Inkjet printing device

Abstract

An inkjet printing apparatus is provided. The inkjet printing method includes generating volume data by measuring a volume of ink droplets discharged from each of a plurality of nozzles, generating particle number data by measuring a number of solute particles within the ink droplets discharged from each of the plurality of nozzles, forming a first nozzle group by grouping nozzles from among the plurality of nozzles to discharge ink into a first area based on the volume data and the particle number data, and discharging the ink into the first area through the nozzles of the first nozzle group.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0098962, filed on July 25, 2024, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] One or more embodiments relate to methods and apparatus, and for example, to inkjet printing methods, inkjet printing apparatus, and electronic devices formed using the inkjet printing method or inkjet printing apparatus. Background Technology

[0004] Mobility-based electronic devices are already widely used. In addition to small electronic devices such as mobile phones, tablet PCs have recently become widely used as mobile electronic devices.

[0005] Such mobile electronic devices include display devices for providing users with various functions, such as visual information like images and / or videos. Recently, the proportion of display devices in electronic devices has been increasing, and structures that can bend from a flat state to a set or specific angle have also been developed.

[0006] Display devices may include various layers formed via various processes. For example, a display device may include functional layers that perform optical functions and color filter layers for improving color purity, and these layers may be formed via a process of ejecting ink onto a display substrate (e.g., inkjet printing). For inkjet printing, the apparatus for manufacturing the display device may include an ejection unit for ejecting ink.

[0007] The above background information is information that the inventor possessed or obtained in the process of deriving this disclosure, and cannot be said to be known technology that was publicly disclosed before the filing of this disclosure. Utility Model Content

[0008] In embodiments of display devices employing inkjet printing processes, a uniform (e.g., substantially uniform) quality may be used or required during droplet application to prevent mura.

[0009] One or more embodiments include an inkjet printing method and an inkjet printing apparatus capable of providing a uniform (e.g., substantially uniform) mass of droplet application during inkjet printing.

[0010] However, the foregoing is merely an example, and the purpose of the embodiments of this disclosure is not limited thereto.

[0011] Other aspects of the implementation will be set forth in part in the description which follows, and in part will be apparent from the description, or may be learned by practice of the implementations presented in this disclosure.

[0012] According to one or more embodiments, an inkjet printing method includes: generating volume data by measuring the volume of each ink droplet ejected from a plurality of nozzles; generating particle number data by measuring the number of solute particles within each ink droplet ejected from the plurality of nozzles; forming a first nozzle group by grouping nozzles from the plurality of nozzles that are to eject ink into a first region based on the volume data and the particle number data; and ejecting ink into the first region through the nozzles of the first nozzle group.

[0013] In one embodiment, forming the first nozzle group may include selecting some of a plurality of nozzles such that the number of solute particles in the ink droplets discharged into the first region is close to the target number of particles.

[0014] In one embodiment, the sum of the number of solute particles in each ink droplet ejected from the nozzles of the first nozzle group can be the same as the target number of particles.

[0015] In one embodiment, forming the first nozzle group may further include selecting some of the plurality of nozzles such that the volume of the ink droplets discharged into the first region is close to the target volume.

[0016] In one implementation, the sum of the volumes of the individual ink droplets ejected from the nozzles of the first nozzle group can be the same as the target volume.

[0017] In one embodiment, forming the first nozzle group may further include selecting a combination of nozzles adjacent to the first region from a combination of nozzles that satisfy the target number and target volume of particles.

[0018] In an embodiment, the inkjet printing method may further include forming a second nozzle group by grouping nozzles from a plurality of nozzles that are to discharge ink into a second region based on volume data and particle number data.

[0019] In one embodiment, forming the second nozzle group may include selecting some of a plurality of nozzles such that the number of solute particles in the ink droplets discharged into the second region is close to the target number of particles.

[0020] In one embodiment, forming the second nozzle group may further include selecting some of the plurality of nozzles such that the volume of the ink droplets discharged into the second region is close to the target volume.

[0021] In one implementation, generating particle data may include measuring the number of solute particles in each of the ink droplets ejected from the nozzle using laser-induced breakdown spectroscopy.

[0022] In an implementation, generating volume data and generating particle number data may include information about the volume of the droplets according to the discharge waveform of each of the plurality of nozzles and information about the number of solute particles within the droplets.

[0023] In one implementation, generating volume data may include slightly adjusting the volume of the ejected ink droplets by slightly adjusting the voltage applied to each of the plurality of nozzles.

[0024] According to one or more embodiments, an inkjet printing apparatus includes: a stage on which a display substrate is disposed; an ejection unit facing the stage and configured to eject ink onto the display substrate; and a controller configured to control the ejection unit, wherein the ejection unit includes: a head unit including a plurality of nozzles; a volume measuring unit adjacent to the head unit and configured to measure the volume of ink droplets ejected from the nozzles; and a particle number measuring unit adjacent to the head unit and configured to measure the number of solute particles within the ink droplets ejected from the nozzles.

[0025] In one implementation, the particle number measuring unit can be configured to measure the number of solute particles in each of the ink droplets ejected from the nozzle by using laser-induced breakdown spectroscopy.

[0026] In an implementation, the volume measurement unit may include at least one selected from a line scan camera and a color confocal sensor.

[0027] In one implementation, the controller can be configured to generate volume data by measuring the volume of each ink droplet ejected from a plurality of nozzles.

[0028] In one implementation, the controller can also be configured to select some of the multiple nozzles based on volume data, such that the volume of the ink droplets discharged into the first region is close to the target volume.

[0029] In one implementation, the controller can also be configured to generate particle count data by measuring the number of solute particles within each ink droplet ejected from a plurality of nozzles.

[0030] In one implementation, the controller can also be configured to select some of the multiple nozzles based on particle number data, such that the number of solute particles in the ink droplets discharged into the first region is close to the target number of particles.

[0031] According to one or more embodiments, an electronic device includes a layer formed by an inkjet printing method, the inkjet printing method comprising: generating volume data by measuring the volume of ink droplets ejected from each of a plurality of nozzles; generating particle number data by measuring the number of solute particles within each ink droplet ejected from the plurality of nozzles; forming a first nozzle group by grouping nozzles from the plurality of nozzles that are to eject ink into a first region based on the volume data and the particle number data; and ejecting ink into the first region through the nozzles of the first nozzle group.

[0032] Aspects and features of embodiments other than those described above will become apparent from the following drawings, claims and detailed description, in order to implement the following disclosure. Attached Figure Description

[0033] The above and other aspects and features of certain embodiments of this disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0034] Figure 1 This is a perspective view schematically showing an apparatus for manufacturing a display device according to an embodiment;

[0035] Figure 2 This is a schematic plan view of the injection unit according to an embodiment;

[0036] Figures 3 to 7 This is a diagram schematically illustrating a method for manufacturing a display device according to an embodiment;

[0037] Figures 8 to 9 This is a diagram schematically illustrating a method for manufacturing a display device according to an embodiment;

[0038] Figures 10 to 11 This is a diagram schematically illustrating a method for manufacturing a display device according to an embodiment;

[0039] Figure 12 This is a schematic perspective view of a display device according to an embodiment;

[0040] Figure 13 This is a schematic cross-sectional view of a display device according to an embodiment;

[0041] Figure 14 It shows Figure 13 Each of the functional layers in the optical layer;

[0042] Figure 15 This is an equivalent circuit diagram showing a light-emitting diode included in a display device according to an embodiment and a sub-pixel circuit electrically connected to the light-emitting diode; and

[0043] Figure 16 This is a schematic cross-sectional view of a display device according to an embodiment. Detailed Implementation

[0044] Reference will now be made in more detail to embodiments, examples of which are shown in the accompanying drawings, wherein similar reference numerals denote similar elements throughout this specification. In this respect, embodiments may take different forms and should not be construed as limited to the description set forth herein. Therefore, embodiments are described below only by reference to the accompanying drawings to illustrate aspects of this specification. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Throughout this disclosure, the expression “at least one of a, b, and c” means only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0045] Various suitable modifications can be applied to this embodiment, and exemplary embodiments will be shown in the accompanying drawings and described in the detailed description section. The effects and features of the embodiments of this disclosure, as well as methods for achieving these effects and features, will become clearer with reference to the following detailed description taken in conjunction with the accompanying drawings. However, this embodiment can be implemented in various suitable forms and is not limited to the embodiments presented below.

[0046] In the following description, embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings, in which the same or corresponding components are indicated by the same reference numerals and redundant descriptions thereof are omitted.

[0047] In the following implementation, it will be understood that although the terms “first,” “second,” etc., may be used herein to describe various components, these components should not be limited by these terms. These terms are used only to distinguish one component from another.

[0048] In the following embodiments, singular expressions in this specification include plural expressions unless otherwise expressly stated in the context.

[0049] In the following embodiments, it will also be understood that the terms “comprising” and / or “including” as used herein specify the presence of the stated features or components, but do not exclude the presence or addition of one or more other features or components.

[0050] In the following implementation, it will be understood that if (for example, when) a layer, region, or component is referred to as being "on" or "formed" on another layer, region, or component, then it may be directly or indirectly formed on or on another layer, region, or component. For example, intermediate layers, regions, or components may exist.

[0051] For ease of explanation, the dimensions of the components in the accompanying drawings may be exaggerated. In the embodiments, since the dimensions and thicknesses of the components in the accompanying drawings may be arbitrarily shown for ease of explanation, the following embodiments are not limited thereto.

[0052] In the following implementation, the x-axis, y-axis, and z-axis are not limited to the three axes of a Cartesian coordinate system and can be interpreted in a broader sense. For example, the x-axis, y-axis, and z-axis can be perpendicular to each other, or they can represent different directions that are not perpendicular to each other.

[0053] If (for example, when) a particular implementation can be implemented differently, then a specific process sequence can be performed differently than the described sequence. For example, two consecutively described processes can be performed substantially simultaneously, or in the reverse order of their description.

[0054] Figure 1 This is a schematic perspective view of an apparatus 2 for manufacturing a display device according to an embodiment. In this embodiment, the apparatus 2 for manufacturing a display device includes an inkjet printing apparatus for dispensing ink onto a display substrate DS, but this disclosure is not necessarily limited thereto.

[0055] refer to Figure 1 The apparatus 2 for manufacturing a display device may include a support 10, a hanger 20, a first moving unit 30, a second moving unit 40, a spraying unit 50, a maintenance unit 60, and a controller 90.

[0056] Support member 10 is an assembly on which other components are mounted or disposed, and in an embodiment, support member 10 may have a first direction (e.g., Figure 1 (x-direction) and a second direction that intersects the first direction (e.g., the x-direction) and the second direction that intersects the first direction (e.g., the x-direction) Figure 1 The plane defined by the y-direction. In an embodiment, the support member 10 may have, as shown in the example... Figure 1 The quadrilateral plane shown is not limited to this, and the support 10 may have various suitable planar shapes such as another polygon or a circle (e.g., a generally circular shape).

[0057] A stage 11 may also be provided on the support 10. The stage 11 is on the support 10 and may have a plane defined by a first direction and a second direction. A display substrate DS may be mounted or disposed on the stage 11, and the stage 11 may include alignment marks for aligning the display substrate DS. At this point, the display substrate DS is part of a display device being manufactured and may be the object on which the ink jetting unit 50 ejects ink. In an embodiment, the ejected ink may adhere to the display substrate DS and form a partial layer of the display device. The stage 11 may form a working area for inkjet printing processes.

[0058] Guide units 12 may also be disposed between the support 10 and the table 11. The guide units 12 are on the support 10 and may be spaced apart from each other below the table 11. For example, there may be two guide units 12, and the guide units 12 may be spaced apart from each other in a second direction so as to be adjacent to the sides of the table 11. Each of the guide units 12 may extend in a first direction, and the extension length of each of the guide units 12 in the first direction may be greater than the length of the table 11 in the first direction.

[0059] The guide unit 12 can guide the stage 11 so that linear movement can be performed along the extension direction of the guide unit 12. The guide unit 12 may include, for example, a linear motion track.

[0060] In this embodiment, the stage 11 can reciprocate linearly along the guide unit 12. The stage 11 can perform linear motion manually or automatically via a motor cylinder or similar device. For example, the stage 11 can automatically perform linear motion by including a linear motion block that moves along a linear motion track.

[0061] The hanger 20 can be on the support 10 and may include a vertical member 21 and a horizontal member 22. Figure 1 The vertical member 21 and the horizontal member 22 are shown to each have a rectangular bar shape, but the shapes of the vertical member 21 and the horizontal member 22 are not limited to this.

[0062] The vertical member 21 of the hanger 20 can be in a third direction (e.g., intersecting with each of the first and second directions) Figure 1 It extends in the z-direction. The number of vertical members 21 can be, for example, two, and the vertical members 21 can be arranged on both sides of the platform 11, with the platform 11 between the vertical members 21.

[0063] The horizontal member 22 of the hanger 20 may extend in a second direction between the vertical members 21. Both ends of the horizontal member 22 may be connected to the upper portions of the vertical members 21, respectively. The horizontal member 22 may include a first groove 23 extending along its extension direction (e.g., in the second direction). The first groove 23 may be disposed in a side surface of the horizontal member 22. For example, the first groove 23 may be disposed in a surface of the horizontal member 22 facing the first direction. The first groove 23 may guide the first moving unit 30 to enable linear reciprocating motion along the extension direction of the first groove 23.

[0064] In the preceding description, it has been described that the hanger 20 is fixed to the support member 10, and the platform 11 moves across the horizontal member 22 of the hanger 20 in a first direction; however, this disclosure is not limited thereto. In one embodiment, the platform 11 is fixed to the support member 10, and the hanger 20 can move on the support member 10 in the first direction. In another embodiment, both the platform 11 and the hanger 20 can move in the first direction. In yet another embodiment, the hanger 20 and the platform 11 can move relative to each other in the first direction. Hereinafter, for ease of explanation, since the hanger 20 and the platform 11 move relative to each other in the first direction, the description will assume that the hanger 20 moves in the first direction.

[0065] The first moving unit 30 can move linearly in the second direction. The first moving unit 30 can be movably connected to a side surface of the horizontal member 22 of the hanger 20. For example, the first moving unit 30 can be on the surface of the horizontal member 22 in which a first groove 23 is provided. The first moving unit 30 can reciprocate linearly along the first groove 23 in the second direction. In an embodiment, the first moving unit 30 may include a linear motor.

[0066] In one embodiment, the second moving unit 40 is located on one side surface of the first moving unit 30 and can reciprocate linearly in a third-direction upward direction. For example, the second moving unit 40 may be located on the lower surface of the first moving unit 30. In another embodiment, the lower surface of the first moving unit 30 may be the surface of the first moving unit 30 facing the platform 11. In another embodiment, the second moving unit 40 may include a pneumatic cylinder. In yet another embodiment, the second moving unit 40 may rotate and move about an axis extending in a third-direction upward direction. For this purpose, the second moving unit 40 may include, for example, an electric motor, a pneumatic motor, etc.

[0067] In one embodiment, the spraying unit 50 may be located on the lower surface of the second moving unit 40. The spraying unit 50 may move together with the first moving unit 30 and the second moving unit 40. In another embodiment, the first moving unit 30 may transport the spraying unit 50 in a second direction, and the second moving unit 40 may transport the spraying unit 50 in a third upward direction. For example, the range of motion of the spraying unit 50 may be substantially the same as the area occupied by the support member 10. The spraying unit 50 may also be rotated by the second moving unit 40 about an axis extending upward in a third direction.

[0068] The ejection unit 50 can eject ink droplets toward the display substrate DS. In one embodiment, the ink can be a material applied for forming a color filter layer on the display substrate DS. In another embodiment, the ink can be a polymer and / or a low molecular weight organic material corresponding to the emitting layer of an organic light-emitting display device. In yet another embodiment, the ink can be a red, green, or blue liquid mixed with liquid crystal, an alignment agent, and / or a solvent. In still another embodiment, the ink can comprise a solution containing inorganic particles such as quantum dot materials.

[0069] The maintenance unit 60 is mounted on the support 10 and may be spaced apart from the platform 11 in a second direction. The maintenance unit 60 may be located between the two vertical members 21 of the hanger 20. The maintenance unit 60 may be a platform for maintaining the jetting unit 50. In one embodiment, the maintenance unit 60 may include an ink removal unit to remove ink residue from the jetting unit 50. Therefore, ink discharge defects caused by ink residue in the jetting unit 50 can be prevented or reduced. The jetting unit 50 may be movable in a second direction via the horizontal member 22 of the hanger 20 and may be moved to the maintenance unit 60.

[0070] The controller 90 can be electrically connected to the workbench 11, the guide unit 12, the first moving unit 30, the second moving unit 40, and the spraying unit 50. The controller 90 can control the position and operation of each component. In one embodiment, the controller 90 is electrically connected to the maintenance unit 60 and can control the operation of the maintenance unit 60.

[0071] Figure 2 This is a schematic plan view of the spray unit 50 according to an embodiment.

[0072] refer to Figure 2 The spraying unit 50 may include a head unit 51, a particle number measuring unit 52, and a volume measuring unit 53.

[0073] The head unit 51 can receive and discharge ink. More specifically, the head unit 51 may include a plurality of nozzles NZ. For example, the head unit 51 may extend in a second direction (y direction), and the plurality of nozzles NZ may be arranged side by side along the extension direction of the head unit 51.

[0074] In embodiments, multiple head units 51 may be provided, and the multiple head units 51 may be arranged side by side in a first direction (x direction). The accompanying drawings show four head units 51, and in embodiments, the head units 51 may include a first head unit 51A to a fourth head unit 51D. The foregoing is for illustrative purposes only, and this disclosure is not limited thereto.

[0075] In one embodiment, the head unit 51 may include a piezoelectric element. The head unit 51 may be configured to eject ink using the piezoelectric effect. The piezoelectric element is disposed within the internal space of the head unit 51 and is connected to a switching module, which may be connected to a rod extending in the third direction (z-direction). In one embodiment, an elastic member (e.g., a spring) may be disposed on the rod to surround it. For the operation of the head unit 51, a power source is connected to the piezoelectric element, and thus, power can be provided. Therefore, the piezoelectric element can repeatedly contract and expand due to the piezoelectric effect, and thus, the switching module and the rod connected to the switching module can be vertically raised or lowered. The rod can eject ink solution from the nozzle NZ by the vertical movement of rising or falling. This is an example, and the ejection method of the head unit 51 is not limited to this.

[0076] The particle number measuring unit 52 can measure the number of solute particles within an ink droplet ejected from the head unit 51 (e.g., from the nozzle NZ). In an embodiment, the ink may include a solvent as a base and a solute within the solvent. For example, the ink may include a solvent and functional particles within the solvent. The particle number measuring unit 52 can measure the number of solute particles in an ink droplet ejected from the nozzle NZ. In an embodiment, the particle number measuring unit 52 can measure the number of solute particles within the droplet using laser-induced breakdown spectroscopy (LIBS).

[0077] The particle number measuring unit 52 may be adjacent to the head unit 51. The particle number measuring unit 52 may be arranged adjacent to the head unit 51 and may measure the number of solute particles in each droplet while moving throughout the droplet ejected from the nozzle NZ. For example, if (e.g., when) the number of head units 51 is four as shown in the figures, then the number of particle number measuring units 52 may correspond to the number of head units 51 by four. In an embodiment, the particle number measuring unit 52 may include a first particle number measuring unit 52A, a second particle number measuring unit 52B, a third particle number measuring unit 52C, and a fourth particle number measuring unit 52D. The first particle number measuring unit 52A may measure the number of solute particles in the ink droplet ejected from the nozzle NZ of the first head unit 51A, and, for example, may measure the number of solute particles in the ink droplet while moving in a second direction. In an embodiment, it is understood that the second particle number measuring units 52B to the fourth particle number measuring units 52D may measure the number of solute particles in the ink droplet ejected from the nozzle NZ of the second head unit 51B to the fourth head unit 51D. In this implementation, the particle number measuring unit 52 and the head unit 51 can be integrally formed into a single entity.

[0078] The volume measurement unit 53 can measure the volume of ink droplets ejected from the head unit 51 (e.g., from the nozzle NZ). In an embodiment, the volume measurement unit 53 may include at least one selected from a line scan camera and a color confocal sensor.

[0079] Volume measuring unit 53 may be adjacent to head unit 51. Volume measuring unit 53 may be adjacent to head unit 51 and may measure the volume of each droplet while moving throughout the droplet ejected by nozzle NZ. In an embodiment, volume measuring unit 53 may be arranged adjacent to head unit 51, and if (e.g., when) nozzle NZ ejects droplets, the volume of the droplets may be measured by measuring the diameter of the droplets. For example, if (e.g., when) the number of head units 51 is four as shown in the figures, the number of volume measuring units 53 may correspond to the number of head units 51 being four. In an embodiment, volume measuring unit 53 may include a first volume measuring unit 53A, a second volume measuring unit 53B, a third volume measuring unit 53C, and a fourth volume measuring unit 53D. The first volume measuring unit 53A may measure the volume of ink droplets ejected by nozzle NZ of the first head unit 51A, and may, for example, measure the volume of the ink droplets while moving in a second direction. In this embodiment, it is understood that the second volume measuring unit 53B to the fourth volume measuring unit 53D can measure the volume of ink droplets ejected from the nozzles NZ of the second head unit 51B to the fourth head unit 51D. In this embodiment, the volume measuring unit 53 is configured as a single unit, and therefore, a single volume measuring unit 53 can measure the volume of all ink droplets ejected from the first head unit 51A to the fourth head unit 51D. In this embodiment, the volume measuring unit 53 and the head unit 51 can be integrally formed into a single body.

[0080] In one embodiment, the head unit 51, the particle number measuring unit 52, and the volume measuring unit 53 can be connected to a controller 90. The controller 90 can control the movement of the head unit 51, control the ink ejected from the nozzle NZ of the head unit 51, and / or control the drive of the particle number measuring unit 52 and the volume measuring unit 53. In another embodiment, as further described herein, the controller 90 can generate data from information obtained from the particle number measuring unit 52 and the volume measuring unit 53, and can apply ink efficiently and with excellent quality through a predetermined nozzle NZ to which ink is to be applied to a set or specific area based on this data.

[0081] Figures 3 to 7 This diagram schematically illustrates a method for manufacturing a display device according to an embodiment. The method for manufacturing the display device may use the apparatus 2 used for manufacturing a display device, but is not necessarily limited thereto.

[0082] refer to Figures 3 to 7Ink droplets can be ejected from each of the nozzles NZ of the head unit 51. In one embodiment, the ejected ink droplets can be ejected onto the test substrate TS. The controller 90 can measure the volume of the droplets ejected onto the test substrate TS and the number of solute particles within the droplets by driving the particle number measuring unit 52 and the volume measuring unit 53. Hereinafter, droplets ejected by the first head unit 51A and the second head unit 51B are described primarily. It will be understood that the same description applies to droplets ejected by the third head unit 51C and the fourth head unit 51D.

[0083] The nozzles of the first head unit 51A can be sequentially defined as first nozzle NZ1, second nozzle NZ2, third nozzle NZ3, and fourth nozzle NZ4. The nozzles of the second head unit 51B can be sequentially defined as fifth nozzle NZ5, sixth nozzle NZ6, seventh nozzle NZ7, and eighth nozzle NZ8. The ink droplets ejected from the nozzles of the first head unit 51A (e.g., first nozzles NZ1 to fourth nozzles NZ4) can be sequentially defined as first droplet DR1, second droplet DR2, third droplet DR3, and fourth droplet DR4. The ink droplets ejected from the nozzles of the second head unit 51B (e.g., fifth nozzles NZ5 to eighth nozzles NZ8) can be sequentially defined as fifth droplet DR5, sixth droplet DR6, seventh droplet DR7, and eighth droplet DR8. The first droplet DR1 to fourth droplet DR4 can be measured by a first particle number measuring unit 52A. The first particle number measuring unit 52A can measure the number of solute particles (e.g., functional particles) included in each of the first droplets DR1 to fourth droplets DR4. The fifth droplet DR5 through the eighth droplet DR8 can be measured by the second particle number measuring unit 52B. The second particle number measuring unit 52B can measure the number of solute particles (e.g., functional particles) included in each of the fifth droplet DR5 through the eighth droplet DR8. In this embodiment, the volume of the first droplet DR1 through the fourth droplet DR4 can be measured by the first volume measuring unit 53A. The volume of the fifth droplet DR5 through the eighth droplet DR8 can be measured by the second volume measuring unit 53B.

[0084] refer to Figure 5The controller 90 can generate volume data and concentration data based on information obtained from the volume measurement unit 53 and the particle number measurement unit 52. For example, the controller 90 can generate volume data by matching the volume of each of the first droplets DR1 to the eighth droplets DR8 with the nozzle NZ to which the corresponding droplets have been applied. In one embodiment, the controller 90 can generate particle number data by matching the number of solute particles in each of the first droplets DR1 to the eighth droplets DR8 with the nozzle NZ to which the corresponding droplets have been applied. Next, the particle concentration can be defined as the number of solute particles in the droplet divided by the droplet volume, and therefore, concentration data can be generated using both volume data and particle number data. The volume data, particle number data, and concentration data corresponding to each nozzle are... Figure 5 The example shown is for illustrative purposes. Figure 5 The data is given as an example, and therefore it is understandable that units of volume and concentration are omitted.

[0085] refer to Figure 6 The controller 90 can determine from a plurality of nozzles NZ which nozzles NZ will apply droplets to the printing area. More specifically, the printing area is the area where ink is applied, and in embodiments, the printing area may correspond to the emission area of ​​a pixel, and the ink may be a material applied to form a color filter layer for the pixel. In embodiments, the printing area may correspond to the emission area of ​​a pixel, and the ink may be a material comprising quantum dots to form a functional layer of the pixel. In embodiments, there may be a plurality of printing areas, and at least one nozzle may apply droplets to each of the plurality of printing areas to fill each of the printing areas with ink. For example, the printing areas may include a first area A1 and a second area A2. At least one nozzle NZ (e.g., three nozzles NZ) may apply ink droplets to each of the first area A1 and the second area A2. However, this is for illustrative purposes, and the present disclosure is not necessarily limited thereto, and three or more nozzles NZ or three or fewer nozzles NZ may apply ink droplets to each of the first area A1 and the second area A2. In embodiments, the number of nozzles NZ that apply ink droplets to each of the first area A1 and the second area A2 may be the same, but is not necessarily limited thereto, and may be different.

[0086] The printing areas need to be coated with ink to have a uniform (e.g., substantially uniform) volume and a uniform (e.g., substantially uniform) number of solute particles to prevent unevenness (or reduce the likelihood, degree, or occurrence of unevenness). For example, to prevent unevenness (or reduce the likelihood, degree, or occurrence of unevenness), the volume of ink applied to each of the printing areas (e.g., first area A1 and second area A2) can be made uniform (e.g., substantially uniform). In an embodiment, the concentration of solute particles may vary for each of the nozzles NZ due to the precipitation of solute particles within the head unit 51 or the non-uniformity of the ink flow rate, and therefore, it is useful or necessary not only to ensure that the volume of ink applied to each of the printing areas (e.g., first area A1 and second area A2) is uniform (e.g., substantially uniform), but also to ensure that the number of solute particles in the ink is uniform (e.g., substantially uniform).

[0087] For further reference Figure 7 In this embodiment, the controller 90 can determine which nozzles NZ will apply ink droplets to each of the printing areas by considering at least one selected from volume data, particle number data, and concentration data. More specifically, the controller 90 may have a preset target volume and a preset target particle number. In this context, the target volume may refer to the required volume of ink to be discharged into each of the printing areas (e.g., first area A1 and second area A2). The target particle number may refer to the required number of solute particles within the ink to be discharged into each of the printing areas (e.g., first area A1 and second area A2). Figure 7 The example shown is a case where the target volume is 30 and the target number of particles is 300.

[0088] In one implementation, the controller 90 may have a preset tolerance for each of the target volume and the target number of particles. In this context, the tolerance may refer to the degree to which the target volume and the target number of particles are approximated, within which the target volume and the target number of particles are considered to have been achieved. The tolerance may be set as a percentage or as a unit for each of the target volume and the target number of particles. Figure 7 An example is shown where the tolerance for the target volume is set to ±1 (e.g., ±1%) and the tolerance for the target number of particles is set to ±5 (e.g., ±5%).

[0089] Next, the controller 90 can determine the nozzles NZ (e.g., three nozzles NZ) to which ink droplets should be applied to the first region A1, and the determined nozzles NZ can form a first nozzle group. In an embodiment, the controller 90 can select the nozzles NZ to meet the target volume and the target number of particles. For example, the controller 90 can group any three nozzles NZ. Figure 7In the figures (a) to (d), various suitable combinations of nozzles NZ are shown. In one embodiment, the controller 90 can select a combination of nozzles NZ that allows the sum of the volumes of ink droplets ejected by the three nozzles NZ to be at least 29 and no more than 31. In another embodiment, the controller 90 can select a combination of nozzles NZ that allows the sum of the number of solute particles included in the ink droplets ejected by the three nozzles NZ to be at least 295 and no more than 305. Figure 7 Each of (a) and (d) illustrates a case where nozzles are grouped to meet permissible requirements for target volume and target number of particles. For example, the first, fifth, and ninth nozzles, or the second, sixth, and seventh nozzles, meet permissible requirements for target volume and target number of particles, and thus, one of these two combinations can form a first nozzle group. In an embodiment, the sum of the volumes of the individual ink droplets ejected by the nozzles of the first nozzle group can be the same as the target volume, or can be within the tolerance range of the target volume. In an embodiment, the sum of the numbers of solute particles in the individual droplets ejected by the nozzles of the first nozzle group can be the same as the target number of particles, or can be within the tolerance range of the target number of particles. As a comparative example, Figure 7 (b) shows a combination of nozzles that meets the permissible requirements for target volume but not the permissible requirements for the target number of particles, and Figure 7 (c) shows a combination of nozzles that meets the permissible requirement for the target number of particles but not the permissible requirement for the target volume.

[0090] The controller 90 can identify either combination (a) or combination (d) as the first nozzle group and can control the first nozzle group to apply ink droplets to the first region A1.

[0091] In one implementation, the controller 90 can determine, in a similar manner, the nozzles NZ (e.g., three nozzles NZ) to be applied to the second region A2, and the determined nozzles NZ can form a second nozzle group. Figure 7 In the example, controller 90 can identify, for example, the nozzles in combination (d) as a second nozzle group, and can control the second nozzle group to apply ink droplets to the second region A2. Controller 90 can similarly form combinations of nozzles to apply ink to other printing regions (e.g., a third region, a fourth region, etc.). In an embodiment, controller 90 can pre-group the nozzles to which ink is to be applied to each printing region, and determine the nozzle group before the jetting unit 50 applies ink. Based on this, controller 90 can generate a printed image, and jetting unit 50 can apply ink via the nozzles according to the printed image. In an embodiment, if (e.g., when) jetting unit 50 applies ink, controller 90 can group the nozzles and determine the nozzle group in real time.

[0092] In an implementation, if (e.g., when) controller 90 forms a nozzle group, additional data may be considered. This additional data could be data regarding the distance between the nozzle and the printing area to be coated. For example, in Figure 7 In this case, the combination of nozzles that meets the permissible requirements for target volume and target particle number can be (a) and (d). In an embodiment, the controller 90 can form a combination (a) consisting of nozzles NZ closer to the first region A1 as a first nozzle group, and can form a combination (d) consisting of nozzles NZ closer to the second region A2 as a second nozzle group.

[0093] According to the embodiment described above, the volume of ink applied to each of the printing areas can be uniform (e.g., substantially uniform), and the number of solute particles can be uniform. The controller 90 can select and determine a combination of nozzles from a plurality of nozzles NZ that satisfies the permissible requirements for the target volume and the target number of particles. Therefore, even if the nozzles have slightly different discharge volumes and discharge particle numbers, it can be ensured that each of the printing areas is uniformly (e.g., substantially uniformly) coated with ink, and thus, for example, unevenness related to the number of solute particles can be prevented (or the likelihood, degree, or occurrence of unevenness can be reduced).

[0094] Figures 8 to 9 This diagram schematically illustrates a method for manufacturing a display device according to an embodiment. The manufacturing method according to this embodiment is similar to the manufacturing method described above; therefore, in the following text, only the differences will be primarily described.

[0095] refer to Figure 8 In this implementation, the controller 90 can generate volume data and particle number data by additionally considering the discharge waveform information of the nozzle NZ. For example, the controller 90 can receive discharge waveform information applicable to the nozzle NZ. The discharge waveform information is the waveform information of the voltage applied to the head unit 51 and may include multiple different waveforms, for example, three waveforms: a first waveform (A), a second waveform (B), and a third waveform (C). Each of the nozzles NZ can apply droplets according to different discharge waveforms (e.g., the first waveform (A), the second waveform (B), and the third waveform (C)), and even if (e.g., when) discharged from the same nozzle NZ, the individual droplets according to the discharge waveforms may have different volumes from each other.

[0096] Next, ink droplets can be ejected from each of the nozzles NZ of the head unit 51, and each nozzle NZ can eject ink droplets according to different voltage waveforms of the waveform information. In this embodiment, the ejected ink droplets can then be ejected onto the test substrate. Next, as described above, the controller 90 can measure the volume of the droplets ejected onto the test substrate and the number of solute particles within the droplets by driving the particle number measurement unit 52 and the volume measurement unit 53. Figure 8 The image below shows, as an example, volume data, particle number data, and concentration data of each droplet ejected from the nozzle in different waveforms, obtained in the manner described above.

[0097] refer to Figure 9 The controller 90 can determine which nozzles NZ should apply droplets to the printing area from a plurality of nozzles NZ. In an embodiment, the controller 90 can determine which nozzles NZ should apply ink droplets to each of the printing areas based on at least one of volume data, particle number data, and concentration data that have already taken into account ejection waveform information. The controller 90 can group the nozzles NZ to meet the allowable requirements for the target volume and target particle number. In an embodiment, if (e.g., when) the controller 90 may additionally take into account ejection waveform information compared to the above-described embodiment. For example, Figure 9 (a) illustrates a combination of a first nozzle discharging in a third waveform, a third nozzle discharging in a third waveform, and a fifth nozzle discharging in a third waveform that satisfies the permissible requirements for the target volume and the target number of particles. In the embodiment, Figure 9 (b) and (c) show that the number of nozzles NZ grouped to meet the requirements can be one or two, indicating that the number of nozzles NZ is not limited. The controller 90 can form the nozzle combination (a) as a first nozzle group to allow ink droplets to be applied to a first region A1. In an embodiment, the nozzle combination (b) can be formed as a second nozzle group to allow ink droplets to be applied to a second region A2, and the nozzle combination (c) can be formed as a third nozzle group to allow ink droplets to be applied to a third region.

[0098] According to the embodiment described above, the volume of ink applied to each of the printing areas can be uniform (e.g., substantially uniform), and the number of solute particles can be uniform (e.g., substantially uniform). Even when (e.g.) printing a combination of different types (or varieties) of waveforms with different discharge volumes, information about the volume of droplets to be discharged from the nozzle and the number of solute particles is determined by measurement, and therefore, the controller 90 can control the discharge of ink into each of the printing areas such that the volume and number of solute particles are uniform.

[0099] Figures 10 to 11This diagram schematically illustrates a method for manufacturing a display device according to an embodiment. The manufacturing method according to this embodiment is similar to the manufacturing method described above; therefore, in the following text, only the differences will be primarily described.

[0100] refer to Figure 10 In one embodiment, the controller 90 can adjust the volume of the droplets so that the number of solute particles in the ink droplets ejected from the nozzle NZ is the same. More specifically, the ink droplets ejected from each of the plurality of nozzles NZ may have different concentrations from each other. Therefore, the amount (e.g., volume) of the droplets ejected from each of the nozzles NZ can be adjusted to ensure that the number of solute particles in each droplet is the same. For this purpose, in one embodiment, the head unit 51 may include a per-nozzle driver (DPN) head. In one embodiment, the head unit 51 can increase or decrease the volume of the ejected droplets by appropriately changing the voltage applied to each of the nozzles. For example, if (e.g., when) the voltage applied to each of the nozzles increases, each of the nozzles can eject droplets with a larger volume. If (e.g., when) the voltage applied to each of the nozzles decreases, each of the nozzles can eject droplets with a smaller volume.

[0101] The volume, solute concentration, and number of solute particles of each droplet discharged from the nozzle NZ have been measured via the volume measurement unit 53 and the particle number measurement unit 52. Therefore, in this embodiment, the controller 90 can change the voltage applied to the head unit 51 (nozzle NZ) to adjust the droplet discharge rate so that each droplet discharged from the nozzle NZ has the same number of solute particles. Figure 10 The figure shows, as an example, the droplet volume data, particle number data, and concentration data for each nozzle calculated in the above manner.

[0102] refer to Figure 11 The controller 90 can determine from multiple nozzles NZ which nozzles NZ should apply droplets to the printing area. The controller 90 can group the nozzles NZ to meet the allowable requirements for the target volume and target number of particles mentioned above. For example, Figure 11 Combination (a) illustrates that the combination of the first, sixth, and seventh nozzles, whose discharge volume has been adjusted due to voltage regulation, meets the permissible requirements for the target volume and the target number of particles. The controller 90 can configure nozzle combination (a) as a first nozzle group to allow ink droplets to be applied to the first region A1. In this embodiment, it is understood that by further configuring the nozzle combination to meet the permissible requirements for the target volume and the target number of particles in the above manner, ink droplets can be applied to another printing area, such as the second region A2.

[0103] According to the embodiment described above, the volume of ink applied to each of the printing areas can be uniform (e.g., substantially uniform), and the number of solute particles can be uniform (e.g., substantially uniform). More specifically, information regarding the discharge volume of each nozzle and the number of solute particles in the droplets is determined by measurement, and therefore, the discharge volume can be slightly adjusted so that the number of solute particles in the droplets discharged from each nozzle is the same. Therefore, the number of solute particles in the droplets discharged from each nozzle is constant (e.g., substantially constant), and thus, the requirement for the target number of particles is easily met, and only the requirement for the target volume needs to be considered. Therefore, the time required for the controller 90 to group and select nozzles can be shortened.

[0104] Figure 12 This is a schematic perspective view of the display device 1 according to an embodiment.

[0105] refer to Figure 12 The display device 1 may include a display area DA in which an image is displayed and a non-display area NDA in which no image is displayed. The display device 1 may provide an image via an array of multiple sub-pixels arranged in a two-dimensional plane on the xy plane of the display area DA. Each of the sub-pixels may emit light of a different color, and may be, for example, one selected from red sub-pixels, green sub-pixels, and blue sub-pixels.

[0106] In an implementation, the plurality of sub-pixels may include a first sub-pixel PX1, a second sub-pixel PX2, and a third sub-pixel PX3. In the following description, for ease of explanation, an implementation in which the first sub-pixel PX1 is a red sub-pixel, the second sub-pixel PX2 is a green sub-pixel, and the third sub-pixel PX3 is a blue sub-pixel is described.

[0107] The first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 can emit red light Lr, green light Lg, and blue light Lb, respectively (see [link]). Figure 13 The display device 1 can provide an image by using light emitted from the sub-pixels in the area of ​​the sub-pixels.

[0108] The non-display area NDA is the area that does not provide an image and may completely surround the display area DA. Drivers or main voltage lines for supplying electrical signals or power to pixel circuitry can be provided in the non-display area NDA. The non-display area NDA may include pads, which are areas where electronic devices or printed circuit boards can be electrically connected.

[0109] The display area DA can have features such as Figure 12The quadrilateral polygon shape shown is an example. For instance, the display area DA can be a rectangle with a horizontal length greater than its vertical length, or a rectangle with a horizontal length less than its vertical length, or it can be a square. In embodiments, the display area DA can be circular (e.g., generally circular), elliptical (e.g., generally elliptical), or a polygon such as a triangle or pentagon. In embodiments, Figure 12 The display device 1 is a flat panel display device, but the display device 1 can be implemented in various suitable forms such as flexible display devices, foldable display devices and / or rollable display devices.

[0110] In one embodiment, the display device 1 may be an organic light-emitting display device. In another embodiment, the display device 1 may be an inorganic light-emitting display device and / or a quantum dot light-emitting display device. For example, the emitting layer of the display element included in the display device may include organic materials, inorganic materials, quantum dots, organic materials and quantum dots, inorganic materials and quantum dots, or organic materials, inorganic materials and quantum dots. Hereinafter, for ease of explanation, the embodiment where the display device 1 is an organic light-emitting display device is primarily described.

[0111] Figure 13 This is a schematic cross-sectional view of the display device 1 according to an embodiment.

[0112] refer to Figure 13 The display device 1 may include a circuit layer PCL on the substrate 100. The circuit layer PCL may include a first sub-pixel circuit PC1, a second sub-pixel circuit PC2, and a third sub-pixel circuit PC3, as well as an insulating layer (e.g., an electrically insulating layer or multiple electrically insulating layers). Each of the first sub-pixel circuit PC1, the second sub-pixel circuit PC2, and the third sub-pixel circuit PC3 may include a thin-film transistor and / or a capacitor. The display element layer DEL may include a first light-emitting diode LED1, a second light-emitting diode LED2, and a third light-emitting diode LED3 as display elements. The first sub-pixel circuit PC1, the second sub-pixel circuit PC2, and the third sub-pixel circuit PC3 may be electrically connected to the first light-emitting diode LED1, the second light-emitting diode LED2, and the third light-emitting diode LED3 of the display element layer DEL, respectively.

[0113] Each of the first light-emitting diode (LED1), the second light-emitting diode (LED2), and the third light-emitting diode (LED3) can be an organic light-emitting diode (OLED) comprising organic materials. In some embodiments, each of the first light-emitting diode (LED1), the second light-emitting diode (LED2), and the third light-emitting diode (LED3) can be an inorganic light-emitting diode comprising inorganic materials. The inorganic light-emitting diode can include a PN junction diode comprising materials based on inorganic semiconductors. If (e.g., when) a voltage is applied to the PN junction diode in the forward direction, holes and electrons are injected, and the energy generated due to the recombination of holes and electrons is converted into light energy, thereby emitting light of a set or specific color. The inorganic light-emitting diode can have a width of several to several hundred micrometers or several to several hundred nanometers. In some embodiments, each of the first light-emitting diode (LED1), the second light-emitting diode (LED2), and the third light-emitting diode (LED3) can be a light-emitting diode comprising quantum dots. As described above, the emitting layer of each of the first light-emitting diode (LED1), the second light-emitting diode (LED2), and the third light-emitting diode (LED3) can include organic materials, inorganic materials, quantum dots, organic materials and quantum dots, or inorganic materials and quantum dots.

[0114] The first light-emitting diode (LED1), the second light-emitting diode (LED2), and the third light-emitting diode (LED3) can emit light of the same color. For example, the first light-emitting diode (LED1), the second light-emitting diode (LED2), and the third light-emitting diode (LED3) can emit blue light (Lb). However, this disclosure is not limited thereto. In embodiments, the first light-emitting diode (LED1), the second light-emitting diode (LED2), and the third light-emitting diode (LED3) can emit light of different colors. The light emitted from the first light-emitting diode (LED1), the second light-emitting diode (LED2), and the third light-emitting diode (LED3) (e.g., blue light (Lb)) can pass through the first thin-film encapsulation layer (TFE1) and the functional layer (FNL) on the display element layer (DEL).

[0115] The functional layer FNL may include an optical layer that may or may not convert the color of light (e.g., blue light Lb) emitted from the display element layer DEL and transmit that light. For example, the functional layer FNL may include a quantum dot layer that converts light (e.g., blue light Lb) emitted from the display element layer DEL into a different color, and a transmissive layer that does not convert the color of light (e.g., blue light Lb) emitted from the display element layer DEL and transmits that light. The functional layer FNL may include a first quantum dot layer 510 corresponding to the first sub-pixel PX1, a second quantum dot layer 520 corresponding to the second sub-pixel PX2, and a transmissive layer 530 corresponding to the third sub-pixel PX3. The first quantum dot layer 510 can convert blue light Lb into red light Lr, and the second quantum dot layer 520 can convert blue light Lb into green light Lg. The transmissive layer 530 can transmit blue light Lb without conversion.

[0116] The color filter CFL can be on the functional layer FNL. The second thin-film encapsulation layer TFE2 can be between the functional layer FNL and the color filter CFL. The color filter CFL can include a first color filter 810, a second color filter 820, and a third color filter 830 of different colors. In an embodiment, the first color filter 810 can be a red color filter, the second color filter 820 can be a green color filter, and the third color filter 830 can be a blue color filter.

[0117] Each of the color-converted light and transmitted light from the functional layer FNL can have improved color purity by passing through the first color filter 810, the second color filter 820, and the third color filter 830. In an embodiment, the color filter CFL can prevent, minimize, or reduce the reflection of external light (e.g., light incident on the display device 1 from outside the display device 1) and its visibility to the user.

[0118] The outer coating 900 may be on the color filter CFL. The outer coating 900 may include an organic material. For example, the outer coating 900 may include a light-transmitting organic material such as acrylic resin.

[0119] In some embodiments, after the functional layer FNL, the second thin-film encapsulation layer TFE2, and the color filter CFL are sequentially formed on the first thin-film encapsulation layer TFE1, the outer coating 900 can be formed by directly applying and curing it onto the color filter CFL. In some embodiments, another optical film (e.g., an anti-reflective (AR) film) may be on the outer coating 900. In some embodiments, a window may further be on the outer coating 900.

[0120] The display device 1 having the above structure may include electronic devices capable of displaying moving images and / or still images, such as televisions, billboards, cinema screens, monitors, tablet PCs, laptop computers, etc.

[0121] Figure 14 It shows Figure 13 Each of the functional layers FNL in the optical layer.

[0122] refer to Figure 14 The first quantum dot layer 510 can convert incoming blue light Lb into red light Lr. As shown in the figure, the first quantum dot layer 510 may include a first photosensitive polymer BR1, a first quantum dot QD1, and a first scattering particle SC1, wherein the first quantum dot QD1 and the first scattering particle SC1 are dispersed in the first photosensitive polymer BR1.

[0123] The first quantum dot QD1 can be excited by blue light Lb and isotropically emit red light Lr with a wavelength longer than that of blue light Lb. The first photosensitive polymer BR1 can be a light-transmitting organic material. The first scattering particle SC1 can scatter the blue light Lb that is not absorbed by the first quantum dot QD1, thereby allowing more first quantum dots QD1 to be excited and improving color conversion efficiency. The first scattering particle SC1 can be, for example, titanium oxide (TiO2) and / or metal particles. The first quantum dot QD1 can be selected from group II-VI compounds, group III-V compounds, group IV-VI compounds, group IV elements, group IV compounds, and combinations thereof.

[0124] The second quantum dot layer 520 can convert incoming blue light Lb into green light Lg. As shown in the attached figure, the second quantum dot layer 520 may include a second photosensitive polymer BR2, a second quantum dot QD2, and a second scattering particle SC2, wherein the second quantum dot QD2 and the second scattering particle SC2 are dispersed in the second photosensitive polymer BR2.

[0125] The second quantum dot QD2 can be excited by blue light Lb and isotropically emit green light Lg with a wavelength longer than that of blue light Lb. The second photosensitive polymer BR2 can be a light-transmitting organic material.

[0126] The second scattering particle SC2 can scatter blue light Lb that is not absorbed by the second quantum dot QD2, thereby allowing more second quantum dots QD2 to be excited and improving color conversion efficiency. The second scattering particle SC2 can be, for example, titanium oxide (TiO2) and / or metal particles. The second quantum dot QD2 can be selected from group II-VI compounds, group III-V compounds, group IV-VI compounds, group IV elements, group IV compounds, and combinations thereof.

[0127] In some embodiments, the first quantum dot QD1 and the second quantum dot QD2 may comprise the same material. In some embodiments, the size of the second quantum dot QD2 may be larger than the size of the first quantum dot QD1.

[0128] The transmission layer 530 can transmit blue light Lb without converting the blue light Lb incident on the transmission layer 530. As shown in the figures, the transmission layer 530 may include a third photosensitive polymer BR3 in which third scattering particles SC3 are dispersed. The third photosensitive polymer BR3 may be a light-transmitting organic material such as silicone resin, epoxy resin, etc., and may include the same material as the first photosensitive polymer BR1 and the second photosensitive polymer BR2. The third scattering particles SC3 can scatter and emit blue light Lb, and may include the same material as the first scattering particles SC1 and the second scattering particles SC2.

[0129] Figure 15This is an equivalent circuit diagram showing a light-emitting diode (LED) included in a display device according to an embodiment and a sub-pixel circuit PC electrically connected to the LED. Figure 15 The sub-pixel circuit PC shown can correspond to the above reference. Figure 13 Each of the first sub-pixel circuit PC1, the second sub-pixel circuit PC2, and the third sub-pixel circuit PC3 is described, and Figure 15 The light-emitting diodes (LEDs) mentioned above can correspond to the above references. Figure 13 Each of the first light-emitting diode LED1, the second light-emitting diode LED2, and the third light-emitting diode LED3 is described.

[0130] refer to Figure 15 The sub-pixel electrode (e.g., anode) of a light-emitting diode (e.g., LED) can be connected to a sub-pixel circuit PC, and the opposite electrode (e.g., cathode) of the LED can be connected to a common voltage line VSL or auxiliary wiring configured to provide a common voltage ELVSS. The LED can emit light with a brightness corresponding to the amount of current supplied from the sub-pixel circuit PC.

[0131] The sub-pixel circuit PC can be configured to control the amount of current flowing from the driving voltage ELVDD through the light-emitting diode (LED) to the common voltage ELVSS in accordance with the data signal. The sub-pixel circuit PC may include a first thin-film transistor (TFT) T1, a second TFT T2, a third TFT T3, and a storage capacitor Cst.

[0132] Each of the first thin-film transistor T1, the second thin-film transistor T2, and the third thin-film transistor T3 may be an oxide semiconductor transistor comprising a semiconductor layer containing an oxide semiconductor, or a silicon semiconductor transistor comprising a semiconductor layer containing polycrystalline silicon. Depending on the type (or kind) of the thin-film transistor, the first electrode may be selected from the source electrode and the drain electrode, and the second electrode may be selected from the source electrode and the drain electrode.

[0133] The first thin-film transistor T1 can be a driving thin-film transistor. The first electrode of the first thin-film transistor T1 can be connected to a driving voltage line VDL configured to provide a driving voltage ELVDD, and the second electrode of the first thin-film transistor T1 can be connected to a sub-pixel electrode of a light-emitting diode (LED). The gate electrode of the first thin-film transistor T1 can be connected to a first node N1. The first thin-film transistor T1 can be configured to control the amount of current flowing from the driving voltage ELVDD to the LED in accordance with the voltage at the first node N1.

[0134] The second thin-film transistor T2 can be a switching thin-film transistor. The first electrode of the second thin-film transistor T2 can be connected to the data line DL, and the second electrode of the second thin-film transistor T2 can be connected to the first node N1. The gate electrode of the second thin-film transistor T2 can be connected to the scan line SL. If (e.g., when) a scan signal is provided to the scan line SL, the second thin-film transistor T2 can be turned on, and the second thin-film transistor T2 can be configured to electrically connect the data line DL and the first node N1 together.

[0135] The third thin-film transistor T3 can be an initialization thin-film transistor and / or a sensing thin-film transistor. The first electrode of the third thin-film transistor T3 can be connected to the second node N2, and the second electrode of the third thin-film transistor T3 can be connected to the sensing line ISL. The gate electrode of the third thin-film transistor T3 can be connected to the control line CL.

[0136] The storage capacitor Cst can be connected between the first node N1 and the second node N2. For example, the first capacitor electrode of the storage capacitor Cst can be connected to the gate electrode of the first thin-film transistor T1, and the second capacitor electrode of the storage capacitor Cst can be connected to the sub-pixel electrode of the light-emitting diode LED.

[0137] Figure 15 The first thin-film transistor T1, the second thin-film transistor T2, and the third thin-film transistor T3 are shown to be NMOS transistors, but this disclosure is not limited thereto. For example, at least one of the first thin-film transistor T1, the second thin-film transistor T2, and the third thin-film transistor T3 can be formed as a PMOS transistor.

[0138] exist Figure 15 Three transistors are shown, but this disclosure is not limited thereto. The subpixel circuit PC may include at least four thin-film transistors.

[0139] Figure 16 This is a schematic cross-sectional view of the display device 1 according to an embodiment. (Reference) Figure 16 The display device 1 may include a first sub-pixel PX1, a second sub-pixel PX2, and a third sub-pixel PX3 that emit light of different colors. For example, the first sub-pixel PX1 may emit red light Lr, the second sub-pixel PX2 may emit green light Lg, and the third sub-pixel PX3 may emit blue light Lb.

[0140] The display device 1 may include a stacked structure of a substrate 100, a circuit layer PCL, a display element layer DEL, a lower color filter, a functional layer FNL, and a color filter CFL, wherein the circuit layer PCL, the display element layer DEL, the lower color filter, the functional layer FNL, and the color filter CFL are on the substrate 100. The display element layer DEL may include a first light-emitting diode LED1, a second light-emitting diode LED2, and a third light-emitting diode LED3 electrically connected to the sub-pixel circuits of the circuit layer PCL. The circuit layer PCL may include a plurality of sub-pixel circuits corresponding to the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3, respectively, and each of the plurality of sub-pixel circuits may include, as shown in the reference... Figure 15 The description includes multiple thin-film transistors (TFTs) and a storage capacitor Cst. For example, each of the multiple thin-film transistors (TFTs) can be a driving thin-film transistor T1 (… Figure 15 ).

[0141] Substrate 100 may include glass and / or polymer resin. In embodiments, the polymer resin may include at least one selected from polyethersulfone, polyarylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyimide, polycarbonate, cellulose triacetate, and cellulose acetate propionate. Substrate 100 may have a single-layer or multi-layer structure comprising the above materials. In embodiments, substrate 100 may have an organic / inorganic / organic material structure.

[0142] The circuit layer PCL can be on the substrate 100. Figure 16 The circuit layer PCL is shown to include a thin-film transistor (TFT), a storage capacitor Cst, a first buffer layer 111, a second buffer layer 112, a gate insulating layer 113, an interlayer insulating layer 115, and a planarization layer 118, wherein the first buffer layer 111, the second buffer layer 112, the gate insulating layer 113, the interlayer insulating layer 115, and the planarization layer 118 are below and / or above the thin-film transistor (TFT) and the storage capacitor Cst.

[0143] The first buffer layer 111 and the second buffer layer 112 can reduce or block the penetration of foreign matter, moisture and / or external air from under the substrate 100. The first buffer layer 111 and the second buffer layer 112 may include inorganic insulating materials (e.g., inorganic electrical insulating materials) such as silicon nitride, silicon oxide and / or silicon oxide, and may be a single layer or multiple layers including the above-mentioned inorganic insulating materials.

[0144] A bias electrode BSM can be located on the first buffer layer 111 to correspond to the thin-film transistor (TFT). In some embodiments, a voltage can be applied to the bias electrode BSM. Furthermore, the bias electrode BSM can prevent or reduce external light incident on the semiconductor layer Act. Therefore, the characteristics of the thin-film transistor (TFT) can be stabilized. In some embodiments, the bias electrode BSM can be omitted.

[0145] The semiconductor layer Act may be on the second buffer layer 112. The semiconductor layer Act may include amorphous silicon or polycrystalline silicon. In embodiments, the semiconductor layer Act may include an oxide of at least one material selected from the group consisting of indium (In), gallium (Ga), tin (Sn), zirconium (Zr), vanadium (V), hafnium (Hf), cadmium (Cd), germanium (Ge), chromium (Cr), titanium (Ti), aluminum (Al), cesium (Cs), cerium (Ce), and zinc (Zn). In some embodiments, the semiconductor layer Act may include Zn oxide, In-Zn oxide, and / or Ga-In-Zn oxide as a Zn oxide-based material. In some embodiments, the semiconductor layer Act may be an In-Ga-Zn-O (IGZO), In-Sn-Zn-O (ITZO), and / or In-Ga-Sn-Zn-O (IGTZO) semiconductor that contains metals such as indium (In), gallium (Ga), and / or tin (Sn) in ZnO. The semiconductor layer Act may include a channel region, a source region, and a drain region, wherein the source region and the drain region are respectively located on opposite sides of the channel region. The gate electrode GE may overlap with the channel region of the semiconductor layer Act.

[0146] The gate electrode GE may include a low-resistance metallic material (e.g., a low-resistance metal material). The gate electrode GE may include a conductive material (e.g., an electrically conductive material) such as molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), etc., and may be formed as a single layer or multiple layers including the above materials.

[0147] The gate insulating layer 113 may be located between the semiconductor layer Act and the gate electrode GE. The gate insulating layer 113 may include inorganic insulating materials (e.g., inorganic electrical insulating materials) such as silicon oxide, silicon nitride, silicon nitride, aluminum oxide, titanium oxide, tantalum oxide, hafnium oxide and / or zinc oxide.

[0148] The first electrode CE1 of the storage capacitor Cst can be on the same layer as the gate electrode GE. The first electrode CE1 can be made of the same material as the gate electrode GE. Figure 16The diagram shows the gate electrode GE of the thin-film transistor TFT and the first electrode CE1 of the storage capacitor Cst spaced apart from each other; however, in an embodiment, the storage capacitor Cst may overlap with the thin-film transistor TFT. In an embodiment, the gate electrode GE of the thin-film transistor TFT can be used as the first electrode CE1 of the storage capacitor Cst.

[0149] Interlayer insulating layer 115 may cover gate electrode GE. Interlayer insulating layer 115 may include inorganic insulating materials (e.g., inorganic electrical insulating materials) such as silicon oxide, silicon nitride, silicon nitride, aluminum oxide, titanium oxide, tantalum oxide, hafnium oxide and / or zinc oxide.

[0150] The second electrode CE2, the source electrode SE, and the drain electrode DE of the storage capacitor Cst can be on the interlayer insulating layer 115.

[0151] The second electrode CE2, source electrode SE, and drain electrode DE of the storage capacitor Cst may comprise conductive materials (e.g., electrically conductive materials) including molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), etc., and may be formed as a single layer or multiple layers comprising the aforementioned materials. For example, the second electrode CE2, source electrode SE, and drain electrode DE of the storage capacitor Cst may have a Ti / Al / Ti multilayer structure. The source electrode SE and drain electrode DE may be connected to the source or drain region of the semiconductor layer Act via contact holes.

[0152] The second electrode CE2 of the storage capacitor Cst may overlap with the first electrode CE1, with an interlayer insulating layer 115 between them, and the first electrode CE1 and the second electrode CE2 may form the storage capacitor Cst. In an embodiment, the interlayer insulating layer 115 may serve as the dielectric layer of the storage capacitor Cst.

[0153] Planarization layer 118 may cover the second electrode CE2, source electrode SE, and drain electrode DE of storage capacitor Cst. Planarization layer 118 may be formed as a single layer or multiple layers comprising organic materials and may provide a flat top surface. Planarization layer 118 may include general polymers such as benzocyclobutene (BCB), polyimide, hexamethyldisiloxane (HMDSO), polymethyl methacrylate (PMMA), and / or polystyrene (PS), polymer derivatives having phenol-based groups, acrylic polymers, imide-based polymers, aromatic ether-based polymers, amide-based polymers, fluorine-based polymers, p-xylene-based polymers, vinyl alcohol-based polymers, and / or blends thereof.

[0154] The display element layer (DEL) can be on the circuit layer (PCL) having the above-described structure. The display element layer (DEL) can include a first light-emitting diode (LED1), a second light-emitting diode (LED2), and a third light-emitting diode (LED3) as display elements. The first light-emitting diode (LED1), the second light-emitting diode (LED2), and the third light-emitting diode (LED3) can each include a first sub-pixel electrode 210R, a second sub-pixel electrode 210G, and a third sub-pixel electrode 210B. In an embodiment, the first light-emitting diode (LED1), the second light-emitting diode (LED2), and the third light-emitting diode (LED3) can collectively include an emission layer 220 and a counter electrode 230.

[0155] Each of the first sub-pixel electrode 210R, the second sub-pixel electrode 210G, and the third sub-pixel electrode 210B may be a (semi-)transmissive electrode or a reflective electrode. In some embodiments, the first sub-pixel electrode 210R, the second sub-pixel electrode 210G, and the third sub-pixel electrode 210B may include conductive oxides (e.g., electrically conductive oxides) such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO), and / or aluminum zinc oxide (AZO). In embodiments, each of the first sub-pixel electrode 210R, the second sub-pixel electrode 210G, and the third sub-pixel electrode 210B may include a reflective film comprising silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), and / or compounds thereof. In embodiments, a film comprising ITO, IZO, ZnO, and / or In2O3 may be further included above and / or below the aforementioned film. For example, each of the first sub-pixel electrode 210R, the second sub-pixel electrode 210G, and the third sub-pixel electrode 210B may be provided as ITO / Ag / ITO.

[0156] A first dam layer 215 may be located on the planarization layer 118. The first dam layer 215 may include openings 215OP that expose the central portions of the first sub-pixel electrode 210R, the second sub-pixel electrode 210G, and the third sub-pixel electrode 210B, respectively. The first dam layer 215 may cover the edges of each of the first sub-pixel electrodes 210R, 210G, and 210B. The first dam layer 215 may prevent (or reduce the likelihood, extent, or occurrence of) electric arcs or the like at the edges of the first sub-pixel electrodes 210R, 210G, and 210B by increasing the distance between the edges of the first sub-pixel electrodes 210R, 210G, and 210B and the opposing electrodes 230 above them.

[0157] The first dam layer 215 may be at least one organic insulating material (e.g., an organic electrical insulating material) selected from the group consisting of polyimide, polyamide, acrylic resin, benzocyclobutene and phenolic resin.

[0158] The emitting layers 220 of the first light-emitting diode LED1, the second light-emitting diode LED2, and the third light-emitting diode LED3 may include organic materials, including fluorescent and / or phosphorescent materials that emit red, green, blue, or white light. The emitting layers 220 may be low-molecular-weight organic materials and / or polymeric organic materials, and additional functional layers such as hole transport layers (HTL), hole injection layers (HIL), electron transport layers (ETL), and electron injection layers (EIL) may be selectively provided below and above the emitting layers 220. Figure 16 As shown, the emitting layer 220 may be integrally formed across the first sub-pixel electrode 210R, the second sub-pixel electrode 210G, and the third sub-pixel electrode 210B, but this disclosure is not limited thereto. In some embodiments, the emitting layer 220 may include a layer patterned to correspond to each of the first sub-pixel electrode 210R, the second sub-pixel electrode 210G, and the third sub-pixel electrode 210B. In one embodiment, the emitting layer 220 may be a first color emitting layer. The first color emitting layer may emit light in a first wavelength band, and for example, may emit blue light. In another embodiment, the emitting layer 220 may emit light having a wavelength of about 450 nm to about 495 nm.

[0159] The counter electrode 230 may be located on the emitter layer 220 and may correspond to the first sub-pixel electrode 210R, the second sub-pixel electrode 210G, and the third sub-pixel electrode 210B. The counter electrode 230 may be integrally formed across the first sub-pixel electrode 210R, the second sub-pixel electrode 210G, and the third sub-pixel electrode 210B. In embodiments, the counter electrode 230 may include a conductive material having a low work function (e.g., an electrically conductive material). For example, the counter electrode 230 may include a (semi-)transparent layer comprising silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), and / or alloys thereof. In embodiments, the counter electrode 230 may also include a layer comprising ITO, IZO, ZnO, and / or In2O3 on a (semi-)transparent layer comprising the aforementioned materials.

[0160] The first emission region EA1, the second emission region EA2, and the third emission region EA3 can correspond to the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3, respectively. The first emission region EA1, the second emission region EA2, and the third emission region EA3 can be regions where light generated by the first light-emitting diode LED1, the second light-emitting diode LED2, and the third light-emitting diode LED3 is emitted to the outside. The first emission region EA1 can be defined as the portion of the first sub-pixel electrode 210R exposed by the opening 215OP in the first barrier layer 215. The second emission region EA2 can be defined as the portion of the second sub-pixel electrode 210G exposed by the opening 215OP in the first barrier layer 215. The third emission region EA3 can be defined as the portion of the third sub-pixel electrode 210B exposed by the opening 215OP in the first barrier layer 215. In an embodiment, each of the first emission region EA1, the second emission region EA2, and the third emission region EA3 can be defined by its corresponding opening 215OP in the first barrier layer 215.

[0161] The first emission area EA1, the second emission area EA2, and the third emission area EA3 can be spaced apart from each other. The area in the display area DA other than the first emission area EA1, the second emission area EA2, and the third emission area EA3 can be a non-emission area. The first emission area EA1, the second emission area EA2, and the third emission area EA3 can be distinguished by non-emission areas.

[0162] Spacers for preventing mask scratching (or for reducing its likelihood, extent, or occurrence) may be further included on the first dam layer 215. In embodiments, the spacers and the first dam layer 215 may be integrally formed as a single entity. For example, the spacers and the first dam layer 215 may be formed concurrently (e.g., simultaneously) in the same process using a halftone masking process.

[0163] The first thin-film encapsulation layer TFE1 may cover the display element layer DEL. The first light-emitting diode LED1, the second light-emitting diode LED2, and the third light-emitting diode LED3 may be easily damaged by moisture and / or oxygen introduced from the outside, and therefore can be protected by covering them with the first thin-film encapsulation layer TFE1. The first thin-film encapsulation layer TFE1 may cover the display area DA and may extend beyond the display area DA. The first thin-film encapsulation layer TFE1 may include at least one organic encapsulation layer and at least one inorganic encapsulation layer. For example, the first thin-film encapsulation layer TFE1 may include a first inorganic encapsulation layer 310, a first organic encapsulation layer 320, and a second inorganic encapsulation layer 330 stacked sequentially.

[0164] The first inorganic encapsulation layer 310 and the second inorganic encapsulation layer 330 may comprise at least one inorganic material selected from aluminum oxide, titanium oxide, tantalum oxide, hafnium oxide, zinc oxide, silicon oxide, silicon nitride, and silicon nitride. The first organic encapsulation layer 320 may comprise a polymer-based material. Polymer-based materials may include acrylic resins, epoxy-based resins, polyimides, and / or polyethylene. In an embodiment, the first organic encapsulation layer 320 may comprise an acrylate. The first organic encapsulation layer 320 may be formed by curing monomers and / or applying polymers.

[0165] The first thin-film encapsulation layer TFE1 has the aforementioned multilayer structure, and therefore, even if (for example, when) cracks occur in the first thin-film encapsulation layer TFE1, the propagation of cracks between the first inorganic encapsulation layer 310 and the first organic encapsulation layer 320 and / or between the first organic encapsulation layer 320 and the second inorganic encapsulation layer 330 can be prevented, minimized, or reduced. The formation of pathways for moisture and / or oxygen to permeate from the outside into the display area DA via these pathways can be prevented, minimized, or reduced.

[0166] In some embodiments, other layers, such as a capping layer, may be further between the first inorganic encapsulation layer 310 and the opposing electrode 230.

[0167] The second barrier layer 600 may be on the first thin-film encapsulation layer TFE1. The second barrier layer 600 may include organic and / or inorganic materials. For example, the second barrier layer 600 may include inorganic materials such as silicon oxide, silicon nitride, and / or silicon nitride. In some embodiments, the second barrier layer 600 may include a light-blocking material to serve as a light-blocking layer. The light-blocking material may include at least one selected from, for example, black pigments, black dyes, black particles, and / or metal particles.

[0168] In the second dam layer 600, the opening COP can be defined by a partition wall. The first opening COP1 in the second dam layer 600 can correspond to the opening 215OP of the first dam layer 215 exposing the first sub-pixel electrode 210R, the second opening COP2 in the second dam layer 600 can correspond to the opening 215OP of the first dam layer 215 exposing the second sub-pixel electrode 210G, and the third opening COP3 in the second dam layer 600 can correspond to the opening 215OP of the first dam layer 215 exposing the third sub-pixel electrode 210B. In an embodiment, if (for example, when) viewed in a direction perpendicular to the substrate 100 (z-axis direction), the first opening COP1 in the second dam layer 600 may overlap with the opening 215OP of the first dam layer 215 exposing the first sub-pixel electrode 210R, the second opening COP2 in the second dam layer 600 may overlap with the opening 215OP of the first dam layer 215 exposing the second sub-pixel electrode 210G, and the third opening COP3 in the second dam layer 600 may overlap with the opening 215OP of the first dam layer 215 exposing the second sub-pixel electrode 210G. A partition wall may be located in the second dam layer 600 between the first opening COP1, the second opening COP2, and the third opening COP3.

[0169] The functional layer FNL may occupy the opening COP in the second dam layer 600. In an embodiment, the functional layer FNL may include at least one selected from quantum dots and scattering particles (e.g., light scattering particles). The functional layer FNL may include a first quantum dot layer 510, a second quantum dot layer 520, and a transmission layer 530.

[0170] The first quantum dot layer 510 may occupy the first opening COP1 in the second embankment layer 600. The first quantum dot layer 510 may overlap with the first emission region EA1. The first sub-pixel PX1 may include the first light-emitting diode LED1 and the first quantum dot layer 510.

[0171] The first quantum dot layer 510 can convert light in a first wavelength band generated from the emission layer 220 on the first sub-pixel electrode 210R into light in a second wavelength band. The first quantum dot layer 510 can convert blue light into red light. For example, if light with a wavelength of about 450 nm to about 495 nm is generated from the emission layer 220 on the first sub-pixel electrode 210R, the first quantum dot layer 510 can convert that light into light with a wavelength of about 630 nm to about 780 nm. Therefore, in the first sub-pixel PX1, light with a wavelength of about 630 nm to about 780 nm can be emitted to the outside.

[0172] The first quantum dot layer 510 may include a first photosensitive polymer BR1, a first quantum dot QD1, and a first scattering particle SC1, wherein the first quantum dot QD1 and the first scattering particle SC1 are dispersed in the first photosensitive polymer BR1.

[0173] The second quantum dot layer 520 may occupy the second opening COP2 in the second embankment layer 600. The second quantum dot layer 520 may overlap with the second emission region EA2. The second sub-pixel PX2 may include the second light-emitting diode LED2 and the second quantum dot layer 520.

[0174] The second quantum dot layer 520 can convert light in a first wavelength band generated from the emission layer 220 on the second sub-pixel electrode 210G into light in a third wavelength band. The second quantum dot layer 520 can convert blue light into green light. For example, if light with a wavelength of about 450 nm to about 495 nm is generated from the emission layer 220 on the second sub-pixel electrode 210G, the second quantum dot layer 520 can convert that light into light with a wavelength of about 495 nm to about 570 nm. Therefore, in the second sub-pixel PX2, light with a wavelength of about 495 nm to about 570 nm can be emitted to the outside.

[0175] The second quantum dot layer 520 may include a second photosensitive polymer BR2, a second quantum dot QD2, and a second scattering particle SC2, wherein the second quantum dot QD2 and the second scattering particle SC2 are dispersed in the second photosensitive polymer BR2.

[0176] The transmissive layer 530 may occupy the third opening COP3 in the second embankment layer 600. The transmissive layer 530 may overlap with the third emission region EA3. The third sub-pixel PX3 may include a third light-emitting diode LED3 and the transmissive layer 530.

[0177] The transmissive layer 530 can emit light generated from the emission layer 220 on the third sub-pixel electrode 210B to the outside without wavelength conversion. The transmissive layer 530 can transmit blue light without conversion. For example, if light with a wavelength of about 450 nm to about 495 nm is generated from the emission layer 220 on the third sub-pixel electrode 210B, the transmissive layer 530 can emit light to the outside without wavelength conversion.

[0178] The transmission layer 530 may include a third photosensitive polymer BR3 in which third scattering particles SC3 are dispersed. In some embodiments, the transmission layer 530 may not include quantum dots.

[0179] At least one of the first quantum dot QD1 and the second quantum dot QD2 may include a semiconductor material such as cadmium sulfide (CdS), cadmium telluride (CdTe), zinc sulfide (ZnS), and / or indium phosphide (InP). The quantum dots may have a size of several nanometers, and the wavelength of the converted light can be appropriately changed according to the size of the quantum dots.

[0180] In this embodiment, the nucleus of the quantum dot may be selected from group II-VI compounds, group III-V compounds, group IV-VI compounds, group IV elements, group IV compounds and combinations thereof.

[0181] Group II-VI compounds can be selected from the group consisting of binary, ternary, and quaternary compounds. Binary compounds are selected from the group consisting of CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and mixtures thereof. Ternary compounds are selected from the group consisting of AgInS, CuInS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, and HgSTe. The group consisting of CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS and mixtures thereof, and the quaternary compound selected from the group consisting of HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe and mixtures thereof.

[0182] III-V group compounds can be selected from the group consisting of binary, ternary, and quaternary compounds. Binary compounds are selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof. Ternary compounds are selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, and mixtures thereof. Quaternary compounds are selected from the group consisting of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof.

[0183] Group IV-VI compounds can be selected from groups consisting of binary, ternary, and quaternary compounds. Binary compounds are selected from groups consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof. Ternary compounds are selected from groups consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof. Quaternary compounds are selected from groups consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof. Group IV elements can be selected from groups consisting of Si, Ge, and mixtures thereof. Group IV compounds can be binary compounds selected from groups consisting of SiC, SiGe, and mixtures thereof.

[0184] In embodiments, binary, ternary, and / or quaternary compounds may exist in the particles at a uniform (e.g., substantially uniform) concentration, or the binary, ternary, and quaternary compounds may have partially different concentration distributions and exist in the same particle. Furthermore, the quantum dots may have a core / shell structure in which one quantum dot surrounds another. The interface between the core and shell may have a concentration gradient in which the concentration of the element present in the shell decreases along a direction toward the center of the quantum dot.

[0185] In some embodiments, quantum dots can have a core-shell structure comprising a core and a shell surrounding the core. The shell of the quantum dot can act as a protective layer to prevent or reduce chemical denaturation of the core to maintain semiconductor properties, and / or as a charge layer to impart electrophoretic properties to the quantum dot. The shell can be monolayered or multilayered. The interface between the core and the shell can have a concentration gradient in which the concentration of elements present in the shell decreases along the direction toward the center of the quantum dot. Examples of shells for quantum dots can be oxides of metals and / or nonmetals, semiconductor compounds, or combinations thereof.

[0186] For example, oxides of metals and / or nonmetals may include binary compounds such as SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4, NiO, etc., and / or ternary compounds such as MgAl2O4, CoFe2O4, NiFe2O4, CoMn2O4, etc., but this disclosure is not limited thereto.

[0187] In embodiments, examples of semiconductor compounds may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, etc., but this disclosure is not limited thereto.

[0188] In embodiments, the full width at half maximum (FWHM) of the emission wavelength spectrum of the quantum dot can be about 45 nm or less, for example, about 40 nm or less, for example, about 30 nm or less, and within these ranges, color purity and / or color reproducibility can be improved. In embodiments, light emitted by the quantum dot is emitted in all (e.g., substantially all) directions, and therefore, a wide viewing angle can be improved.

[0189] Furthermore, the shape of quantum dots is not particularly limited to the shapes commonly used in the relevant fields, but more specifically, quantum dots can be spherical nanoparticles, pyramidal nanoparticles, multi-armed nanoparticles, cubic nanoparticles, nanotubes, nanowires, nanofibers and / or nanoplate particles.

[0190] Quantum dots can adjust the color of the emitted light according to their particle size, and therefore, quantum dots can have a variety of suitable emission colors, such as blue, red, green, etc.

[0191] The first scattering particles SC1, the second scattering particles SC2, and the third scattering particles SC3 can scatter light to allow for the emission of more light. The first scattering particles SC1, the second scattering particles SC2, and the third scattering particles SC3 can increase light extraction efficiency. At least one of the first scattering particles SC1, the second scattering particles SC2, and the third scattering particles SC3 can include any suitable material among metals and / or metal oxides to scatter light uniformly (e.g., substantially uniformly). For example, at least one of the first scattering particles SC1, the second scattering particles SC2, and the third scattering particles SC3 can be at least one of TiO2, ZrO2, Al2O3, In2O3, ZnO, SnO2, Sb2O3, and ITO. In embodiments, at least one of the first scattering particles SC1, the second scattering particles SC2, and the third scattering particles SC3 can have a refractive index of 1.5 or greater. Therefore, the light extraction efficiency of the functional layer FNL can be improved. In some embodiments, at least one of the first scattering particles SC1, the second scattering particles SC2, and the third scattering particles SC3 can be omitted.

[0192] The first photopolymer BR1, the second photopolymer BR2, and the third photopolymer BR3 can be light-transmitting organic materials. For example, at least one selected from the first photopolymer BR1, the second photopolymer BR2, and the third photopolymer BR3 may include a polymer resin, such as acryloyl, benzocyclobutene (BCB), and / or hexamethyldisiloxane (HMDSO).

[0193] The second thin-film encapsulation layer TFE2 can be applied to the second diaphragm layer 600 and the functional layer FNL. The second thin-film encapsulation layer TFE2 can prevent, minimize, or reduce damage or contamination of the functional layer FNL caused by external penetration of impurities such as moisture and / or air, and can also prevent or reduce the occurrence and propagation of cracks due to external forces. The second thin-film encapsulation layer TFE2 can improve reliability by strengthening the protection of the functional layer FNL in the display device 1, which has a structure in which components are stacked on a single substrate 100 and excluding an upper substrate.

[0194] The second thin-film encapsulation layer TFE2 can cover the display area DA and extend to the outside of the display area DA. The second thin-film encapsulation layer TFE2 may include at least one organic encapsulation layer and at least one inorganic encapsulation layer. For example, the second thin-film encapsulation layer TFE2 may include a third inorganic encapsulation layer 710, a second organic encapsulation layer 720 and a fourth inorganic encapsulation layer 730 stacked in sequence.

[0195] The third inorganic encapsulation layer 710 and the fourth inorganic encapsulation layer 730 may comprise at least one inorganic material selected from aluminum oxide, titanium oxide, tantalum oxide, hafnium oxide, zinc oxide, silicon oxide, silicon nitride, and silicon nitride. The second organic encapsulation layer 720 may comprise a polymer-based material. Polymer-based materials may include acrylic resins, epoxy-based resins, polyimides, and / or polyethylene. In an embodiment, the second organic encapsulation layer 720 may comprise acrylates. The second organic encapsulation layer 720 may be formed by curing monomers and / or applying polymers.

[0196] The color filter CFL can be located above the second thin-film encapsulation layer TFE2. In an embodiment, the color filter CFL can be directly on the top surface of the second thin-film encapsulation layer TFE2 (in the z-axis direction) and can include a first color filter 810, a second color filter 820, and a third color filter 830. The first color filter 810 can be located above the first quantum dot layer 510 to correspond to the first sub-pixel PX1, the second color filter 820 can be located above the second quantum dot layer 520 to correspond to the second sub-pixel PX2, and the third color filter 830 can be located above the transmissive layer 530 to correspond to the third sub-pixel PX3. The first color filter 810, the second color filter 820, and the third color filter 830 can include a photosensitive resin. In an embodiment, each of the first color filter 810, the second color filter 820, and the third color filter 830 can include a pigment and / or dye that presents its set or unique color.

[0197] The first color filter 810 can be a red color filter. For example, the first color filter 810 can transmit only light with wavelengths from about 630 nm to about 780 nm. The first color filter 810 may include red pigments and / or dyes. The second color filter 820 can be a green color filter. For example, the second color filter 820 can transmit only light with wavelengths from about 495 nm to about 570 nm. The second color filter 820 may include green pigments and / or dyes. The third color filter 830 can be a blue color filter. For example, the third color filter 830 can transmit only light with wavelengths from about 450 nm to about 495 nm. The third color filter 830 may include blue pigments and / or dyes.

[0198] Color filters (CFLs) can reduce external light reflection from the display device 1. For example, if (e.g., when) external light reaches the first color filter 810, only light of a predetermined wavelength as described above can pass through the first color filter 810, and other wavelengths of light can be absorbed or reflected by the first color filter 810. Therefore, only light of a predetermined wavelength among the external light incident on the display device 1 can pass through the first color filter 810, and a portion of it can be reflected from the opposing electrode 230 and / or the first sub-pixel electrode 210R below it, and can be emitted to the outside again. The first color filter 810 can reduce external light reflection by allowing only a portion of the external light incident on the area in which the first sub-pixel PX1 is disposed to be reflected to the outside. The same description applies to the second color filter 820 and the third color filter 830.

[0199] At least two of the color filters selected from the first color filter 810, the second color filter 820, and the third color filter 830 can overlap each other in the non-emission region. At this point, Figure 16 The diagram shows that corresponding portions of the first color filter 810, the second color filter 820, and the third color filter 830 can overlap each other in the non-emissive region. The first color filter 810, the second color filter 820, and the third color filter 830 can at least partially overlap each other to define the light-blocking portion BP. Therefore, even without additional light-blocking components such as a black matrix, the color filter CFL can prevent or reduce color mixing.

[0200] In the implementation, the portions where the first color filter 810 and the second color filter 820 overlap, the portions where the second color filter 820 and the third color filter 830 overlap, and the portions where the first color filter 810 and the third color filter 830 overlap can each serve as a black matrix. For example, this is because if (e.g., when) the first color filter 810 transmits only light with a wavelength of about 630 nm to about 780 nm and the third color filter 830 transmits only light with a wavelength of about 450 nm to about 495 nm, then theoretically, in the portions where the first color filter 810 and the third color filter 830 overlap, there is no light that can pass through both the first color filter 810 and the third color filter 830.

[0201] The light-blocking portion BP may overlap with the partition wall between openings in the second embankment 600 (e.g., the partition wall between the first opening COP1 and the second opening COP2, the partition wall between the second opening COP2 and the third opening COP3, or the partition wall between the first opening COP1 and the third opening COP3).

[0202] The outer coating 900 may cover the color filter CFL. The outer coating 900 may be an organic layer comprising organic materials. For example, the outer coating 900 may comprise a colorless, translucent organic material, such as acrylic resin. The outer coating 900 may protect the color filter CFL and may flatten the top surface of the color filter CFL. Due to the stacked structure of the first color filter 810, the second color filter 820, and the third color filter 830 of the color filter CFL, the bottom surface of the outer coating 900 may have an uneven structure. The top surface of the outer coating 900 may be a flat surface. In some embodiments, another layer, such as a capping layer, may be further placed above the outer coating 900 and / or between the outer coating 900 and the color filter CFL. The capping layer may comprise an inorganic material. In some embodiments, the outer coating 900 may be a window cover.

[0203] According to the implementation method, ink droplets discharged into each of the printing areas can be applied uniformly (e.g., substantially uniformly).

[0204] Therefore, it is possible to improve inkjet printing quality and to enable display devices that prevent or reduce defects such as unevenness.

[0205] It should be understood that the embodiments described herein are to be considered descriptive only and not for limiting purposes. The description of features or aspects within each embodiment should generally be considered applicable to other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those skilled in the art that various suitable changes in form and detail may be made therein without departing from the spirit and scope defined by the appended claims and their equivalents.

Claims

1. An inkjet printing apparatus, characterized in that, include: A platform on which a display substrate is mounted; An ink jetting unit, facing the stage and configured to eject ink onto the display substrate; as well as The controller is configured to control the injection unit. The injection unit includes: The head unit includes multiple nozzles; A volume measurement unit, adjacent to the head unit and configured to measure the volume of ink droplets ejected from the nozzle; and A particle number measuring unit, adjacent to the head unit and configured to measure the number of solute particles within the ink droplets ejected from the nozzle.

2. The inkjet printing apparatus according to claim 1, characterized in that, The particle number measurement unit is also configured to measure the number of solute particles in each of the ink droplets ejected from the nozzle by using laser-induced breakdown spectroscopy.

3. The inkjet printing apparatus according to claim 1, characterized in that, The volume measurement unit includes at least one selected from a line scan camera and a color confocal sensor.

4. The inkjet printing apparatus according to claim 1, characterized in that, The controller is also configured to generate volume data by measuring the volume of ink droplets ejected from each of the plurality of nozzles.

5. The inkjet printing apparatus according to claim 4, characterized in that, The controller is also configured to select some of the plurality of nozzles based on the volume data, such that the volume of the ink droplets discharged into the first region is close to the target volume.

6. The inkjet printing apparatus according to claim 1, characterized in that, The controller is also configured to generate particle count data by measuring the number of solute particles within each of the plurality of nozzles ejected from the ink droplets.

7. The inkjet printing apparatus according to claim 6, characterized in that, The controller is also configured to select some of the plurality of nozzles based on the particle number data, such that the number of solute particles in the ink droplets discharged into the first region is close to the target number of particles.

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