit SPL3 may be one of the supply units of the printing apparatus 1 described above.

[0119] The third unit 400 may further include a stirring member 420 for stirring the contents INK in the third storage container 410. The stirring member 420 may be a centrifugal pump (impeller) provided on one side surface of the third storage container 410 and connected to the driving unit 430, but the present invention is not limited thereto. According to an embodiment, a magnetic stirrer, an ultrasonic vibrator, thermal convection, etc. may also be used as the stirring member 420. The stirring member 420 may diffuse the contents INK in the third storage container 410, thereby further preventing the light emitting element LD of the contents INK from sinking.

[0120] In the above embodiment, although the stirring member 420 is described as being provided only in the third unit 400 , the present invention is not limited thereto. Depending on the embodiment, the stirring member 420 may also be provided in each of the first unit 200 and the second unit 300 .

[0121] The print head unit 500 can print the content INK on the target substrate SUB. The content INK supplied from the third unit 400 as the supply unit can be ejected (or discharged) onto the target substrate SUB side through the print head unit 500. The print head unit 500 can be arranged above the substrate support member SPM. At this time, the print head unit 500 can be placed on a bracket (not shown) to be spaced a specified distance from the substrate support member SPM.

[0122] The print head unit 500 may include a print head 510 and a plurality of nozzles 520 located on the bottom surface of the print head 510. The print head 510 may have a shape extending in one direction, but the present invention is not limited thereto. The print head 510 may include an internal tube 530 formed along the extension direction. The plurality of nozzles 520 may be arranged along the extension direction of the print head 510. Each nozzle 520 may be connected to the internal tube 530 of the print head 510. The internal tube 530 of the print head 510 is supplied with content INK, and the above-mentioned content INK may flow along the internal tube 530 so as to be ejected (or discharged) through each nozzle 520. The content INK ejected by each nozzle 520 may be supplied to the upper surface of the target substrate SUB. The ejection amount of the content INK by each nozzle 520 may be adjusted according to the signal applied to the corresponding nozzle 520.

[0123] As described above, according to one embodiment, a printing device 1 can arrange a first electrode EL1 and a second electrode EL2 that form an electric field in a vertical direction on the outer surface of each of the storage containers 210, 310 and 410 of the first unit 200, the second unit 300 and the third unit 400 that accommodate (or store) the contents INK including the light-emitting element LD, thereby preventing the sinking of the light-emitting element LD in each of the above-mentioned first unit 200 to the above-mentioned third unit 400 and making the movement of the above-mentioned contents INK between the above-mentioned first unit 200, the second unit 300 and the third unit 400 smooth.

[0124] The content INK that is ultimately ejected (or discharged) from the printing device 1 onto the target substrate SUB may not include a thickening additive or a high-viscosity solvent used to increase the dispersion stability of the light-emitting element LD included therein. If the content INK including a thickening additive or a high-viscosity solvent is ejected onto the target substrate SUB, the thickening additive or the high-viscosity solvent may not be removed during the process of removing the solvent SLV included in the content INK, but may remain on the target substrate SUB. Such residues may produce unexpected reactions in subsequent processes, thereby causing physical and / or chemical damage to the target substrate SUB. For example, the residues may interfere with the adsorption and alignment of the light-emitting element LD or change the element characteristics of the light-emitting element LD, thereby reducing the reliability of the device using the light-emitting element LD as a light source.

[0125] Therefore, the present invention does not include the above-mentioned thickening additives or high-viscosity solvents in the content INK including the light-emitting element LD, and a pair of electrodes that form an electric field in the vertical direction are arranged on the outer surface of the storage container containing the above-mentioned content INK, thereby preventing the above-mentioned light-emitting element LD from sinking in the above-mentioned storage container, and reducing defects that may occur due to the above-mentioned thickening additives or the above-mentioned high-viscosity solvents, thereby improving the reliability of the above-mentioned device using the light-emitting element LD as a light source.

[0126] The printing device 1 and the external ink supply unit 100 described above can be used to manufacture a device (eg, a display device) using the light emitting element LD as a light source, which will be described in detail below.

[0127] Figure 8 is a schematic plan view of a display device manufactured by a method according to one embodiment.

[0128] exist Figure 8 , for convenience, the structure of the display device is briefly shown with the display area DA where an image is displayed being the main focus.

[0129] refer to Figure 8 According to one embodiment of the present invention, a display device may include a substrate SUB, a plurality of pixels PXL, a driving portion, and a wiring portion, wherein the plurality of pixels PXL are provided on the substrate SUB and respectively include at least one light emitting element LD, the driving portion is provided on the substrate SUB and drives the pixels PXL, and the wiring portion connects the pixels PXL and the driving portion.

[0130] The present invention can be applied if the display device is an electronic device such as a smartphone, a television, a tablet PC, a mobile phone, a video phone, an e-book reader, a desktop PC, a laptop PC, a netbook computer, a workstation, a server, a PDA, a PMP (portable multimedia player), an MP3 player, a medical device, a camera, or a wearable device, which has a display surface applied on at least one surface thereof.

[0131] Depending on how the light-emitting element LD is driven, display devices can be classified as either passive matrix type display devices or active matrix type display devices. For example, when the display device is implemented as an active matrix type, each pixel PXL may include a driving transistor and a switching transistor, wherein the driving transistor controls the amount of current supplied to the light-emitting element LD and the switching transistor transmits a data signal to the driving transistor.

[0132] The display device can be provided in various shapes, and for example, can be provided in the shape of a rectangular plate having two pairs of parallel sides, but the present invention is not limited thereto. In the case where the display device is provided in the shape of a rectangular plate, one of the two pairs of sides can be provided to be longer than the other pair of sides. For convenience, the case where the display device is provided in the shape of a rectangle having a pair of long sides and a pair of short sides is shown, and the direction extending in the long sides is shown as the second direction DR2, the direction extending in the short sides is shown as the first direction DR1, and the direction perpendicular to the extending directions of the long sides and the short sides is shown as the third direction DR3. In the display device provided in the shape of a rectangular plate, the corner portion where one long side contacts (or intersects) one short side can have a rounded shape.

[0133] The substrate SUB may include a display area DA and a non-display area NDA.

[0134] The display area DA may be an area where pixels PXL displaying an image are provided. The non-display area NDA may be an area where a driving portion for driving the pixels PXL and a portion of a wiring portion for connecting the pixels PXL and the driving portion are provided. Figure 8 Only one pixel PXL is shown in FIG. 1 , but a plurality of pixels PXL may be provided in the display area DA of the substrate SUB.

[0135] The non-display area NDA may be provided on at least one side of the display area DA. The non-display area NDA may surround the periphery (or edge) of the display area DA. A wiring portion and a driving portion may be provided in the non-display area NDA, wherein the wiring portion is connected to the pixels PXL, and the driving portion is connected to the wiring portion and is used to drive the pixels PXL.

[0136] The wiring portion can electrically connect the driving unit and the pixels PXL. The wiring portion can be a signal line that provides signals to each pixel PXL and is connected to each pixel PXL (for example, a fan-out line connected to a scan line, a data line, a light-emitting control line, etc.). Furthermore, the wiring portion can be a signal line that is connected to each pixel PXL to compensate for changes in the electrical characteristics of each pixel PXL in real time (for example, a fan-out line connected to a control line, a sensing line, etc.).

[0137] The substrate SUB may include a transparent insulating material so as to transmit light. The substrate SUB may be a rigid substrate or a flexible substrate.

[0138] One area on the substrate SUB is provided as a display area DA for arranging the pixels PXL, and the remaining area on the substrate SUB can be provided as a non-display area NDA. For example, the substrate SUB may include a display area DA and a non-display area NDA, wherein the display area DA includes a pixel region where the pixels PXL are arranged, and the non-display area NDA is arranged around (or adjacent to) the display area DA.

[0139] Each of the pixels PXL may be provided in a display area DA on a substrate SUB. In one embodiment of the present invention, the pixels PXL may be arranged in the display area DA in a stripe arrangement structure or a pentile arrangement structure, but the present invention is not limited thereto.

[0140] Each pixel PXL may include at least one light-emitting element LD driven by corresponding scan signals and data signals. The light-emitting element LD may have a size ranging from nanometers to micrometers and may be connected in parallel with adjacent light-emitting elements LD, but the present invention is not limited thereto. The light-emitting element LD may constitute the light source of each pixel PXL.

[0141] Each pixel PXL may include at least one light source (eg, a first light source) driven by a prescribed signal (eg, a scan signal and a data signal) and / or a prescribed power source (eg, a first driving power source and a second driving power source). Figure 1 However, in the embodiment of the present invention, the kind of the light emitting element LD that can be used as the light source of each pixel PXL is not limited thereto.

[0142] The driving unit provides a predetermined signal and a predetermined power supply to each pixel PXL through a wiring unit, and thus can control the driving of the above-mentioned pixel PXL. The driving unit may include a scan driving unit, a light emitting driving unit, a data driving unit, and a timing control unit.

[0143] Figure 9is a circuit diagram illustrating an electrical connection relationship among constituent elements included in each pixel of a display device according to one embodiment.

[0144] For example, Figure 9 The electrical connection relationship of the components included in each pixel PXL applicable to an active display device is shown according to one embodiment. However, the types of components included in each pixel PXL to which the embodiment of the present invention can be applied are not limited thereto.

[0145] exist Figure 9 In Figure 8 The constituent elements included in each of the illustrated pixels and the region where the constituent elements are provided are collectively referred to as a pixel PXL.

[0146] refer to Figure 8 and Figure 9 Each pixel (hereinafter referred to as a “pixel”) PXL may include a light emitting unit EMU that generates light with brightness corresponding to a data signal. In addition, the pixel PXL may further optionally include a pixel circuit PXC for driving the light emitting unit EMU.

[0147] According to an embodiment, the light emitting unit EMU may include a plurality of light emitting elements LD connected in parallel between a first power line PL1 to which a voltage of a first driving power source VDD is applied and a second power line PL2 to which a voltage of a second driving power source VSS is applied. For example, the light emitting unit EMU may include a first pixel electrode (or "first alignment electrode") PEL1, a second pixel electrode (or "second alignment electrode") PEL2 and a plurality of light emitting elements LD, wherein the first pixel electrode PEL1 is connected to the first driving power source VDD via a pixel circuit PXC and a first power line PL1, the second pixel electrode PEL2 is connected to the second driving power source VSS via a second power line PL2, and the plurality of light emitting elements LD are connected in parallel between the above-mentioned first pixel electrode PEL1 and the above-mentioned second pixel electrode PEL2 in the same direction as each other. In one embodiment of the present invention, the first pixel electrode PEL1 may be an anode electrode, and the second pixel electrode PEL2 may be a cathode electrode. The above-mentioned light emitting element LD included in the light emitting unit EMU may be substantially the same as the reference electrode. Figure 1 and Figure 2 The described light emitting elements LD are similar or identical.

[0148] Each of the light-emitting elements LD included in the light-emitting unit EMU may include one end connected to a first driving power source VDD via a first pixel electrode PEL1 and the other end connected to a second driving power source VSS via a second pixel electrode PEL2. The first driving power source VDD and the second driving power source VSS may have different potentials. For example, the first driving power source VDD may be set to a high potential power source, and the second driving power source VSS may be set to a low potential power source. In this case, during the light-emitting period of the pixel PXL, the potential difference between the first driving power source VDD and the second driving power source VSS may be set to be greater than the threshold voltage of the light-emitting element LD.

[0149] As described above, the light emitting elements LD connected in parallel in the same direction (e.g., forward direction) between the first pixel electrode PEL1 and the second pixel electrode PEL2 supplied with voltages of different potentials can constitute effective light sources. Such effective light sources can be aggregated to form the light emitting unit EMU of the pixel PXL.

[0150] The light-emitting elements LD of the light-emitting units EMU can emit light at a brightness corresponding to the drive current supplied by the corresponding pixel circuits PXC. For example, during each frame, the pixel circuits PXC can supply a drive current corresponding to the grayscale value of the corresponding frame data to the light-emitting units EMU. The drive current supplied to the light-emitting units EMU can be split to each of the light-emitting elements LD. As a result, each light-emitting element LD emits light at a brightness corresponding to the drive current flowing through it, and the light-emitting units EMU can emit light at a brightness corresponding to the drive current.

[0151] In addition, although an embodiment is shown in which both ends of the light-emitting element LD are connected in the same direction between the first driving power supply VDD and the second driving power supply VSS, the present invention is not limited thereto. According to an embodiment, in addition to the light-emitting elements LD constituting each effective light source, the light-emitting unit EMU may further include at least one non-effective light source (e.g., a reverse light-emitting element LDr). Such a reverse light-emitting element LDr is connected in parallel with the light-emitting elements LD constituting the effective light source between the first pixel electrode PEL1 and the second pixel electrode PEL2, that is, it can be connected between the first pixel electrode PEL1 and the second pixel electrode PEL2 in the opposite direction to the light-emitting element LD. Even if a specified driving voltage (e.g., a forward driving voltage) is applied between the first pixel electrode PEL1 and the second pixel electrode PEL2, such a reverse light-emitting element LDr remains in an inactive state, and therefore, current does not substantially flow to the reverse light-emitting element LDr.

[0152] The pixel circuit PXC can be coupled to the scan line Si and data line Dj of the corresponding pixel PXL. For example, if the pixel PXL is arranged in the i-th (i is a natural number) row and the j-th (j is a natural number) column of the display area DA, the pixel circuit PXC of the pixel PXL can be coupled to the i-th scan line Si and the j-th data line Dj of the display area DA. In addition, the pixel circuit PXC can be coupled to the i-th control line CLi and the j-th sensing line SENj of the display area DA.

[0153] The pixel circuit PXC may include a first transistor T1 , a second transistor T2 , and a third transistor T3 and a storage capacitor Cst.

[0154] A first terminal of the second transistor T2 (switching transistor) may be coupled to the j-th data line Dj, and a second terminal may be coupled to the first node N1. Here, the first terminal and the second terminal of the second transistor T2 are different terminals. For example, if the first terminal is a drain electrode, the second terminal may be a source electrode. Furthermore, a gate electrode of the second transistor T2 may be coupled to the i-th scan line Si.

[0155] Such a second transistor T2 is turned on when a scan signal having a voltage capable of turning on the second transistor T2 is supplied from the i-th scan line Si, thereby electrically connecting the j-th data line Dj and the first node N1. At this time, the data signal of the corresponding frame is supplied to the j-th data line Dj, and thus the data signal is transferred to the first node N1. The data signal transferred to the first node N1 is charged to the storage capacitor Cst.

[0156] A first terminal of the first transistor T1 (driving transistor) may be coupled to a first driving power source VDD, and a second terminal may be electrically coupled to a first pixel electrode PEL1 of the light emitting unit EMU. A gate electrode of the first transistor T1 may be coupled to a first node N1. Such a first transistor T1 may control the amount of driving current supplied to the light emitting element LD in accordance with the voltage of the first node N1.

[0157] The third transistor T3 can be coupled between the first transistor T1 and the j-th sensing line SENj. For example, the first terminal of the third transistor T3 can be coupled to the first terminal (e.g., the source electrode) of the first transistor T1 connected to the first pixel electrode PEL1, and the second terminal of the third transistor T3 can be coupled to the j-th sensing line SENj. The gate electrode of the third transistor T3 can be coupled to the i-th control line CLi. Such a third transistor T3 is turned on by a control signal having a gate-on voltage supplied to the i-th control line CLi during a predetermined sensing period, thereby electrically connecting the j-th sensing line SENj and the first transistor T1.

[0158] The sensing period may be a period for extracting characteristic information (eg, a threshold voltage of the first transistor T1 , etc.) of each of the pixels PXL arranged in the display area DA.

[0159] One electrode of the storage capacitor Cst may be coupled to the first driving power source VDD, and the other electrode may be coupled to the first node N1. Such a storage capacitor Cst may be charged with a voltage corresponding to the data signal supplied to the first node N1 and maintain the charged voltage until the data signal of the next frame is supplied.

[0160] Although Figure 9 The embodiment in which the first transistor T1, the second transistor T2 and the third transistor T3 are all N-type transistors is disclosed, but the present invention is not limited thereto. For example, at least one of the first transistor T1, the second transistor T2 and the third transistor T3 can also be changed to a P-type transistor. In addition, although Figure 9 , discloses an embodiment in which the light emitting unit EMU is connected between the pixel circuit PXC and the second driving power source VSS, but the light emitting unit EMU may also be connected between the first driving power source VDD and the pixel circuit PXC.

[0161] The structure of the pixel circuit PXC may be modified in various ways. For example, the pixel circuit PXC may further include at least one transistor element (such as a transistor element for initializing the first node N1 and / or a transistor element for controlling the light-emitting time of the light-emitting element LD) or other circuit elements (such as a boost capacitor for boosting the voltage of the first node N1).

[0162] In addition, although Figure 9 , wherein all the light-emitting elements LD constituting each light-emitting unit (EMU) are connected in parallel, but the present invention is not limited thereto. Depending on the embodiment, the light-emitting unit (EMU) may also be configured to include at least one series terminal, wherein the at least one series terminal includes multiple light-emitting elements LD connected in parallel. In other words, the light-emitting unit (EMU) may also be configured in a hybrid series / parallel structure.

[0163] The structure of the pixel PXL applicable to the present invention is not limited to Figure 9 The embodiment shown in FIG. 1 is shown, and the corresponding pixel PXL can have various structures. For example, each pixel PXL can also be configured within a passive light-emitting display device, etc. In this case, the pixel circuit PXC can be omitted, and both ends of the light-emitting element LD included in the light-emitting unit EMU can be directly connected to the i-th scan line Si, the j-th data line Dj, the first power line PL1 to which the first drive power VDD is applied, the second power line PL2 to which the second drive power VSS is applied, and / or a specified control line, etc.

[0164] Figure 10 FIG. 1 is a plan view schematically showing each pixel of a display device according to one embodiment.

[0165] exist Figure 10 In the figure, for convenience, illustration of the transistor T electrically connected to the light emitting element LD and the signal line connected to the above transistor T is omitted.

[0166] In addition, in one embodiment of the present invention, for ease of description, a transverse direction (or horizontal direction) on a plane is shown as a first direction DR1, a longitudinal direction (or vertical direction) on a plane is shown as a second direction DR2, and a thickness direction of the substrate SUB on a cross section is shown as a third direction DR3. The first direction DR1, the second direction DR2, and the third direction DR3 may refer to directions indicated by the first direction DR1, the second direction DR2, and the third direction DR3, respectively.

[0167] refer to Figure 10 , each pixel PXL can be provided in the display area of ​​the substrate SUB (refer to Figure 8 The display area DA may include a pixel area PXA in which pixels PXL are arranged. The pixel area PXA may include a light-emitting area and a peripheral area, wherein light is emitted from the light-emitting area and the peripheral area is adjacent to the light-emitting area (or surrounds the light-emitting area). The peripheral area may include a non-light-emitting area that does not emit light.

[0168] Each pixel PXL may include a plurality of light emitting elements LD.

[0169] Each of the light emitting elements LD may include a semiconductor, wherein one end of the semiconductor is doped with one of a first conductive dopant and a second conductive dopant, and the other end thereof is doped with the other dopant. The first conductive dopant may be an n-type dopant, and the second conductive dopant may be a p-type dopant. Each of the light emitting elements LD may be a reference Figure 1 and Figure 2 The light emitting element LD is described.

[0170] At least two to several dozen light-emitting elements LD may be aligned and / or provided in the pixel region PXA of each pixel PXL, but the number of the light-emitting elements LD is not limited thereto. Depending on the embodiment, the number of light-emitting elements LD aligned and / or provided in the pixel region PXA may be variously changed.

[0171] Each of the light emitting elements LD can emit any one of colored light and / or white light. When viewed on a plane, each of the light emitting elements LD can be aligned between the first pixel electrode PEL1 and the second pixel electrode PEL2 so that its length direction is parallel to the first direction DR1. The light emitting element LD can be printed by the printing device described in the above embodiment (refer to Figure 6 "1" in the solvent (reference Figure 6 The morphology within the "SLV") is put into the pixel area PXA.

[0172] Each pixel PXL may include an electrode portion, which may include a plurality of electrodes.

[0173] The electrode portion may be electrically connected to each of the light-emitting elements LD to apply an electrical signal so that the light-emitting elements LD emit light (or rays). At least a portion of the electrodes included in the electrode portion may function as alignment electrodes that form an electric field to align the light-emitting elements LD within the pixel area PXA.

[0174] The electrode part may include a first pixel electrode PEL1 and a second pixel electrode PEL2 .

[0175] The first pixel electrode PEL1 may be provided for each pixel PXL. For example, the first pixel electrode PEL1 provided for each pixel PXL may be separate from the first pixel electrode PEL1 provided for the pixel PXL adjacent to the corresponding pixel PXL. The second pixel electrode PEL2 may be a common electrode provided for the pixels PXL arranged in one direction, but the present invention is not limited thereto. Depending on the embodiment, the second pixel electrode PEL2 may also be provided for each pixel PXL.

[0176] In each pixel PXL, the first pixel electrode PEL1 can be connected to the pixel circuit of the corresponding pixel PXL through the first contact hole CH1 (refer to Figure 9 The second pixel electrode PEL2 can be electrically connected to the pixel electrode of the second driving power supply (reference 1) through the second contact hole CH2. Figure 9 "VSS") voltage of the second power supply line (reference Figure 9 The first pixel electrode PEL1 can be a reference Figure 9 The first pixel electrode PEL1 described above and the second pixel electrode PEL2 described above may be reference Figure 9 The second pixel electrode PEL2 is described.

[0177] The first pixel electrode PEL1 may branch from a first connection wiring CNL1 extending along its extension direction (e.g., the first direction DR1 intersecting the second direction DR2). The first connection wiring CNL1 may be provided integrally with the first pixel electrode PEL1. Therefore, the first connection wiring CNL1 may be considered as a region of the first pixel electrode PEL1.

[0178] After the light-emitting elements LD are aligned in the pixel region PXA of each pixel PXL, in order to drive each pixel PXL individually (or independently), a portion of the first connection wiring CNL1 located between the pixels PXL adjacent in one direction can be removed. Therefore, the first pixel electrode PEL1 of each pixel PXL can be electrically and / or physically separated from the first pixel electrode PEL1 provided for each of the adjacent pixels PXL. The first connection wiring CNL1 can be a common wiring provided in common for the pixels PXL arranged along the first direction DR1 before the light-emitting elements LD are aligned in the above-mentioned pixel region PXA, and after the above-mentioned light-emitting elements LD are aligned, a portion of the first connection wiring CNL1 can be removed from between the adjacent pixels PXL so that it is located only within the pixel region PXA of the corresponding pixel PXL.

[0179] The second pixel electrode PEL2 may branch from a second connection wiring CNL2 extending along the first direction DR1. The second connection wiring CNL2 may be integrally provided with the second pixel electrode PEL2. Therefore, the second connection wiring CNL2 may be regarded as a region of the second pixel electrode PEL2.

[0180] In one embodiment of the present invention, the first pixel electrode PEL1 may be an anode electrode, and the second pixel electrode PEL2 may be a cathode electrode.

[0181] A plurality of light emitting elements LD may be arranged (or aligned) between the first pixel electrode PEL1 and the second pixel electrode PEL2. At least some of the light emitting elements LD may have one end electrically connected to the first pixel electrode PEL1 and the other end electrically connected to the second pixel electrode PEL2.

[0182] The light-emitting elements LD may be spaced apart in one direction (e.g., the second direction DR2) and arranged substantially parallel to each other (or aligned) between the first pixel electrode PEL1 and the second pixel electrode PEL2. According to an embodiment, a portion of the light-emitting elements LD may be arranged adjacent to each other to form a group, while another portion of the light-emitting elements LD may be spaced apart at certain intervals to form a group. The light-emitting elements LD may have uneven density and may be oriented and aligned in one direction.

[0183] The electrode part may further include a first contact electrode CNE1 and a second contact electrode CNE2 .

[0184] The first contact electrode CNE1 may be provided on one end portion of each of the first pixel electrode PEL1 and the light emitting element LD, and the second contact electrode CNE2 may be provided on the other end portion of each of the second pixel electrode PEL2 and the light emitting element LD, respectively.

[0185] In the following, reference will be made to Figure 11 and Figure 12 The description is mainly based on the stacking structure of each pixel PXL.

[0186] Figure 11 It is along Figure 10 A schematic cross-sectional view of line II', and Figure 12 It is along Figure 10 Schematic cross-sectional view along line II-II'.

[0187] Although Figure 11 and Figure 12 One pixel PXL is shown in a simplified manner, such as each electrode is shown as an electrode of a single film, each insulating layer is shown as an insulating layer of a single film, etc., but the present invention is not limited thereto.

[0188] Furthermore, in one embodiment of the present invention, the term "connection" between two structures may encompass both electrical and physical connections.

[0189] refer to Figures 10 to 12 Each pixel PXL may include a pixel circuit layer PCL and a display element layer DPL on a substrate SUB, wherein the pixel circuit layer PCL includes a pixel circuit (refer to Figure 9 'PXC'), and the display element layer DPL includes a plurality of light emitting elements LD.

[0190] For convenience, the display element layer DPL will be described after first describing the pixel circuit layer PCL.

[0191] The substrate SUB may include a transparent insulating material so as to transmit light. The substrate SUB may be a rigid substrate or a flexible substrate.

[0192] For example, the rigid substrate may be one of a glass substrate, a quartz substrate, a glass ceramic substrate, and a crystallized glass substrate.

[0193] The flexible substrate may be a film substrate or a plastic substrate containing a polymer organic substance. For example, the flexible substrate may include at least one of polystyrene, polyvinyl alcohol, polymethyl methacrylate, polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, triacetate cellulose, and cellulose acetate propionate.

[0194] In the manufacturing process of the display device, the material applied to the substrate SUB may preferably be resistant to higher processing temperatures (or heat-resistant).

[0195] The pixel circuit layer PCL may include a buffer layer BFL, a pixel circuit PXC, and a protection layer PSV.

[0196] The buffer layer BFL is provided and / or formed on the substrate SUB and can prevent impurities from diffusing into the transistor T included in the pixel circuit PXC. The buffer layer BFL can be an inorganic insulating film including an inorganic material. The buffer layer BFL can include a silicon nitride (SiN x ), silicon oxide (SiO x ), silicon oxynitride (SiO x N y ) and aluminum oxide (AlO x ) at least one of the metal oxides of the present invention. The buffer layer BFL can be provided as a single film, but can also be provided as a multilayer film of at least two films. When the buffer layer BFL is provided as a multilayer film, each layer can be formed of the same material or different materials. Depending on the material of the substrate SUB and process conditions, the buffer layer BFL can also be omitted.

[0197] The pixel circuit PXC may include at least one transistor T and a storage capacitor Cst. The transistor T may include a driving transistor Tdr and a switching transistor Tsw, wherein the driving transistor Tdr controls the driving current of the light emitting element LD and the switching transistor Tsw is connected to the driving transistor Tdr. However, the present invention is not limited thereto, and in addition to the driving transistor Tdr and the switching transistor Tsw, the pixel circuit PXC may also include circuit elements that perform other functions. In the following embodiments, when named including the driving transistor Tdr and the switching transistor Tsw, it is referred to as a transistor T or a plurality of transistors T. The driving transistor Tdr may be a transistor Tdr having a plurality of transistors Ts. Figure 9 The first transistor T1 has the same structure as described above, and the switch transistor Tsw can be the same as that of the reference Figure 9 The second transistor T2 has the same structure as described.

[0198] Each of the driving transistor Tdr and the switching transistor Tsw may include a semiconductor pattern SCL, a gate electrode GE, a first terminal SE, and a second terminal DE. The first terminal SE may be either a source electrode or a drain electrode, and the second terminal DE may be the other electrode. For example, when the first terminal SE is a source electrode, the second terminal DE may be a drain electrode.

[0199] A semiconductor pattern SCL may be provided and / or formed on the buffer layer BFL. The semiconductor pattern SCL may include a first contact region and a second contact region, wherein the first contact region contacts the first terminal SE and the second contact region contacts the second terminal DE. The region between the first contact region and the second contact region may be a channel region. Such a channel region may overlap with the gate electrode GE of the corresponding transistor T. The semiconductor pattern SCL may be a semiconductor pattern formed of polysilicon, amorphous silicon, an oxide semiconductor, or the like. For example, as a semiconductor pattern not doped with impurities, the channel region may be an intrinsic semiconductor. The first contact region and the second contact region may be semiconductor patterns doped with impurities.

[0200] The gate electrode GE may be provided and / or formed on the gate insulating layer GI to correspond to the channel region of the semiconductor pattern SCL. The gate electrode GE may be provided on the gate insulating layer GI so as to overlap the channel region of the semiconductor pattern SCL. The gate electrode GE may be formed of a single film made of a single material selected from the group consisting of copper (Cu), molybdenum (Mo), tungsten (W), aluminum neodymium (AlNd), titanium (Ti), aluminum (Al), silver (Ag), and alloys thereof, or a mixture thereof. Alternatively, the gate electrode GE may be formed as a double-layer film or a multi-layer film structure of molybdenum (Mo), titanium (Ti), copper (Cu), aluminum (Al), or silver (Ag), which are low-resistance materials, to reduce wiring resistance.

[0201] The gate insulating layer GI may be an inorganic insulating film including an inorganic material. For example, the gate insulating layer GI may include a silicon nitride (SiN x ), silicon oxide (SiO x ), silicon oxynitride (SiO x N y ), aluminum oxide (AlO x ) at least one of metal oxides. However, the material of the gate insulating layer GI is not limited to the above-described embodiment, and various substances that impart insulating properties to the gate insulating layer GI may be applied depending on the embodiment. For example, the gate insulating layer GI may also be formed of an organic insulating film including an organic material. The gate insulating layer GI may be provided as a single film, but may also be provided as a multilayer film of at least two films.

[0202] The first terminal SE and the second terminal DE are respectively provided and / or formed on the second interlayer insulating layer ILD2 and can contact the first contact region and the second contact region of the semiconductor pattern SCL via contact holes that sequentially penetrate the gate insulating layer GI, the first interlayer insulating layer ILD1, and the second interlayer insulating layer ILD2. For example, the first terminal SE can contact the first contact region of the semiconductor pattern SCL, and the second terminal DE can contact the second contact region of the semiconductor pattern SCL. Each of the first terminal SE and the second terminal DE can include the same material as the gate electrode GE, or include one or more materials selected from the materials exemplified as the constituent materials of the gate electrode GE.

[0203] The first interlayer insulating layer ILD1 may include the same material as the gate insulating layer GI, or include one or more materials selected from the materials exemplified as constituent materials of the gate insulating layer GI.

[0204] A second interlayer insulating layer ILD2 may be provided and / or formed on the first interlayer insulating layer ILD1. The second interlayer insulating layer ILD2 may be an inorganic insulating film including an inorganic material or an organic insulating film including an organic material. Depending on the embodiment, the second interlayer insulating layer ILD2 may include the same material as the first interlayer insulating layer ILD1, but the present invention is not limited thereto. The second interlayer insulating layer ILD2 may be provided as a single film, but may also be provided as a multilayer film including at least two films.

[0205] Although the above embodiment describes that the first terminal SE and the second terminal DE of each of the driving transistor Tdr and the switching transistor Tsw are separate electrodes electrically connected to the semiconductor pattern SCL via contact holes that sequentially penetrate the gate insulating layer GI, the first interlayer insulating layer ILD1, and the second interlayer insulating layer ILD2, the present invention is not limited thereto. According to an embodiment, the first terminal SE of each of the driving transistor Tdr and the switching transistor Tsw may be a first contact region adjacent to the channel region of the corresponding semiconductor pattern SCL, and the second terminal DE of each of the driving transistor Tdr and the switching transistor Tsw may be a second contact region adjacent to the channel region of the corresponding semiconductor pattern SCL. In this case, the second terminal DE of the driving transistor Tdr may be electrically connected to the light-emitting element LD of the corresponding pixel PXL via a separate connection device such as a bridge electrode.

[0206] In one embodiment of the present invention, the transistor T may be composed of a low-temperature polysilicon thin film transistor (LTPSTFT), but the present invention is not limited thereto. According to the embodiment, the above-mentioned transistor T may be composed of an oxide semiconductor thin film transistor. In addition, although the case where the transistor T is a top-gate thin film transistor is described as an example in the above-mentioned embodiment, the present invention is not limited thereto, and the structures of the plurality of transistors T may be variously changed.

[0207] The storage capacitor Cst may include a lower electrode LE and an upper electrode UE, wherein the lower electrode LE is provided on the gate insulating layer GI and the upper electrode UE is provided on the first interlayer insulating layer ILD1 to overlap with the lower electrode LE.

[0208] The lower electrode LE is provided on the same layer as the gate electrode GE of each of the drive transistor Tdr and the switching transistor Tsw and may include the same material. The lower electrode LE may be provided integrally with the gate electrode GE of the drive transistor Tdr. In this case, the lower electrode LE may be regarded as a region of the gate electrode GE of the drive transistor Tdr. Depending on the embodiment, the lower electrode LE may also be provided as a structure separate from the gate electrode GE of the drive transistor Tdr (or not provided integrally with the gate electrode GE of the drive transistor Tdr). In this case, the lower electrode LE and the gate electrode GE of the drive transistor Tdr may be electrically connected by a separate connection device.

[0209] The upper electrode UE overlaps with the lower electrode LE and may cover the lower electrode LE. By increasing the overlapping area between the upper electrode UE and the lower electrode LE, the capacitance of the storage capacitor Cst may be increased. The upper electrode UE may be electrically connected to the first power line PL1.

[0210] The storage capacitor Cst may be covered by the second interlayer insulating layer ILD2 .

[0211] The pixel circuit layer PCL may include a driving voltage wiring DVL provided and / or formed on the second interlayer insulating layer ILD2. The driving voltage wiring DVL may be connected to the reference Figure 9 The pixel circuit layer PCL may further include a first power line PL1 connected to the first drive power source VDD. Although not directly shown in the drawings, the first power line PL1 may be provided on the same layer as the drive voltage line DVL, or on a different layer from the drive voltage line DVL.

[0212] Each of the first power line PL1 and the drive voltage wiring DVL may include a conductive material. For example, each of the first power line PL1 and the drive voltage wiring DVL may be formed into a single film of a single material selected from the group consisting of copper (Cu), molybdenum (Mo), tungsten (W), aluminum neodymium (AlNd), titanium (Ti), aluminum (Al), silver (Ag), and alloys thereof, or a mixture thereof. Alternatively, to reduce wiring resistance, each of the first power line PL1 and the drive voltage wiring DVL may be formed into a double-layer film or a multi-layer film structure of molybdenum (Mo), titanium (Ti), copper (Cu), aluminum (Al), or silver (Ag), which are low-resistance materials. For example, each of the first power line PL1 and the drive voltage wiring DVL may be formed of a double-layer film stacked in the order of titanium (Ti) / copper (Cu).

[0213] A protection layer PSV may be provided and / or formed on the transistor T and the driving voltage wiring DVL.

[0214] The protective layer PSV may be provided in the form of an organic insulating film, an inorganic insulating film, or an organic insulating film disposed on an inorganic insulating film. For example, the inorganic insulating film may include a silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (SiO x N y ), aluminum oxide (AlO x). For example, the organic insulating film may include at least one of polyacrylates resin, epoxy resin, phenolic resin, polyamides resin, polyimides rein, unsaturated polyesters resin, poly-phenylene ethers resin, poly-phenylene sulfides resin, and benzocyclobutene resin.

[0215] The protection layer PSV may include a first contact hole CH1 and a second contact hole CH2 , wherein the first contact hole CH1 exposes one region of the driving transistor Tdr and the second contact hole CH2 exposes one region of the driving voltage wiring DVL.

[0216] A display element layer DPL may be provided on the protection layer PSV.

[0217] The display element layer DPL may include first and second banks BNK1 and BNK2, first and second connection wirings CNL1 and CNL2, first and second pixel electrodes PEL1 and PEL2, a light emitting element LD, and first and second contact electrodes CNE1 and CNE2. Furthermore, the display element layer DPL may include first, second, and third insulating layers INS1, INS2, and INS3.

[0218] In the pixel region PXA of each pixel PXL, the first bank BNK1 may be located in a light-emitting region where light is emitted. In order to change the surface profile (or shape) of each of the first pixel electrode PEL1 and the second pixel electrode PEL2 in the third direction DR3 to guide light emitted from the light-emitting element LD toward the image display direction (e.g., the front direction) of the display device, the first bank BNK1 may be a supporting member that supports each of the first pixel electrode PEL1 and the second pixel electrode PEL2. That is, the first bank BNK1 may change the surface profile (or shape) of each of the first pixel electrode PEL1 and the second pixel electrode PEL2 in the third direction DR3.

[0219] In the light emitting region of the corresponding pixel PXL, the first bank BNK1 may be provided and / or formed between the protective layer PSV and the corresponding electrode. For example, the first bank BNK1 may be provided and / or formed between the protective layer PSV and the first pixel electrode PEL1 and between the protective layer PSV and the second pixel electrode PEL2, respectively.

[0220] The first bank BNK1 may be an inorganic insulating film including an inorganic material or an organic insulating film including an organic material. Depending on the embodiment, the first bank BNK1 may include a single organic insulating film and / or a single inorganic insulating film, but the present invention is not limited thereto. Depending on the embodiment, the first bank BNK1 may also be provided in the form of a multilayer film stacked with at least one organic insulating film and at least one inorganic insulating film. However, the material of the first bank BNK1 is not limited to the above-described embodiments and, depending on the embodiment, the first bank BNK1 may also include a conductive substance.

[0221] The first bank BNK1 may have a trapezoidal cross-section whose width narrows from one surface (e.g., the upper surface) of the protective layer PSV toward the upper portion along the third direction DR3, but the present invention is not limited thereto. Depending on the embodiment, the first bank BNK1 may also include a curved surface having a cross-section having a semi-elliptical shape, a semi-circular shape (or a hemispherical shape), or the like, whose width narrows from one surface of the protective layer PSV toward the upper portion along the third direction DR3. When viewed in cross-section, the shape of the first bank BNK1 is not limited to the above-described embodiment and may be variously modified within a range that improves the efficiency of light emitted from each of the light-emitting elements LD. First banks BNK1 adjacent in the first direction DR1 may be arranged on the same surface of the protective layer PSV and may have the same height (or thickness) as each other in the third direction DR3.

[0222] Although the above embodiments describe that the first bank BNK1 is provided and / or formed on the protective layer PSV, and that the first bank BNK1 and the protective layer PSV are formed using different processes, the present invention is not limited thereto. Depending on the embodiment, the first bank BNK1 and the protective layer PSV may be formed using the same process. In this case, the first bank BNK1 may be a region of the protective layer PSV.

[0223] The second bank BNK2 serves as a structure that defines (or divides) the pixel area PXA (or light-emitting area) of each pixel PXL and its adjacent pixels PXL. For example, it can be a pixel-defining film. Such a second bank BNK2 can be configured to include at least one light-shielding material and / or reflective material to prevent light (or light rays) from leaking between each pixel PXL and its adjacent pixels PXL. According to an embodiment, the second bank BNK2 may include a transparent substance (or material). For example, the transparent substance may include polyamide resin, polyimide resin, etc., but the present invention is not limited to this. According to another embodiment, in order to further improve the efficiency of light emitted from each pixel PXL, a reflective material layer may also be formed on the second bank BNK2.

[0224] The second bank BNK2 may be provided and / or formed on a different layer from the first bank BNK1, but the present invention is not limited thereto, and according to an embodiment, the second bank BNK2 may also be provided and / or formed on the same layer as the first bank BNK1. In one embodiment of the present invention, the second bank BNK2 may be formed on a different layer from the first bank BNK1 and provided and / or formed on the first insulating layer INS1.

[0225] The first pixel electrode PEL1 and the second pixel electrode PEL2 may be provided and / or formed on the corresponding first bank BNK1 .

[0226] In order to make the light emitted from each of the light-emitting elements LD travel in the image display direction of the display device, each of the first pixel electrode PEL1 and the second pixel electrode PEL2 can be made of a material with a certain reflectivity. Each of the first pixel electrode PEL1 and the second pixel electrode PEL2 can be made of a conductive material with a certain reflectivity. The conductive material may include an opaque metal that is conducive to reflecting the light emitted from the light-emitting element LD in the image display direction of the display device. For example, the opaque metal may include metals such as silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), titanium (Ti) and alloys thereof. According to an embodiment, each of the first pixel electrode PEL1 and the second pixel electrode PEL2 may include a transparent conductive material. Transparent conductive materials may include conductive oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium gallium zinc oxide (IGZO), and indium tin zinc oxide (ITZO), as well as conductive polymers such as PEDOT (poly(3,4-ethylenedioxythiophene)). When each of the first pixel electrode PEL1 and the second pixel electrode PEL2 includes a transparent conductive material, an additional conductive layer formed of an opaque metal for reflecting light emitted from the light-emitting element LD in the image display direction of the display device may also be added. However, the material of each of the first pixel electrode PEL1 and the second pixel electrode PEL2 is not limited to the above-mentioned materials.

[0227] Each of the first pixel electrode PEL1 and the second pixel electrode PEL2 may be provided and / or formed as a single film, but the present invention is not limited thereto. According to an embodiment, each of the first pixel electrode PEL1 and the second pixel electrode PEL2 may also be provided and / or formed as a multilayer film in which at least two substances selected from metals, alloys, conductive oxides, and conductive polymers are stacked. When transmitting a signal (or voltage) to the two ends of each of the light-emitting elements LD, in order to minimize the distortion caused by signal delay, each of the first pixel electrode PEL1 and the second pixel electrode PEL2 may also be formed as a multilayer film of at least two films. For example, each of the first pixel electrode PEL1 and the second pixel electrode PEL2 may also be formed as a multilayer film stacked in the order of indium tin oxide (ITO) / silver (Ag) / indium tin oxide (ITO).

[0228] As described above, the first pixel electrode PEL1 may be electrically connected to the driving transistor Tdr through the first contact hole CH1 , and the second pixel electrode PEL2 may be electrically connected to the driving voltage wiring DVL through the second contact hole CH2 .

[0229] Each of the first pixel electrode PEL1 and the second pixel electrode PEL2 can receive a prescribed alignment signal (or alignment voltage) from a corresponding portion of the structure of the pixel circuit layer PCL, thereby serving as an alignment electrode (or alignment wiring) for aligning the light-emitting element LD. For example, the first pixel electrode PEL1 can receive a first alignment signal (or first alignment voltage) from a portion of the structure of the pixel circuit layer PCL, thereby serving as a first alignment electrode (or first alignment wiring), and the second pixel electrode PEL2 can receive a second alignment signal (or second alignment voltage) from another structure of the above-mentioned pixel circuit layer PCL, thereby serving as a second alignment electrode (or second alignment wiring).

[0230] After the light-emitting element LD is aligned in the pixel area PXA of each pixel PXL, in order to drive the pixel PXL individually (or independently), a portion of the first pixel electrode PEL1 (e.g., a portion of the first connection wiring CNL1) located between adjacent pixels PXL along one direction (e.g., the first direction DR1 and / or the second direction DR2) can be removed.

[0231] After the light emitting element LD is aligned in the pixel area PXA, the first pixel electrode PEL1 and the second pixel electrode PEL2 may function as driving electrodes for driving the light emitting element LD.

[0232] Each of the light emitting elements LD may be an ultra-small (e.g., a size as small as nanometer to micrometer) light emitting diode using an inorganic crystal structure material. Each of the light emitting elements LD may be an ultra-small light emitting diode manufactured by etching or an ultra-small light emitting diode manufactured by growth. Each of the above light emitting elements LD may be a reference Figure 1 and Figure 2 The light emitting element LD is described.

[0233] A first insulating layer INS1 may be provided and / or formed on the first and second pixel electrodes PEL1 and PEL2 .

[0234] The first insulating layer INS1 may include an inorganic insulating film formed of an inorganic material or an organic insulating film formed of an organic material. The first insulating layer INS1 may be formed of an inorganic insulating film that is beneficial for protecting the light emitting element LD from being affected by the pixel circuit layer PCL of each pixel PXL. For example, the first insulating layer INS1 may include a silicon nitride (SiN x ), silicon oxide (SiO x ), silicon oxynitride (SiO x N y ), aluminum oxide (AlO x ), but the present invention is not limited thereto. According to an embodiment, the first insulating layer INS1 may also be formed of an organic insulating film that facilitates planarization of the support surface of the light emitting element LD.

[0235] The first insulating layer INS1 may include a first opening OPN1 and a second opening OPN2, wherein the first opening OPN1 exposes a region of the first pixel electrode PEL1 and the second opening OPN2 exposes a region of the second pixel electrode PEL2. The light emitting element LD may be arranged (or aligned) on the first insulating layer INS1 between the first pixel electrode PEL1 and the second pixel electrode PEL2.

[0236] The first pixel electrode PEL1 may be in direct contact with the first contact electrode CNE1 through the first opening OPN1 and thus connected to the first contact electrode CNE1, and the second pixel electrode PEL2 may be in direct contact with the second contact electrode CNE2 through the second opening OPN2 of the first insulating layer INS1 and thus connected to the second contact electrode CNE2. The first insulating layer INS1 may cover the remaining area except for one area of ​​each of the first pixel electrode PEL1 and the second pixel electrode PEL2.

[0237] A second insulating layer INS2 may be provided and / or formed on each of the light-emitting elements LD. The second insulating layer INS2 may be provided and / or formed on the light-emitting elements LD to partially cover the outer peripheral surface (or surface) of each of the light-emitting elements LD, thereby exposing both ends of each of the light-emitting elements LD to the outside. The second insulating layer INS2 may be formed as an independent insulating pattern in the pixel area PXA of each pixel PXL, but the present invention is not limited thereto.

[0238] The second insulating layer INS2 can be composed of a single film or a multilayer film, and can include an inorganic insulating film containing at least one inorganic material or an organic insulating film containing at least one organic material. The second insulating layer INS2 can include an inorganic insulating film that helps protect the active layer 12 of each light-emitting element LD from external influences such as oxygen and moisture. However, the present invention is not limited to this. Depending on the design conditions of the display device in which the light-emitting element LD is used, the second insulating layer INS2 can also be composed of an organic insulating film containing an organic material. After the light-emitting element LD is aligned in the pixel area PXA of each pixel PXL, forming the second insulating layer INS2 on the light-emitting element LD can prevent the light-emitting element LD from deviating from the aligned position.

[0239] By forming the second insulating layer INS2 on the light emitting elements LD, the active layer (refer to Figure 1 The second insulating layer INS2 may cover only a portion of the outer peripheral surface (or surface) of each of the light emitting elements LD, thereby exposing both ends of each of the light emitting elements LD to the outside.

[0240] The first contact electrode CNE1 may be provided on the first pixel electrode PEL1, thereby being connected to the first pixel electrode PEL1 through the first opening OPN1 of the first insulating layer INS1. According to an embodiment, if a cover layer (not shown) is provided on the first pixel electrode PEL1, the first contact electrode CNE1 may be provided on the cover layer, thereby being connected to the first pixel electrode PEL1 through the cover layer. The cover layer may protect the first pixel electrode PEL1 from defects generated during the manufacturing process of the display device, and further enhance the adhesion between the first pixel electrode PEL1 and the pixel circuit layer PCL located thereunder. The cover layer may include a transparent conductive material (or substance) such as indium zinc oxide (IZO).

[0241] Furthermore, a first contact electrode CNE1 may be provided and / or formed on one end portion of each of the light emitting elements LD so as to be connected to one end portion of each of the light emitting elements LD. Therefore, the first pixel electrode PEL1 and one end portion of each of the light emitting elements LD may be electrically connected to each other via the first contact electrode CNE1.

[0242] The second contact electrode CNE2 may be provided on the second pixel electrode PEL2 to be connected to the second pixel electrode PEL2 through the second opening OPN2 of the first insulating layer INS1. According to an embodiment, when an overcoat layer is disposed on the second pixel electrode PEL2, the second contact electrode CNE2 may be disposed on the overcoat layer to be connected to the second pixel electrode PEL2 through the overcoat layer.

[0243] In addition, a second contact electrode CNE2 may be provided and / or formed on the other end of each of the light emitting elements LD so as to be connected to the other end of each of the light emitting elements LD. Therefore, the second pixel electrode PEL2 and the other end of each of the light emitting elements LD may be electrically connected to each other via the second contact electrode CNE2.

[0244] The first and second contact electrodes CNE1 and CNE2 can be made of various transparent conductive materials to allow light emitted from each of the light-emitting elements LD and reflected by the first and second pixel electrodes PEL1 and PEL2 to travel unimpeded toward the image display direction of the display device. For example, the first and second contact electrodes CNE1 and CNE2 include at least one of various transparent conductive materials (or substances) including indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium gallium zinc oxide (IGZO), and indium tin zinc oxide (ITZO). These materials can be substantially transparent or translucent to meet a specified light transmittance (or transmittance). However, the materials of the first and second contact electrodes CNE1 and CNE2 are not limited to the above-described embodiments. Depending on the embodiment, the first and second contact electrodes CNE1 and CNE2 can also be made of various opaque conductive materials (or substances). The first contact electrode CNE1 and the second contact electrode CNE2 may also be formed as a single film or a multi-layer film.

[0245] When viewed in a planar manner, each of the first contact electrode CNE1 and the second contact electrode CNE2 may have a bar shape extending along the second direction DR2, but the present invention is not limited thereto. Depending on the embodiment, the shapes of the first contact electrode CNE1 and the second contact electrode CNE2 may be variously modified within the scope of stably electrically connecting to each of the light-emitting elements LD. Furthermore, the shapes of the first contact electrode CNE1 and the second contact electrode CNE2 may be variously modified in consideration of the connection relationship with the electrodes arranged thereunder.

[0246] The first contact electrode CNE1 and the second contact electrode CNE2 may be spaced apart from each other in the first direction DR1. For example, the first contact electrode CNE1 and the second contact electrode CNE2 may be spaced apart and spaced apart from each other on the second insulating layer INS2 on the light-emitting element LD. The first contact electrode CNE1 and the second contact electrode CNE2 may be provided on the same layer and formed by the same process. However, the present invention is not limited thereto, and according to embodiments, the first contact electrode CNE1 and the second contact electrode CNE2 may be provided on different layers and formed by different processes.

[0247] A third insulating layer INS3 may be provided and / or formed on the first contact electrode CNE1 and the second contact electrode CNE2. The third insulating layer INS3 may be an inorganic insulating film including an inorganic material or an organic insulating film including an organic material. For example, the third insulating layer INS3 may have a structure in which at least one inorganic insulating film or at least one organic insulating film is alternately stacked. The third insulating layer INS3 may completely cover the display element layer DPL, thereby preventing moisture or humidity from flowing from the outside into the display element layer DPL including the light-emitting element LD.

[0248] According to an embodiment, in addition to the third insulating layer INS3, the display element layer DPL may also be configured to further selectively include an optical layer. Here, the optical layer may include a color conversion layer including color conversion particles that convert light emitted from the light emitting element LD into light of a specific color.

[0249] Hereinafter, a method for manufacturing the above-mentioned display device will be described.

[0250] Figures 13 to 15 1 is a cross-sectional view schematically illustrating a method for manufacturing a display device according to one embodiment, in process steps.

[0251] For ease of description, Figures 13 to 15 In the figure, the structure arranged below the protective layer PSV is omitted from illustration.

[0252] refer to Figure 13, prepare a substrate including a protective layer PSV, a first bank BNK1, a first pixel electrode PEL1 and a second pixel electrode PEL2, and an insulating material layer INSM, wherein the first bank BNK1 is provided on the protective layer PSV, the first pixel electrode PEL1 and the second pixel electrode PEL2 are provided on the corresponding first bank BNK1 and are spaced apart in the first direction DR1, and the insulating material layer INSM is arranged to cover the first pixel electrode PEL1 and the second pixel electrode PEL2. The above substrate can be a reference Figure 7 The above-described structure provided on the substrate SUB is generally formed by performing a process using a mask to pattern a conductive layer (or metal layer), an inorganic substance or an organic substance, or the like.

[0253] Then, refer to Figure 14 , using a printing device to eject ink INK including light emitting elements LD onto the substrate SUB. The printing device can be a reference Figure 6 and Figure 7 A printing device 1 is described.

[0254] The ink INK may be a mixture including a fluid solvent SLV and a plurality of light emitting elements LD contained (or dispersed) in the solvent SLV.

[0255] refer to Figure 15 , an alignment signal corresponding to each of the first pixel electrode PEL1 and the second pixel electrode PEL2 is applied to form an electric field between the first pixel electrode PEL1 and the second pixel electrode PEL2. Due to the electric field, the light-emitting element LD in the ink INK can be stably aligned to the target area (e.g., the area between the first pixel electrode PEL1 and the second pixel electrode PEL2). After the light-emitting element LD is aligned, the solvent SLV contained in the ink INK can be volatilized or removed by other means, so that the light-emitting element LD is ultimately aligned on the insulating material layer INSM.

[0256] Then, subsequent additional processes may be performed to form the reference Figure 11 and Figure 12 The first and second insulating layers INS1 and INS2, the first and second contact electrodes CNE1 and CNE2, and the third insulating layer INS3 are formed to manufacture a display device according to one embodiment. In particular, in order to electrically connect the first contact electrode CNE1 and the first pixel electrode PEL1, and the second contact electrode CNE2 and the second pixel electrode PEL2, the insulating material layer INSM may be partially removed to form the first insulating layer INS1.

[0257] According to the display device manufactured as described above, as the printing device 1 stably ejects the ink INK including the light-emitting elements LD, the light-emitting elements LD can be aligned in the target area with a high degree of alignment. Since the alignment of the light-emitting elements LD is improved, connection or contact defects between the light-emitting elements LD and the structures included in the electrode portion (for example, the first and second pixel electrodes PEL1 and PEL2 and the first and second contact electrodes CNE1 and CNE2) can be reduced. As a result, the reliability of the display device can be improved.

[0258] Although the present invention has been described above with reference to preferred embodiments, it will be understood by those skilled in the art or those of ordinary skill in the art that various modifications and changes may be made to the present invention without departing from the scope of the ideas and technical field of the invention as set forth in the appended claims.

[0259] Therefore, the technical scope of the present invention is not limited to the contents described in the detailed description of the specification, but should be determined only by the claims.

Claims

1. A storage device for a light-emitting element, comprising: a storage container containing contents including a solvent in which at least one light-emitting element is dispersed; a first electrode disposed on a lower surface of the storage container; a second electrode disposed on an upper surface of the storage container opposite to the lower surface; as well as a power supply unit electrically connected to each of the first electrode and the second electrode to apply a signal corresponding to each of the first electrode and the second electrode, The first electrode and the second electrode form an electric field in the vertical direction. The light emitting element includes a first end portion and a second end portion located at both ends in a length direction, and The longitudinal direction is parallel to the vertical direction.

2. The light emitting element storage device according to claim 1, wherein The light emitting element comprises: a first semiconductor layer corresponding to the first end portion and doped with a first conductive dopant; a second semiconductor layer corresponding to the second end portion and doped with a second conductive dopant different from the first conductive dopant; and The active layer is located between the first semiconductor layer and the second semiconductor layer.

3. The light emitting element storage device according to claim 2, wherein: The light emitting element includes a light emitting diode ranging from nanometer scale to micrometer scale.

4. The light emitting element storage device according to claim 1, wherein Each of the first electrode and the second electrode is applied with signals of polarities different from each other.

5. The light emitting element storage device according to claim 4, wherein The first electrode and the second electrode are arranged on an outer surface of the storage container.

6. The light emitting element storage device according to claim 5, wherein The first electrode and the second electrode have the same size and include a conductive material.

7. A printing device comprising a printing head unit, the printing device comprising: a storage portion accommodating contents including a solvent in which at least one light-emitting element is dispersed; at least one storage unit receiving the contents contained in the storage portion through a first supply portion to contain the contents; as well as a supply unit that receives the content contained in the storage unit through a second supply portion to supply the content to the print head unit, Wherein, the storage unit includes: a storage container for containing the contents; a first electrode provided on a lower surface of the storage container; a second electrode provided on an upper surface of the storage container; and a power supply unit electrically connected to each of the first electrode and the second electrode to apply a signal corresponding to each of the first electrode and the second electrode, The first electrode and the second electrode form an electric field in the vertical direction. The light emitting element includes a first end portion and a second end portion located at both ends in a length direction, and The longitudinal direction is parallel to the vertical direction.

8. The printing device according to claim 7, wherein: The light emitting element comprises: a first semiconductor layer corresponding to the first end portion and doped with a first conductive dopant; a second semiconductor layer corresponding to the second end portion and doped with a second conductive dopant; and The active layer is located between the first semiconductor layer and the second semiconductor layer.

9. The printing device according to claim 8, wherein The light emitting element includes a light emitting diode ranging from nanometer scale to micrometer scale.

10. The printing device according to claim 8, wherein The storage unit includes: a first storage container for accommodating the content in the storage portion delivered by the first supply portion; a first electrode disposed on a lower surface of the first storage container; and A second electrode is disposed on an upper surface of the first storage container.

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