Display device

Abstract

A display device includes a substrate including a plurality of subpixels, a transistor formed in each of the plurality of subpixels, an organic light emitting element formed in each of the plurality of subpixels, an encapsulation layer formed on the organic light emitting element, a reflective member disposed in a boundary region between the plurality of subpixels and formed inside the encapsulation layer, and a color filter layer disposed on the encapsulation layer.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2021-0191085, filed on December 29, 2021, the entire contents of which are incorporated herein by reference for all purposes, as if fully set forth herein. Technical Field

[0003] This invention relates to a high-resolution display device with improved light efficiency. Background Technology

[0004] Recently, with the development of multimedia, the importance of flat panel display devices has increased. In response, flat panel display devices such as liquid crystal displays, plasma displays, and organic light-emitting diode (OLED) displays have been commercialized. Among these, OLED displays are currently widely used due to their high response speed, high brightness, and good viewing angle.

[0005] Meanwhile, with virtual reality and augmented reality attracting much attention in recent years, the demand for compact display devices with high resolution capable of realizing virtual reality and augmented reality is increasing. However, organic electroluminescent display devices based on related technologies struggle to meet this high resolution and compactness requirements. Summary of the Invention

[0006] Therefore, the present invention aims to provide a display device that substantially overcomes one or more problems caused by the limitations and disadvantages of related technologies.

[0007] One advantage of the present invention is that it provides a display device that can achieve high resolution and improve light efficiency.

[0008] Additional features and advantages of the invention will be set forth in the description which follows, will be apparent in part from the description, or may be learned by practice of the invention. These and other advantages of the invention will be realized and obtained by means of the structures specifically pointed out in the written description, the claims, and the drawings.

[0009] To achieve these and other advantages and in accordance with the intent of the invention, as embodied and broadly described herein, a display device includes: a substrate comprising a plurality of sub-pixels; a transistor formed in each of the plurality of sub-pixels; an organic light-emitting element formed in each of the plurality of sub-pixels; an encapsulation layer formed on the organic light-emitting element; a reflective member disposed in a boundary region between the plurality of sub-pixels and formed inside the encapsulation layer; and a color filter layer disposed on the encapsulation layer.

[0010] It will be understood that the foregoing general description and the following detailed description are exemplary and illustrative, intended to provide further explanation of the claimed invention. Attached Figure Description

[0011] The accompanying drawings, which provide a further understanding of the invention and are incorporated in and form a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings:

[0012] Figure 1 This is a schematic block diagram of an organic electroluminescent display device according to the present invention;

[0013] Figure 2 yes Figure 1 A schematic block diagram of the sub-pixels in the diagram;

[0014] Figure 3 This is a conceptual diagram illustrating the circuit diagram of a sub-pixel of an organic electroluminescent display device according to the present invention;

[0015] Figure 4 This is a schematic cross-sectional view illustrating the structure of an organic electroluminescent display device according to a first embodiment of the present invention;

[0016] Figure 5 This is a cross-sectional view showing the structure of an organic electroluminescent display device according to a first embodiment of the present invention;

[0017] Figure 6 It is a diagram illustrating the output path of light emitted from the organic light-emitting element of an organic electroluminescent display device in which no air layer has been formed;

[0018] Figure 7 It is a diagram illustrating the output path of light emitted from the organic light-emitting element of the organic electroluminescent display device according to the first embodiment of the present invention;

[0019] Figures 8A to 8C This is a diagram showing the brightness of R, G, and B sub-pixels in an organic electroluminescent display device without an air layer and in an organic electroluminescent display device with an air layer according to the first embodiment of the present invention.

[0020] Figures 9A to 9G These are diagrams illustrating a method for manufacturing an organic electroluminescent display device according to a first embodiment of the present invention;

[0021] Figure 10 This is a schematic diagram illustrating the reflective component of an organic electroluminescent display device according to a second embodiment of the present invention;

[0022] Figure 11A and 11BThis is a diagram illustrating other structures of the organic electroluminescent display device according to a second embodiment of the present invention. Detailed Implementation

[0023] The advantages and features of the present invention, as well as its implementation methods, will become clear from the embodiments described below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below, but can be implemented in various different forms. These embodiments are provided only to make the disclosure of the present invention thorough and complete. The present invention is provided to fully convey the scope of the invention to those skilled in the art, and the invention is defined only by the scope of the claims.

[0024] The shapes, sizes, proportions, angles, quantities, etc., disclosed in the accompanying drawings to explain embodiments of the present invention are exemplary, and the present invention is not limited to the details illustrated. Throughout the application, the same reference numerals refer to the same components. Furthermore, when describing the present invention, detailed descriptions of related known technologies may be omitted when it is determined that such detailed descriptions would unnecessarily obscure the subject matter of the present invention. Where the terms "comprising," "having," and "including" are used in the description in this application, other parts may be added unless "only" is used.

[0025] When interpreting components, although not explicitly stated otherwise, components should be interpreted as including a margin range.

[0026] When describing positional relationships, such as when the positional relationship between two parts is described as "on," "above," "below," and "next to," one or more other parts can be placed between the two parts, unless "exactly" or "directly" is used.

[0027] When describing temporal relationships, such as when the chronological order is described as "after", "following", "next", "before", etc., discontinuous situations may be included unless "exactly" or "directly" is used.

[0028] Although terms such as "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are merely used to distinguish one component from another. Therefore, within the technical spirit of this invention, the first component mentioned below can be the second component.

[0029] The corresponding features of the various embodiments of the present invention can be combined or integrated with each other in part or in whole, and can be interlocked and driven with each other in various ways. The various embodiments can be implemented independently or together in an associated relationship.

[0030] The following description will refer to the accompanying drawings to illustrate embodiments of the present invention.

[0031] This invention can be applied to various display devices. For example, it can be applied to various display devices such as liquid crystal displays, organic electroluminescent displays, and electrophoretic displays. However, for ease of explanation, organic electroluminescent displays will be described below.

[0032] Figure 1 This is a schematic block diagram of an organic electroluminescent display device according to the present invention; Figure 2 yes Figure 1 A schematic block diagram of the sub-pixels in the diagram.

[0033] like Figure 1 As shown, the organic electroluminescent display device 100 may include an image processing unit 102, a timing control unit 104, a gate driving unit 106, a data driving unit 107, a power supply unit 108, and a display panel 109.

[0034] The image processing unit 102 can output drive signals for driving various devices along with image data provided from the outside. For example, the drive signals output from the image processing unit 102 may include data enable signals, vertical synchronization signals, horizontal synchronization signals, clock signals, etc.

[0035] The timing control unit 104 can receive image data and drive signals together with the image processing unit 102. The timing control unit 104 can generate and output a gate timing control signal GDC for controlling the operation timing of the gate driving unit 106 and a data timing control signal DDC for controlling the operation timing of the data driving unit 107 based on the drive signals input from the image processing unit 102.

[0036] The gate driving unit 106 can output a scan signal to the display panel 109 in response to the gate timing control signal GDC provided by the timing control unit 104. The gate driving unit 106 can output scan signals to multiple gate lines GL1 to GLm. In this case, the gate driving unit 106 can be configured as an IC (integrated circuit), but is not limited thereto.

[0037] The data driver unit 107 can output a data voltage to the display panel 109 in response to a data timing control signal DDC input from the timing control unit 104. The data driver unit 107 can sample and latch the digital data signal DATA provided from the timing control unit 104 and convert it into an analog data voltage based on the gamma voltage. The data driver unit 107 can output data voltages to multiple data lines DL1 to DLn. In this case, the data driver unit 107 can be configured as an IC (integrated circuit), but is not limited thereto.

[0038] The power supply unit 108 can output a high-potential voltage VDD and a low-potential voltage VSS and supply them to the display panel 109. The high-potential voltage VDD can be supplied to the display panel 109 via a first power line EVDD, and the low-potential voltage VSS can be supplied to the display panel 109 via a second power line EVSS. At this time, the voltage output from the power supply unit 108 can be output to the gate driving unit 106 and / or the data driving unit 107 to drive the gate driving unit 106 and / or the data driving unit 107.

[0039] The display panel 109 can display an image corresponding to the data voltage and scan signal provided from the gate driving unit 106 and the data driving unit 107, and the power supply provided from the power supply unit 108.

[0040] Display panel 109 may include a plurality of subpixels SP for displaying an actual image. Subpixels SP may include red, green, and blue subpixels, or white, red, green, and blue subpixels. In this case, the white, red, green, and blue subpixels SP may all have the same area or may have different areas.

[0041] like Figure 2 As shown, a sub-pixel SP can be connected to the gate line GL, the data line DL, the first power line EVDD, and the second power line EVSS. The number of transistors and capacitors, as well as the driving method of the sub-pixel SP, can be determined based on the configuration of the pixel circuit.

[0042] Figure 3 This is a conceptual diagram illustrating the circuit diagram of a sub-pixel of an organic electroluminescent display device according to the present invention.

[0043] like Figure 3 As shown, the organic electroluminescent display device according to the present invention may include gate lines GL, data lines DL, and power lines PL that intersect each other and define sub-pixels SP. Switching transistors Ts, driving transistors Td, storage capacitors Cst, and organic light-emitting elements D may be disposed in the sub-pixels SP.

[0044] The switching transistor Ts can be connected to the gate line GL and the data line DL. The driving transistor Td and the storage capacitor Cst can be connected between the switching transistor Ts and the power line PL. The organic light-emitting element D can be connected to the driving transistor Td.

[0045] In an organic electroluminescent display device with this structure, when the switching transistor Ts is turned on according to the gate signal applied to the gate line GL, the data signal applied to the data line DL is switched to be applied to the gate of the driving transistor Td and one electrode of the storage capacitor Cst via the switching transistor Ts.

[0046] The driving transistor Td is turned on according to the data signal applied to its gate. As a result, a current proportional to the data signal flows from the power line PL through the driving transistor Td to the organic light-emitting element D. Thus, the organic light-emitting element D emits light with a brightness proportional to the current flowing through the driving transistor Td.

[0047] At this time, the storage capacitor Cst is charged with a voltage proportional to the data signal, thereby keeping the gate voltage of the driving transistor Td constant for one frame.

[0048] Although only two transistors Td and Ts and one capacitor Cst are shown in the figure, the invention is not limited thereto, and three or more transistors and two or more capacitors may be provided.

[0049] Figure 4 This is a schematic cross-sectional view illustrating the structure of an organic electroluminescent display device according to a first embodiment of the present invention.

[0050] The organic electroluminescent display device 100 according to the present invention can be applied to various structures. Hereinafter, a so-called OLEDoS (organic light-emitting diode on silicon) structure is described, wherein the organic light-emitting element is formed on a silicon wafer substrate using semiconductor processes. However, the present invention is not limited to the organic electroluminescent display device 100 having this structure.

[0051] like Figure 4 As shown, the organic electroluminescent display device 100 according to the first embodiment of the present invention may include a wafer substrate 110, a first electrode 132, an organic light-emitting layer 134, a second electrode 136, an encapsulation layer 160, and a color filter layer 180.

[0052] The wafer substrate 110 may be a silicon wafer substrate formed using semiconductor processes. An active layer may be formed inside the wafer substrate 110, and gate lines, data lines, and transistors may be disposed on the wafer substrate 110.

[0053] A first electrode 132, an organic light-emitting layer 134, and a second electrode 136 are sequentially formed to form an organic light-emitting element E. In the first electrode 132, a plurality of red sub-pixels, green sub-pixels, and blue sub-pixels may each have their own first electrode 132, which are arranged on the wafer substrate 110 and spaced apart from each other at a predetermined interval.

[0054] An organic light-emitting layer 134 is formed on the entire wafer substrate 110 to cover the wafer substrate 110 and the first electrode 132. The organic light-emitting layer 134 may be formed together for all red, green and blue sub-pixels to emit white light from these sub-pixels.

[0055] The second electrode 136 may be formed on the organic light-emitting layer 134. The second electrode 136 may be formed on all sub-pixels, so that the signal is applied to all sub-pixels simultaneously.

[0056] An encapsulation layer 160 may be formed on the second electrode 136 to prevent oxygen or moisture from penetrating into the organic light-emitting element E. The encapsulation layer 160 may be configured with multiple layers of inorganic and organic layers.

[0057] Color filter layer 180 may be formed on encapsulation layer 160. Color filter layer 180 may include red color filter, green color filter and blue color filter.

[0058] In the organic electroluminescent display device 100 with an OLEDoS structure, since an active layer is formed in the wafer substrate 110 to form transistors, a single-crystal transistor with excellent electromobility can be formed. Therefore, the size of the sub-pixels can be significantly reduced, thereby manufacturing a high-resolution display device.

[0059] Furthermore, in the organic electroluminescent display device 100 with an OLEDoS structure, not only the transistors in the sub-pixels, but also the transistors in the gate driving section and the data driving section can be formed from single-crystal transistors, thereby enabling a fast response speed.

[0060] The organic electroluminescent display device 100 with an OLEDoS structure can be applied to various fields. For example, the organic electroluminescent display device 100 with an OLEDoS structure can be applied to a metaverse device that presents a virtual world based on the recently popular virtual reality (VR) and augmented reality (AR).

[0061] Figure 5 It shows along Figure 4 The image shows a cross-sectional view of the specific structure of the organic electroluminescent display device according to the first embodiment of the present invention, taken along line I-I'. Although the organic electroluminescent display device 100 includes red (R), green (G), and blue (B) sub-pixels, for ease of explanation, only the R and G sub-pixels that are adjacent to each other are described below.

[0062] like Figure 5 As shown, in the organic electroluminescent display device 100 according to the first embodiment of the present invention, transistor T may be disposed on the wafer substrate 110 of each of sub-pixels R and G.

[0063] The transistor T may include: an active region 112 disposed inside the wafer substrate 110; a gate insulating layer 122 formed on the upper surface of the wafer substrate 110; a gate 114 disposed on the gate insulating layer 122; a first interlayer insulating layer 124 formed on the gate insulating layer 122 and the gate 114; and a source 116 and a drain 117 disposed on the first interlayer insulating layer 124.

[0064] The wafer substrate 110 may be a single-crystal silicon wafer formed by growing single-crystal silicon (Si), but is not limited thereto; it may be a wafer made of various semiconductor materials.

[0065] An active region 112 may be formed in a wafer substrate 110. A portion of the active region 112 of the wafer substrate 110 may be doped with impurities inside the wafer substrate 110, so that the active region 112 may include an undoped central channel region 112a, and a source region 112b and a drain region 112c located on both sides of the channel region 112a and doped with impurities.

[0066] The gate insulating layer 122 may be formed by a single layer or multiple layers made of inorganic materials such as SiOx and / or SiNx, but is not limited thereto.

[0067] The gate 114 may be formed by a single layer or multiple layers of metals such as Cr, Mo, Ta, Cu, Ti, Al and / or Al alloys, but is not limited thereto.

[0068] The first interlayer insulating layer 124 can be formed by a single layer or multiple layers of inorganic materials such as SiNx and / or SiOx, or by organic materials such as photoacrylic. Furthermore, the first interlayer insulating layer 124 may be configured with multiple layers of organic and inorganic materials.

[0069] The source 116 and drain 117 can be formed by a single layer or multiple layers of metals such as Cr, Mo, Ta, Cu, Ti, Al and / or Al alloys, but are not limited thereto.

[0070] The source 116 and drain 117 can make ohmic contact with the source region 112b and drain region 112c of the active region 112 via contact holes formed in the gate insulating layer 122 and the first interlayer insulating layer 124, respectively.

[0071] Passivation layer 126 may be formed on wafer substrate 110 on which transistor T is formed. Passivation layer 126 may be formed of organic materials such as optical acrylic, but is not limited thereto.

[0072] A dike layer 152 may be formed on the passivation layer 126 at the boundary of each sub-pixel. The dike layer 152 may serve as a partition wall defining the sub-pixel. The dike layer 152 may separate sub-pixels to prevent the mixing and output of light of a specific color from adjacent sub-pixels.

[0073] The organic light-emitting element E can be formed on the passivation layer 126 and can be connected to the drain 117 of the transistor T via a contact hole formed in the passivation layer 126.

[0074] The organic light-emitting element E may include a first electrode 132 formed between the dam layers 152 and connected to the drain 117 of the transistor T via a contact hole, an organic light-emitting layer 134 formed on the first electrode 132 and the dam layers 152, and a second electrode 136 formed on the organic light-emitting layer 134.

[0075] The first electrode 132 may be formed by a single layer or multiple layers of metals such as Ca, Ba, Mg, Al, Ag and / or their alloys, or by a transparent metal oxide such as indium tin oxide (ITO) or indium zinc oxide (IZO). The first electrode 132 may be connected to the drain 117 of the transistor T. The first electrode 132 may be made of a transparent metal oxide such as indium tin oxide (ITO) or indium zinc oxide (IZO), or a metal with good conductivity.

[0076] When the first electrode 132 is made of a transparent metal oxide, although not shown in the figure, a reflective electrode with good reflectivity, such as Al or Ag, can be formed below the first electrode 132 to reflect the light incident on the first electrode 132, thereby improving the light efficiency.

[0077] The first electrode 132 can be formed for each sub-pixel. Both ends of the first electrode 132 can be covered by the dike layer 152.

[0078] The organic light-emitting layer 134 may be formed on the first electrode 132 and the dam layer 152. The organic light-emitting layer 134 may include at least one of a hole transport layer, a hole injection layer, a light-emitting layer, an electron transport layer, and an electron injection layer.

[0079] The organic light-emitting layer 134 may be a white organic light-emitting layer that emits white light and is substantially formed throughout the display device 100. The organic light-emitting layer 134 may be formed as two or more stacked layers with a tandem structure. Each stacked layer may include a hole transport layer, a light-emitting layer, and an electron transport layer.

[0080] The light-emitting layer may include multiple light-emitting layers stacked in a series structure. For example, the light-emitting layer may include a red (R) light-emitting layer, a green (G) light-emitting layer, and a blue (B) light-emitting layer stacked in a series structure, so that the red, green, and blue light emitted from the individual light-emitting layers can be mixed to output white light. In this case, a hole transport layer, an electron transport layer, and a charge generation layer may be disposed between such light-emitting layers in the series structure.

[0081] In addition, the light-emitting layer may include a yellow-green light-emitting layer and a blue (B) light-emitting layer stacked in a series structure, so that the yellow-green light and blue light emitted from each light-emitting layer can be mixed to output white light.

[0082] In the organic electroluminescent display device 100 according to the first embodiment of the present invention, the structure of the light-emitting layer for emitting white light is not limited to the structure described above, but can have various structures. The organic light-emitting layer 134 can be formed on the entire wafer substrate 110 by a deposition process or a solution process.

[0083] The second electrode 136 may be made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) or a thin metal that transmits visible light, but is not limited thereto.

[0084] When a voltage is applied to the first electrode 132 and the second electrode 136 in the organic light-emitting element E, holes and electrons migrate to the light-emitting layer via the hole transport layer and the electron transport layer, respectively, and combine with each other in the light-emitting layer to emit light.

[0085] An encapsulation layer 160 may be formed on the second electrode 136. The encapsulation layer 160 may include a first encapsulation layer 162 made of inorganic material, a second encapsulation layer 164 made of organic material, and a third encapsulation layer 166 made of inorganic material. In this case, the inorganic material includes, but is not limited to, SiNx and SiOx. Furthermore, the organic material may include, but is not limited to, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, or mixtures thereof.

[0086] However, in the organic electroluminescent display device 100 according to the first embodiment of the present invention, the encapsulation layer 160 is not limited to the three-layer structure described above, but can be formed into various structures. For example, the encapsulation layer 160 may have a two-layer structure of inorganic and organic layers, or may have a four-layer or more-layer structure.

[0087] The second interlayer insulating layer 170 may be formed on the encapsulation layer 160. The second interlayer insulating layer 170 may be formed of an inorganic material such as SiOx, SiNx or SiON.

[0088] An air layer 172 may be formed within the third encapsulation layer 166 in the boundary region between sub-pixels and extend into the second interlayer insulating layer 170. Since the air layer 172 is formed in the boundary region between sub-pixels, the air layer 172 and the dam layer 152 may overlap each other in a direction perpendicular to the substrate 110. The air layer 172 may serve as a reflective member for reflecting light propagating via the third encapsulation layer 166 and the second interlayer insulating layer 170. The reflective member may be disposed at the location overlapping with the dam layer 152. That is, air has a refractive index of approximately 1.0, while the materials forming the third encapsulation layer 166 and the second interlayer insulating layer 170, such as SiOx, have a refractive index of approximately 1.45, SiNx has a refractive index of approximately 1.5, and SiON has a refractive index of approximately 1.4 to 1.8.

[0089] Therefore, due to the refractive index difference between the air layer 172 and the third encapsulation layer 166 and the second interlayer insulating layer 170, light emission is refracted when light propagating via the third encapsulation layer 166 and the second interlayer insulating layer 170 is incident on the air layer 172. In particular, when light propagating via the third encapsulation layer 166 and the second interlayer insulating layer 170 is incident on the air layer 172 at an angle greater than a threshold, total internal reflection occurs at the interface of the air layer 172.

[0090] Meanwhile, when the encapsulation layer 160 is configured with only a first encapsulation layer 162 made of inorganic material and a second encapsulation layer 164 made of organic material, an air layer 172 can be formed in the second encapsulation layer 164 and the second interlayer insulating layer 170. Since the refractive index of the organic material forming the second encapsulation layer 164 is approximately 2.0 or higher, even in this structure, most of the light propagating through the second encapsulation layer 164 and the second interlayer insulating layer 170 and then incident on the interface of the air layer 172 is totally internally reflected.

[0091] As described later, in the organic electroluminescent display device 100 according to the first embodiment of the present invention, when light emitted from a specific sub-pixel is incident on the boundary region between it and an adjacent sub-pixel, the light is totally reflected by the air layer 172 and output via the specific sub-pixel. Therefore, it is possible to prevent light emitted from the corresponding sub-pixel from being output via the adjacent sub-pixel and to improve the intensity of the light output from the corresponding sub-pixel.

[0092] The color filter layer 180 may be formed on the second interlayer insulating layer 170. The color filter layer 180 may include an R color filter, a G color filter, and a B color filter formed in the R sub-pixel, G sub-pixel, and B sub-pixel, respectively.

[0093] For white light emitted from the organic light-emitting element E, an R filter can be used to output only red light by absorbing light in a wavelength band other than the red light passing through the R filter. For white light emitted from the organic light-emitting element E, a G filter can be used to output only green light by absorbing light in a wavelength band other than the green light passing through the G filter. For white light emitted from the organic light-emitting element E, a B filter can be used to output only blue light by absorbing light in a wavelength band other than the blue light passing through the B filter.

[0094] Although not shown in the figure, an inorganic layer such as AlOx may be formed on the second interlayer insulating layer 170, which may form an adhesive layer for improving the bonding strength with the color filter layer 180.

[0095] Adhesive 192 may be disposed on color filter layer 180, protective member 190 may be disposed on adhesive 192, and protective member 190 may be attached to color filter layer 180 by adhesive 192.

[0096] The protective component 190 can be used to protect and encapsulate the organic electroluminescent display device 100, and can be formed of glass or a transparent film. As such a film, a transparent protective film such as polystyrene (PS) film, polyethylene (PE) film, polyethylene naphthalate (PEN) film, or polyimide (PI) film can be used.

[0097] Adhesive 192 may be a transparent optical adhesive (e.g., OCA (Optically Transparent Adhesive)), but is not limited thereto, and may be used with a variety of adhesive components.

[0098] As described above, in the organic electroluminescent display device 100 according to the first embodiment of the present invention, since the transistor T is formed on the wafer substrate 110 made of single crystal semiconductor instead of glass or plastic film, the desired high-quality image can be presented even if the area of ​​the sub-pixel is significantly reduced, thereby enabling the high-resolution display device 100.

[0099] Furthermore, in the organic electroluminescent display device 100 according to the first embodiment of the present invention, since a black matrix for preventing light leakage between sub-pixels R and G is not formed, finer sub-pixels can be formed. This makes it possible to realize a display device 100 with ultra-high resolution.

[0100] In the organic electroluminescent display device 100 according to the first embodiment of the present invention, an air layer 172 is formed in the boundary region of the sub-pixels in the second interlayer insulating layer 170 formed below the color filter layer 180, thereby improving the light efficiency of the R, G and B sub-pixels, which will be described in detail below.

[0101] Figure 6It is a diagram illustrating the output path of light emitted from the organic light-emitting element E of an organic electroluminescent display device in which no air layer has been formed.

[0102] like Figure 6 As shown, white light emitted from sub-pixels R, G, and B passes through color filter layer 180 and is output. At this time, for the white light passing through the R color filter, light of different wavelength bands is absorbed, and only red light is output. For the white light passing through the G color filter, light of different wavelength bands is absorbed, and only green light is output. For the white light passing through the B color filter, light of different wavelength bands is absorbed, and only blue light is output.

[0103] However, in organic electroluminescent display devices with this structure, since the black matrix is ​​not placed between the R, G, and B color filters in order to achieve high resolution, light passing through a specific sub-pixel can be output through other adjacent sub-pixel regions.

[0104] For example, light ① and ③ passing vertically through the R, G, and B color filters can be output as is via the R, G, and B sub-pixels.

[0105] The color filter layer 180 includes R, G, and B color filters with similar refractive indices, which are in contact with each other at the interfaces between sub-pixels. Thus, the interfaces between sub-pixels have substantially similar refractive indices. Therefore, light incident at a predetermined angle onto a specific sub-pixel and onto the interface between adjacent sub-pixels is output as is through the adjacent sub-pixels without being refracted.

[0106] For example, light ② input to the R color filter at a specific angle is incident on the interface between the R sub-pixel and the G sub-pixel. The incident light is directly input to the G sub-pixel without refraction or reflection. Therefore, not all light output from the R sub-pixel is actually output from the R sub-pixel; some light is output via the adjacent G sub-pixel. Consequently, a mixture of different colors of red and green light is generated in the G sub-pixel, which can produce spots on the screen due to light leakage.

[0107] Figure 7 This is a diagram illustrating the output path of light emitted from the organic light-emitting element of the organic electroluminescent display device according to the first embodiment of the present invention.

[0108] like Figure 7 As shown, in the organic electroluminescent display device 100 according to the first embodiment of the present invention, a color filter layer 180 is formed on the R, G, and B sub-pixels, and an air layer 172 is formed in the encapsulation layer 160 and the second interlayer insulating layer 170 in the boundary region between the R, G, and B sub-pixels. In this respect, it can be seen that the air layer 172 divides the encapsulation layer 160 and the second interlayer insulating layer 170 according to the R, G, and B sub-pixels.

[0109] In this case, the air layer 172 is formed as an elongated band shape along the thickness direction of the encapsulation layer 160 and the interlayer insulation layer 170, but is not limited thereto.

[0110] In the organic light-emitting display device 100 having this structure, white light emitted from the organic light-emitting elements E of the R, G, and B sub-pixels propagates through the encapsulation layer 160 and the second interlayer insulating layer 170, and is then output through the color filter layer 180 thereon. For example, white light emitted from the organic light-emitting element E of the R sub-pixel propagates through the encapsulation layer 160 and the second interlayer insulating layer 170, and then passes through the R color filter while absorbing light of different wavelength bands, thereby outputting only red light. White light emitted from the organic light-emitting element E of the B sub-pixel propagates through the encapsulation layer 160 and the second interlayer insulating layer 170, and then passes through the B color filter while absorbing light of different wavelength bands, thereby outputting only blue light. White light emitted from the organic light-emitting element E of the G sub-pixel propagates through the encapsulation layer 160 and the second interlayer insulating layer 170, and then passes through the G color filter while absorbing light of different wavelength bands, thereby outputting only green light.

[0111] Light ① emitted vertically upward from the organic light-emitting element E of the sub-pixel propagates through the encapsulation layer 160 and the second interlayer insulating layer 170, and is then output through a corresponding color filter.

[0112] Light ② emitted from the organic light-emitting element E of the sub-pixel and output upward at a predetermined angle propagates in the encapsulation layer 160 and the second interlayer insulating layer 170 toward the interface between adjacent sub-pixels. However, an air layer 172 is formed in the boundary region between the sub-pixels in the encapsulation layer 160 and the second interlayer insulating layer 170. Therefore, due to the difference in refractive index between the encapsulation layer 160 and the second interlayer insulating layer 170 and the air layer 172, the light propagating toward adjacent sub-pixels in the encapsulation layer 160 and the second interlayer insulating layer 170 does not propagate to the sub-pixels, but is reflected at the interface. In other words, the light propagating to the interface between the sub-pixels propagates through the encapsulation layer 160 and the second interlayer insulating layer 170 of the respective sub-pixels by reflection, and is then output through the corresponding color filter layer 180.

[0113] Therefore, in the organic electroluminescent display device 100 according to the first embodiment of the present invention, the light emitted from the organic light-emitting element E of the corresponding sub-pixel does not propagate to the adjacent sub-pixel, but is entirely output through the corresponding color filter. Thus, defects caused by color mixing with adjacent sub-pixels are prevented, and the brightness in the corresponding sub-pixel can be significantly increased.

[0114] Figures 8A to 8CThis diagram illustrates the brightness of the R, G, and B sub-pixels in an organic electroluminescent display device without an air layer and in an organic electroluminescent display device with an air layer according to the first embodiment of the present invention. In the diagram, the solid line (reference example) represents the brightness without an air layer, and the dashed line (air gap) represents the brightness of the organic electroluminescent display device according to the first embodiment of the present invention.

[0115] like Figure 8A As shown, when no air layer is set, the brightness of the red light output through the R sub-pixel is about 0.11, while when air layer 172 is set, the brightness of the red light output through the R sub-pixel increases to about 0.14.

[0116] like Figure 8B As shown, when no air layer is set, the brightness of the green light output through the G sub-pixel is about 0.13, while when the air layer 172 is set, the brightness of the green light output through the G sub-pixel increases to about 0.136.

[0117] like Figure 8C As shown, when no air layer is set, the brightness of the blue light output through the B sub-pixel is about 0.20, while when the air layer 172 is set, the brightness of the blue light output through the B sub-pixel increases to about 0.30.

[0118] As described above, in the organic electroluminescent display device 100 according to the first embodiment of the present invention, light output from the organic light-emitting element E of the R, G and B sub-pixels and incident on the interface of the R, G and B sub-pixels is totally reflected and then output again via the R, G and B sub-pixels, thus greatly improving the brightness of the R, G and B sub-pixels.

[0119] Figures 9A to 9G This is a diagram illustrating a method for manufacturing an organic electroluminescent display device according to a first embodiment of the present invention.

[0120] First, such as Figure 9A As shown, after fabricating a wafer substrate 110 formed by growing a single-crystal semiconductor material such as single-crystal silicon, impurities are doped into each sub-pixel of the wafer substrate 110. By doping these impurities, an active region 112 including a source region 112b, a drain region 112c, and an undoped central channel region 112a can be formed in the wafer substrate 110.

[0121] Subsequently, as Figure 9B As shown, a gate insulating layer 122 can be formed by laminating inorganic materials such as SiOx or SiNx as a single layer or multiple layers using a CVD (chemical vapor deposition) method. Then, metal can be deposited on the gate insulating layer 122 and etched to form the gate 114.

[0122] Next, inorganic materials can be laminated to form a single or multiple interlayer insulating layer 124. Then, metal can be laminated and etched to form source 116 and drain 117, which are electrically connected to source region 112b and drain region 112c of active region 112, respectively, via corresponding contact holes. Thus, transistor T is completed.

[0123] Subsequently, as Figure 9C As shown, a passivation layer 126 can be formed by laminating an organic material or a mixture of inorganic and organic materials onto the transistor T. Then, a transparent conductive material such as ITO or IZO or a metal can be laminated and etched to form a first electrode 132 in each sub-pixel. At this time, although not shown in the figure, when the first electrode 132 is formed of a transparent conductive material, a metal with good reflectivity, such as Al or Ag, can be laminated onto the passivation layer 126 to form a reflective electrode before the first electrode 132 is formed and etched.

[0124] Subsequently, a dam layer 152 can be formed on the passivation layer 126 on which the first electrode 132 is formed. Then, as... Figure 9D As shown, organic light-emitting materials can be coated on the entire wafer substrate 110 to form an organic light-emitting layer 134.

[0125] Next, a second electrode 136 is formed by laminating a transparent conductive material such as ITO or IZO onto the entire organic light-emitting layer 134 using a sputtering method.

[0126] Subsequently, as Figure 9E As shown, an encapsulation layer 160 can be formed on the second electrode 136. The encapsulation layer 160 may include a first encapsulation layer 162, a second encapsulation layer 164, and a third encapsulation layer 166. The first encapsulation layer 162 can be formed by laminating inorganic materials such as SiOx or SiNx using a CVD method. The second encapsulation layer 164 can be formed by coating organic materials such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, or polyarylate. The third encapsulation layer 166 can be formed by laminating inorganic materials such as SiNx and SiOx using a CVD method.

[0127] Subsequently, a third encapsulation layer 166 may be etched to form an opening 172a in the boundary region between subpixels.

[0128] Next, as Figure 9F As shown, inorganic materials such as SiOx, SiNx or SiON can be laminated on the third encapsulation layer 166 using a CVD method to form a second interlayer insulating layer 170.

[0129] When the second interlayer insulating layer 170 is formed by CVD, the insulating material is deposited most abundantly on the overhang of the opening 172a, second most abundantly on the bottom of the opening 172a, and least abundantly on the sides of the opening 172a. Therefore, as the CVD process proceeds, blank spaces without deposited inorganic material are created inside the opening 172a, and these blank spaces are formed as air layers 172.

[0130] In this case, when the width of the opening 172a exceeds 1 μm, SiOx or SiNx is deposited therein, thus preventing the formation of an air layer inside the opening 172a. Therefore, preferably, the width of the opening 172a is 1 μm or less. Furthermore, the width-to-depth ratio of the opening 172a is preferably set to 1:1.

[0131] Next, as Figure 9G As shown, a color filter layer 180 can be formed on the second interlayer insulating layer 170. Then, a protective member 190 can be attached to the color filter layer 180 using an adhesive 192 such as OCA. Thus, an organic electroluminescent display device 100 is manufactured.

[0132] As described above, in the organic electroluminescent display device 100 according to the first embodiment of the present invention, an air layer 172 is formed below the color filter layer 180 in the boundary region between sub-pixels. Therefore, light penetration into the color filter layer 180 can be prevented, and the intensity of light incident on the color filter layer 180 of the respective sub-pixel can be increased.

[0133] Figure 10 This is a schematic diagram illustrating the reflective member of an organic electroluminescent display device according to a second embodiment of the present invention. In this case, since the organic electroluminescent display device 200 of this embodiment has a substantially identical structure to the organic electroluminescent display device 100 according to the first embodiment except for the reflective member 272, the identical structures are omitted from the figure, and the structure of the reflective member 272 is mainly shown.

[0134] like Figure 10 As shown, in the organic electroluminescent display device 200 according to the second embodiment of the present invention, an organic light-emitting element E may be formed on a wafer substrate 210, and an encapsulation layer 260 may be formed on the organic light-emitting element E. An interlayer insulating layer 270 may be formed on the encapsulation layer 260, and a color filter layer 280 may be formed on the interlayer insulating layer 270.

[0135] Although not shown in the figure, the organic light-emitting element E may include: a first electrode disposed in each R, G and B sub-pixels; an organic light-emitting layer formed on the first electrode and over the entire wafer substrate 210; and a second electrode formed on the organic light-emitting layer over the entire wafer substrate 210.

[0136] The color filter layer 280 may include R, G and B color filters formed in the R, G and B sub-pixels, respectively.

[0137] Although not shown in the figures, the encapsulation layer 260 may include a first encapsulation layer made of inorganic material, a second encapsulation layer made of organic material and formed on the first encapsulation layer, and a third encapsulation layer made of inorganic material and formed on the second encapsulation layer.

[0138] The reflective member 272 may be formed inside the encapsulation layer 260 in the boundary region between sub-pixels. The reflective member 272 may perform the same function as the air layer 172 in the first embodiment. That is, the reflective member 272 may reflect light emitted from the organic light-emitting element E and propagating to adjacent sub-pixels, and output the reflected light through the respective sub-pixels, thereby preventing defects caused by color mixing between adjacent sub-pixels and improving the brightness of the organic electroluminescent display device 200.

[0139] The reflective member 272 is formed by filling the openings formed in the encapsulation layer 260 with a material having a refractive index lower than that of the encapsulation layer 260.

[0140] When the encapsulation layer 260 is formed using the first inorganic encapsulation layer, the second organic encapsulation layer, and the third inorganic encapsulation layer, the reflective member 272 may be formed inside the third inorganic encapsulation layer and may be made of a material having a refractive index lower than that of SiOx or SiNx used to form the third inorganic encapsulation layer.

[0141] When the encapsulation layer 260 is formed using a first inorganic encapsulation layer and a second organic encapsulation layer, the reflective member 272 may be formed inside the second organic encapsulation layer and may be made of a material having a lower refractive index than the organic material.

[0142] As described above, instead of an air layer, the reflective member 272 is formed of a material having a lower refractive index than the material used to form the encapsulation layer. This increases the degree of freedom in the process of forming the reflective member 272. Therefore, the reflective member 272 can be formed only in the encapsulation layer 260 and not in the interlayer insulating layer 270, and the reflective member 272 can have various shapes.

[0143] For example, such as Figure 11A As shown, the reflective member 272 can be configured to narrow in width from top to bottom. Alternatively, as... Figure 11B As shown, the reflective member 272 can be configured to widen in the direction from top to bottom.

[0144] In addition to this structure, the reflective member 272 can be formed in various shapes. The shape of the reflective member 272 can be modified in various ways according to the structure of the organic electroluminescent display device 200.

[0145] Various modifications and variations may be made to this invention without departing from the spirit or scope thereof, as will be apparent to those skilled in the art. Therefore, this invention is intended to cover any modifications and variations that fall within the scope of the appended claims and their equivalents.

Claims

1. A display device, comprising: A substrate comprising multiple sub-pixels; A transistor formed in each of the plurality of sub-pixels; An organic light-emitting element formed in each of the plurality of sub-pixels; An encapsulation layer formed on the organic light-emitting element; An air layer is disposed in the boundary region between the plurality of sub-pixels and formed in an opening inside the encapsulation layer; as well as A color filter layer disposed on the encapsulation layer The width of the opening is 1 μm or less.

2. The display device according to claim 1, wherein the substrate is formed of a semiconductor wafer.

3. The display device according to claim 2, wherein the transistor comprises: An active region formed inside the semiconductor wafer; A gate insulating layer formed on the semiconductor wafer; A gate formed on the gate insulating layer; A first interlayer insulating layer is formed on the gate; as well as The source and drain are formed on the first interlayer insulating layer.

4. The display device according to claim 1, wherein the encapsulation layer comprises: The first encapsulation layer is made of inorganic materials; A second encapsulation layer made of organic material and formed on the first encapsulation layer; as well as A third encapsulation layer made of inorganic materials and formed on the second encapsulation layer.

5. The display device according to claim 4, wherein the air layer is formed in the third encapsulation layer.

6. The display device according to claim 5 further includes a second interlayer insulating layer formed on the encapsulation layer.

7. The display device of claim 6, wherein the air layer extends into the second interlayer insulating layer.

8. The display device of claim 6, wherein a portion of the second interlayer insulating layer fills an opening formed in the third encapsulation layer.

9. The display device according to claim 1, wherein the encapsulation layer comprises: The first encapsulation layer is made of inorganic materials; as well as A second encapsulation layer made of organic material and formed on the first encapsulation layer.

10. The display device of claim 9, wherein the air layer is formed in the second encapsulation layer.

11. The display device of claim 9, further comprising a second interlayer insulating layer formed on the encapsulation layer, A portion of the second interlayer insulating layer fills the opening formed in the second encapsulation layer.

12. The display device according to claim 1, wherein the organic light-emitting element comprises: First electrode; An organic light-emitting layer disposed on the first electrode; as well as The second electrode is disposed on the organic light-emitting layer.

13. The display device according to claim 12, wherein the organic light-emitting layer emits white light.

14. The display device of claim 12, further comprising a dike layer covering both ends of the first electrode. The air layer is located at the point where it overlaps with the embankment layer.

15. The display device of claim 1, wherein the plurality of sub-pixels includes red, green and blue sub-pixels.

16. The display device of claim 7, wherein the air layer is formed as an elongated strip along the thickness direction of the encapsulation layer and the interlayer insulating layer.

17. The display device according to claim 1, wherein the ratio of the width to the depth of the opening is 1:

1.

18. The display device of claim 1, wherein the air layer reflects light emitted from the organic light-emitting element and propagating to adjacent sub-pixels, and outputs the reflected light via the respective sub-pixels.

19. The display device according to claim 1, further comprising an adhesive disposed on the color filter layer and a protective member disposed on the adhesive. The protective member is attached to the color filter layer by the adhesive.

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