Organic light emitting display device and unit pixel

Abstract

The present disclosure relates to an organic light emitting display device and a unit pixel. The organic light emitting display device can include a display panel including a plurality of data lines and a plurality of scan lines crossing each other and unit pixels disposed in a matrix arrangement, each of the unit pixels being disposed in an area where one scan line and three data lines cross; a data driving circuit configured to drive the plurality of data lines; and a gate driving circuit configured to drive a plurality of gate lines. Further, each of the unit pixels includes two sub-pixels, and each of the two sub-pixels has a structure in which a red light emitting element, a green light emitting element, and a blue light emitting element are stacked.

Description

Technical Field

[0001] This invention relates to organic light-emitting display devices, and more particularly to organic light-emitting display devices using a stacked structure. Background Technology

[0002] Various technologies are being developed in connection with display devices used to display visual information in the form of images or pictures. Among these display devices, organic light-emitting diode (OLED) displays are attracting attention as the next generation of displays because they use organic light-emitting diodes (OLEDs), which are self-emissive elements configured to emit light from their light-emitting material layers through the recombination of electrons and holes. This allows them to not only possess characteristics such as fast response time, high brightness, low driving voltage, and ultra-thinness, but also to be implemented in various shapes. Summary of the Invention

[0003] A unit pixel typically consists of three subpixels, each displaying a different color of light (e.g., red, green, and blue). However, the lifespan of a unit pixel can be limited by the weakest of the three subpixels (e.g., lifespan may be determined by the first subpixel that fails). For example, once one of the three subpixels of different colors fails, the unit pixel's ability to display an image is impaired or destroyed. Therefore, dead pixels may exist within a display panel, which can degrade image quality and reduce the lifespan of the device.

[0004] Therefore, this disclosure aims to provide an organic light-emitting display device that substantially eliminates one or more problems caused by the limitations and disadvantages of the prior art.

[0005] The purpose of this invention is to provide an organic light-emitting display device with high resolution and long lifespan that uses a stacked structure.

[0006] Further advantages, objects, and features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon reading the following, or may be learned by practice of the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures particularly pointed out in the written description and its claims, as well as the accompanying drawings.

[0007] To achieve these objectives and other advantages, and in accordance with the purposes of the invention, as implemented and broadly described herein, an organic light-emitting display device includes a unit pixel, each unit pixel comprising two sub-pixels, wherein each sub-pixel has a red light-emitting element, a green light-emitting element, and a blue light-emitting element arranged in a stacked structure. For example, each unit pixel may comprise a pair of sub-pixels.

[0008] The red and green light-emitting elements of the first sub-pixel of the two sub-pixels can be stacked to form a hole-only device (HOD) structure, and the red and green light-emitting elements of the second sub-pixel of the two sub-pixels can be stacked to form an electron-only device (EOD) structure.

[0009] The first sub-pixel may include a first electrode to a third electrode stacked in sequence, a first blue light-emitting element may be disposed between the first electrode and the second electrode, and a first red light-emitting element and a first green light-emitting element may be disposed between the second electrode and the third electrode to form a HOD structure.

[0010] The first blue light-emitting element may include a hole injection layer, a first hole transport layer, a first blue light-emitting material layer and an electron transport layer stacked sequentially between the first electrode and the second electrode in the following order: and the first red light-emitting element and the first green light-emitting element may include a second hole injection layer, a first electron blocking layer, a first red light-emitting material layer, a charge generation layer, a first green light-emitting material layer, a second electron blocking layer and a third hole injection layer stacked sequentially between the second electrode and the third electrode in the following order:

[0011] When a negative (-) voltage is applied to the first and third electrodes and a positive (+) voltage is applied to the second electrode, only the first red luminescent material layer can be activated to emit light, and when a positive (+) voltage is applied to the first and third electrodes and a negative (-) voltage is applied to the second electrode, only the first blue luminescent material layer and the first green luminescent material layer can be activated to emit light.

[0012] The second sub-pixel may include a first electrode to a third electrode stacked in sequence, a second blue light-emitting element may be disposed between the first electrode and the second electrode, and a second red light-emitting element and a second green light-emitting element may be disposed between the second electrode and the third electrode to form a HOD structure.

[0013] The second blue light-emitting element may include a hole injection layer, a first hole transport layer, a second blue light-emitting material layer, and an electron transport layer stacked sequentially between the first electrode and the second electrode in the following order: and the second red light-emitting element and the second green light-emitting element may include a second electron injection layer, a first hole blocking layer, a second red light-emitting material layer, a charge generation layer, a second green light-emitting material layer, a second hole blocking layer, and a third electron injection layer stacked sequentially between the second electrode and the third electrode in the following order:

[0014] When a negative (-) voltage is applied to the first and third electrodes and a positive (+) voltage is applied to the second electrode, only the second green luminescent material layer can be activated to emit light, and when a positive (+) voltage is applied to the first and third electrodes and a negative (-) voltage is applied to the second electrode, only the second red luminescent material layer and the second blue luminescent material layer can be activated to emit light.

[0015] A unit pixel can be driven by a scan line and a first data line to a third data line. The unit pixel may include: a first red LED and a first green LED connected in reverse order; a second red LED and a second green LED connected in reverse order; and a blue LED; a first switching transistor including a gate connected to the scan line, a first electrode connected to the first data line, and a second electrode connected to a first node, thereby being controlled by the scan pulse of the scan line to transmit the data voltage of the first data line to the first node; a first driving transistor including a gate connected to the first node, a first electrode connected to a third power stage, and a second electrode connected to a second node, thereby controlling the current flowing through the first red LED and the first green LED according to the voltage of the first node; and a second switching transistor including a gate connected to the scan line, a first electrode connected to the second data line, and a second electrode connected to the third node. The system comprises: a second electrode, thereby controlled by the scan pulse of the scan line to transmit the data voltage of the second data line to the third node; a second driving transistor, comprising a gate connected to the third node, a first electrode connected to the first power stage, and a second electrode connected to the fourth node, thereby controlling the current flowing through the blue LED according to the voltage of the third node; a third switching transistor, comprising a gate connected to the scan line, a first electrode connected to the third data line, and a second electrode connected to the fifth node, thereby controlled by the scan pulse of the scan line to transmit the data voltage of the third data line to the fifth node; and a third driving transistor, comprising a gate connected to the fifth node, a first electrode connected to the third power stage, and a second electrode connected to the sixth node, thereby controlling the current flowing through the second red LED and the second green LED according to the voltage of the fifth node. The first red LED and the first green LED can be connected between the second node and the second power stage, the blue LED can be connected between the fourth node and the second power stage, and the second red LED and the second green LED can be connected between the sixth node and the second power stage.

[0016] The unit pixel may also include a first capacitor connected between the first node and the second node, a second capacitor connected between the third node and the fourth node, and a third capacitor connected between the fifth node and the sixth node.

[0017] The unit pixel may also include a multiplexer, each multiplexer being connected to a corresponding power level among the first to third power levels and configured to select one of a positive (+) voltage and a negative (-) voltage according to a selection signal, and to provide the selected voltage to the corresponding power level among the first to third power levels.

[0018] When a positive (+) voltage is applied to the first and third power stages, a negative (-) voltage is applied to the second power stage, and a data voltage is supplied to the first data line, only the first green LED illuminates. When a positive (+) voltage is applied to the first and third power stages, a negative (-) voltage is applied to the second power stage, and a data voltage is supplied to the third data line, only the second red LED illuminates.

[0019] When a positive (+) voltage is applied to the first and third power stages, a negative (-) voltage is applied to the second power stage, and a data voltage is supplied to the second data line, only the blue LED can emit light.

[0020] When a positive (+) voltage is applied to the first and third power stages, a negative (-) voltage is applied to the second power stage, and a data voltage is provided to each of the first to third data lines, the first green LED, the second red LED, and the blue LED can emit light, and thus, a unit pixel can display white.

[0021] When a negative (-) voltage is applied to the first and third power stages, a positive (+) voltage is applied to the second power stage, and a data voltage is supplied to the first data line, only the first red LED illuminates. When a negative (-) voltage is applied to the first and third power stages, a positive (+) voltage is applied to the second power stage, and a data voltage is supplied to the third data line, only the second green LED illuminates.

[0022] When a negative (-) voltage is applied to the first and third power stages, a positive (+) voltage is applied to the second power stage, and a data voltage is provided to each of the first to third data lines, the first red LED and the second green LED can emit light, and thus, a unit pixel can display yellow.

[0023] The organic light-emitting display device having the above-described features according to an exemplary embodiment of the present invention has the following effects.

[0024] First, each pixel consists of two sub-pixels and is driven by a DC voltage Ac, thus enabling the emission of red, green, blue, and white. Therefore, resolution enhancement is achieved.

[0025] Secondly, the light-emitting layers used to emit white light and those that emit red and green light can be driven differently, thus enabling organic light-emitting display devices with a long lifespan.

[0026] Third, in the case of blue light-emitting diodes with relatively short lifespans, the blue light-emitting diodes drive two sub-pixels simultaneously, and thus, an organic light-emitting display device with a long lifespan can be realized. Attached Figure Description

[0027] The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application. The drawings illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings:

[0028] Figure 1 This is a diagram illustrating an organic light-emitting display device according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic cross-sectional view of a unit pixel according to an embodiment of the present invention;

[0030] Figure 3 This is a diagram illustrating the structure of a HOD element according to an embodiment of the present invention;

[0031] Figure 4 This describes an embodiment of the present invention. Figure 3 Energy level diagram illustrating the operating principle of HOD elements;

[0032] Figure 5 This illustrates the basis of embodiments according to the present invention. Figure 3 A graph of the spectrum of the HOD element;

[0033] Figure 6 This is a diagram illustrating the structure of an EOD element according to an embodiment of the present invention;

[0034] Figure 7 This describes an embodiment of the present invention. Figure 6 Energy level diagram illustrating the operating principle of EOD elements;

[0035] Figure 8 This illustrates the basis of embodiments according to the present invention. Figure 6 A graph of the spectrum of the EOD element;

[0036] Figure 9 This is a circuit diagram of the circuit configuration of a unit pixel of an organic light-emitting display panel according to an embodiment of the present invention;

[0037] Figure 10 This is a layout diagram of unit pixels according to an embodiment of the present invention;

[0038] Figure 11 It is according to an embodiment of the present invention. Figure 10 A plan view of the first electrode, second electrode, third electrode, and dam structure shown;

[0039] Figure 12 This is a diagram showing the specific cross-sectional structure of a sub-pixel of a unit pixel according to an embodiment of the present invention;

[0040] Figure 13 This is a circuit diagram illustrating the green emission state of a unit pixel in an organic light-emitting display device according to an embodiment of the present invention;

[0041] Figure 14 This illustrates an embodiment of the invention for use with Figure 13 A table showing the status of each power stage and each data line in the circuit diagram;

[0042] Figure 15 This is a circuit diagram illustrating the state of red emission per pixel of an organic light-emitting display device according to an embodiment of the present invention;

[0043] Figure 16 This illustrates the basis of embodiments according to the present invention. Figure 15 A table showing the status of each power stage and each data line in the circuit diagram;

[0044] Figure 17 This is a circuit diagram illustrating the state of blue emission per pixel of an organic light-emitting display device according to an embodiment of the present invention;

[0045] Figure 18 This illustrates the basis of embodiments according to the present invention. Figure 17 A table showing the status of each power stage and each data line in the circuit diagram;

[0046] Figure 19 This is a circuit diagram illustrating the state in which a unit pixel of an organic light-emitting display device emits white light according to an embodiment of the present invention;

[0047] Figure 20 This illustrates the basis of embodiments according to the present invention. Figure 19 A table showing the status of each power stage and each data line in the circuit diagram;

[0048] Figure 21 This is a circuit diagram illustrating the state of red emission per pixel of an organic light-emitting display device according to another embodiment of the present invention;

[0049] Figure 22 This illustrates the basis of embodiments according to the present invention. Figure 21 A table showing the status of each power stage and each data line in the circuit diagram;

[0050] Figure 23 This is a circuit diagram illustrating the green emission state of a unit pixel in an organic light-emitting display device according to an embodiment of the present invention;

[0051] Figure 24 This illustrates the basis of embodiments according to the present invention. Figure 23 A table showing the status of each power stage and each data line in the circuit diagram;

[0052] Figure 25 This is a circuit diagram illustrating the state of yellow emission per pixel of an organic light-emitting display device according to an embodiment of the present invention; and

[0053] Figure 26 This illustrates the basis of embodiments according to the present invention. Figure 25 A table showing the status of each power stage and each data line in the circuit diagram. Detailed Implementation

[0054] In the following description, a pixel circuit having the above-described features according to an exemplary embodiment of the present invention and an organic light-emitting display device including the pixel circuit will be described in detail with reference to the accompanying drawings. Throughout the specification, the same reference numerals denote substantially the same constituent elements.

[0055] Descriptions of embodiments of this disclosure will now be given in detail, examples of which are illustrated in the accompanying drawings. In the following description, detailed descriptions of well-known functions or configurations relevant to this document will be omitted where such obscuration of the essential points of the inventive concept would be unnecessarily obscure. The progression of the described processing steps and / or operations is exemplary; however, the order of steps and / or operations is not limited to the order set forth herein, except that they must occur in a specific order, and can be varied as is known in the art. The same reference numerals always denote the same elements. The names of the elements used in the following description are chosen solely for ease of writing this specification and may therefore differ from those used in actual products.

[0056] It should be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0057] Although the device described below will be illustrated with examples of devices including n-type thin-film transistors (TFTs), the device can be implemented as including p-type TFTs or TFTs having both n-type and p-type characteristics. A TFT can be a three-electrode element comprising a gate, a source, and a drain. The source is the electrode configured to supply charge carriers to the transistor. Charge carriers in the TFT first flow out from the source. The drain is the electrode from which charge carriers discharge from the TFT to the outside of the TFT. That is, charge carriers in the TFT flow from the source to the drain.

[0058] In the case of an n-type TFT, the source voltage is lower than the drain voltage, allowing electrons to flow from the source to the drain, since electrons are charge carriers. In an n-type TFT, because electrons flow from the source to the drain, current flows from the drain to the source. Conversely, in the case of a p-type TFT, the source voltage is higher than the drain voltage, allowing holes to flow from the source to the drain, since holes are charge carriers. In a p-type TFT, because holes flow from the source to the drain, current flows from the source to the drain. However, in a TFT, the source and drain can be interchanged depending on the voltage applied to them. Considering this, one of the source and drain will be called the "first electrode," and the other will be called the "second electrode."

[0059] Figure 1 An organic light-emitting display device according to an embodiment of the present invention is shown.

[0060] Reference Figure 1 An organic light-emitting display device according to an embodiment of the present invention includes a display panel 100 having a unit pixel PXL, a data driving circuit 300 configured to drive data lines 114, a gating driving circuit 400 configured to drive gating lines 115, and a timing controller 200 configured to control the driving timing of the data driving circuit 300 and the gating driving circuit 400.

[0061] Multiple data lines 114 and multiple gate lines 115 intersect each other at the display panel 100. Unit pixels PXL are arranged in a matrix such that each unit pixel in PXL is located in the area where one gate line 115 intersects with three data lines 114. Unit pixels PXL positioned on the same horizontal line form a pixel row. Unit pixels PXL positioned in a pixel row are connected to one gate line 115, and one gate line 115 may include one or more scan lines and one or more light-emitting lines.

[0062] In other words, each unit pixel PXL can be connected to three data lines 114, one or more scan lines, and one or more emission lines. The unit pixel PXL can receive both a high-level voltage VDD and a low-level voltage VSS from the power generator.

[0063] The TFT constituting a single pixel PXL can be implemented as an oxide TFT including an oxide semiconductor layer. Considering all electron mobility, process variations, etc., oxide TFTs are advantageous in terms of expanding the display panel 100. Of course, the exemplary embodiments of the present invention are not limited to the above conditions, and the semiconductor layer of the TFT can be formed from amorphous silicon, polycrystalline silicon, etc.

[0064] Each unit pixel PXL consists of two sub-pixels (e.g., a pair of sub-pixels), and each sub-pixel has a stacked structure of red light-emitting elements, green light-emitting elements, and blue light-emitting elements.

[0065] The first of the two sub-pixels constituting a unit pixel PXL is composed of a hole-only device (HOD) structure, and the second of the two sub-pixels is composed of an electronic-only device (EOD) stacked structure. Specific configurations will be described later.

[0066] The timing controller 200 rearranges the digital video data RGB input from the external display panel 100 according to the resolution of the display panel 100, and provides the rearranged digital video data RGB to the data drive circuit 300. Additionally, the timing controller 200 generates a data control signal DDC for controlling the operation timing of the data drive circuit 300 and a gating control signal GDC for controlling the operation timing of the gating drive circuit 400 based on timing signals such as the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the dot clock signal DCLK, and the data enable signal DE.

[0067] The data drive circuit 300 converts the digital video data RGB input from the timing controller 200 into analog data voltage based on the data control signal DDC.

[0068] The gating drive circuit 400 can generate scan signals and emission signals based on the gating control signal GDC. The gating drive circuit 400 may include a scan driver and an emission driver. The scan driver can generate scan signals in a row-sequential manner to drive one or more scan lines connected to each pixel row and can provide scan signals to the scan lines. The emission driver can generate emission signals in a row-sequential manner to drive one or more emission lines connected to each pixel row and can provide emission signals to the emission lines.

[0069] The gating drive circuit 400 described above can be directly formed in the display panel 100 as an in-panel gating driver (GIP).

[0070] Figure 2 This is a schematic cross-sectional view of a unit pixel according to an embodiment of the present invention.

[0071] like Figure 2 As shown, a unit pixel includes a first subpixel 1 and a second subpixel 2, and each subpixel in the first subpixel 1 and the second subpixel 2 has a structure of two stacked layers, Stack1 and Stack2.

[0072] That is, the first electrode 10 is disposed on the substrate Sub, the first stack 1 is disposed on the first electrode 10, and the second electrode 20 is disposed on the first stack 1. In addition, the second stack 2 is disposed on the second electrode 20, and the third electrode 30 is disposed on the second stack 2.

[0073] The first stack 1 includes blue luminescent materials B1 and B2, and the second stack 2 includes red luminescent materials R1 and R2 and green luminescent materials G1 and G2.

[0074] In this case, the first subpixel 1 is composed of hole-only (HOD) elements, and the second subpixel 2 is composed of electronic-only (EOD) elements.

[0075] Figure 3 This is a diagram showing the structure of a HOD element according to an embodiment of the present invention. Figure 4 This is an explanation Figure 3 Energy level diagram illustrating the operating principle of HOD elements. Figure 5 It shows the basis Figure 3 A graph of the spectrum of the HOD element.

[0076] like Figure 3 As shown, in the first subpixel 1 according to an embodiment of the present invention, the first stack 1 is disposed between the first electrode 10 and the second electrode 20, and the second stack 2 is disposed between the second electrode 20 and the third electrode 30.

[0077] The first stack 1 is configured to be stacked sequentially on the first electrode 10 in the following order: a first hole injection layer (HIL) 11, a first hole transport layer (HTL) 12, a first blue luminescent material layer (B1 EML) 13, and an electron transport layer (ETL) 14.

[0078] The second stack 2 is configured to be stacked on the second electrode 20 in the following order: a second hole injection layer (HIL) 21, a first electron blocking layer (EBL) 22, a first red luminescent material layer (R1 EML) 23, a charge generation layer (CGL) 24, a first green luminescent material layer (G1 EML) 25, a second electron blocking layer (EBL) 26, and a third hole injection layer (HIL) 27.

[0079] The second stack 2 of the first sub-pixel 1 has a HOD structure.

[0080] like Figure 3 and Figure 4 The second stack in the HOD structure shown is configured such that the first red luminescent material layer 23 and the first green luminescent material layer 25 are symmetrical about the charge generation layer 24.

[0081] Figure 4 The charge generation layer (CGL) 24 is shown to have a structure in which a p-CGL is disposed between two n-CGLs. The n-CGL / p-CGL / n-CGL structure of the charge generation layer (CGL) 24 can be formed from a ZnO / PEDOT:PSS / ZnO layer.

[0082] like Figure 4 As shown, when a positive bias is applied to the HOD structure such that a positive (+) voltage is applied to the second electrode 20 and a negative (-) voltage is applied to the third electrode 30, holes and electrons are generated in the charge generation layer (CGL) 24. Electrons and holes are generated at the interface between the n-CGL and p-CGL of the charge generation layer (CGL) 24 by drifting due to the positive bias caused by the applied voltage.

[0083] Holes transitioning from the second electrode 20 and electrons generated in the charge generation layer 24 move to the first red luminescent material layer (R1 EML) 23, thereby forming excitons. As a result, the first red luminescent material layer (R1 EML) 23 produces visible light.

[0084] In this situation, electrons transitioning from the third electrode 30 are blocked by the second electron blocking layer (EBL) 26. Therefore, because electrons transitioning from the third electrode 30 cannot move to the first green luminescent material layer (G1 EML) 25, the first green luminescent material layer (G1 EML) 25 does not emit light.

[0085] Conversely, when a reverse bias is applied to the HOD structure, resulting in a negative (-) voltage applied to the second electrode 20 and a positive (+) voltage applied to the third electrode 30, holes and electrons are generated in the charge generation layer (CGL) 24. Electrons and holes are generated at the interface between the n-CGL and p-CGL of the charge generation layer (CGL) 24 by drifting due to the reverse bias caused by the applied voltage.

[0086] Holes transitioning from the third electrode 30 and electrons generated in the charge generation layer (CGL) 24 move to the first green luminescent material layer (G1 EML) 25, thereby forming excitons. As a result, the first green luminescent material layer (G1 EML) 25 produces visible light.

[0087] In this situation, electrons transitioning from the second electrode 20 are blocked by the first electron blocking layer (EBL) 22. Therefore, because electrons transitioning from the second electrode 20 cannot move to the first red luminescent material layer (R1 EML) 23, the first red luminescent material layer (R1 EML) 23 does not emit light.

[0088] because Figure 3 The structure uses only hole current in principle, hence it is called a "hole-only device (HOD)".

[0089] Based on the above principles, such as Figure 5 As shown, when a forward bias is applied to the HOD element, the HOD element emits red, while when a reverse bias is applied to the HOD element, the HOD element emits green. In other words, the first subpixel 1 can selectively switch between displaying two different colors depending on how it is biased (e.g., forward bias to emit red, reverse bias to emit green).

[0090] Figure 6 This is a diagram illustrating the structure of an EOD element according to an embodiment of the present invention. Figure 7 This is an explanation Figure 6 Energy level diagram illustrating the operating principle of EOD element. Figure 8 It shows the basis Figure 6 A graph of the spectrum of the EOD element.

[0091] like Figure 6 As shown, in the second subpixel 2 according to an embodiment of the present invention, the first stack 1 is disposed between the first electrode 10 and the second electrode 20, and the second stack 2 is disposed between the second electrode 20 and the third electrode 30.

[0092] The first stack 1 is configured to be stacked sequentially on the first electrode 10 in the following order: a first hole injection layer (HIL) 11, a first hole transport layer (HTL) 12, a second blue luminescent material layer (B2 EML) 13, and an electron transport layer (ETL) 14.

[0093] The second stack 2 is configured to be stacked on the second electrode 20 in the following order: a first electron injection layer (EIL) 31, a first hole blocking layer (HBL) 32, a second red luminescent material layer (R2 EML) 33, a charge generation layer (CGL) 34, a second green luminescent material layer (G2 EML) 35, a second hole blocking layer (HBL) 36, and a second electron injection layer (EIL) 37.

[0094] The second stack 2 of the second subpixel 2 has an EOD structure.

[0095] like Figure 6 and Figure 7 The second stack in the EOD structure shown is configured such that the second red luminescent material layer 33 and the second green luminescent material layer 35 are symmetrical about the charge generation layer 34.

[0096] Figure 7 The charge generation layer (CGL) 34 is shown to have an n-CGL disposed between two p-CGLs. The p-CGL / n-CGL / p-CGL structure of the charge generation layer (CGL) 34 can be formed from a PVK / PEDOT:PSS / PVK layer.

[0097] like Figure 7 As shown, when a positive bias is applied to the EOD structure such that a positive (+) voltage is applied to the second electrode 20 and a negative (-) voltage is applied to the third electrode 30, holes and electrons are generated in the charge generation layer (CGL) 34. Electrons and holes are generated at the interface between the n-CGL and p-CGL of the charge generation layer (CGL) 34 by drifting due to the positive bias caused by the applied voltage.

[0098] Electrons transitioning from the third electrode 30 and holes generated in the charge generation layer (CGL) 34 move to the second green luminescent material layer (G2 EML) 35, thereby forming excitons. As a result, the second green luminescent material layer (G2 EML) 35 produces visible light.

[0099] In this situation, holes transitioning from the second electrode 20 are blocked by the first hole blocking layer (HBL) 32. Therefore, because holes transitioning from the second electrode 20 cannot move to the second red luminescent material layer (R2 EML) 33, the second red luminescent material layer (R2 EML) 33 does not emit light.

[0100] Conversely, when a reverse bias is applied to the EOD structure, resulting in a negative (-) voltage applied to the second electrode 20 and a positive (+) voltage applied to the third electrode 30, holes and electrons are generated in the charge generation layer (CGL) 34. Electrons and holes are generated at the interface between the n-CGL and p-CGL of the charge generation layer (CGL) 34 by drifting due to the reverse bias caused by the applied voltage.

[0101] Electrons transitioning from the second electrode 20 and holes generated in the charge generation layer (CGL) 34 move to the second red luminescent material layer (R2 EML) 33, thereby forming excitons. As a result, the second red luminescent material layer (R2 EML) 33 produces visible light.

[0102] In this situation, holes transitioning from the third electrode 30 are blocked by the second hole blocking layer (HBL) 36. Therefore, because holes transitioning from the third electrode 30 cannot move to the second green luminescent material layer (G2 EML) 35, the second green luminescent material layer (G2 EML) 35 does not emit light.

[0103] because Figure 6 The structure uses only electronic current in principle, hence it is called an "electronic-only device (EOD)".

[0104] Based on the above principle, when a forward bias is applied to the EOD element, the EOD element emits green, and when a reverse bias is applied to the EOD element, the EOD element emits red. In other words, the second subpixel 2 can selectively switch between displaying two different colors depending on how it is biased (e.g., forward bias to emit green, reverse bias to emit red). Furthermore, the second subpixel 2 can operate in the opposite way to the first subpixel 1. For example, when the first subpixel 1 is forward biased, it emits red, but when the second subpixel 2 is forward biased, it emits green. Similarly, when the first subpixel 1 is reverse biased, it emits green, but when the second subpixel 2 is reverse biased, it emits red.

[0105] In the following text, the circuit configuration, layout, and cross-sectional structure of a unit pixel according to an embodiment of the present invention, configured as described above, will be described.

[0106] Figure 9This is a circuit diagram of the circuit configuration of a unit pixel of an organic light-emitting display panel according to an embodiment of the present invention.

[0107] First of all, Figure 9 middle, Figure 3 As shown and by Figure 3 The first stack 1, consisting of the first electrode 10, hole injection layer (HIL) 11, first hole transport layer (HTL) 12, first blue light emitting material layer (B1 EML) 13, electron transport layer (ETL) 14, and second electrode 20, is shown as a first blue light emitting diode OLED B1.

[0108] Figure 3 As shown and by Figure 3 The second stack 2, consisting of the second electrode 20, the second hole injection layer (HIL) 21, the first electron blocking layer (EBL) 22, the first red light-emitting material layer (R1 EML) 23, the charge generation layer (CGL) 24, the first green light-emitting material layer (G1 EML) 25, the second electron blocking layer (EBL) 26, the third hole injection layer (HIL) 27, and the third electrode 30, is shown as the first red light-emitting diode OLED R1 and the first green light-emitting diode OLED G1.

[0109] in addition, Figure 6 As shown and by Figure 6 The first stack 1, consisting of the first electrode 10, the first hole injection layer (HIL) 11, the first hole transport layer (HTL) 12, the second blue light emitting material layer (B2 EML) 13, the electron transport layer (ETL) 14, and the second electrode 20, is shown as a second blue light emitting diode OLED B2.

[0110] Figure 6 As shown and by Figure 6 The second stack 2, consisting of the second electrode 20, the first electron injection layer (EIL) 31, the first hole blocking layer (HBL) 32, the second red light-emitting material layer (R2 EML) 33, the charge generating layer (CGL) 34, the second green light-emitting material layer (G2 EML) 35, the second hole blocking layer (HBL) 36, the second electron injection layer (EIL) 37 and the third electrode 30, is shown as a second red light-emitting diode OLED R2 and a second green light-emitting diode OLED G2.

[0111] The first red OLED R1 and the first green OLED G1 are symmetrical about their corresponding charge generation layers CGL. The second red OLED R2 and the second green OLED G2 are symmetrical about their corresponding charge generation layers CGL.

[0112] Therefore, the first red light-emitting diode OLED R1 and the first green light-emitting diode OLED G1 are shown to be connected in reverse to each other, and the second red light-emitting diode OLED R2 and the second green light-emitting diode OLED G2 are shown to be connected in reverse to each other.

[0113] Furthermore, the first blue light-emitting diode OLED B1 and the second blue light-emitting diode OLED B2 have the same stacked structure and are therefore shown as a single blue light-emitting diode OLED B1-B2 (e.g., shown as an equivalent circuit). Therefore, in Figure 9 In the image, a single pixel is shown as consisting of five light-emitting diodes.

[0114] In embodiments of the present invention, it is also required to switch the voltage applied to the first electrode 10, the second electrode 20 and the third electrode 30 to selectively drive the five light-emitting diodes constituting a unit pixel.

[0115] For this purpose, a unit pixel uses at least three power stages P / L1, P / L2, and P / L3, and three multiplexers MUX1, MUX2, and MUX3 are connected to power stages P / L1, P / L2, and P / L3, respectively. Each of the multiplexers MUX1, MUX2, and MUX3 is switched by a selection signal SS, thereby outputting either a high-level voltage VDD or a low-level voltage VSS. For example, by changing the selection of the high-level voltage VDD and the low-level voltage VSS only via the multiplexer and the selection signal SS, the unit pixel can switch between being driven with a forward bias and being driven with a reverse bias (e.g., the unit pixel can switch back and forth between two different driving modes).

[0116] like Figure 9 As shown, a unit pixel includes a scan line SCAN1, three data lines DATA1, DATA2 and DATA3, and a first red light-emitting diode OLED R1 and a first green light-emitting diode OLED G1, driven by three power stages P / L1, P / L2 and P / L3, which are connected in opposite directions to each other, a second red light-emitting diode OLED R2 and a second green light-emitting diode OLED G2, and blue light-emitting diodes OLED B1-B2, which are also connected in opposite directions to each other.

[0117] Here, the first power stage P / L1 is used to... Figure 2 , Figure 3and Figure 6 The power line that applies voltage to the first electrode 10 shown is the power line, and the second power stage P / L2 is used to apply voltage to... Figure 2 , Figure 3 and Figure 6 The second electrode 20 shown is a power supply line for applying voltage, and the third power stage P / L3 is used to supply voltage to... Figure 2 , Figure 3 and Figure 6 The power supply line to which the voltage is applied to the third electrode 30 shown (for example, the second power stage P / L2 is connected between the first power stage P / L1 and the third power stage P / L3, which corresponds to the second electrode, the first electrode and the third electrode in each of the first subpixel 1 and the second subpixel 2, respectively).

[0118] The following describes the configuration of the pixel circuits of the light-emitting diodes OLED R1, OLED R2 and OLED G1, OLED G2 and OLED B1-B2 configured as described above.

[0119] According to an embodiment of the present invention, a pixel circuit for a unit pixel includes a first switching transistor SW1 to a third switching transistor SW3, a first driving transistor DR1 to a third driving transistor DR3, and a first capacitor C1 to a third capacitor C3.

[0120] The first switching transistor SW1 is connected to the scan line SCAN1 at its gate, to the first data line DATA1 at its first electrode, and to node N1 at its second electrode. Thus, it is controlled by the scan pulse of the scan line SCAN1, thereby transmitting the data voltage of the first data line DATA1 to node N1.

[0121] The second switching transistor SW2 is connected to the scan line SCAN1 at its gate, to the second data line DATA2 at its first electrode, and to node N2 at its second electrode. Thus, it is controlled by the scan pulse of the scan line SCAN1, thereby transmitting the data voltage of the second data line DATA2 to node N2.

[0122] The third switching transistor SW3 is connected to the scan line SCAN1 at its gate, to the third data line DATA3 at its first electrode, and to node N3 at its second electrode. Thus, it is controlled by the scan pulse of the scan line SCAN1, thereby transmitting the data voltage of the third data line DATA3 to node N3.

[0123] The first driving transistor DR1 is connected to node N1 at its gate, to the third power stage P / L3 at its first electrode, and to node S1 at its second electrode, and thus controls the current flowing through the first red light-emitting diode OLED R1 and the first green light-emitting diode OLED G1 according to the voltage of node N1.

[0124] The second driving transistor DR2 is connected to node N2 at its gate, to the first power stage P / L1 at its first electrode, and to node S2 at its second electrode, and thus controls the current flowing through the blue light-emitting diodes OLED B1-B2 according to the voltage of node N2.

[0125] The third driving transistor DR3 is connected to node N3 at its gate, to the third power stage P / L3 at its first electrode, and to node S3 at its second electrode, and thus controls the current flowing through the second red light-emitting diode OLED R2 and the second green light-emitting diode OLED G2 according to the voltage of node N3.

[0126] The first capacitor C1 is connected between node N1 and node S1, and thus stores the data voltage provided to node N1 within one frame.

[0127] The second capacitor C2 is connected between node N2 and node S2, and thus stores the data voltage provided to node N2 within one frame.

[0128] The third capacitor C3 is connected between node N3 and node S3, and thus stores the data voltage provided to node N3 within one frame.

[0129] In this configuration, the first red LED OLED R1 and the first green LED OLED G1, which are connected in opposite directions, are connected between node S1 and the second power stage P / L2. The blue LEDs OLED B1-B2 are connected between node S2 and the second power stage P / L2. The second red LED OLED R2 and the second green LED OLED G2, which are connected in opposite directions, are connected between node S3 and the second power stage P / L2.

[0130] Next, the layout and cross-sectional view of a unit pixel having the above-described circuit configuration according to an embodiment of the present invention will be described.

[0131] Figure 10 This is a layout diagram of unit pixels according to an embodiment of the present invention. Figure 11 yes Figure 10 The diagram shows the first electrode, second electrode, third electrode, and dam structure.

[0132] According to an embodiment of the present invention, a unit pixel includes two sub-pixels (see...). Figure 2 It is driven by one scan line SCAN, three data lines DATA1, DATA2 and DATA3, and two power stages P / L1 or P / L3 and P / L2.

[0133] Figure 10 The first power stage P / L1 or the third power stage P / L3 shown is used to supply power to... Figure 6 The power supply lines shown apply voltage to the first electrode 10 and the third electrode 30, and the second power stage P / L2 is used to supply voltage to... Figure 3 and Figure 6 The second electrode 20 shown is a power supply line to which a voltage is applied.

[0134] The first switching transistor SW1 is located in the area where the scan line SCAN and the first data line DATA1 intersect each other, the second switching transistor SW2 is located in the area where the scan line SCAN and the second data line DATA2 intersect each other, and the third switching transistor SW3 is located in the area where the scan line SCAN and the third data line DATA3 intersect each other.

[0135] In the case of the first switching transistor SW1, its gate is connected to the scan line SCAN, its first electrode protrudes from the first data line DATA1, and its second electrode extends adjacent to the first data line DATA1 along the longitudinal direction of the first data line DATA1 between the first data line DATA1 and the second data line DATA2.

[0136] In the case of the second switching transistor SW2, its gate is connected to the scan line SCAN, its first electrode protrudes from the second data line DATA2, and its second electrode extends adjacent to the second data line DATA2 along the longitudinal direction of the second data line DATA2 between the second data line DATA2 and the third data line DATA3.

[0137] In the case of the third switching transistor SW3, its gate is connected to the scan line SCAN, its first electrode protrudes from the third data line DATA3, and its second electrode extends adjacent to the third data line DATA3 along the longitudinal direction of the third data line DATA3 between the third data line DATA3 and the second data line DATA2.

[0138] The first driving transistor DR1, the second driving transistor DR2, and the third driving transistor DR3 are disposed in the region opposite to the regions of the first switching transistor SW1, the second switching transistor SW2, and the third switching transistor SW3.

[0139] In the case of the first driving transistor DR1, its gate is formed to be integrally arranged with the second electrode of the first switching transistor SW1, its first electrode is connected to the first power stage P / L1 or the third power stage P / L3, and its second electrode is connected to the third electrode 30 of the light-emitting element of the first sub-pixel in the sub-pixel.

[0140] In the case of the second driving transistor DR2, its gate is formed to be integrally arranged with the second electrode of the second switching transistor SW2, its first electrode is connected to the first power stage P / L1 or the third power stage P / L3, and its second electrode is connected to the first electrode 10 of the light-emitting element.

[0141] In the case of the third driving transistor DR3, its gate is formed to be integrally arranged with the second electrode of the third switching transistor SW3, its first electrode is connected to the first power stage P / L1 or the third power stage P / L3, and its second electrode is connected to the third electrode 30 of the light-emitting element.

[0142] The second electrode 20 is connected to the second power stage P / L2 via the first contact hole C1, the second electrode of the second driving transistor DR2 is connected to the first electrode 10 via the second contact hole C2, the second electrode of the third driving transistor DR3 is connected to the third electrode 30 of the second sub-pixel via the third contact hole C3, and the second electrode of the first driving transistor DR1 is connected to the third electrode 30 of the first sub-pixel via the fourth contact hole C4.

[0143] Figure 11 yes Figure 10 The diagram shows the first electrode, second electrode, third electrode, and dam structure.

[0144] like Figure 11 As shown, the first electrode 10 and the second electrode 20 are integrally disposed at the first sub-pixel 50a and the second sub-pixel 50b, and the third electrode 30 is independently disposed at each of the first sub-pixels 50a and the second sub-pixel 50b. For example, the blue light-emitting diode can have a larger size than each of the red and green light-emitting diodes, thus extending the lifespan of the blue light-emitting diode (e.g., the blue light-emitting diode can be greater than or equal to twice the size of each of the red and green light-emitting diodes).

[0145] The first electrode 10, the second electrode 20, and the third electrode 30 are stacked sequentially, as shown in the reference. Figure 3 and Figure 6 As described.

[0146] In the following text, a specific cross-sectional structure of the sub-pixel configured as described above according to an embodiment of the present invention will be described.

[0147] Figure 12 This is a diagram showing the specific cross-sectional structure of a sub-pixel of a unit pixel according to an embodiment of the present invention.

[0148] Figure 12 The cross-sectional structure includes along Figure 10 The cross-sectional structures cut by lines A-A', B-B', C-C' and D-D' in the diagram.

[0149] Each unit pixel includes a first subpixel 1 and a second subpixel 2, and each subpixel in the first subpixel 1 and the second subpixel 2 has a structure of two stacked layers, Stack 1 and Stack 2.

[0150] The stacked structures of the first subpixel 1 and the second subpixel 2 are similar to each other, and... Figure 9 In the circuit configuration of a unit pixel, the configuration of the first red light-emitting diode OLED R1 and the first green light-emitting diode OLED G1, the first switching transistor SW1 and the first driving transistor DR1 is the same as the configuration of the second red light-emitting diode OLED R2 and the second green light-emitting diode OLED G2, the third switching transistor SW3 and the third driving transistor DR3.

[0151] Therefore, the cross-sectional configuration of only one subpixel will be described.

[0152] Multiple gates G1, G2 and G3 are formed on the substrate Sub, and a gate insulating layer GI is formed on the entire surface of the substrate Sub, which includes the multiple gates G1, G2 and G3.

[0153] Multiple active layers A1, A2 and A3 are formed on the gate insulating layer GI to overlap with multiple gates G1, G2 and G3 respectively, and multiple sources S1, S2 and S3 and multiple drains D1, D2 and D3 are formed on opposite sides of the multiple active layers A1, A2 and A3 respectively.

[0154] Interlayer insulating layer IL and outer coating layer OC are formed on the entire surface of gate insulating layer GI, which has multiple active layers A1, A2 and A3, multiple sources S1, S2 and S3 and multiple drains D1, D2 and D3.

[0155] Figure 9 The second driving transistor DR2 shown is composed of a gate G1, an active layer A1, a source S1, and a drain D1.

[0156] Figure 9 The third switching transistor SW3 shown consists of a gate G2, an active layer A2, a source S2, and a drain D2.

[0157] Figure 9 The third driving transistor DR3 shown consists of a gate G3, an active layer A3, a source S3, and a drain D3.

[0158] Therefore, the drain D2 of the third switching transistor SW3 is electrically connected to the gate G3 of the third driving transistor DR3.

[0159] Furthermore, the first electrode 10, blue luminescent material B1 or B2, the second electrode 20, red luminescent material R1 or R2, green luminescent material G1 or G2, and the third electrode 30 are sequentially stacked on the outer coating OC of the luminescent region of the sub-pixel in this order, as shown in the reference. Figure 2 As stated above.

[0160] Figure 2 , Figure 3 and Figure 6 This shows a green luminescent material G1 or G2 stacked on a red luminescent material R1 or R2, while Figure 12 This illustrates a red luminescent material R1 or R2 stacked on a green luminescent material G1 or G2. The order in which the green luminescent material G1 or G2 and the red luminescent material R1 or R2 are placed does not affect the image display.

[0161] The second contact hole C2 is formed at the interlayer insulating layer IL and the outer coating layer OC to expose the drain D1 of the second driving transistor DR2, and thereby the first electrode 10 is electrically connected to the drain D1 of the second driving transistor DR2.

[0162] The third contact hole C3 is formed at the interlayer insulating layer IL and the outer coating layer OC to expose the drain D3 of the third driving transistor DR3, and thereby the third electrode 30 is electrically connected to the drain D3 of the third driving transistor DR3.

[0163] In addition, the second power stage P / L2 is electrically connected to the second electrode 20 via the first contact hole C1.

[0164] Figure 12 The second electrode 20 is electrically connected to the second power stage P / L2 via a stack of materials connecting electrode CE1 and the first electrode 10, and the third electrode 30 is electrically connected to the drain D3 of the third driving transistor DR3 via a stack of materials connecting electrode CE2 and the first electrode 10.

[0165] In addition, a dike layer 40 defining the sub-pixel region is formed on the outer coating OC in the non-light-emitting region of each sub-pixel.

[0166] In addition, the source S1 of the second driving transistor DR2 can be electrically connected to the first power stage P / L1 or the third power stage P / L3.

[0167] The gate G2 of the third switching transistor SW3 can be electrically connected to the scan line SCAN or can be formed as an integral arrangement with the scan line SCAN, and the source S2 of the third switching transistor SW3 can be electrically connected to the third data line DATA3 or can be formed as an integral arrangement with the third data line DATA3.

[0168] The source S3 of the third driving transistor DR3 can be electrically connected to either the first power stage P / L1 or the third power stage P / L3.

[0169] In the following, a method for driving a unit pixel of an organic light-emitting display device configured as described above according to an embodiment of the present invention will be described.

[0170] Figure 13 This is a circuit diagram illustrating the green emission state of a unit pixel in an organic light-emitting display device according to an embodiment of the present invention. Figure 14 It shows the basis Figure 13 A table showing the status of each power stage and each data line in the implementation.

[0171] For green emission per unit pixel, a selection signal is output to multiplexers MUX1, MUX2, and MUX3, which are respectively connected to the three power stages P / L1, P / L2, and P / L3. Thus, a high-level voltage VDD is applied to the first power stage P / L1 and the third power stage P / L3, and a low-level voltage VSS is applied to the second power stage P / L2.

[0172] In this case, when only the data voltage is supplied to the first data line DATA1, only the first green light-emitting diode OLED G1 can be driven.

[0173] Figure 15 This is a circuit diagram illustrating the state in which a unit pixel of an organic light-emitting display device emits red light according to an embodiment of the present invention. Figure 16 It shows the basis Figure 15 A table showing the status of each power stage and each data line in the implementation.

[0174] For red emission per unit pixel, a high-level voltage VDD is applied to the first power level P / L1 and the third power level P / L3, and a low-level voltage VSS is applied to the second power level P / L2.

[0175] In this case, when only the data voltage is supplied to the third data line DATA3, only the second red light-emitting diode OLED R2 can be driven.

[0176] Figure 17 This is a circuit diagram illustrating the state of blue emission per pixel of an organic light-emitting display device according to an embodiment of the present invention. Figure 18It shows the basis Figure 17 A table showing the status of each power stage and each data line in the implementation.

[0177] For blue emission per unit pixel, a high-level voltage VDD is applied to the first power level P / L1 and the third power level P / L3, and a low-level voltage VSS is applied to the second power level P / L2.

[0178] In this case, when only the data voltage is supplied to the second data line DATA2, only the blue light-emitting diodes OLED B1-B2 can be driven.

[0179] Figure 19 This is a circuit diagram illustrating the state in which a unit pixel of an organic light-emitting display device emits white light according to an embodiment of the present invention. Figure 20 It shows the basis Figure 19 A table showing the status of each power stage and each data line in the implementation.

[0180] For white emission per unit pixel, a high-level voltage VDD is applied to the first power level P / L1 and the third power level P / L3, and a low-level voltage VSS is applied to the second power level P / L2.

[0181] In this case, when data voltage is supplied to all the first data lines DATA1, the second data line DATA2, and the third data line DATA3, the first green light-emitting diode OLED G1, the second red light-emitting diode OLED R2, and the blue light-emitting diodes OLED B1-B2 can be driven simultaneously, thereby emitting white light.

[0182] Furthermore, when different voltages are applied to the power levels P / L1, P / L2, and P / L3, a single pixel can emit red and green.

[0183] Figure 21 This is a circuit diagram illustrating the state in which a unit pixel of an organic light-emitting display device emits red light according to another embodiment of the present invention. Figure 22 It shows the basis Figure 21 A table showing the status of each power stage and each data line in the implementation.

[0184] For red emission per unit pixel, a low-level voltage VSS is applied to the first power level P / L1 and the third power level P / L3, and a high-level voltage VDD is applied to the second power level P / L2.

[0185] In this case, when a data voltage is applied to the first data line DATA1, only the first red light-emitting diode OLED R1 can be driven.

[0186] Figure 23This is a circuit diagram illustrating the green emission state of a unit pixel in an organic light-emitting display device according to an embodiment of the present invention. Figure 24 It shows the basis Figure 23 A table showing the status of each power stage and each data line in the implementation.

[0187] For green emission per unit pixel, a low-level voltage VSS is applied to the first power level P / L1 and the third power level P / L3, and a high-level voltage VDD is applied to the second power level P / L2.

[0188] In this case, when only the data voltage is supplied to the third data line DATA3, only the second green light-emitting diode OLED G2 can be driven.

[0189] Figure 25 This is a circuit diagram illustrating the state in which a unit pixel of an organic light-emitting display device emits yellow light according to an embodiment of the present invention. Figure 26 It shows the basis Figure 25 A table showing the status of each power stage and each data line in the implementation.

[0190] In this case, a low-level voltage VSS is applied to the first power stage P / L1 and the third power stage P / L3, and a high-level voltage VDD is applied to the second power stage P / L2.

[0191] In this case, when data voltage is supplied to the first data line DATA1 and the third data line DATA3, the first red light-emitting diode OLED R1 and the second green light-emitting diode OLED G2 can be driven, thereby emitting yellow light.

[0192] Furthermore, with a high-level voltage VDD applied to the first power stage P / L1 and the third power stage P / L3, and a low-level voltage VSS applied to the second power stage P / L2, as referred to Figures 12 to 22 Specifically, when a data voltage is selectively applied to at least one of the first data line DATA1, the second data line DATA2, and the third data line DATA3, the unit pixel can emit red, green, and blue; and when a data voltage is applied to all of the first data line DATA1, the second data line DATA2, and the third data line DATA3, the unit pixel can emit white.

[0193] Therefore, it can be omitted. Figure 9 The three multiplexers shown are shown.

[0194] As is evident from the above description, a single pixel consists of two sub-pixels and is driven by a DC voltage Ac, thus enabling the emission of red, green, blue, white, and yellow. Therefore, an enhancement in resolution can be achieved.

[0195] The light-emitting layers used to emit white light and those emitting red and green light can be driven differently, thus enabling an organic light-emitting display device with a long lifespan. This allows for a type of failover system per pixel. For example, if the red light-emitting diode in the first subpixel S1 fails or becomes damaged over time, the red light-emitting diode in the second subpixel S2 can be used; or if the red light-emitting diode in the second subpixel S2 fails or becomes damaged over time, the red light-emitting diode in the first subpixel S1 can be used. This effectively doubles the lifespan of the unit pixel when it comes to its ability to emit red light. Similarly, if the green light-emitting diode in the second subpixel S2 fails or becomes damaged over time, the green light-emitting diode in the first subpixel S1 can be used; or if the green light-emitting diode in the first subpixel S1 fails or becomes damaged over time, the green light-emitting diode in the second subpixel S2 can be used, and so on. In addition, alternating drive schemes and time-division drive schemes can be used to average the usage of each of the same color LEDs, thereby extending the lifespan of each pixel.

[0196] Furthermore, in the case of blue light-emitting diodes with relatively short lifespans, larger blue light-emitting diodes can drive two sub-pixels simultaneously, thus enabling organic light-emitting display devices with long lifespans.

[0197] The foregoing description and accompanying drawings have been provided to illustrate the technical concept of the present invention. Those skilled in the art will understand that various modifications and variations are possible by combining, dividing, substituting, or changing the constituent elements without altering the essential characteristics of the invention. Therefore, the foregoing embodiments disclosed herein are to be interpreted as merely illustrative and not as limiting the principles and scope of the invention. It should be understood that the scope of the invention is defined by the appended claims, and all equivalents thereof fall within the scope of the invention.

[0198] Cross-reference to related applications

[0199] This application claims priority to Korean Patent Application No. 10-2021-0194682, filed in Korea on December 31, 2021, the entire contents of which are incorporated herein by reference as if fully set forth herein.

Claims

1. An organic light-emitting display device, the organic light-emitting display device comprising: The display panel includes multiple data lines and multiple scan lines that intersect each other, as well as unit pixels arranged in a matrix, wherein each unit pixel is located in an area where one scan line and three data lines intersect. A data driving circuit, configured to drive the plurality of data lines; and A gating drive circuit, configured to drive the plurality of scan lines. Each unit pixel in the unit pixel comprises two sub-pixels, and Each of the two sub-pixels has a structure in which red light-emitting elements, green light-emitting elements, and blue light-emitting elements are stacked. In this configuration, the red and green light-emitting elements of the first sub-pixel of the two sub-pixels are stacked to form a hole-only device (HOD) structure. In this configuration, the red and green light-emitting elements of the second sub-pixel are stacked to form an electronic-only device (EOD) structure. The unit pixel switches between being driven by a forward bias voltage and being driven by a reverse bias voltage.

2. The organic light-emitting display device according to claim 1, wherein, The first sub-pixel includes a first electrode, a second electrode, and a third electrode stacked sequentially; A first blue light-emitting element is disposed between the first electrode and the second electrode; and A first red light-emitting element and a first green light-emitting element are disposed between the second electrode and the third electrode to form a HOD structure.

3. The organic light-emitting display device according to claim 2, wherein, The first blue light-emitting element includes a hole injection layer, a first hole transport layer, a first blue light-emitting material layer, and an electron transport layer sequentially stacked between the first electrode and the second electrode; and The first red light-emitting element and the first green light-emitting element include a second hole injection layer, a first electron blocking layer, a first red light-emitting material layer, a charge generation layer, a first green light-emitting material layer, a second electron blocking layer, and a third hole injection layer, which are sequentially stacked between the second electrode and the third electrode.

4. The organic light-emitting display device according to claim 3, wherein, The first red luminescent material layer and the first green luminescent material layer are symmetrical about the charge generation layer.

5. The organic light-emitting display device according to claim 3, wherein, When a negative voltage is applied to both the first electrode and the third electrode and a positive voltage is applied to the second electrode, only the first red luminescent material layer can emit light; and When a positive voltage is applied to both the first electrode and the third electrode and a negative voltage is applied to the second electrode, only the first blue luminescent material layer and the first green luminescent material layer can emit light.

6. The organic light-emitting display device according to claim 1, wherein, The second sub-pixel includes a first electrode, a second electrode, and a third electrode stacked sequentially; A second blue light-emitting element is disposed between the first electrode and the second electrode; and The second red light-emitting element and the second green light-emitting element are disposed between the second electrode and the third electrode to form an EOD structure.

7. The organic light-emitting display device according to claim 6, wherein, The second blue light-emitting element includes a hole injection layer, a first hole transport layer, a second blue light-emitting material layer, and an electron transport layer sequentially stacked between the first electrode and the second electrode; and The second red light-emitting element and the second green light-emitting element include a first electron injection layer, a first hole blocking layer, a second red light-emitting material layer, a charge generating layer, a second green light-emitting material layer, a second hole blocking layer, and a second electron injection layer, which are sequentially stacked between the second electrode and the third electrode.

8. The organic light-emitting display device according to claim 7, wherein, The second red luminescent material layer and the second green luminescent material layer are symmetrical about the charge generating layer.

9. The organic light-emitting display device according to claim 7, wherein, When a negative voltage is applied to both the first electrode and the third electrode and a positive voltage is applied to the second electrode, only the second green luminescent material layer can emit light; and When a positive voltage is applied to both the first electrode and the third electrode and a negative voltage is applied to the second electrode, only the second red luminescent material layer and the second blue luminescent material layer can emit light.

10. The organic light-emitting display device according to claim 1, wherein, The unit pixel is connected to a scan line and a first data line, a second data line, and a third data line; The unit pixel includes: A first red light-emitting diode and a first green light-emitting diode, wherein the first red light-emitting diode and the first green light-emitting diode are connected in reverse to each other; A second red LED and a second green LED are connected in reverse to each other; Blue LED; A first switching transistor, the first switching transistor including a gate connected to the scan line, a first electrode connected to the first data line and a second electrode connected to the first node, the first switching transistor being configured to transmit a data voltage of the first data line to the first node in response to a scan pulse from the scan line; A first driving transistor, the first driving transistor including a gate connected to the first node, a first electrode connected to a third power stage and a second electrode connected to a second node, the first driving transistor being configured to control the current flowing through the first red light-emitting diode and the first green light-emitting diode based on the voltage of the first node; A second switching transistor, the second switching transistor including a gate connected to the scan line, a first electrode connected to the second data line and a second electrode connected to the third node, the second switching transistor being configured to transmit a data voltage of the second data line to the third node in response to a scan pulse from the scan line; A second driving transistor, comprising a gate connected to the third node, a first electrode connected to the first power stage, and a second electrode connected to the fourth node, the second driving transistor being configured to control the current flowing through the blue light-emitting diode based on the voltage of the third node; A third switching transistor, the third switching transistor including a gate connected to the scan line, a first electrode connected to the third data line, and a second electrode connected to the fifth node, the third switching transistor being configured to transmit a data voltage of the third data line to the fifth node in response to a scan pulse from the scan line; and A third driving transistor, comprising a gate connected to the fifth node, a first electrode connected to the third power stage, and a second electrode connected to the sixth node, is configured to control the current flowing through the second red LED and the second green LED based on the voltage of the fifth node. The first red LED and the first green LED are connected between the second node and the second power stage, the blue LED is connected between the fourth node and the second power stage, and the second red LED and the second green LED are connected between the sixth node and the second power stage.

11. The organic light-emitting display device according to claim 10, wherein, The unit pixel also includes: A first capacitor is connected between the first node and the second node; A second capacitor, the second capacitor being connected between the third node and the fourth node; and A third capacitor is connected between the fifth node and the sixth node.

12. The organic light-emitting display device according to claim 10, wherein, The unit pixel also includes: A first multiplexer, a second multiplexer, and a third multiplexer are respectively connected to the first power stage, the second power stage, and the third power stage. Each of the first, second, and third multiplexers is configured to select one of a positive voltage and a negative voltage based on a selection signal, and to provide the positive voltage and the negative voltage to a corresponding one of the first, second, and third power stages.

13. The organic light-emitting display device according to claim 10, wherein, When a positive voltage is applied to the first power stage and the third power stage, a negative voltage is applied to the second power stage, and a data voltage is provided to the first data line, only the first green LED emits light; and When a positive voltage is applied to the first power stage and the third power stage, a negative voltage is applied to the second power stage, and a data voltage is provided to the third data line, only the second red LED emits light.

14. The organic light-emitting display device according to claim 10, wherein, When a positive voltage is applied to the first power stage and the third power stage, a negative voltage is applied to the second power stage, and a data voltage is provided to the second data line, only the blue LED emits light.

15. The organic light-emitting display device according to claim 10, wherein, When a positive voltage is applied to the first power stage and the third power stage, a negative voltage is applied to the second power stage, and a data voltage is provided to each of the first, second, and third data lines, the first green LED, the second red LED, and the blue LED emit light to display white.

16. The organic light-emitting display device according to claim 10, wherein, When a negative voltage is applied to the first power stage and the third power stage, a positive voltage is applied to the second power stage, and a data voltage is supplied to the first data line, only the first red LED emits light; and When a negative voltage is applied to the first power stage and the third power stage, a positive voltage is applied to the second power stage, and a data voltage is provided to the third data line, only the second green LED emits light.

17. The organic light-emitting display device according to claim 10, wherein, When a negative voltage is applied to the first power stage and the third power stage, a positive voltage is applied to the second power stage, and a data voltage is provided to each of the first data line and the third data line, the first red LED and the second green LED emit light to display yellow.

18. A unit pixel, the unit pixel comprising: A pair of sub-pixels, the pair of sub-pixels constituting the unit pixel, and including a first sub-pixel and a second sub-pixel. The first sub-pixel includes: A first stack, the first stack including a first blue light-emitting element disposed between a first electrode and a second electrode; and The second stack includes a first red light-emitting element and a first green light-emitting element disposed between the second electrode and the third electrode, and a first charge-generating layer disposed between the first red light-emitting element and the first green light-emitting element. The second stack of the first sub-pixel is stacked on the first stack of the first sub-pixel. The second sub-pixel includes: A first stack, the first stack including a second blue light-emitting element disposed between the first electrode and the second electrode; and The second stack includes a second red light-emitting element and a second green light-emitting element disposed between the second electrode and the third electrode, and a second charge-generating layer disposed between the second red light-emitting element and the second green light-emitting element. The second stack of the second sub-pixel is stacked on the first stack of the second sub-pixel. The first red light-emitting element and the first green light-emitting element are stacked to form a hole-only device (HOD) structure. The second red light-emitting element and the second green light-emitting element are stacked to form an electronic device-only (EOD) structure, and The unit pixel switches between being driven by a forward bias voltage and being driven by a reverse bias voltage.

19. The unit pixel according to claim 18, wherein, The unit pixel is configured as follows: In response to the failure of one of the first and second red light-emitting elements, the remaining red light-emitting element is used to emit red light, or In response to the failure of one of the first and second green light-emitting elements, green light is emitted using the remaining green light-emitting element.

20. The unit pixel according to claim 18, wherein, The unit pixel is configured to emit five different colors of light.

21. The unit pixel according to claim 20, wherein, The five different colors of light include red, green, blue, yellow, and white light.

22. The unit pixel according to claim 18, wherein, The unit pixel is connected to a first data line, a second data line, a third data line, and a scan line.

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