Inkjet printing equipment

Abstract

An inkjet printing apparatus according to one embodiment includes: a first ink storage unit for providing ink comprising a plurality of particles; a second ink storage unit for supplying ink from the first ink storage unit to the second ink storage unit via a first conduit; a printhead unit for discharging the ink received from the second ink storage unit via a second conduit; and a first branching member and a second branching member, respectively disposed between the first ink storage unit and the second ink storage unit and between the second ink storage unit and the printhead unit, and for branching the ink, wherein the first branching member and the second branching member each include: a first base portion in which the ink moves; and a first partition portion disposed in the first base portion and including a first partition and a second partition that branch the interior of the first base portion.

Description

Technical Field

[0001] This invention relates to inkjet printing apparatus. Background Technology

[0002] With the development of multimedia, the importance of display devices is increasing. In response, various display devices such as Organic Light Emitting Display (OLED) and Liquid Crystal Display (LCD) are being used.

[0003] Display devices for displaying images include display panels such as organic light-emitting display panels or liquid crystal display panels. The light-emitting display panel may include light-emitting elements, such as organic light-emitting diodes (OLEDs) that use organic materials as fluorescent materials, and inorganic light-emitting diodes that use inorganic materials as fluorescent materials.

[0004] Furthermore, inkjet printing apparatus can be used to form the organic layer included in the display device or to form inorganic light-emitting diodes. Post-processing processes can also be performed after inkjet printing any ink or solution to transfer the aforementioned inorganic light-emitting diode element or form the organic layer. In the inkjet printing apparatus, a predetermined ink or solution can be supplied to the inkjet head, and the inkjet head can perform the process of jetting the ink or solution onto the substrate being processed (e.g., the target substrate). Summary of the Invention

[0005] Technical problems to be solved

[0006] The technical problem to be solved by the present invention is to provide an inkjet printing apparatus that can prevent particles from settling in the inkjet printing apparatus, thereby improving the inkjet printing quality.

[0007] The technical problems of this invention are not limited to those mentioned above, and those skilled in the art will clearly understand from the following description other technical problems not mentioned.

[0008] Solution

[0009] An inkjet printing apparatus according to an embodiment for solving the above-mentioned technical problems may include: a first ink storage unit for providing ink comprising a plurality of particles; a second ink storage unit for which the ink is supplied from the first ink storage unit to the second ink storage unit via a first conduit; a printhead unit for discharging the ink received from the second ink storage unit via a second conduit; and a first branching member and a second branching member, respectively disposed between the first ink storage unit and the second ink storage unit and between the second ink storage unit and the printhead unit, and for branching the ink, wherein the first branching member and the second branching member may each include: a first base portion in which the ink moves; and a first partition portion disposed in the first base portion and including a first partition and a second partition that branch the interior of the first base portion.

[0010] The first partition may include a first opening in which a portion of the ink moving inside the first base moves, and the second partition may include a second opening and a third opening in which the remaining ... third opening in which the second partition and the third opening in which the second partition and the third opening in the second partition and the third opening in the third opening in the second partition and the third opening in the third opening.

[0011] The center of the first opening may overlap with the center of the first base portion, and the second opening and the third opening may not overlap with the center of the first base portion along the length direction of the first base portion.

[0012] The second opening and the third opening may surround the first opening, and the second opening may be arranged above the first opening, and the third opening may be arranged below the first opening.

[0013] Furthermore, an inkjet printing apparatus according to one embodiment may include: a first ink storage unit for providing ink comprising a plurality of particles; a second ink storage unit for storing the ink provided from the first ink storage unit; a gas storage unit for providing gas to the second ink storage unit; a pump for supplying the ink from the first ink storage unit and the gas from the gas storage unit to the second ink storage unit; a main pipe through which the ink and the gas are supplied from the pump to the second ink storage unit; and a printhead unit for discharging the ink received from the second ink storage unit.

[0014] The inkjet printing apparatus may further include: a first conduit connecting the first ink storage unit and the pump, and equipped with a first valve; a second conduit connecting the gas storage unit and the pump, and equipped with a second valve; a third conduit connecting the second ink storage unit and the gas storage unit, and equipped with a third valve; a sound pressure chamber for drawing in gas present in the second ink storage unit; and a fourth conduit connecting the sound pressure chamber and the second ink storage unit, and equipped with a fourth valve, wherein the sound pressure chamber can draw in gas from the second ink storage unit by closing the first valve, the second valve, and the third valve and opening the fourth valve.

[0015] The gas in the gas storage unit can be supplied to the main pipeline by closing the first valve, the third valve, and the fourth valve, opening the second valve, and driving the pump.

[0016] The ink in the first ink storage unit can be supplied to the main pipeline by closing the second valve, opening the first valve, and driving the pump. The ink supplied to the main pipeline can be supplied to the second ink storage unit by driving the pump after closing the first valve and opening the second valve, thereby supplying the gas from the gas storage unit to the main pipeline. The gas supplied to the second ink storage unit can be recycled back to the gas storage unit by closing the first valve, the second valve, and the fourth valve and opening the third valve.

[0017] The pump can be a metering pump and can supply a quantity of ink for performing one inkjet printing process, and the metering pump can be a diaphragm pump or a tubular pump.

[0018] The first ink storage unit can be directly connected to the pump.

[0019] Specific details of other embodiments are included in the detailed description and accompanying drawings.

[0020] Beneficial effects

[0021] According to the embodiment of the inkjet printing apparatus, by forming branching components in the pipeline, ink including precipitated particles can be separated and recycled, and ink in which the particles are uniformly dispersed can be supplied.

[0022] Furthermore, according to the embodiment of the inkjet printing apparatus, by including a metering pump and a gas storage unit, gas can be used to move the ink in the pipeline, thereby preventing particles from settling in the pipeline.

[0023] Therefore, the variation in the number or concentration of particles in the ink caused by the sedimentation of particles in the ink in the pipe can be minimized, thereby improving the quality of inkjet printing.

[0024] The effects of the embodiments are not limited to those illustrated above, and many more effects are included in this specification. Attached Figure Description

[0025] Figure 1 This is a schematic plan view of a display device according to one embodiment.

[0026] Figure 2 This is a schematic cross-sectional view of a portion of a sub-pixel of a display device according to one embodiment.

[0027] Figure 3 This is a plan view showing a pixel of a display device according to an embodiment.

[0028] Figure 4 It is along Figure 3 The sectional views taken from lines Q1-Q1', Q2-Q2', and Q3-Q3'.

[0029] Figure 5 This is a schematic diagram of a light-emitting element according to one embodiment.

[0030] Figure 6 This is a schematic perspective view of an inkjet printing apparatus according to one embodiment.

[0031] Figure 7 This is a schematic top view of a printhead unit according to one embodiment.

[0032] Figure 8 This is a schematic diagram illustrating the operation of a printhead unit according to one embodiment.

[0033] Figure 9 This is a schematic diagram showing the ink circulation section of an inkjet printing apparatus according to an embodiment.

[0034] Figure 10 This is a cross-sectional view showing a first branch component according to an embodiment.

[0035] Figure 11 This is a cross-sectional view showing a first branch component according to an embodiment.

[0036] Figure 12 This is a cross-sectional view showing the first branch component according to another embodiment.

[0037] Figure 13 This is a cross-sectional view showing the first branch component according to another embodiment.

[0038] Figure 14This is a schematic diagram showing the ink circulation section of an inkjet printing apparatus according to yet another embodiment.

[0039] Figures 15 to 18 This is a schematic diagram illustrating a driving method for the ink circulation section of an inkjet printing apparatus according to yet another embodiment.

[0040] Figure 19 This is a schematic diagram showing the ink circulation section of an inkjet printing apparatus according to yet another embodiment.

[0041] Explanation of reference numerals in the attached figures

[0042] 90: Ink 95: Particles

[0043] 100: Printhead unit; 300: Inkjet head

[0044] 500: Ink circulation section; 510: First ink storage section

[0045] 520: Second ink storage unit; 530: First pressure pump

[0046] 540: Second pressure pump; 550: First branch component

[0047] 570: Second branch component; 710: Gas storage section

[0048] 700: Pump; 730: Sound pressure chamber

[0049] PP1~PP4: Pipeline 1 to Pipeline 4; MP: Main Pipeline

[0050] VA1~VA4: First valve to fourth valve; BP1: First foundation section

[0051] BR1: First partition section

[0052] PR1~PR2: First septum and second septum

[0053] PS1~PS2: First Sub-pipe and Second Sub-pipe Specific Implementation

[0054] The advantages and features of the present invention, as well as the methods for achieving these advantages and features, will be described with reference to the following appendix. Figure 1 The invention becomes clear from the detailed description of the embodiments. However, the invention is not limited to the embodiments disclosed below, but can be implemented in many different forms. These embodiments are provided only to make the disclosure of the invention complete and to fully inform those skilled in the art of the scope of the invention, which is defined only by the scope of the claims.

[0055] Elements or layers are referred to as being "on" another element or layer, including both cases where they are directly on another element or in between other layers or other elements. Throughout this specification, the same reference numerals refer to the same constituent elements. The shapes, sizes, proportions, angles, quantities, etc., disclosed in the accompanying drawings used to illustrate embodiments are exemplary, and therefore, the invention is not limited to the matters shown.

[0056] Although terms such as "first" and "second" are used to describe various constituent elements, these constituent elements are clearly not limited by these terms. These terms are only used to distinguish one constituent element from another. Therefore, the first constituent element mentioned below can obviously also be a second constituent element within the technical concept of this invention.

[0057] The various features of the various embodiments of the present invention can be combined or integrated with each other in part or in whole, and can be linked and driven in various ways in a technical manner. Furthermore, the embodiments can be implemented independently of each other or together in an associated relationship.

[0058] Hereinafter, specific embodiments will be described with reference to the accompanying drawings. Following the description of the display device, an inkjet printing apparatus for manufacturing the display device and a method for manufacturing the display device using the same will be described.

[0059] Figure 1 This is a schematic plan view of a display device according to one embodiment.

[0060] Reference Figure 1 The display device 10 displays video or still images. The display device 10 can refer to any electronic device that provides a display screen. For example, the display device 10 may include televisions, laptops, monitors, billboards, Internet of Things (IoT) products, mobile phones, smartphones, tablet PCs, electronic clocks, smartwatches, watch phones, head-mounted displays, mobile communication terminals, electronic manuals, e-books, portable multimedia players (PMPs), navigators, game consoles, digital cameras, portable video cameras, etc.

[0061] The display device 10 includes a display panel that provides a display image. Examples of display panels may include inorganic light-emitting diode (LED) display panels, organic light-emitting diode (OLED) display panels, quantum dot (QD) light-emitting diode (OLED) display panels, plasma display panels, field emission display panels, etc. The following example illustrates the use of an inorganic LED display panel, but it is not limited to this, and other display panels can be applied if the same technical concept is applicable.

[0062] In the accompanying drawings illustrating the display device 10, a first direction DR1, a second direction DR2, and a third direction DR3 are defined. The first direction DR1 and the second direction DR2 can be directions perpendicular to each other in a plane. The third direction DR3 can be a direction perpendicular to the plane containing the first direction DR1 and the second direction DR2. The third direction DR3 is perpendicular to each of the first direction DR1 and the second direction DR2. In an embodiment illustrating the display device 10, the third direction DR3 represents the thickness direction of the display device 10.

[0063] The shape of the display device 10 can be varied. For example, the display device 10 can have a rectangular shape on a plane, including a longer side in the first direction DR1 than in the second direction DR2. As another example, the display device 10 can also have a rectangular shape on a plane, including a longer side in the second direction DR2 than in the first direction DR1. However, it is not limited to this, and can have shapes such as squares, quadrilaterals with rounded corners (vertices), other polygons, circles, etc. The shape of the display area DPA of the display device 10 can also be similar to the overall shape of the display device 10. Figure 1 The example illustrates a rectangular display device 10 that is longer in the first direction DR1 than in the second direction DR2, and a display area DPA.

[0064] The display device 10 may include a display area DPA and a non-display area NDA. The display area DPA is the area where an image can be displayed, and the non-display area NDA is the area where no image is displayed. The display area DPA may also be referred to as an active area, and the non-display area NDA may also be referred to as a passive area. The display area DPA may occupy approximately the center of the display device 10.

[0065] The display area DPA may include multiple pixels PX. The multiple pixels PX may be arranged in a row and column direction. The shape of each pixel PX in a plane may be rectangular or square, but is not limited to these; it may also be a rhombus shape with each side tilted relative to one direction. The pixels PX may be arranged alternately in a stripe pattern or a PenTile pattern. Furthermore, each of the pixels PX may include more than one light-emitting element 30 that emits light of a specific wavelength band (see [link to relevant documentation]). Figure 2 ( ), to display a specific color.

[0066] Non-display areas NDA can be arranged around the display area DPA. The non-display areas NDA can completely or partially surround the display area DPA. The display area DPA can be rectangular, and the non-display areas NDA can be arranged adjacent to the four sides of the display area DPA. The non-display areas NDA can form the frame of the display device 10. Wiring or circuit driving parts included in the display device 10 can be arranged in each non-display area NDA, or external devices can be mounted thereon.

[0067] Figure 2 This is a schematic cross-sectional view of a portion of a sub-pixel of a display device according to one embodiment.

[0068] Reference Figure 2 The display area DPA of the display device 10 may include a first light-emitting area LA1, a second light-emitting area LA2, and a third light-emitting area LA3. Each of the first light-emitting area LA1, the second light-emitting area LA2, and the third light-emitting area LA3 may be an area from which light generated from the light-emitting element 30 of the display device 10 is emitted to the outside of the display device 10.

[0069] The display device 10 may include a substrate 11, a buffer layer 12, a transistor layer TFTL, a light-emitting element layer EML, a wavelength conversion layer WLCL, a color filter layer CFL, and an encapsulation layer TFE.

[0070] The substrate 11 can be a base substrate or a base component, and can be formed of an insulating material such as a polymer resin. For example, the substrate 11 can be a flexible substrate capable of bending, folding, rolling, etc. The substrate 11 may include, but is not limited to, polyimide (PI).

[0071] The buffer layer 12 can be disposed on the substrate 11. The buffer layer 12 can be formed of an inorganic film capable of preventing the penetration of air or moisture. For example, the buffer layer 12 may include a plurality of inorganic films stacked alternately.

[0072] A transistor layer TFTL may be disposed on the buffer layer 12. The transistor layer TFTL may include a first transistor T1, a gate insulating layer 13, an interlayer insulating layer 15, and a via layer 17.

[0073] The first transistor T1 can be disposed on the buffer layer 12 and can constitute a pixel circuit for each of the multiple pixels. For example, the first transistor T1 can be a driving transistor or a switching transistor of the pixel circuit. The first transistor T1 may include an active layer ACT, a gate electrode G1, a source electrode SE, and a drain electrode DE. The active layer ACT may include multiple conductive regions ACTa, ACTb, and a channel region ACTc between them.

[0074] A light-emitting element layer (EML) may be disposed on the transistor layer (TFTL). The EML may include a first pattern (BNL1), a light-emitting element (30), and a second pattern (BNL2). The light-emitting element (30) may be disposed on the first transistor (T1). The light-emitting element (30) may be disposed between the first electrode and the second electrode, and may be connected to the first connection electrode and the second connection electrode, respectively.

[0075] Refer to later Figures 3 to 5 The transistor layer TFTL and the light-emitting element layer EML described above will be explained in detail.

[0076] A first planarization layer 41 may be disposed on the light-emitting element layer EML to planarize the upper end of the light-emitting element layer EML. The first planarization layer 41 may include an organic material. For example, the first planarization layer 41 may include at least one selected from acrylic resin, epoxy resin, phenolic resin, polyamide resin, and polyimide resin.

[0077] The wavelength conversion layer WLCL may include a first capping layer CAP1, a first light-shielding component BK1, a first wavelength conversion part WLC1, a second wavelength conversion part WLC2, a light-transmitting part LTU, a second capping layer CAP2, and a second planarization layer 43.

[0078] The first capping layer CAP1 can be disposed on the first planarization layer 41 of the light-emitting element layer EML. The first capping layer CAP1 can seal the lower surface of the first wavelength conversion section WLC1, the second wavelength conversion section WLC2, and the light-transmitting section LTU. The first capping layer CAP1 can include an inorganic material. For example, the first capping layer CAP1 can include at least one of silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide, and silicon oxide nitride.

[0079] The first light-shielding component BK1 can be arranged in the first light-shielding area BA1, the second light-shielding area BA2, and the third light-shielding area BA3 on the first capping layer CAP1. The first light-shielding component BK1 can overlap with the second pattern BNL2 in the thickness direction. The first light-shielding component BK1 can block the transmission of light. The first light-shielding component BK1 can prevent light from entering between the first light-emitting area LA1, the second light-emitting area LA2, and the third light-emitting area LA3 and causing color mixing, thereby improving color reproduction. The first light-shielding component BK1 can be arranged in the form of a grid surrounding the first light-emitting area LA1, the second light-emitting area LA2, and the third light-emitting area LA3 on a plane.

[0080] The first light-shielding component BK1 may include an organic light-shielding material and a hydrophobic component. Here, the hydrophobic component may consist of a fluorinated monomer or a fluorinated polymer, and specifically may include a fluorinated aliphatic polycarbonate. For example, the first light-shielding component BK1 may be formed from a black organic material including the hydrophobic component. The first light-shielding component BK1 may be formed through processes such as coating and exposure of the organic light-shielding material including the hydrophobic component.

[0081] The first light-shielding component BK1 can separate the first wavelength conversion section WLC1, the second wavelength conversion section WLC2, and the light-transmitting section LTU to their respective light-emitting regions LA1, LA2, and LA3 by including a hydrophobic component. For example, when the first wavelength conversion section WLC1, the second wavelength conversion section WLC2, and the light-transmitting section LTU are formed by inkjet printing, the ink composition can flow onto the upper surface of the first light-shielding component BK1. In this case, the first light-shielding component BK1 can guide the ink composition to flow to each light-emitting region by including a hydrophobic component. Therefore, the first light-shielding component BK1 can prevent the ink composition from mixing.

[0082] The first wavelength conversion unit WLC1 can be disposed in the first light-emitting region LA1 on the first capping layer CAP1. The first wavelength conversion unit WLC1 can be surrounded by the first light-shielding member BK1. The first wavelength conversion unit WLC1 may include the first base resin BS1, the first scatterer SCT1, and the first wavelength shifter WLS1.

[0083] The first base resin BS1 may include substances with relatively high light transmittance. The first base resin BS1 may be formed from a transparent organic substance. For example, the first base resin BS1 may include at least one of the organic substances selected from epoxy resins, acrylic resins, calomel resins, and imide resins.

[0084] The first scatterer SCT1 may have a different refractive index than the first base resin BS1 and may form an optical interface with the first base resin BS1. For example, the first scatterer SCT1 may include a light-scattering material or light-scattering particles that scatter at least a portion of the transmitted light. For example, the first scatterer SCT1 may include materials such as titanium oxide (TiO2), zirconium oxide (ZrO2), and aluminum oxide (Al). x O y The first scatterer SCT1 can scatter light in random directions, independent of the incident light's incident direction, without substantially altering the peak wavelength of the incident light. It may contain metal oxide particles such as indium oxide (In₂O₃), zinc oxide (ZnO), or tin oxide (SnO₂), or organic particles such as acrylic resins or polyurethane resins.

[0085] The first wavelength shifter WLS1 can convert or shift the peak wavelength of the incident light to a first peak wavelength. For example, the first wavelength shifter WLS1 can convert blue light provided from the display device 10 into red light with a single peak wavelength in the range of 610 nm to 650 nm and emit red light. The first wavelength shifter WLS1 can be a quantum dot, a quantum rod, or a phosphor. A quantum dot can be a particulate material that emits a specific color when an electron transitions from the conduction band to the valence band.

[0086] For example, quantum dots can be semiconductor nanocrystal materials. Quantum dots can have specific band gaps depending on their composition and size, thereby emitting light with an inherent wavelength after absorbing light. Examples of semiconductor nanocrystals containing quantum dots can include group IV nanocrystals, group II-VI compound nanocrystals, group III-V compound nanocrystals, group IV-VI compound nanocrystals, or combinations thereof.

[0087] For example, quantum dots can have a core-shell structure, comprising a core including the aforementioned nanocrystals and a shell surrounding the core. The shell of the quantum dot can function as a protective layer to prevent chemical degradation of the core, thus maintaining its semiconductor properties, and as a charging layer to impart electrophoretic properties to the quantum dot. The shell can be single-layered or multi-layered. The core-shell interface can have a concentration gradient where the concentration of elements present in the shell decreases towards the center. The shell of the quantum dot can be formed from metal or non-metal oxides, semiconductor compounds, or combinations thereof.

[0088] The light emitted by the first wavelength shifter WLS1 can have a full width at half maximum (FWHM) of an emission wavelength spectrum below 45 nm, 40 nm, or 30 nm, and can further improve the color purity and color reproducibility of the colors displayed by the display device 10. The light emitted by the first wavelength shifter WLS1 can be emitted in multiple directions regardless of the incident direction of the incident light. Therefore, the lateral visibility of red displayed in the first emitting region LA1 can be improved.

[0089] A portion of the blue light supplied from the light-emitting element layer EML can pass through the first wavelength conversion unit WLC1 without being converted into red light by the first wavelength shifter WLS1. Light from the blue light supplied from the light-emitting element layer EML that is not converted by the first wavelength conversion unit WLC1 and is incident on the first color filter CF1 can be blocked by the first color filter CF1. Furthermore, red light from the blue light supplied from the light-emitting element layer EML that has been converted by the first wavelength conversion unit WLC1 can pass through the first color filter CF1 and exit to the outside. Therefore, the first light-emitting region LA1 can emit red light.

[0090] The second wavelength conversion unit WLC2 can be arranged in the second light-emitting region LA2 on the first capping layer CAP1. The second wavelength conversion unit WLC2 can be surrounded by the first light-shielding member BK1. The second wavelength conversion unit WLC2 may include the second base resin BS2, the second scatterer SCT2, and the second wavelength shifter WLS2.

[0091] The second base resin BS2 may include a substance with relatively high light transmittance. The second base resin BS2 may be formed from a transparent organic substance. For example, the second base resin BS2 may be formed from the same substance as the first base resin BS1, or from a substance illustrated in the description of the first base resin BS1.

[0092] The second scatterer SCT2 may have a different refractive index than the second base resin BS2 and may form an optical interface with the second base resin BS2. For example, the second scatterer SCT2 may include a light-scattering material or light-scattering particles that scatter at least a portion of the transmitted light. For example, the second scatterer SCT2 may be formed of the same material as the first scatterer SCT1, or of the material illustrated in the description of the first scatterer SCT1. The second scatterer SCT2 may scatter light in random directions, independent of the incident direction, without substantially changing the peak wavelength of the incident light.

[0093] The second wavelength shifter WLS2 can convert or shift the peak wavelength of the incident light to a second peak wavelength different from the first peak wavelength of the first wavelength shifter WLS1. For example, the second wavelength shifter WLS2 can convert blue light provided from the display device 10 into green light having a single peak wavelength in the range of 510 nm to 550 nm and emit green light. The second wavelength shifter WLS2 can be a quantum dot, a quantum rod, or a phosphor. The second wavelength shifter WLS2 can include the same material as illustrated in the description of the first wavelength shifter WLS1. The second wavelength shifter WLS2 can be formed from quantum dots, quantum rods, or phosphors such that the wavelength conversion range of the second wavelength shifter WLS2 is different from the wavelength conversion range of the first wavelength shifter WLS1.

[0094] The light-transmitting portion LTU can be disposed in the third light-emitting region LA3 on the first capping layer CAP1. The light-transmitting portion LTU can be surrounded by the first light-shielding member BK1. The light-transmitting portion LTU can maintain the peak wavelength of the incident light and transmit the incident light. The light-transmitting portion LTU may include a third base resin BS3 and a third diffuser SCT3.

[0095] The third base resin BS3 may include a substance with relatively high light transmittance. The third base resin BS3 may be formed from a transparent organic substance. For example, the third base resin BS3 may be formed from the same substance as the first base resin BS1 or the second base resin BS2, or from the substance illustrated in the description of the first base resin BS1 or the second base resin BS2.

[0096] The third scatterer SCT3 may have a different refractive index than the third base resin BS3 and may form an optical interface with the third base resin BS3. For example, the third scatterer SCT3 may include a light-scattering material or light-scattering particles that scatter at least a portion of the transmitted light. For example, the third scatterer SCT3 may be formed of the same material as the first scatterer SCT1 or the second scatterer SCT2, or of the material illustrated in the description of the first scatterer SCT1 or the second scatterer SCT2. The third scatterer SCT3 may scatter light in random directions, independent of the incident direction, without substantially changing the peak wavelength of the incident light.

[0097] The wavelength conversion layer WLCL can be directly disposed on the first planarization layer 41 of the light-emitting element layer EML, so that the display device 10 does not require an additional substrate for the first wavelength conversion section WLC1, the second wavelength conversion section WLC2, and the light-transmitting section LTU. Therefore, the first wavelength conversion section WLC1, the second wavelength conversion section WLC2, and the light-transmitting section LTU can be easily aligned with each of the first light-emitting region LA1, the second light-emitting region LA2, and the third light-emitting region LA3, and the thickness of the display device 10 can be relatively reduced.

[0098] The second capping layer CAP2 may cover the first wavelength conversion section WLC1, the second wavelength conversion section WLC2, the light-transmitting section LTU, and the first light-shielding member BK1. For example, the second capping layer CAP2 may seal the first wavelength conversion section WLC1, the second wavelength conversion section WLC2, and the light-transmitting section LTU to prevent damage or contamination to these components. The second capping layer CAP2 may be formed of the same material as the first capping layer CAP1, or of the material illustrated in the description of the first capping layer CAP1.

[0099] The second planarization layer 43 can be disposed on the upper part of the second capping layer CAP2, thereby planarizing the upper ends of the first wavelength conversion section WLC1, the second wavelength conversion section WLC2, and the light-transmitting section LTU. The second planarization layer 43 may include an organic material. For example, the second planarization layer 43 may include at least one of acrylic resin, epoxy resin, phenolic resin, polyamide resin, and polyimide resin.

[0100] The color filter layer CFL may include a second light-shielding component BK2, a first color filter CF1, a second color filter CF2 and a third color filter CF3, and a protective layer PRT.

[0101] The second light-shielding component BK2 can be disposed on the second planarization layer 43 of the wavelength conversion layer WLCL within the first light-shielding region BA1, the second light-shielding region BA2, and the third light-shielding region BA3. The second light-shielding component BK2 can overlap with the first light-shielding component BK1 or the second pattern BNL2 in the thickness direction. The second light-shielding component BK2 can block light transmission. The second light-shielding component BK2 can prevent light from entering between the first light-emitting region LA1, the second light-emitting region LA2, and the third light-emitting region LA3 and causing color mixing, thereby improving color reproducibility. The second light-shielding component BK2 can be arranged in a grid shape surrounding the first light-emitting region LA1, the second light-emitting region LA2, and the third light-emitting region LA3 on a plane.

[0102] A first color filter CF1 can be disposed in a first light-emitting region LA1 on the second planarization layer 43. The first color filter CF1 can be surrounded by a second light-shielding member BK2. The first color filter CF1 can overlap with the first wavelength conversion section WLC1 in the thickness direction. The first color filter CF1 can selectively transmit light of a first color (e.g., red light) and block or absorb light of a second color (e.g., green light) and a third color (e.g., blue light). For example, the first color filter CF1 can be a red color filter and can include a red colorant. The red colorant can be formed from a red dye or a red pigment.

[0103] The second color filter CF2 can be disposed in the second light-emitting region LA2 on the second planarization layer 43. The second color filter CF2 can be surrounded by the second light-shielding member BK2. The second color filter CF2 can overlap with the second wavelength conversion section WLC2 in the thickness direction. The second color filter CF2 can selectively transmit light of a second color (e.g., green light) and block or absorb light of a first color (e.g., red light) and a third color (e.g., blue light). For example, the second color filter CF2 can be a green color filter and can include a green colorant. The green colorant can be formed from a green dye or a green pigment.

[0104] A third color filter CF3 can be disposed in the third light-emitting region LA3 on the second planarization layer 43. The third color filter CF3 can be surrounded by the second light-shielding member BK2. The third color filter CF3 can overlap with the light-transmitting portion LTU in the thickness direction. The third color filter CF3 can selectively transmit light of a third color (e.g., blue light) and block or absorb light of a first color (e.g., red light) and a second color (e.g., green light). For example, the third color filter CF3 can be a blue color filter and can include a blue colorant. The blue colorant can be formed from blue dye or blue pigment.

[0105] The first color filter CF1, the second color filter CF2, and the third color filter CF3 can absorb a portion of the light flowing in from the outside of the display device 10, thereby reducing reflected light caused by external light. Therefore, the first color filter CF1, the second color filter CF2, and the third color filter CF3 can prevent color distortion caused by the reflection of external light.

[0106] The first color filter CF1, the second color filter CF2, and the third color filter CF3 can be directly disposed on the second planarization layer 43 of the wavelength conversion layer WLCL, so that the display device 10 does not require an additional substrate for the first color filter CF1, the second color filter CF2, and the third color filter CF3. Therefore, the thickness of the display device 10 can be relatively reduced.

[0107] The protective layer PRT can cover the first color filter CF1, the second color filter CF2, and the third color filter CF3. The protective layer PRT can protect the first color filter CF1, the second color filter CF2, and the third color filter CF3.

[0108] The encapsulation layer TFE can be disposed on the protective layer PRT of the color filter layer CFL. The encapsulation layer TFE can cover the upper and side surfaces of the display layer. For example, the encapsulation layer TFE may include at least one inorganic film to prevent oxygen or moisture penetration. Furthermore, the encapsulation layer TFE may include at least one organic film to protect the display device 10 from foreign substances such as dust. For example, the encapsulation layer TFE may be formed by a structure in which at least one organic film is laminated between two inorganic films. The inorganic films may include silicon nitrides, aluminum nitrides, zirconium nitrides, titanium nitrides, hafnium nitrides, tantalum nitrides, silicon oxides, aluminum oxides, titanium oxides, tin oxides, cerium oxides, silicon nitrides, lithium fluorides, etc. The organic films may include acrylic resins, methacrylic resins, polyisoprene, vinyl resins, epoxy resins, polyurethane resins, cellulose resins, and dinaphthalene-based resins, etc. However, the structure of the encapsulation layer TFE is not limited to the examples described above, and the laminated structure can be varied.

[0109] Hereinafter, the transistor layer TFTL and the light-emitting element layer EML will be described in detail by means of the planar structure and cross-sectional structure of a pixel of a display device according to an embodiment.

[0110] Figure 3 This is a plan view showing a pixel of a display device according to an embodiment.

[0111] Reference Figure 3 Each of a plurality of pixels PX can include a plurality of subpixels SPXn (n is an integer from 1 to 3). For example, a pixel PX can include a first subpixel SPX1, a second subpixel SPX2, and a third subpixel SPX3. The first subpixel SPX1 can emit light of a first color, the second subpixel SPX2 can emit light of a second color, and the third subpixel SPX3 can emit light of a third color. As an example, the first color can be blue, the second color can be green, and the third color can be red. However, it is not limited to this, and each subpixel SPXn (SPX1, SPX2, SPX3) can also emit light of the same color. Furthermore, although in Figure 3 The example illustrates that pixel PX comprises three sub-pixels SPXn, but is not limited to this, and pixel PX may include a greater number of sub-pixels SPXn.

[0112] Each sub-pixel SPXn of the display device 10 may include a light-emitting region EMA and a non-light-emitting region (not shown). The light-emitting region EMA may be a region where a light-emitting element 30 is arranged so that light of a specific wavelength band is emitted, and the non-light-emitting region may be a region where no light-emitting element 30 is arranged and where light does not emit because the light emitted from the light-emitting element 30 does not reach it. The light-emitting region EMA may include a region where a light-emitting element 30 is arranged, and includes a region where light emitted from the light-emitting element 30 is emitted as a region adjacent to the light-emitting element 30.

[0113] However, this is not the only limitation; the light-emitting region EMA may also include the area where light emitted from the light-emitting element 30 is reflected or refracted by other components. Multiple light-emitting elements 30 may be arranged in each sub-pixel SPXn, and may include the area where they are arranged and the area adjacent to them to form a light-emitting region.

[0114] Furthermore, each sub-pixel SPXn may include a cut-out region CBA disposed in a non-light-emitting area. The cut-out region CBA may be disposed on one side of the light-emitting region EMA in the second direction DR2. The cut-out region CBA may be disposed between the light-emitting regions EMA of adjacent sub-pixels SPXn in the second direction DR2. A plurality of light-emitting regions EMA and cut-out regions CBA may be arranged in the display area DPA of the display device 10. For example, the plurality of light-emitting regions EMA and cut-out regions CBA may be repeatedly arranged in the first direction DR1, and the light-emitting regions EMA and cut-out regions CBA may be alternately arranged in the second direction DR2. Furthermore, the spacing between the cut-out regions CBA in the first direction DR1 may be smaller than the spacing between the light-emitting regions EMA in the first direction DR1. A second pattern BNL2 may be disposed between the cut-out regions CBA and the light-emitting regions EMA, and the spacing between them may vary according to the width of the second pattern BNL2. The cut-out regions CBA do not have light-emitting elements 30 disposed thereon so that no light is emitted, but may have a portion of electrodes 21, 22 disposed in each sub-pixel SPXn. Electrodes 21 and 22 arranged in each sub-pixel SPXn can be arranged separately from each other in the cut region CBA.

[0115] Figure 4 It is along Figure 3 The sectional views taken from lines Q1-Q1', Q2-Q2', and Q3-Q3'. Figure 4 It shows the transverse arrangement in Figure 3 The cross-section of the two ends of the light-emitting element 30 in the first sub-pixel SPX1.

[0116] Combination Figure 3 Reference Figure 4The display device 10 may include a substrate 11 and a semiconductor layer, a plurality of conductive layers, and a plurality of insulating layers disposed on the substrate 11. The semiconductor layer, conductive layer, and insulating layer may respectively constitute the circuit layer and the light-emitting element layer of the display device 10.

[0117] A light-shielding layer BML can be disposed on the substrate 11. The light-shielding layer BML can be disposed to overlap with the active layer ACT of the first transistor T1 of the display device 10. The light-shielding layer BML may include a light-blocking material, thereby preventing light from incident on the active layer ACT of the first transistor T1. For example, the light-shielding layer BML may be formed of an opaque metallic material that blocks light transmission. However, it is not limited to this, and depending on the situation, the light-shielding layer BML may be omitted. In addition, the light-shielding layer BML may also be electrically connected to the source electrode SE, thereby suppressing voltage changes in the transistor. Furthermore, the light-shielding layer BML may also be used as wiring (e.g., power wiring, data wiring, or gate wiring, etc.).

[0118] The buffer layer 12 may include a light-shielding layer BML and be disposed entirely on the substrate 11. The buffer layer 12 may be formed on the substrate 11 to protect the first transistor T1 of the pixel PX from moisture that may permeate through the moisture-permeable substrate 11, and to perform a surface planarization function. The buffer layer 12 may be formed of multiple inorganic layers stacked alternately. For example, the buffer layer 12 may be composed of silicon oxide (SiO2). x ), silicon nitride (SiN) x ), silicon nitride oxide (SiO) x N y Multilayer formation of at least any one of the inorganic layers in ) alternatingly stacked.

[0119] Semiconductor layers may be disposed on buffer layer 12. Semiconductor layers may include the active layer ACT of the first transistor T1. They may be arranged to partially overlap with the gate electrode G1 of the first gate conductive layer described below.

[0120] Furthermore, although only the first transistor T1 of the transistors included in the sub-pixel SPXn of the display device 10 is shown in the accompanying drawings, it is not limited thereto. The display device 10 may include a greater number of transistors. For example, in addition to the first transistor T1, the sub-pixel SPXn of the display device 10 may also include more than one transistor, thereby including two or three transistors.

[0121] The semiconductor layer may include polycrystalline silicon, monocrystalline silicon, oxide semiconductors, etc. When the semiconductor layer includes an oxide semiconductor, each active layer ACT may include multiple conductive regions ACTa, ACTb, and a channel region ACTc between them. The aforementioned oxide semiconductor may be an indium (In)-containing oxide semiconductor. For example, the aforementioned oxide semiconductor may be indium-tin oxide (ITO), indium-zinc oxide (IZO), indium-gallium oxide (IGO), indium-zinc-tin oxide (IZTO), indium-gallium-tin oxide (IGTO), indium-gallium-zinc oxide (IGZO), indium-gallium-zinc-tin oxide (IGZTO), etc.

[0122] In another embodiment, the semiconductor layer may also comprise polycrystalline silicon. Polycrystalline silicon can be formed by crystallizing amorphous silicon, and in this case, the conductive regions of the active layer ACT can be doped regions doped with impurities.

[0123] A gate insulating layer 13 may be disposed on the semiconductor layer and the buffer layer 12. The gate insulating layer 13 may include a semiconductor layer and be disposed on the buffer layer 12. The gate insulating layer 13 may perform the function of the gate insulating film of each transistor. The gate insulating layer 13 may be made of inorganic materials (e.g., silicon oxide (SiO2)). x ), silicon nitride (SiN) x ), silicon nitride oxide (SiO) x N y Inorganic layers are formed, or they can be formed by stacking layers of them.

[0124] The first conductive layer may be disposed on the gate insulating layer 13. The first conductive layer may include the gate electrode G1 of the first transistor T1. The gate electrode G1 may be arranged to overlap with the channel region ACTc of the active layer ACT in the thickness direction. The first conductive layer may be formed of a single layer or multiple layers of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu) or their alloys. However, it is not limited thereto.

[0125] An interlayer insulating layer 15 may be disposed on the first conductive layer. The interlayer insulating layer 15 may function as an insulating film between the first conductive layer and other layers disposed thereon. Furthermore, the interlayer insulating layer 15 may be arranged to cover the first conductive layer, thereby performing the function of protecting the first conductive layer. The interlayer insulating layer 15 may be made of inorganic materials (e.g., silicon oxide (SiO2)). x ), silicon nitride (SiN) x ), silicon nitride oxide (SiO) x N y Inorganic layers are formed, or they can be formed by stacking layers of them.

[0126] The second conductive layer may be disposed on the interlayer insulating layer 15. The second conductive layer may include the source electrode SE and the drain electrode DE of the first transistor T1.

[0127] The source electrode SE and drain electrode DE of the first transistor T1 can contact the doped regions ACTa and ACTb of the active layer ACT, respectively, through contact holes that penetrate the interlayer insulating layer 15 and the gate insulating layer 13. Furthermore, the source electrode SE of the first transistor T1 can be electrically connected to the light-shielding layer BML through another contact hole.

[0128] Furthermore, the second conductive layer may include a first voltage wiring VL1, a second voltage wiring VL2, and a first conductive pattern CDP. A high potential voltage (or a first power supply voltage) supplied to the first transistor T1 may be applied to the first voltage wiring VL1, and a low potential voltage (or a second power supply voltage) supplied to the second electrode 22 may be applied to the second voltage wiring VL2. Additionally, in the manufacturing process of the display device 10, alignment signals required for aligning the light-emitting element 30 may also be applied to the second voltage wiring VL2.

[0129] The first conductive pattern CDP can be integrated with the source electrode SE of the first transistor T1, and the first conductive pattern CDP can be electrically connected to the source electrode SE. The first conductive pattern CDP can also contact the first electrode 21 described below, and the first transistor T1 can transmit the first power supply voltage applied from the first voltage wiring VL1 to the first electrode 21 through the first conductive pattern CDP. Furthermore, although the second conductive layer is shown in the figures as including one second voltage wiring VL2 and one first voltage wiring VL1, it is not limited thereto. The second conductive layer can include a greater number of first voltage wirings VL1 and second voltage wirings VL2. However, it is not limited thereto; the first conductive layer can also function as a signal for transmitting power supply voltage, etc., and in this case, the second conductive layer can be omitted.

[0130] The second conductive layer can be formed of a single layer or multiple layers of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu) or their alloys. However, it is not limited to this.

[0131] The via layer 17 can be disposed on the second conductive layer. The via layer 17 may include an organic insulating material (e.g., an organic material such as polyimide (PI)) and perform a surface planarization function.

[0132] Multiple first patterns BNL1, multiple electrodes 21 and 22, light-emitting elements 30, multiple connecting electrodes CNE1 and CNE2, and a second pattern BNL2 can be arranged on the via layer 17. In addition, multiple insulating layers PAS1, PAS2, PAS3, and PAS4 can be arranged on the via layer 17.

[0133] Multiple first patterns BNL1 can be directly arranged on the via layer 17. The multiple first patterns BNL1 can have a shape extending in the second direction DR2 within each sub-pixel SPXn, and the multiple first patterns BNL1 may not extend to other adjacent sub-pixels SPXn in the second direction DR2, and can be arranged in the light-emitting area EMA. Furthermore, the multiple first patterns BNL1 can be arranged spaced apart from each other in the first direction DR1, and light-emitting elements 30 can be arranged between them. The multiple first patterns BNL1 can be arranged in each sub-pixel SPXn, thereby forming a linear pattern in the display area DPA of the display device 10. Although two first patterns BNL1 are shown in the figures, the arrangement is not limited to this. A greater number of first patterns BNL1 can be arranged depending on the number of electrodes 21, 22.

[0134] The first pattern BNL1 may have a structure in which at least a portion protrudes from the upper surface of the via layer 17. The protruding portion of the first pattern BNL1 may have inclined side surfaces, and light emitted from the light-emitting element 30 may be reflected from the electrodes 21, 22 disposed on the first pattern BNL1 and emitted towards the upper direction of the via layer 17. The first pattern BNL1 may function as a reflective partition reflecting light emitted from the light-emitting element 30 towards the upper direction while providing an area for arranging the light-emitting element 30. The side surfaces of the first pattern BNL1 may be inclined in a linear shape, but are not limited thereto, and the first pattern BNL1 may also have a semi-circular or semi-elliptical shape with a curved outer surface. The first pattern BNL1 may include, but is not limited to, an organic insulating material such as polyimide (PI).

[0135] Multiple electrodes 21, 22 may be arranged on the first pattern BNL1 and the via layer 17. The multiple electrodes 21, 22 may include a first electrode 21 and a second electrode 22. The first electrode 21 and the second electrode 22 may extend in the second direction DR2, and the first electrode 21 and the second electrode 22 may be arranged to be spaced apart from each other in the first direction DR1.

[0136] The first electrode 21 and the second electrode 22 extend in the sub-pixel SPXn along the second direction DR2, respectively, and the first electrode 21 and the second electrode 22 can be separated from other electrodes 21 and 22 in the cut-out region CBA. For example, a cut-out region CBA is arranged between the light-emitting regions EMA of adjacent sub-pixels SPXn along the second direction DR2, and the first electrode 21 and the second electrode 22 can be separated in the cut-out region CBA from other first electrodes 21 and second electrodes 22 arranged in adjacent sub-pixels SPXn along the second direction DR2. However, this is not a limitation; some electrodes 21 and 22 may not be separated in each sub-pixel SPXn and may extend across adjacent sub-pixels SPXn along the second direction DR2, or only one of the first electrodes 21 and the second electrode 22 may be separated.

[0137] The first electrode 21 can be electrically connected to the first transistor T1 through the first contact hole CT1, and the second electrode 22 can be electrically connected to the second voltage wiring VL2 through the second contact hole CT2. For example, the first electrode 21 can contact the first conductive pattern CDP through the first contact hole CT1, wherein the first contact hole CT1 penetrates the via layer 17 in the portion of the second pattern BNL2 extending in the first direction DR1. The second electrode 22 can also contact the second voltage wiring VL2 through the second contact hole CT2, wherein the second contact hole CT2 penetrates the via layer 17 in the portion of the second pattern BNL2 extending in the first direction DR1. However, this is not the only possibility. In another embodiment, the first contact hole CT1 and the second contact hole CT2 can also be arranged in the light-emitting region EMA surrounded by the second pattern BNL2, so as not to overlap with the second pattern BNL2.

[0138] Although the accompanying drawings illustrate one first electrode 21 and one second electrode 22 arranged in each sub-pixel SPXn, this is not a limitation, and the number of first electrodes 21 and second electrodes 22 arranged in each sub-pixel SPXn can be greater. Furthermore, the first electrodes 21 and second electrodes 22 arranged in each sub-pixel SPXn do not necessarily have a shape extending in one direction, and the first electrodes 21 and second electrodes 22 can be arranged in various structures. For example, the first electrode 21 and second electrode 22 can have a partially bent or folded shape, and either electrode can be arranged to surround the other electrode.

[0139] The first electrode 21 and the second electrode 22 can be directly disposed on the first pattern BNL1. The first electrode 21 and the second electrode 22 can be formed to have a width larger than the first pattern BNL1. For example, the first electrode 21 and the second electrode 22 can be disposed to cover the outer surface of the first pattern BNL1. The first electrode 21 and the second electrode 22 can be disposed on the side surface of the first pattern BNL1, and the spacing between the first electrode 21 and the second electrode 22 can be narrower than the spacing between the first patterns BNL1. Furthermore, at least a portion of the first electrode 21 and the second electrode 22 can be disposed directly on the via layer 17 so as to be disposed on the same plane. However, this is not a limitation. Depending on the situation, the width of each electrode 21, 22 can also be smaller than the first pattern BNL1. However, each electrode 21, 22 can be disposed to at least cover one side surface of the first pattern BNL1, thereby reflecting the light emitted from the light-emitting element 30.

[0140] Each electrode 21, 22 may include a conductive material with high reflectivity. For example, as a material with high reflectivity, each electrode 21, 22 may include metals such as silver (Ag), copper (Cu), aluminum (Al), or alloys including aluminum (Al), nickel (Ni), lanthanum (La), etc. Each electrode 21, 22 may reflect light emitted from the light-emitting element 30 and traveling in parallel to the side surface of the first pattern BNL1 towards the upper direction of each sub-pixel SPXn.

[0141] However, this is not the only possibility; each electrode 21, 22 may also include a transparent conductive material. For example, each electrode 21, 22 may include materials such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), or ITZO (Indium Tin-Zinc Oxide). In some embodiments, each electrode 21, 22 may form a structure in which a transparent conductive material and a highly reflective metal layer are stacked in more than one layer, or it may include a transparent conductive material and a highly reflective metal layer in a single layer. For example, each electrode 21, 22 may have a stacked structure such as ITO / silver (Ag) / ITO, ITO / Ag / IZO, or ITO / Ag / ITZO / IZO.

[0142] Multiple electrodes 21 and 22 can be electrically connected to the light-emitting element 30, and a predetermined voltage can be applied to the multiple electrodes 21 and 22 to make the light-emitting element 30 emit light. The multiple electrodes 21 and 22 can be electrically connected to the light-emitting element 30 through connecting electrodes CNE1 and CNE2, and the electrical signals applied to the electrodes 21 and 22 can be transmitted to the light-emitting element 30 through the connecting electrodes CNE1 and CNE2.

[0143] Either the first electrode 21 or the second electrode 22 can be electrically connected to the anode electrode of the light-emitting element 30, and the other can be electrically connected to the cathode electrode of the light-emitting element 30. However, this is not a limitation, and the opposite can also be true.

[0144] Furthermore, electrodes 21 and 22 can also be used to form an electric field in the sub-pixel SPXn to align the light-emitting element 30. The light-emitting element 30 can be arranged between the first electrode 21 and the second electrode 22 by means of the electric field formed on the first electrode 21 and the second electrode 22. The light-emitting element 30 of the display device 10 can be jetted onto the electrodes 21 and 22 by an inkjet printing process. When ink including the light-emitting element 30 is jetted onto the electrodes 21 and 22, an alignment signal is applied to the electrodes 21 and 22 to generate an electric field. The light-emitting element 30 dispersed in the ink can be aligned on the electrodes 21 and 22 by being subjected to dielectric electrophoretic force by the electric field generated on the electrodes 21 and 22.

[0145] The first insulating layer PAS1 can be disposed on the via layer 17. The first insulating layer PAS1 can be arranged to cover the first pattern BNL1 and the first electrode 21 and the second electrode 22. The first insulating layer PAS1 can protect the first electrode 21 and the second electrode 22 while insulating them from each other. In addition, it can also prevent the light-emitting element 30 disposed on the first insulating layer PAS1 from being damaged by direct contact with other components.

[0146] In one embodiment, the first insulating layer PAS1 may include openings OP that partially expose the first electrode 21 and the second electrode 22. Each opening OP may partially expose a portion of each electrode 21, 22 disposed on the upper surface of the first pattern BNL1. A portion of the connecting electrodes CNE1, CNE2 may contact the electrodes 21, 22 exposed through the openings OP.

[0147] The first insulating layer PAS1 can be formed into a step, such that a portion of its upper surface is recessed between the first electrode 21 and the second electrode 22. For example, since the first insulating layer PAS1 is arranged to cover the first electrode 21 and the second electrode 22, the upper surface of the first insulating layer PAS1 can be formed into a step according to the shape of the electrodes 21 and 22 arranged below the first insulating layer PAS1. However, it is not limited to this.

[0148] The second pattern BNL2 can be arranged on the first insulating layer PAS1. The second pattern BNL2 can include portions extending in the first direction DR1 and the second direction DR2 in a plane, thereby arranging it as a grid pattern on the entire surface of the display area DPA. The second pattern BNL2 can be arranged across the boundaries of each sub-pixel SPXn, thereby distinguishing adjacent sub-pixels SPXn.

[0149] Furthermore, the second pattern BNL2 can be arranged to surround the light-emitting region EMA and the cut-out region CBA arranged in each sub-pixel SPXn, thereby distinguishing the light-emitting region EMA and the cut-out region CBA. The first electrode 21 and the second electrode 22 can extend in the second direction DR2 and pass through the portion of the second pattern BNL2 that extends in the first direction DR1. In the portion of the second pattern BNL2 that extends in the second direction DR2, the portion arranged between the light-emitting regions EMA can have a larger width than the portion arranged between the cut-out regions CBA. Therefore, the spacing between the cut-out regions CBA can be smaller than the spacing between the light-emitting regions EMA.

[0150] The second pattern BNL2 can be formed to have a greater height than the first pattern BNL1. The second pattern BNL2 prevents ink from overflowing into adjacent sub-pixels SPXn during the inkjet printing process in the manufacturing process of the display device 10, thereby separating the ink containing the different light-emitting elements 30 in each different sub-pixel SPXn so that they do not mix with each other. The second pattern BNL2 may include polyimide (PI) like the first pattern BNL1, but is not limited to this.

[0151] The light-emitting element 30 can be arranged on the first insulating layer PAS1. Multiple light-emitting elements 30 can be arranged spaced apart from each other along the second direction DR2 extending from each electrode 21, 22, and can be substantially parallel to each other. The light-emitting element 30 can have a shape extending in one direction, and the direction of extension of each electrode 21, 22 can be substantially perpendicular to the direction of extension of the light-emitting element 30. However, it is not limited to this; the light-emitting element 30 can also be arranged at an angle, not perpendicular to the direction of extension of each electrode 21, 22.

[0152] The light-emitting elements 30 arranged in each sub-pixel SPXn may include light-emitting layers containing different materials from each other. Figure 5 The "36" in the image emits light of different wavelengths to the outside. Therefore, light of the first color, the second color, and the third color can be emitted from the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3, respectively. However, this is not a limitation; each sub-pixel SPXn may also include the same type of light-emitting element 30, thereby emitting light of substantially the same color.

[0153] The two ends of the light-emitting element 30 can be arranged on each of the electrodes 21 and 22 between the first pattern BNL1. The extended length of the light-emitting element 30 can be longer than the distance between the first electrode 21 and the second electrode 22, and the two ends of the light-emitting element 30 can be arranged on the first electrode 21 and the second electrode 22, respectively. For example, the light-emitting element 30 can be arranged such that one end is placed on the first electrode 21 and the other end is placed on the second electrode 22.

[0154] In the light-emitting element 30, multiple layers may be arranged in a direction perpendicular to the upper surface of the substrate 11 or the via layer 17. The light-emitting element 30 may be arranged such that one direction extends parallel to the upper surface of the via layer 17, and the multiple semiconductor layers included in the light-emitting element 30 may be arranged sequentially along a direction parallel to the upper surface of the via layer 17. However, it is not limited to this; when the light-emitting element 30 has different structures, the multiple semiconductor layers may also be arranged in a direction perpendicular to the upper surface of the via layer 17.

[0155] The two ends of the light-emitting element 30 can respectively contact the connecting electrodes CNE1 and CNE2. For example, an insulating film may not be formed on the surface of the end of the light-emitting element 30 extending in one direction. Figure 5 The “38”), and the exposed semiconductor layer ( Figure 5 (31 and 32) or electrode layer ( Figure 5 Part of “37”), and the aforementioned exposed semiconductor layer ( Figure 5 (31 and 32) or electrode layer ( Figure 5 The “37” of the light-emitting element 30 can contact the connecting electrodes CNE1 and CNE2. However, it is not limited to this; at least a portion of the insulating film 38 of the light-emitting element 30 can be removed, so that the semiconductor layer ( Figure 5 The two end surfaces of “31” and “32” are partially exposed. The exposed semiconductor layer ( Figure 5 The side surfaces of “31” and “32” can also be in direct contact with the connecting electrodes CNE1 and CNE2.

[0156] The second insulating layer PAS2 can be partially disposed on the light-emitting element 30. For example, the second insulating layer PAS2 can surround the light-emitting element 30 while having a width smaller than the length of the light-emitting element 30, thus exposing both ends of the light-emitting element 30, and is disposed on the light-emitting element 30. In the manufacturing process of the display device 10, the second insulating layer PAS2 can be arranged such that it covers the light-emitting element 30, electrodes 21, 22, and the first insulating layer PAS1 before being removed, thus exposing both ends of the light-emitting element 30. The second insulating layer PAS2 can be disposed on a plane extending along the second direction DR2 on the first insulating layer PAS1, thereby forming a linear pattern or an island pattern in each sub-pixel SPXn. The second insulating layer PAS2 can protect the light-emitting element 30 while fixing the light-emitting element 30 in the manufacturing process of the display device 10.

[0157] Multiple connecting electrodes CNE1, CNE2 and a third insulating layer PAS3 can be arranged on the second insulating layer PAS2.

[0158] Multiple connecting electrodes CNE1 and CNE2 may have a shape extending in one direction and are arranged on each electrode 21 and 22. Connecting electrodes CNE1 and CNE2 may include a first connecting electrode CNE1 arranged on the first electrode 21 and a second connecting electrode CNE2 arranged on the second electrode 22. The connecting electrodes CNE1 and CNE2 may be spaced apart from each other or arranged opposite each other. For example, the first connecting electrode CNE1 and the second connecting electrode CNE2 may be arranged on the first electrode 21 and the second electrode 22 respectively, thus being spaced apart from each other in the first direction DR1. Each connecting electrode CNE1 and CNE2 may form a striped pattern in the light-emitting area EMA of each sub-pixel SPXn.

[0159] Multiple connecting electrodes CNE1 and CNE2 can each contact the light-emitting element 30. The first connecting electrode CNE1 can contact one end of the light-emitting element 30, and the second connecting electrode CNE2 can contact the other end of the light-emitting element 30. The light-emitting element 30 can expose a semiconductor layer at both end surfaces in its extending direction, and each connecting electrode CNE1 and CNE2 can contact the semiconductor layer of the light-emitting element 30 to achieve electrical connection. The sides of the connecting electrodes CNE1 and CNE2 that contact the two ends of the light-emitting element 30 can be disposed on the second insulating layer PAS2. Furthermore, the first connecting electrode CNE1 can contact the first electrode 21 through an opening OP exposing a portion of the upper surface of the first electrode 21, and the second connecting electrode CNE2 can contact the second electrode 22 through an opening OP exposing a portion of the upper surface of the second electrode 22.

[0160] The width of each connecting electrode CNE1, CNE2, measured in one direction, may be smaller than the width of electrodes 21, 22, measured in the aforementioned one direction. Connecting electrodes CNE1, CNE2 may be arranged to cover a portion of the upper surface of the first electrode 21 and the second electrode 22 while respectively contacting one end and the other end of the light-emitting element 30. However, this is not a limitation; connecting electrodes CNE1, CNE2 may also be formed with a width larger than electrodes 21, 22, thereby covering both sides of electrodes 21, 22.

[0161] The connecting electrodes CNE1 and CNE2 may include transparent conductive materials. For example, they may include ITO, IZO, ITZO, aluminum (Al), etc. Light emitted from the light-emitting element 30 can pass through the connecting electrodes CNE1 and CNE2 and travel toward electrodes 21 and 22. However, it is not limited to this.

[0162] Although the accompanying drawings show two connecting electrodes CNE1 and CNE2 arranged in a sub-pixel SPXn, the arrangement is not limited thereto. The number of each connecting electrode CNE1 and CNE2 can vary depending on the number of electrodes 21 and 22 arranged in each sub-pixel SPXn.

[0163] The third insulating layer PAS3 can be arranged to cover the first connecting electrode CNE1. The third insulating layer PAS3 can also be arranged to cover the side of the first connecting electrode CNE1, which is arranged with reference to the second insulating layer PAS2, including the first connecting electrode CNE. For example, the third insulating layer PAS3 can be arranged to cover both the first connecting electrode CNE1 and the first insulating layer PAS1 arranged on the first electrode 21. Such an arrangement can be formed by partially removing the insulating material layer after the insulating material layer constituting the third insulating layer PAS3 has been fully arranged in the light-emitting region EMA, in order to form the second connecting electrode CNE2. In this process, the insulating material layer constituting the third insulating layer PAS3 can be removed together with the insulating material layer constituting the second insulating layer PAS2, and one side of the third insulating layer PAS3 can be aligned with one side of the second insulating layer PAS2. One side of the second connecting electrode CNE2 can be arranged on the third insulating layer PAS3, and the second connecting electrode CNE2 can be insulated from the first connecting electrode CNE1 through the third insulating layer PAS3.

[0164] The fourth insulating layer, PAS4, can be fully disposed within the display area DPA of the substrate 11. The fourth insulating layer, PAS4, functions to protect the components disposed on the substrate 11 from the influence of the external environment. However, the fourth insulating layer, PAS4, can also be omitted.

[0165] Each of the aforementioned first insulating layer PAS1, second insulating layer PAS2, third insulating layer PAS3, and fourth insulating layer PAS4 may comprise an inorganic insulating material or an organic insulating material. For example, the first insulating layer PAS1, second insulating layer PAS2, third insulating layer PAS3, and fourth insulating layer PAS4 may comprise materials such as silicon oxide (SiO2). x ), silicon nitride (SiN) x ), silicon nitride oxide (SiO) x N y ), aluminum oxide (Al) x O y Inorganic insulating materials such as aluminum nitride (AlN) can be used. Alternatively, these insulating layers can include organic insulating materials such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene resin, polyphenylene sulfide resin, benzocyclobutene, cationic cyclohexane resin, siloxane resin, silsesquioxane resin, polymethyl methacrylate, polycarbonate, and polymethyl methacrylate-polycarbonate synthetic resin. However, these are not the only options available.

[0166] Figure 5 This is a schematic diagram of a light-emitting element according to one embodiment.

[0167] Reference Figure 5 The aforementioned light-emitting element 30 can be a granular element and can be a rod or cylindrical shape with a predetermined aspect ratio. The light-emitting element 30 can have a size ranging from nanometer (1 nm to 1 μm) to micrometer (1 μm to 1 mm). In one embodiment, both the diameter and length of the light-emitting element 30 can be nanometer-sized, or both can be micrometer-sized. In some other embodiments, the diameter of the light-emitting element 30 can be nanometer-sized, while the length of the light-emitting element 30 can be micrometer-sized. In some embodiments, some light-emitting elements 30 may have a diameter and / or length of nanometer-sized, while others may have a diameter and / or length of micrometer-sized.

[0168] In one embodiment, the light-emitting element 30 may be an inorganic light-emitting diode. Specifically, the light-emitting element 30 may include a semiconductor layer doped with impurities of any conductivity type (e.g., p-type or n-type). The semiconductor layer may receive electrical signals applied from an external power source and emit the electrical signals as light of a specific wavelength band.

[0169] According to one embodiment, the light-emitting element 30 may include a first semiconductor layer 31, a light-emitting layer 36, a second semiconductor layer 32, and an electrode layer 37 stacked sequentially in the longitudinal direction. The light-emitting element 30 may also include an insulating film 38 surrounding the outer surfaces of the first semiconductor layer 31, the second semiconductor layer 32, and the light-emitting layer 36.

[0170] The first semiconductor layer 31 may be an n-type semiconductor. When the light-emitting element 30 emits light in the blue wavelength band, the first semiconductor layer 31 may include materials with the chemical formula Al. x Ga y In 1-x-y The semiconductor material is N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). For example, it can be any one or more of AlGaInN, GaN, AlGaN, InGaN, AlN, and InN doped with n-type dopant. The first semiconductor layer 31 can be doped with an n-type dopant, and the n-type dopant can be Si, Ge, Se, Sn, etc. For example, the first semiconductor layer 31 can be n-GaN doped with n-type Si. The length of the first semiconductor layer 31 can be in the range of 1.5 μm to 5 μm, but is not limited thereto.

[0171] The second semiconductor layer 32 can be disposed on the light-emitting layer 36 described below. The second semiconductor layer 32 can be a p-type semiconductor, and when the light-emitting element 30 emits light in the blue or green wavelength band, the second semiconductor layer 32 can include a semiconductor with the chemical formula Al. x Ga y In 1-x-y The semiconductor material is N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). For example, it can be any one or more of AlGaInN, GaN, AlGaN, InGaN, AlN, and InN doped with p-type dopant. The second semiconductor layer 32 can be doped with a p-type dopant, and the p-type dopant can be Mg, Zn, Ca, Ba, etc. For example, the second semiconductor layer 32 can be p-GaN doped with p-type Mg. The length of the second semiconductor layer 32 can be in the range of 0.05 μm to 0.10 μm, but is not limited thereto.

[0172] Furthermore, although the first semiconductor layer 31 and the second semiconductor layer 32 are shown in the accompanying drawings as consisting of a single layer, this is not a limitation. Depending on the material of the light-emitting layer 36, the first semiconductor layer 31 and the second semiconductor layer 32 may also include a greater number of layers, such as a cladding layer or a tensile strain barrier reducing (TSBR) layer.

[0173] The light-emitting layer 36 can be disposed between the first semiconductor layer 31 and the second semiconductor layer 32. The light-emitting layer 36 can comprise a material with a single or multiple quantum well structure. When the light-emitting layer 36 comprises a material with a multiple quantum well structure, it can also be a structure in which multiple quantum layers and well layers are alternately stacked. The light-emitting layer 36 can emit light through the recombination of electron-hole pairs based on an electrical signal applied through the first semiconductor layer 31 and the second semiconductor layer 32. When the light-emitting layer 36 emits light in the blue wavelength band, it can comprise materials such as AlGaN and AlGaInN. Specifically, when the light-emitting layer 36 has a multiple quantum well structure with alternating quantum layers and well layers, the quantum layers can comprise materials such as AlGaN or AlGaInN, and the well layers can comprise materials such as GaN or AlInN. For example, the light-emitting layer 36 can comprise AlGaInN as a quantum layer and AlInN as a well layer, thereby, as described above, the light-emitting layer 36 can emit blue light with a center wavelength band in the range of 450 nm to 495 nm.

[0174] However, it is not limited to this. The light-emitting layer 36 can also be a structure in which semiconductor materials with large band gap energy and semiconductor materials with small band gap energy are stacked alternately, and it can also include other group III to group V semiconductor materials depending on the wavelength band of the emitted light. The light emitted by the light-emitting layer 36 is not limited to the blue wavelength band, and can also emit red and green wavelength bands depending on the situation. The length of the light-emitting layer 36 can be in the range of 0.05 μm to 0.10 μm, but is not limited to this.

[0175] Furthermore, the light emitted from the light-emitting layer 36 can be emitted not only to the outside of the light-emitting element 30 along its length, but also to both sides of the light-emitting element 30. The directionality of the light emitted from the light-emitting layer 36 is not limited to one direction.

[0176] Electrode layer 37 can be an ohmic connection electrode. However, it is not limited to this and can also be a Schottky connection electrode. The light-emitting element 30 may include at least one electrode layer 37. Although in Figure 5 The diagram shows a light-emitting element 30 including an electrode layer 37, but it is not limited to this. Depending on the situation, the light-emitting element 30 may include more electrode layers 37, or the electrode layers 37 may be omitted. Even if the number of electrode layers 37 changes or other structures are included, the following description of the light-emitting element 30 remains equally applicable.

[0177] In a display device 10 according to one embodiment, when the light-emitting element 30 is electrically connected to an electrode or a connecting electrode, the electrode layer 37 can reduce the resistance between the light-emitting element 30 and the electrode or connecting electrode. The electrode layer 37 may include a conductive metal. For example, the electrode layer 37 may include at least one of aluminum (Al), titanium (Ti), indium (In), gold (Au), silver (Ag), indium tin oxide (ITO), indium zinc oxide (IZO), and indium-tin-zinc oxide (ITZO). Furthermore, the electrode layer 37 may also include a semiconductor material doped with n-type or p-type materials. The electrode layer 37 may include the same material, or it may include different materials, and is not limited thereto.

[0178] The insulating film 38 can be arranged to surround the outer surfaces of the plurality of semiconductor layers and electrode layers described above. For example, the insulating film 38 can be arranged to at least surround the outer surface of the light-emitting layer 36 and extend in one direction in which the light-emitting element 30 extends. The insulating film 38 can perform the function of protecting the aforementioned components. The insulating film 38 can be formed to surround the side surface portion of the aforementioned components and can be formed such that two ends of the light-emitting element 30 are exposed in the longitudinal direction.

[0179] Although the insulating film 38 is shown in the figures as extending along the length of the light-emitting element 30 and covering the side surfaces from the first semiconductor layer 31 to the electrode layer 37, it is not limited thereto. The insulating film 38 may also cover only the outer surface of the semiconductor layer including a portion of the light-emitting layer 36, or it may cover only a portion of the outer surface of the electrode layer 37, leaving the outer surface of each electrode layer 37 partially exposed. Furthermore, the insulating film 38 may also be formed such that the cross-section of the region adjacent to at least one end of the light-emitting element 30 has a circular upper surface.

[0180] The thickness of the insulating film 38 can range from 10 nm to 1.0 μm, but is not limited thereto. Preferably, the thickness of the insulating film 38 can be around 40 nm.

[0181] The insulating film 38 may include a material with insulating properties, such as silicon oxide (SiO2). x ), silicon nitride (SiN) x ), silicon nitride oxide (SiO) x N y Aluminum nitride (AlN) and aluminum oxide (Al) x O yThe insulating film 38 can be formed from a single layer or multiple layers of a material with insulating properties. Therefore, it can prevent electrical short circuits that may occur when the light-emitting layer 36 is in direct contact with the electrodes of the light-emitting element 30 to which the electrical signal is transmitted. Furthermore, since the insulating film 38 protects the outer surface of the light-emitting element 30, including the light-emitting layer 36, it can prevent a decrease in luminous efficiency.

[0182] Furthermore, the outer surface of the insulating film 38 can be surface-treated. The light-emitting element 30 can be sprayed onto the electrode and aligned in a dispersed state in a predetermined ink. Here, the surface of the insulating film 38 can be treated with a hydrophobic or hydrophilic method so that the light-emitting element 30 does not aggregate with other adjacent light-emitting elements 30 in the ink and remains dispersed. For example, the outer surface of the insulating film 38 can be surface-treated with substances such as stearic acid or 2,3-naphthalene dicarboxylicacid.

[0183] In manufacturing the display device 10, the first wavelength conversion section WLC1, the second wavelength conversion section WLC2, and the light-transmitting section LTU in the display device 10 can be formed by spraying a predetermined ink onto the substrate 11 using base resins BS1, BS2, and BS3 dispersed therein as scatterers SCT1, SCT2, and SCT3. Furthermore, the light-emitting element 30 of the display device 10 can also be sprayed onto the substrate 11 and aligned while dispersed in a predetermined ink.

[0184] The aforementioned scatterers SCT1, SCT2, SCT3 and the light-emitting element 30 can be formed from fine particles, dispersed in ink, and sprayed onto the substrate 11. Ink is supplied to the printhead unit of the inkjet printing apparatus and ejected through nozzles, with the remaining ink then recycled back to the inkjet printing apparatus. However, in the ink flow path, fine particles may settle to the bottom due to weight, and may also settle due to variations in flow rate within the path. Therefore, the number of fine particles in the ink ejected through the nozzles may be reduced.

[0185] The following will describe an inkjet printing apparatus that can prevent the deposition of fine particles in the inkjet printing apparatus.

[0186] Figure 6 This is a schematic perspective view of an inkjet printing apparatus according to one embodiment. Figure 7 This is a schematic top view of a printhead unit according to one embodiment. Figure 8 This is a schematic diagram illustrating the operation of a printhead unit according to one embodiment. Figure 9 This is a schematic diagram showing the ink circulation section of an inkjet printing apparatus according to an embodiment.

[0187] Reference Figures 6 to 9 According to one embodiment, an inkjet printing apparatus 1000 may include: a printhead unit 100 including a plurality of inkjet heads 300, a stage STA, an ink circulation unit 500, and a base frame 600.

[0188] The inkjet printing apparatus 1000 can use the printhead unit 100 to spray predetermined ink 90 onto the target substrate SUB. The target substrate SUB can be supplied to the stage STA.

[0189] The printing station STA can provide an area for mounting the substrate SUB. The inkjet printing apparatus 1000 includes a first track RL1 and a second track RL2 extending in a second direction DR2, and the printing station STA is arranged on the first track RL1 and the second track RL2. The printing station STA can move along the first track RL1 and the second track RL2 in the second direction DR2 via additional moving parts. The printing station STA can move in the second direction DR2 and can pass over the printhead unit 100, onto which ink 90 can be ejected. However, this is not a limitation. Although the structure for the movement of the printing station STA is shown in the figures, in some embodiments, the printing station STA can also be fixed and the printhead unit 100 can move. In this case, the printhead unit 100 can also be mounted on a frame arranged on the first track RL1 and the second track RL2.

[0190] The printhead unit 100 may include a plurality of inkjet heads 300 and is arranged on the base frame 600. The printhead unit 100 can use the inkjet heads 300 connected to individual ink storage sections to jet predetermined ink 90 onto the target substrate SUB.

[0191] The base frame 600 may include a support portion 610 and a moving unit 630. The support portion 610 may include a first support portion 611 extending in a first direction DR1, which is a horizontal direction, and a second support portion 612 connected to the first support portion 611 and extending in a third direction DR3, which is a vertical direction. The extending direction of the first support portion 611 may be the same as the first direction DR1. The printhead unit 100 may be arranged in the moving unit 630, which is mounted on the first support portion 611.

[0192] The moving unit 630 may include a moving part 631 that is mounted on the first support 611 and is movable in one direction, and a fixing part 632 that is disposed on the lower surface of the moving part 631 and on which the print head unit 100 is disposed. The moving part 631 may move along the first direction DR1 on the first support 611, and the print head unit 100 may be fixed to the fixing part 632 and move together with the moving part 631 in the first direction DR1.

[0193] The printhead unit 100 can be arranged on the base frame 600 and can spray ink 90 supplied from the ink storage unit onto the target substrate SUB via the inkjet head 300. The printhead unit 100 can be spaced at a predetermined distance from the stage STA, which passes under the base frame 600. The distance between the printhead unit 100 and the stage STA can be adjusted by the height of the second support 612 of the base frame 600. The distance between the printhead unit 100 and the stage STA can be adjusted within the space required for the printing process by ensuring that the printhead unit 100 is spaced at a certain distance from the target substrate SUB when the target substrate SUB is arranged on the stage STA.

[0194] According to one embodiment, the printhead unit 100 may include an inkjet head 300 comprising a plurality of nozzles 350. The inkjet head 300 may be disposed on the lower surface of the printhead unit 100.

[0195] Multiple inkjet heads 300 can be arranged spaced apart from each other in one direction and can be arranged in one or more columns. The accompanying drawings show inkjet heads 300 arranged in two columns with the inkjet heads 300 in each column spaced apart from each other. However, this is not a limitation; inkjet heads 300 can be arranged in more columns and can also be arranged to overlap each other without being spaced apart. The shape of the inkjet heads 300 is not particularly limited, but as an example, the inkjet heads 300 can have a quadrilateral shape.

[0196] At least one inkjet head 300, for example, two inkjet heads 300 may form a pack and be arranged adjacent to each other. However, the number of inkjet heads 300 included in a pack is not limited to this, and as an example, the number of inkjet heads 300 included in a pack may be from one to five. Furthermore, although only six inkjet heads 300 arranged in the printhead unit 100 are shown in the figures, this is for illustrative purposes, and the number of inkjet heads 300 is not limited to this.

[0197] The inkjet head 300 arranged in the printhead unit 100 can jet ink 90 onto the target substrate SUB arranged on the upper part of the stage STA. According to one embodiment, the printhead unit 100 can move along a direction on the first support 611, and the inkjet head 300 can move in the aforementioned direction and jet ink 90 onto the upper part of the target substrate SUB.

[0198] The printhead unit 100 can move in a first direction DR1 extending from the first support 611, and the inkjet head 300 can move in the first direction DR1 and spray ink 90 onto the upper part of the target substrate SUB.

[0199] In one embodiment, ink 90 may include solvent 91 and a plurality of particles 95 included in solvent 91. In an exemplary embodiment, ink 90 may be provided in a solution state or a colloidal state. For example, solvent 91 can be acetone, water, ethanol, toluene, propylene glycol (PG) or propylene glycol methyl acetate (PGMA), triethylene glycol monobutyl ether (TGBE), diethylene glycol monophenyl ether (DGPE), amide solvents, dicarbonyl solvents, diethylene glycol dibenzoate, tricarbonyl solvents, triethyl citrate, phthalate solvents, Benzyl butyl phthalate, Bis(2-ethlyhexyl)phthalate, Bis(2-ethylhexyl)isophthalate, Ethyl phthalylethyl glycolate, etc., but is not limited to these. Multiple particles 95 may be included in solvent 91 in a dispersed state and supplied to printhead unit 100 for discharge. In an exemplary embodiment, the multiple particles 95 may be the scatterer or light-emitting element described above.

[0200] In some embodiments, when multiple target substrates SUB are provided, the printhead unit 100 can eject ink 90 onto each of the multiple target substrates SUB while moving in the first direction DR1. However, it is not limited to this; the printhead unit 100 may first be positioned outside the first track RL1 and the second track RL2, and then move in the first direction DR1 to eject ink 90 onto the upper part of the target substrates SUB. When the stage STA moves in the second direction DR2 and is positioned below the base frame 600, the printhead unit 100 may move between the first track RL1 and the second track RL2 and eject ink 90 through the inkjet head 300. The operation of this inkjet head 300 is not limited to this and can be modified in various ways within the range that allows for similar processes to be implemented.

[0201] The ink circulation unit 500 can supply ink 90 to the printhead unit 100, and the inkjet head 300 can discharge the received ink 90. ​​The ink 90 can circulate between the ink circulation unit 500 and the inkjet head 300, and a portion of the ink 90 supplied to the inkjet head 300 can be discharged from the inkjet head 300, while the remainder can be supplied back to the ink circulation unit 500.

[0202] The ink circulation unit 500 can be connected to the inkjet head 300 via a first connecting pipe IL1 and a second connecting pipe IL2. For example, the ink circulation unit 500 can supply ink 90 to the inkjet head 300 via the first connecting pipe IL1, and the flow rate of the supplied ink 90 can be adjusted via a first valve VA1. Furthermore, any remaining ink 90 after it has exited the inkjet head 300 can be supplied to the ink circulation unit 500 via the second connecting pipe IL2. The flow rate of the ink 90 supplied to the ink circulation unit 500 via the second connecting pipe IL2 can be adjusted via a second valve VA2. Because the ink 90 circulates through the ink circulation unit 500, the deviation in the number of particles 95 included in the ink 90 exiting the inkjet head 300 can be minimized.

[0203] The ink circulation unit 500 can be arranged by other means, but is not limited thereto. The ink circulation unit 500 is provided in the inkjet printing apparatus 1000, but its position or shape is not particularly limited. For example, the ink circulation unit 500 can be hung on the base frame 600, and if it is connected to the inkjet head 300, it can be arranged in various ways within its range.

[0204] In some embodiments, the ink circulation unit 500 may include a first ink storage unit 510, a second ink storage unit 520, a first pressure pump 530, and a second pressure pump 540. The second ink storage unit 520 of the ink circulation unit 500 may be connected to the inkjet head 300, and they may form an ink circulation system.

[0205] The first ink storage unit 510 may be a storage unit for preparing the manufactured ink 90. ​​The ink 90, including solvent 91 and particles 95, may be prepared in the first ink storage unit 510 of the ink circulation unit 500, and the ink 90 may be supplied to the ink circulation system.

[0206] The second ink storage unit 520 can be connected to the first ink storage unit 510, allowing the prepared ink 90 to be supplied to the second ink storage unit 520. The second ink storage unit 520 can supply ink 90 to the inkjet head 300 via the first connecting pipe IL1. In one embodiment, the second ink storage unit 520 may include a stirrer ST, which can disperse the particles 95 in the ink 90. ​​The ink 90 supplied to the second ink storage unit 520 can maintain a dispersed state where the particles 95 do not sink as the stirrer ST rotates. That is, the stirrer ST of the second ink storage unit 520 can prevent the particles 95 from sinking to the lower part of the second ink storage unit 520, thereby reducing the number of particles 95 in the ink 90 discharged through the inkjet head 300. The second ink storage unit 520 can supply ink 90 with smoothly dispersed particles 95 to the inkjet head 300, and the inkjet head 300 can discharge ink 90 including particles 95 at a certain level or higher.

[0207] Furthermore, the ink 90 remaining after being discharged from the inkjet head 300 can be supplied to the second ink reservoir 520 through the second connecting pipe IL2. The second connecting pipe IL2 can be connected to the first pressure pump 530, so that the remaining ink 90 can be circulated to the second ink reservoir 520 through the first pressure pump 530. The first pressure pump 530 can be a pump that transmits power to the fluid to enable the ink 90 to circulate in the ink circulation system.

[0208] Although not shown, the ink circulation unit 500 may also include a flow meter between the first ink storage unit 510 and the second ink storage unit 520. The flow meter can measure the flow rate of the ink 90 supplied to the second ink storage unit 520. Therefore, the flow rate of the ink 90 supplied to the second ink storage unit 520 can be adjusted based on the flow rate of the ink 90 measured by the flow meter.

[0209] Furthermore, the ink circulation unit 500 may also include a compressor connected to the second ink storage unit 520. The compressor can adjust the pressure in the second ink storage unit 520. The compressor can remove gas to bring the interior of the second ink storage unit 520 into a negative pressure state, or it can introduce external inert gas to bring the interior of the second ink storage unit 520 into a certain pressure.

[0210] Pipes PP1 and PP2 may be respectively arranged between the first ink storage unit 510 and the second ink storage unit 520, and between the second ink storage unit 520 and the printhead unit 100. Each pipe PP1 and PP2 may contain ink 90 comprising multiple particles 95. When ink 90 is not supplied from the ink storage units 510 and 520, the multiple particles 95 arranged in pipes PP1 and PP2 may settle to the bottom of pipes PP1 and PP2. Therefore, when ink 90 is supplied, the number of particles 95 in the discharged ink 90 may vary due to the settled particles 95.

[0211] In this embodiment, a first branch component 550 and a second pressure pump 540 may be included between the first ink storage unit 510 and the second ink storage unit 520, and a second branch component 570 may be included between the second ink storage unit 520 and the printhead unit 100.

[0212] Figure 10 This is a cross-sectional view showing a first branch component according to an embodiment. Figure 11 This is a cross-sectional view showing a first branch component according to an embodiment. Figure 12 This is a cross-sectional view showing the first branch component according to another embodiment. Figure 13 This is a cross-sectional view showing the first branch component according to another embodiment.

[0213] Combination Figure 9 Reference Figure 10 and Figure 11 The first branch component 550 can be arranged between the first ink storage section 510 and the second ink storage section 520, and is provided in the first pipe PP1.

[0214] The first branch component 550 may include a first base portion BP1 connected to the first pipe PP1 and a first partition portion BR1 disposed in the first base portion BP1. The first base portion BP1 may be connected to the first pipe PP1 and formed with a diameter larger than the first pipe PP1 to branch the flow path. The first base portion BP1 may be formed with the same circular shape as the first pipe PP1, but is not limited thereto, and may also be formed with various structures such as quadrilateral.

[0215] The first partition wall BR1 is used to branch the flow path, and it may include a first partition wall PR1 and a second partition wall PR2 arranged around the first partition wall PR1. The first partition wall PR1 may be arranged at the center of the first base part BP1 and may include a first opening OP1 with a circular cross-section. The overall shape of the first partition wall PR1 may be a circular pipe shape. The center C of the first opening OP1 of the first partition wall PR1 may overlap with the center C of the first base part BP1. Therefore, the first partition wall PR1 can serve to branch the ink 90 that moves inside the first base part BP1, corresponding to the center of the first base part BP1.

[0216] The second partition PR2 may extend from the first partition PR1 and be arranged as an inner wall surrounding the first base portion BP1. The second partition PR2 may surround the first partition PR1 and may include a second opening OP2 and a third opening OP3. Each of the second opening OP2 and the third opening OP3 may not overlap with the center C of the first base portion BP1 in the length direction of the first base portion BP1.

[0217] The second partition PR2 can function as a branch for the ink 90 that moves within the interior of the first base BP1, specifically the portion of ink 90 that remains outside the center of the first base BP1. When the center of the first base BP1 is divided horizontally, the second opening OP2 can be positioned at the top, and the third opening OP3 can be positioned at the bottom. Therefore, the second opening OP2 can allow the ink 90 to branch upwards from the center of the first base BP1, and the third opening OP3 can allow the ink 90 to branch downwards from the center of the first base BP1.

[0218] In one embodiment, the length of the first partition PR1 may be longer than the length of the second partition PR2. The longer length of the first partition PR1 compared to the second partition PR2 facilitates the branching of the ink 90 at the center of the first base portion BP1.

[0219] Furthermore, the diameter D2 of the first partition PR1 can be formed in the range of 60% to 80% relative to the diameter D1 of the first base portion BP1. Therefore, ink 90 with a high flow rate can be effectively branched at the center of the first base portion BP1. Conversely, the second partition PR2 can cause ink 90 to branch in the remaining area after subtracting the diameter D2 of the first partition PR1 from the diameter D1 of the first base portion BP1.

[0220] The first partition PR1 can be connected to the first conduit PP1, which connects to the second ink storage unit 520 from the first branch component 550, and supplies ink 90 separated from the first partition PR1 to the second ink storage unit 520. The second opening OP2 of the second partition PR2 can be connected to the first sub-conduit PS1, and the third opening OP3 can be connected to the second sub-conduit PS2. The first sub-conduit PS1 and the second sub-conduit PS2 can be merged into a third conduit PP3 and connected to the first ink storage unit 510. In this embodiment, the ink 90 supplied to the third conduit PP3 can be supplied to the first ink storage unit 510 by a second pressure pump 540.

[0221] The flow rate of ink 90 moving in the first base section BP1 can be fastest in the center and slowest in the periphery. Particles 95 included in the ink 90 may settle in the relatively slow-flowing periphery, especially at the bottom. Conversely, in the center where the flow rate is fastest, the particles 95 do not settle and can move more quickly due to the faster flow rate.

[0222] In this embodiment, by arranging a first partition PR1 that separates the ink 90 at the center of the first base portion BP1, ink 90 with a uniform number of particles 95 can be moved to the second ink storage portion 520. Furthermore, by arranging a second partition PR2 that separates the ink 90 at the periphery of the first base portion BP1, ink 90 with an uneven number of particles 95 due to particle sedimentation can be separated. Therefore, variations in the number or concentration of particles 95 included in the ink 90 due to particle sedimentation can be minimized, thereby improving the quality of inkjet printing.

[0223] The second branch component 570 can be arranged in the second conduit PP2 located between the second ink storage section 520 and the printhead unit 100. The second branch component 570 can be formed with the same structure as the first branch component 550 described above. For example, as... Figure 10 and Figure 11 As shown, the second branch component 570 may include a first partition portion BR1 arranged in the first base portion BP1, and the first partition portion BR1 may include a first partition PR1 and a second partition PR2.

[0224] The above Figure 10 and Figure 11The first partition PR1 of the first branch component 550 is connected to the first pipe PP1, but the difference in the second branch component 570 is that the second branch component 570 is connected to the first connecting pipe IL1. Furthermore, regarding the first branch component 550, the first sub-pipe PS1 and the second sub-pipe PS2 are connected to the third pipe PP3, but the difference in the second branch component 570 is that the second branch component 570 is connected to the fourth pipe PP4 and merges with the second connecting pipe IL2 to connect to the first pressure pump 530.

[0225] In this embodiment, by arranging branch members 550 and 570 between the first ink storage unit 510 and the second ink storage unit 520, and between the second ink storage unit 520 and the printhead unit 100, the ink 90 from which multiple particles 95 have settled can be separated and a uniform supply of ink 90 containing multiple particles 95 can be provided. Therefore, the variation in the number or concentration of particles 95 included in the ink 90 due to ink 90 settling can be minimized, thereby improving the quality of inkjet printing.

[0226] In addition, combined Figure 9 Reference Figure 12 and Figure 13 The first branch component 550 and the second branch component 570 can also be formed into different shapes. Although in Figure 12 and Figure 13 The first branch component 550 is used as an example for explanation, but the same applies to the second branch component 570.

[0227] Specifically, the first partition BR1 may include a first partition PR1 and a second partition PR2. The first partition PR1 and the second partition PR2 can divide the interior of the first base BP1 into two parts. The first partition PR1 may include a first opening OP1, and the second partition PR2 may include a second opening OP2. The diameter D2 of the first partition PR1, extending from the uppermost end of the interior of the first base BP1 through the center C, can be formed within 80% to 90% of the diameter D1 of the first base BP1. In particular, when the first base BP1 is divided into two parts in the horizontal direction, the first opening OP1 of the first partition PR1 can occupy the entire upper part and a portion of the lower part, and the second opening OP2 of the second partition PR2 can occupy a portion of the lower part.

[0228] As described above, the flow rate of the ink 90 moving in the first base section BP1 can be fastest in the center and slowest in the periphery. In particular, the particles 95 included in the ink 90 may settle to the bottom or lower part of the first base section BP1.

[0229] In this embodiment, by forming a second partition PR2 corresponding to the bottom or lower part of the first base portion BP1, ink 90 with uneven particle 95 quantity due to particle 95 sedimentation can be separated. Conversely, by forming a first partition PR1 corresponding to the center and upper part of the first base portion BP1, ink 90 with a relatively uniform particle 95 quantity can be moved to the second ink storage portion 520. Therefore, the variation in the quantity or concentration of particles 95 included in the ink 90 due to ink 90 sedimentation can be minimized, thereby improving the quality of inkjet printing.

[0230] Figure 14 This is a schematic diagram showing the ink circulation section of an inkjet printing apparatus according to yet another embodiment. Figures 15 to 18 This is a schematic diagram illustrating a driving method for the ink circulation section of an inkjet printing apparatus according to yet another embodiment. Figure 19 This is a schematic diagram showing the ink circulation section of an inkjet printing apparatus according to yet another embodiment.

[0231] Reference Figure 14 This embodiment is different from the one described above. Figures 6 to 13 The difference between the embodiments lies in the different configuration of the ink circulation unit 500. Hereinafter, the ink circulation unit 500 with its different features will be described in detail.

[0232] According to one embodiment, the ink circulation unit 500 of the inkjet printing apparatus 1000 may include a first ink storage unit 510, a second ink storage unit 520, a gas storage unit 710, a pump 700, and a sound pressure chamber 730. The second ink storage unit 520 of the ink circulation unit 500 may be connected to the printhead unit 100, and they may form an ink circulation system.

[0233] The first ink storage unit 510 can be a storage unit for preparing the manufactured ink 90. ​​The ink 90, including solvent 91 and particles 95, can be prepared in the first ink storage unit 510 of the ink circulation unit 500, and the ink 90 can be supplied to the ink circulation system.

[0234] The second ink storage unit 520 can be connected to the first ink storage unit 510, and the prepared ink 90 can be supplied to the second ink storage unit 520. The second ink storage unit 520 can supply ink 90 to the printhead unit 100 through the first connecting pipe IL1 and the second connecting pipe IL2. Unlike the above embodiment, the second ink storage unit 520 differs in that the ink 90 remaining after being discharged from the printhead unit 100 is not recycled back to the second ink storage unit 520. As described below, the second ink storage unit 520 supplies an amount of ink 90 sufficient for one inkjet printing to the printhead unit 100, so that no ink 90 is left over and therefore ink 90 recycling is not required. In addition, the second ink storage unit 520 may also have a heating element, thereby allowing control of the temperature of the ink 90.

[0235] A pump 700 may be arranged between the first ink storage unit 510 and the second ink storage unit 520. The pump 700 supplies ink 90 from the first ink storage unit 510 to the second ink storage unit 520. The pump 700 may be a metering pump, such as a diaphragm pump or a tubing pump. The pump 700 can move gas and liquid. The pump 700 can move ink 90 stored in the first ink storage unit 510 to the second ink storage unit 520, and can also supply a single-volume portion of ink 90 from the printhead unit 100 to the second ink storage unit 520.

[0236] A first pipe PP1 can be connected between the first ink storage unit 510 and the pump 700, so that the ink 90 of the first ink storage unit 510 can be supplied to the pump 700 through the first pipe PP1. A first valve VA1 can be provided on the first pipe PP1. The first valve VA1 can open and close the first pipe PP1 to control the movement of the ink 90.

[0237] One end of the pump 700 can be connected to a gas storage unit 710. The gas storage unit 710 can be a storage unit for preparing gas GS. The gas GS stored in the gas storage unit 710 can be a gas that does not react with ink 90, for example, it can be air or nitrogen (N2).

[0238] A second pipe PP2 can be connected between the gas storage unit 710 and the pump 700, allowing the gas GS from the gas storage unit 710 to be supplied to the pump 700 via the second pipe PP2. A second valve VA2 can be installed on the second pipe PP2. The second valve VA2 can open and close the second pipe PP2 to control the movement of the gas GS.

[0239] A main conduit MP may be arranged between the pump 700 and the second ink storage unit 520. The main conduit MP connects the pump 700 and the second ink storage unit 520, thereby serving as a channel for supplying ink 90 and gas GS supplied by the pump 700 to the second ink storage unit 520. Although the diameter of the main conduit MP is shown in the figures to be larger than that of the conduits PP1 and PP2, it is not limited thereto and may have the same diameter as the conduits PP1 and PP2.

[0240] Furthermore, a third conduit PP3 can be connected between the gas storage unit 710 and the second ink storage unit 520. The third conduit PP3 allows the gas GS present in the second ink storage unit 520 to be recirculated back to the gas storage unit 710. A third valve VA3 can be provided on the third conduit PP3, thereby controlling the movement of the gas GS by opening and closing the third conduit PP3.

[0241] A sound pressure chamber 730 may be arranged at one end of the second ink storage unit 520. The sound pressure chamber 730 can reduce the pressure of the second ink storage unit 520 to draw in and remove gases such as air bubbles mixed in the ink 90, and can also control the pressure in the printhead unit 100.

[0242] A fourth conduit PP4 can be connected between the sound pressure chamber 730 and the second ink storage unit 520. The fourth conduit PP4 can serve as a channel for gas present in the second ink storage unit 520 to be drawn into the sound pressure chamber 730. A fourth valve VA4 can be provided on the fourth conduit PP4, thereby controlling the movement of gas by opening and closing the fourth conduit PP4.

[0243] The ink circulation unit 500 of the inkjet printing apparatus 1000 according to this embodiment can be driven as follows.

[0244] Reference Figure 15 In order to supply ink 90 to the printhead unit 100 of the inkjet printing apparatus 1000, the first valve VA1, located between the first ink storage section 510 and the pump 700, is first closed. The third valve VA3, located between the gas storage section 710 and the second ink storage section 520, and the fourth valve VA4, located between the sound pressure chamber 730 and the second ink storage section 520, are then closed. Furthermore, the second valve VA2, located between the pump 700 and the gas storage section 710, is opened.

[0245] Next, the pump 700 is driven, thereby supplying gas GS from the gas storage unit 710 to the second ink storage unit 520 through the main pipe MP. The gas GS stored in the gas storage unit 710 is supplied to the second ink storage unit 520 through the open second valve VA2 via the second pipe PP2 and the main pipe MP.

[0246] Then, refer to Figure 16 The second valve VA2, located between the pump 700 and the gas storage unit 710, is closed, and the first valve VA1, located between the first ink storage unit 510 and the pump 700, is opened. Next, the pump 700 is driven to supply ink 90 from the first ink storage unit 510 to the main pipeline MP. At this time, the pump 700 can quantitatively supply the amount of ink 90 required for a single inkjet printing operation. The ink 90 can be filled into the main pipeline MP simultaneously with the extrusion of the gas GS already filled in the main pipeline MP.

[0247] Here, the ink 90 remains in the main pipe MP for a longer period, which may cause particles 95 to settle to the bottom or lower part of the main pipe MP. In this embodiment, by supplying gas GS into the main pipe MP to extrude the ink 90, the ink 90, including the settled particles 95, will not remain in the main pipe MP and can be completely moved to the second ink storage section 520. Therefore, it is possible to prevent the particles 95 of the ink 90 from settling and remaining in the main pipe MP, thereby preventing changes in the number or concentration of particles 95 in the ink 90. ​​Thus, the quality of the inkjet printing process can be improved.

[0248] Then, refer to Figure 17 and Figure 18 The first valve VA1, located between the first ink storage unit 510 and the pump 700, is closed, and the second valve VA2, located between the pump 700 and the gas storage unit 710, is opened. Next, the pump 700 is driven, thereby supplying gas GS from the gas storage unit 710 to the main pipeline MP. In the main pipeline MP, the ink 90 moves via the supplied gas GS. As gas GS continues to be supplied to the main pipeline MP, the ink 90 can reach and be stored in the second ink storage unit 520.

[0249] As a result, a single batch of ink 90 can be stored in the second ink storage unit 520. Then, an inkjet printing process will be performed. Here, an inkjet printing process may refer to one process cycle, rather than printing once.

[0250] When it is necessary to remove the gas GS filled in the second ink storage section 520, the first valve VA1, the second valve VA2 and the fourth valve VA4 can be closed, and the third valve VA3 can be opened, so that the gas GS can be recirculated from the second ink storage section 520 to the gas storage section 710.

[0251] Furthermore, when it is necessary to remove bubbles or gas from the second ink storage section 520, the first valve VA1, the second valve VA2 and the third valve VA3 can be closed, and the fourth valve VA4 can be opened, thereby drawing the bubbles or gas GS from the second ink storage section 520 into the sound pressure chamber 730 for removal.

[0252] Furthermore, in another embodiment, the first conduit PP1 between the first ink storage unit 510 and the pump 700 can be omitted, and the first ink storage unit 510 and the pump 700 can be directly connected (or directly coupled).

[0253] Reference Figure 19 A first ink storage section 510 may be arranged on the pump 700. The first ink storage section 510 and the pump 700 may be directly connected, and the first conduit PP1 between them is omitted. In this embodiment, by directly connecting the first ink storage section 510 and the pump 700, it is possible to prevent ink particles 95 from settling in the conduit between the first ink storage section 510 and the pump 700.

[0254] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, those skilled in the art should understand that the present invention can be implemented in other specific forms without changing its technical concept or essential features. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims

1. An inkjet printing apparatus, comprising: The first ink storage section provides ink containing multiple particles; A second ink storage unit, wherein the ink is supplied from the first ink storage unit to the second ink storage unit via a first conduit; The printhead unit discharges the ink received from the second ink storage section through a second conduit; as well as The first branch component and the second branch component are respectively arranged between the first ink storage unit and the second ink storage unit, and between the second ink storage unit and the printhead unit, and cause the ink to branch. The first branch component and the second branch component each include: A first base section, in which the ink moves; and A first partition wall is disposed within the first base portion and includes a first partition wall and a second partition wall that branch off the interior of the first base portion. The first partition includes a first opening, in which a portion of the ink moving inside the first base moves. The second partition includes a second opening and a third opening, in which the remaining portion of the ink moving inside the first base moves.

2. The inkjet printing apparatus according to claim 1, wherein, The center of the first opening overlaps with the center of the first base portion, and the second opening and the third opening do not overlap with the center of the first base portion along the length direction of the first base portion.

3. The inkjet printing apparatus according to claim 2, wherein, The second opening and the third opening surround the first opening, with the second opening positioned above the first opening and the third opening positioned below the first opening.

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