Display device

Abstract

This disclosure provides a display device comprising: an upper horizontal current line, a horizontal sensing line, a scan line, and a lower horizontal current line, which extend horizontally and are arranged vertically on a substrate in the order described above; an emission region defined between the horizontal sensing line and the upper horizontal current line; a non-emission region defined between the horizontal sensing line and the lower horizontal current line; a sensing thin-film transistor disposed between the horizontal sensing line and the scan line; a driving thin-film transistor disposed between the scan line and the lower horizontal current line; an anode electrode extending from the emission region to the non-emission region and connected to the driving thin-film transistor; and an anode bottleneck disposed between the horizontal sensing line and the scan line for selectively disconnecting the anode electrode from the driving thin-film transistor.

Description

[0001] This application is a divisional application of National Application No. 201710952088.0, filed on October 13, 2017, entitled "Ultra-high density display device with high aperture ratio". Technical Field

[0002] This disclosure relates to an ultra-high density display device with a high aperture ratio. In particular, this disclosure relates to an ultra-high density organic light-emitting diode display having a bottleneck for darkening defective pixels and having a maximized aperture ratio in the pixel region. Background Technology

[0003] Today, various display devices (or "FPDs") have been developed to overcome many of the drawbacks of bulky cathode ray tubes (or "CRTs"). Display devices include liquid crystal displays (or "LCDs"), field emission displays (or "FEDs"), plasma display panels (or "PDPs"), electroluminescent devices (or "ELs"), etc.

[0004] As self-emitting display devices, electroluminescent devices offer advantages such as extremely fast response times, extremely high brightness, and wide viewing angles. Electroluminescent devices can be categorized into inorganic light-emitting diode (OLED) displays and organic light-emitting diode (OLED) displays. Due to their excellent energy efficiency, low leakage current, and ease of color and brightness representation through current control, OLED displays, which utilize organic light-emitting diodes, are increasingly preferred.

[0005] Figure 1 This is a diagram showing the structure of an organic light-emitting diode (OLED). (For example...) Figure 1 As shown, an organic light-emitting diode (OLED) includes an organic light-emitting material layer, and a cathode and an anode facing each other with the organic light-emitting material layer located therebetween. The organic light-emitting material layer includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL).

[0006] Organic light-emitting diodes (OLEDs) emit light due to the energy from excitons formed in the excited state. In the excited state, holes from the anode and electrons from the cathode recombine at the emitter layer (EML). Figure 1 As shown, an organic light-emitting diode (OLED) display can represent video data by controlling the amount (or "brightness") of light generated and radiated by the OLED's emission layer (EML).

[0007] OLED displays that use organic light-emitting diodes with good energy efficiency can be divided into passive matrix organic light-emitting diode (or "PMOLED") displays and active matrix organic light-emitting diode (or "AMOLED") displays.

[0008] Active matrix organic light-emitting diode (or "AMOLED") displays present video data by controlling the current applied to the organic light-emitting diodes using thin-film transistors (or "TFTs"). The following will refer to... Figure 2 and Figure 3 An organic light-emitting diode display based on related technologies will be described.

[0009] Figure 2 This is an exemplary circuit diagram showing the structure of a pixel in an active matrix organic light-emitting diode (or "AMOLED") display. Figure 3 This is a plan view showing the structure of an AMOLED according to related technologies. Figure 4 This is a cross-sectional view along the cutting line I-I' used to illustrate the structure of a bottom-emitting AMOLED according to related technologies.

[0010] Reference Figure 2 and Figure 3 A pixel in an active-matrix organic light-emitting diode (OLED) display includes a switching thin-film transistor (ST), a driving thin-film transistor (DT) connected to the switching TFT, and an organic light-emitting diode (OLED) connected to the driving TFT. The pixel region is defined by depositing scan lines (SL), data lines (DL), and drive current lines (VDD) on a substrate. Since the organic light-emitting diode is disposed within the pixel region, it defines the emission region.

[0011] A switching thin-film transistor (ST) is formed at the intersection of the scan line SL and the data line DL. The ST is used to select the pixel connected to it. The ST includes a gate electrode SG branching from the gate line GL, a semiconductor channel layer SA overlapping the gate electrode SG, a source electrode SS, and a drain electrode SD. A driving thin-film transistor (DT) is used to drive the anode electrode ANO of the organic light-emitting diode (OLED) located at the pixel selected by the ST.

[0012] The driving thin-film transistor DT includes a gate electrode DG connected to the drain electrode SD of the switching thin-film transistor ST, a semiconductor channel layer DA, a drain electrode DD connected to the drive current line VDD, and a source electrode DS. The source electrode DS of the driving thin-film transistor DT is connected to the anode electrode ANO of the organic light-emitting diode OLED. An organic light-emitting layer OL is disposed between the anode electrode ANO and the cathode electrode CAT. A reference voltage VSS is provided to the cathode electrode CAT. A storage capacitor Cst is formed between the gate electrode DG of the driving thin-film transistor DT and the drive current line VDD, or between the gate electrode DG of the driving thin-film transistor DT and the source electrode DS of the driving thin-film transistor DT.

[0013] Reference Figure 4A bottom-emitting organic light-emitting diode (OLED) display is described. The gate electrode SG of a switching thin-film transistor (TFT) ST and the gate electrode DG of a driving thin-film transistor (DT) are formed on the substrate SUB of the active-matrix OLED display. A gate insulator (GI) is deposited on the gate electrodes SG and DG. Semiconductor layers SA and DA are formed on the gate insulator GI, which overlaps with the gate electrodes SG and DG. Source electrodes SS and DS, and drain electrodes SD and DD, facing each other and separated, are formed on the semiconductor layers SA and DA. The drain electrode SD of the switching TFT ST is connected to the gate electrode DG of the driving TFT DT via a drain contact hole DH passing through the gate insulator GI. A passivation layer PAS is deposited on the substrate SUB containing the switching TFT ST and the driving TFT DT.

[0014] The upper surface of the substrates containing these thin-film transistors (ST and DT) is not uniform and / or smooth, but rather non-uniform and / or rough with many steps. To obtain optimal luminous efficiency, an organic light-emitting layer (OL) is deposited on a uniform or flat surface. Therefore, to make the upper surface flat and uniform, an outer coating (OC) is deposited on the entire surface of the substrate (SUB).

[0015] Then, the anode electrode ANO of the organic light-emitting diode (OLED) is formed on the outer coating OC. Here, the anode electrode ANO is connected to the source electrode DS of the driving thin-film transistor DT through the pixel contact hole PH passing through the outer coating OC and the passivation layer PAS.

[0016] On a substrate SUB having an anode electrode ANO, a dam BA is formed in a region containing a switching thin-film transistor ST, a driving thin-film transistor DT, and various lines DL, SL, and VDD to define a light-emitting region. The portion of the anode electrode ANO exposed through the dam BA will serve as the light-emitting region. A cathode electrode CAT is deposited on an organic light-emitting layer OL.

[0017] Spacers SP are disposed on a substrate SUB having a cathode electrode CAT. Preferably, the spacers SP are disposed on the embankment BA, i.e., the non-emitting region. Using the spacers SP, end caps are bonded to the lower substrate SUB. To attach the end caps to the lower substrate SUB, an adhesive layer or adhesive material (not shown) is deposited between them.

[0018] For bottom-emitting organic light-emitting diode (OLED) displays, light from the organic light-emitting layer (OL) is radiated onto the lower substrate (SUB). Therefore, it is preferable to place a color filter (CF) between the outer coating layer (OC) and the passivation layer (PAS), and the anode electrode (ANO) comprises a transparent conductive material. Furthermore, the cathode electrode (CAT) preferably comprises a highly reflective metallic material to reflect light from the OL to the bottom side. Additionally, the OL and CAT are deposited to cover the entire surface of the substrate.

[0019] The cathode electrode CAT is provided with a reference voltage for the organic light-emitting diode (OLED). To ensure stable operation of the OLED, the reference voltage should be maintained at a stable voltage without flicker. Therefore, it is preferable that the cathode electrode CAT is made of a low-resistance metallic material and is deposited over the entire surface of the substrate SUB.

[0020] When an organic light-emitting diode (OLED) display based on related technologies is used for an extended period, the video quality deteriorates due to changes in the electrical characteristics of the pixels. Compensating elements are needed to recover from these defects by detecting these changes in electrical characteristics.

[0021] When these compensating elements or circuits are installed in the pixel region, it leads to a decrease in the aperture ratio, which is the ratio of the emission region to the pixel region. For ultra-high resolution displays, including UHD or 4K, the pixel region includes switching thin-film transistors, driving thin-film transistors, and compensating thin-film transistors, resulting in a significant reduction in the aperture ratio. New structures are needed for organic light-emitting diode displays with ultra-high density resolution that ensure a high aperture ratio. Summary of the Invention

[0022] To overcome the aforementioned drawbacks, the object of this disclosure is to provide an ultra-high density organic light-emitting diode (OLED) display with a high aperture ratio. Another object of this disclosure is to provide an ultra-high density OLED display with a high aperture ratio and a bottleneck portion that selectively darkens defective pixels.

[0023] To achieve the above objectives, this disclosure provides a display device comprising: an upper horizontal current line, a horizontal sensing line, a scan line, and a lower horizontal current line, which extend horizontally and are arranged vertically on a substrate in the order described above; an emission region defined between the horizontal sensing line and the upper horizontal current line; a non-emission region defined between the horizontal sensing line and the lower horizontal current line; a switching thin-film transistor and a sensing thin-film transistor disposed between the horizontal sensing line and the scan line; a driving thin-film transistor disposed between the scan line and the lower horizontal current line; an anode electrode extending from the emission region to the non-emission region and connected to the driving thin-film transistor; and an anode bottleneck portion disposed between the horizontal sensing line and the scan line for disconnecting the anode electrode from the driving thin-film transistor.

[0024] In one embodiment, the sensing thin-film transistor includes: a sensing source electrode branching from a horizontal sensing line; a sensing gate electrode defined at a first portion of a scan line; a sensing drain electrode facing the sensing source electrode with the sensing gate electrode located in the middle; a sensing semiconductor layer extending from the sensing source electrode to the sensing drain electrode and overlapping the sensing gate electrode; and a sensing bottleneck portion disposed between the horizontal sensing line and the scan line for selectively disconnecting the sensing source electrode from the horizontal sensing line.

[0025] In one embodiment, the anode bottleneck extends vertically between the horizontal sensing line and the scan line, and connects a first portion of the anode electrode disposed in the emission region to a second portion of the anode electrode disposed in the non-emission region.

[0026] In one embodiment, the sensing bottleneck has a segment shape that is spaced at least 6 μm apart from the horizontal sensing line and the anode bottleneck.

[0027] In one embodiment, the horizontal sensing line is connected to the vertical sensing line through a sensing contact hole that exposes a portion of the sensing line.

[0028] In one embodiment, the display further includes: data lines, drive current lines, and vertical sensing lines extending vertically on the substrate.

[0029] In one embodiment, the switching thin-film transistor includes: a switching source electrode branching from a data line; a switching gate electrode defined at a second portion of a scan line; a switching drain electrode facing the switching source electrode with the switching gate electrode located in the middle; and a switching semiconductor layer extending from the switching source electrode to the switching drain electrode and overlapping the switching gate electrode.

[0030] In one embodiment, the switching thin-film transistor further includes a switching bottleneck disposed between the data line and the switching source electrode.

[0031] In one embodiment, the driving thin-film transistor includes: a driving gate electrode connected to the switching thin-film transistor; a driving drain electrode defined at a portion of a driving current line; a driving source electrode facing the driving drain electrode with the driving gate electrode located in between; and a driving semiconductor layer extending from the driving source electrode to the driving drain electrode and overlapping the driving gate electrode.

[0032] In one embodiment, the upper horizontal current line and the lower horizontal current line are connected to the drive current line through a current contact hole that exposes a portion of the drive current line.

[0033] The organic light-emitting diode (OLED) display according to this disclosure includes a compensating thin-film transistor (TFT) for controlling the condition of driving the TFT and / or OLED by detecting pixel degradation. Even under adverse conditions leading to pixel degradation, video quality can be maintained at an excellent level. Furthermore, a bottleneck portion is provided in the pixel, through which any pixel will be a defective pixel (hence the term "darkened pixel") when it has an irreversible defect during manufacturing. Having an element that renders defective pixels unusable in an ultra-high density OLED display can improve manufacturing yield. In the OLED display according to this disclosure, the bottleneck portion for darkening defective pixels is located in a non-emitting region, allowing for a maximized aperture ratio. According to this disclosure, a maximum aperture ratio can be ensured in a UHD-level ultra-high resolution OLED display with a compensating element. Attached Figure Description

[0034] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with this specification, serve to explain the principles of the invention.

[0035] In the attached diagram:

[0036] Figure 1 This is a diagram showing the structure of an organic light-emitting diode according to related technologies.

[0037] Figure 2 This is an exemplary circuit diagram illustrating the structure of a pixel in an active-matrix organic light-emitting diode (or "AMOLED") display according to related technologies.

[0038] Figure 3 This is a plan view showing the structure of a pixel in an AMOLED display according to related technologies.

[0039] Figure 4 This is a cross-sectional view along the cutting line I-I' used to illustrate the structure of a bottom-emitting AMOLED according to the prior art;

[0040] Figure 5 This is an equivalent circuit diagram showing the structure of a pixel in an organic light-emitting diode display with a compensation element according to the present disclosure.

[0041] Figure 6 This is a plan view of the structure of a pixel in an organic light-emitting diode display with a compensation element according to a first embodiment of the present disclosure.

[0042] Figure 7 This is a plan view showing the structure of a pixel in an ultra-high density organic light-emitting diode display having a bottleneck portion for darkening defective pixels, according to a second embodiment of the present disclosure.

[0043] Figure 8 This is a plan view showing the structure of a pixel in an ultra-high density organic light-emitting diode display having a bottleneck portion for darkening defective pixels, according to a third embodiment of the present disclosure. Detailed Implementation

[0044] Referring to the accompanying drawings, preferred embodiments of this disclosure will be described. Throughout the detailed description, the same reference numerals denote the same elements. However, this disclosure is not limited to these embodiments, but can be adapted with various changes or modifications without altering the spirit of the art. In the following embodiments, the names of elements have been chosen for ease of explanation, such that they may differ from their actual names.

[0045] In the following text, reference will be made to Figure 5 This document provides an explanation of the contents of this publication. Figure 5 This is an equivalent circuit diagram showing the structure of a pixel in an organic light-emitting diode display with a compensation element according to the present disclosure.

[0046] Reference Figure 5 A pixel in an organic light-emitting diode (OLED) display includes a switching thin-film transistor (ST), a driving thin-film transistor (DT), a storage capacitor (Cst), a compensation element, and an OLED. The compensation element can be configured in various ways. The case where the compensation element includes a sensing thin-film transistor (ET) and a sensing line (REF) is described here.

[0047] In response to the scan signal provided from the scan line SL, the switching thin-film transistor ST performs a switching operation to store the data signal from the data line DL as a data voltage into the storage capacitor Cst. Based on the data voltage in the storage capacitor Cst, the driving thin-film transistor DT operates to provide a drive current between the drive current line VDD (providing a variable high-level voltage) and the reference voltage line VSS (providing a constant low-level voltage). The organic light-emitting diode (OLED) operates to generate light according to the drive current generated by the driving thin-film transistor DT.

[0048] A sensing thin-film transistor (ET) is an additional component located within a pixel region to compensate for the threshold voltage of the driving thin-film transistor (DT). The sensing ET is connected between the source electrode of the driving DT and the anode electrode (or sensing node) of the organic light-emitting diode (OLED). The sensing ET operates to provide an initial voltage (or sensing voltage) from the sensing line (REF) to the sensing node or to detect (or sense) the voltage or current at the sensing node.

[0049] The switching thin-film transistor ST includes a source electrode connected to the data line DL and a drain electrode connected to the gate electrode of the driving thin-film transistor DT. The driving thin-film transistor DT includes a drain electrode connected to the driving current line VDD and a source electrode connected to the anode electrode of the organic light-emitting diode OLED. The storage capacitor Cst includes a first electrode connected to the gate electrode of the driving thin-film transistor DT and a second electrode connected to the anode electrode of the organic light-emitting diode OLED.

[0050] An organic light-emitting diode (OLED) includes an anode electrode connected to the source electrode of a driving thin-film transistor (DT) and a cathode electrode connected to a reference voltage line (VSS). A sensing transistor (ET) includes a source electrode connected to a sensing line (REF) and a drain electrode connected to a sensing node (the anode electrode of the OLED).

[0051] According to the compensation algorithm, the operating timing of the sensing thin-film transistor ET can be related to the operating timing of the switching thin-film transistor ST. For example, Figure 5 As shown, the gate electrodes of the switching thin-film transistor ST and the sensing thin-film transistor ET can be connected together to the scan line SL. In other aspects, the gate electrode of the switching thin-film transistor ST is connected to one scan line SL, and the gate electrode of the sensing thin-film transistor ET is connected to another scan line (not shown).

[0052] Based on the sensing results, compensation can be applied to digital data signals, analog data signals, or gamma signals. The compensation element used to generate the compensation signal (or compensation voltage) based on the sensing results can be configured as internal circuitry embedded in the data driver or timing controller, or as external circuitry.

[0053] Figure 5 A pixel with a 3T1C (three thin-film transistors and one capacitor) structure is shown, which includes a switching thin-film transistor ST, a driving thin-film transistor DT, a sensing thin-film transistor ET, a storage capacitor Cst, and an organic light-emitting diode (OLED). Furthermore, the pixel may include additional compensation elements, such as 3T2C, 4T2C, 5T1C, 6T2C, etc.

[0054] In the following text, the configuration having in accordance with this disclosure will be described. Figure 5 The structural features of an ultra-high resolution organic light-emitting diode (OLED) display, illustrated in the circuit diagram, are explained. The aperture ratio varies depending on the actual pixel structure. As a measure of resolution, the aperture ratio is crucial in determining the quality of the display. With increasing display resolution, the area per pixel becomes smaller. The size and linewidth of thin-film transistors cannot be infinitely reduced. As the pixel area becomes smaller, the ratio of the emitting area within that pixel area is also smaller.

[0055] Furthermore, when the compensation element is included in the pixel area, the aperture ratio, i.e., the ratio of the emission area to the pixel area, is much smaller. Moreover, as the number of pixels increases, the probability of defective pixels also increases. Defective pixels are a major cause of video quality degradation. Therefore, it is preferable to darken defective pixels so that normal pixels are unaffected by them. To darken defective pixels, it is preferable to cut off the connection between the thin-film transistor and the organic light-emitting diode. Various structures of an organic light-emitting diode display according to this disclosure will be described below.

[0056] <First Implementation Method>

[0057] Reference Figure 6 The first embodiment of the present disclosure will now be described. Figure 6 This is a plan view showing the structure of a pixel in an organic light-emitting diode display with a compensation element according to a first embodiment of the present disclosure.

[0058] An organic light-emitting diode display according to a first embodiment of this disclosure includes: a sensing line REF, a data line DL, a drive current line VDD, a horizontal sensing line REFh, a horizontal current line VDDh, and a scan line SL on a substrate SUB. These lines define a pixel region. Specifically, a unit pixel region is defined as a region surrounded by two adjacent horizontal sensing lines REFh, one data line DL, and one drive current line VDD.

[0059] The scan line SL, horizontal sensing line REFh, and horizontal current line VDDh extend horizontally on the substrate SUB. The data line DL, drive current line VDD, and sensing line REF extend vertically on the substrate SUB. The horizontal sensing line REFh is connected to the sensing line REF via a sensing contact hole RH. The horizontal current line VDDh is connected to the drive current line VDD via a current contact hole VH.

[0060] A horizontal current line VDDh and a scan line SL are positioned between two adjacent horizontal sensing lines REFh. The region between the upper horizontal sensing line REFh and the horizontal current line VDDh is defined as the emission region. The region between the horizontal current line VDDh and the lower horizontal sensing line REFh is defined as the non-emission region. An organic light-emitting diode (OLED) is positioned in the emission region. Thin-film transistors ST, DT, and ET, as well as a storage capacitor Cst, are positioned in the non-emission region.

[0061] The switching thin-film transistor ST includes: a switching source electrode SS connected to a data line DL, a switching gate electrode SG defined in a portion of a scan line SL, a switching semiconductor layer SA, and a switching drain electrode SD. A channel region is defined at the overlap region of the switching semiconductor layer SA and the switching gate electrode SG. The switching semiconductor layer SA is configured to intersect the scan line SL from bottom to top, thus forming the switching thin-film transistor ST.

[0062] The sensing thin-film transistor ET includes: a sensing source electrode ES connected to a lower horizontal sensing line REFh, a sensing gate electrode EG defined in a portion of a scan line SL, a sensing semiconductor layer EA, and a sensing drain electrode ED. A channel region is defined at the overlap region between the sensing semiconductor layer EA and the sensing gate electrode EG. The sensing thin-film transistor ET is formed because the sensing semiconductor layer EA is configured to intersect the scan line SL from bottom to top.

[0063] The driving thin-film transistor DT includes: a driving source electrode DS defined at a portion of a horizontal current line VDDh, a driving gate electrode DG connected to a switching drain electrode SD, a driving semiconductor layer DA, and a driving drain electrode DD. A channel region is defined at the overlap region of the driving semiconductor layer DA and the driving gate electrode DG. The driving thin-film transistor DT is formed because the driving semiconductor layer DA is configured to cross the driving gate electrode DG from the horizontal current line VDDh to the scan line SL. The driving drain electrode DD is connected to a portion of the driving semiconductor layer DA and a portion of the sensing semiconductor layer EA.

[0064] The storage capacitor Cst includes a first electrode and a second electrode. The first electrode is formed as an extension of the switching drain electrode SD. The second electrode is formed as an extension of the driving semiconductor layer DA extending toward the scan line SL across the driving gate electrode DG.

[0065] The driving thin-film transistor DT and the storage capacitor Cst are positioned between the horizontal current line VDDh and the scan line SL. The driving elements, including the thin-film transistors ST, DT, and ET, and the storage capacitor Cst, are positioned between the horizontal current line VDDh and the lower horizontal sensing line REFh. This region is defined as a non-emitting region.

[0066] The anode electrode ANO of the organic light-emitting diode (OLED) is connected to the driving drain electrode DD through the pixel contact hole PH. The opening area of ​​the dam BA is defined as the maximum area exposing the anode electrode ANO. While ensuring the maximum area, the anode electrode ANO occupies the emission area and some portion extends into the non-emission area. Specifically, it is preferable that the anode electrode ANO extends into the driving drain electrode DD. Furthermore, the anode electrode ANO may overlap with the storage capacitor Cst. When it is difficult to form a second electrode of the storage capacitor Cst using the driving semiconductor layer DA, the second electrode of the storage capacitor Cst can be formed by extending the anode electrode ANO to overlap with the first electrode.

[0067] Most of the anode electrode ANO is exposed through the dam BA. An organic light-emitting diode (OLED) is formed by stacking an organic light-emitting layer and a cathode electrode on the dam BA. Preferably, the OLED is formed to have the maximum emission area within the pixel region.

[0068] Figure 6 The illustrated organic light-emitting diode (OLED) display has a structure that includes a compensation element. Using this structure, the connection between the anode electrode ANO and the thin-film transistor (TFT) is severed or disconnected when any pixel is defective. For example, the source electrode SS of the switching TFT ST is disconnected from the data line DL. Furthermore, the source electrode ES of the sensing TFT ET is disconnected from the lower horizontal sensing line REFh.

[0069] To darken any defective pixels upon detection, it is preferable to provide a switching bottleneck SCN between the switching source electrode SS and the data line DL, and a sensing bottleneck ECN between the sensing source electrode ES and the lower horizontal sensing line REFh. These bottlenecks SCN and ECN have a segment shape with a width of at least 4.5 μm and a length of at least 6 μm.

[0070] When a pixel is defined as a defective pixel, these bottleneck SCNs and ECNs are portions that are physically removed or eliminated using a laser beam. Preferably, there is unused space around these bottleneck SCNs and ECNs to prevent interference with other components. For example, these bottleneck SCNs and ECNs will be spaced at least 6 μm apart from all adjacent components. Therefore, a certain area within the pixel region is needed to accommodate these bottleneck SCNs and ECNs. In other words, to ensure sufficient bottlenecks for darkening processing, the aperture ratio will be reduced.

[0071] In such Figure 6 In the illustrated OLED display, the bottleneck does not directly disconnect the anode electrode (ANO) of the OLED from the thin-film transistor (TFT). In other words, after the darkening process, the anode electrode (ANO) remains connected to the driving TFT (DT). Therefore, the OLED will be activated by induced current and / or induced voltage.

[0072] Therefore, even if it has such Figure 6 The organic light-emitting diode (OLED) display with the structure shown has a bottleneck for darkening, and defective pixels are not completely darkened. Therefore, a new bottleneck structure is needed to completely disconnect the OLED from the thin-film transistor.

[0073] <Second Implementation Method>

[0074] In the following text, refer to Figure 7 The organic light-emitting diode display according to the second embodiment will be described, in which the organic light-emitting diode OLED is disconnected from the thin-film transistor. Figure 7 This is a plan view showing the structure of a pixel in an ultra-high density organic light-emitting diode display having a bottleneck portion for darkening defective pixels, according to a second embodiment of the present disclosure.

[0075] The organic light-emitting diode display according to the second embodiment is very similar to the display according to the first embodiment. Components that are the same as or similar to those in the first embodiment will not be repeated. The main difference lies in the structure of the anode electrode ANO.

[0076] The anode electrode ANO according to the second embodiment also includes an anode bottleneck portion PCN on the lower side of the pixel region. The anode bottleneck portion PCN is formed by narrowing the width of some portions of the anode electrode ANO. In other words, the anode bottleneck portion PCN has a short and narrow segment shape that links the main portion of the anode electrode ANO disposed in the emission region to the secondary portion of the anode electrode ANO disposed in the non-emission region.

[0077] Similar to the first embodiment, the gap between the anode bottleneck PCN and other adjacent elements is preferably at least 6 μm. For example, it is preferred that the anode bottleneck PCN is spaced at least 6 μm away from the horizontal current line VDDh. To facilitate cutting, it is preferred that the anode bottleneck PCN has a short segment shape with a width of at least 4.5 μm and a length of 6 μm.

[0078] In order to provide the anode bottleneck section PCN, the opening area of ​​the anode electrode ANO by means of the embankment section BA is smaller than the opening area of ​​the first embodiment. Figure 7 The organic light-emitting diode (OLED) display shown includes an anode bottleneck, which allows the anode electrode (ANO) of the OLED to be physically and electrically disconnected from the driving thin-film transistor (DT). However, to ensure the anode bottleneck (PCN), the aperture ratio will be reduced.

[0079] <Third Implementation Method>

[0080] In the following, in the third embodiment, a unique structure for an organic light-emitting diode display including a bottleneck portion for darkening defective pixels and ensuring the maximum aperture ratio will be proposed. Figure 8 This is a plan view of a pixel in the structure of an ultra-high density organic light-emitting diode display having a bottleneck portion for darkening defective pixels, according to a third embodiment of the present disclosure.

[0081] An organic light-emitting diode (OLED) display according to a third embodiment of this disclosure includes: a sensing line REF, a data line DL, a drive current line VDD, a horizontal sensing line REFh, a horizontal current line VDDh, and a scan line SL. Pixels are defined by these lines. For example, the space enclosed by two adjacent horizontal current lines VDDh, data lines DL, and drive current lines VDD is defined as a unit pixel region.

[0082] The scan line SL, horizontal sensing line REFh, and horizontal current line VDDh extend horizontally on the substrate SUB. The data line DL, drive current line VDD, and sensing line REF extend vertically on the substrate SUB. The horizontal sensing line REFh is connected to the sensing line REF via a sensing contact hole RH. The horizontal current line VDDh is connected to the drive current line VDD via a current contact hole VH.

[0083] A horizontal sensing line REFh and a scan line SL are positioned between two adjacent horizontal current lines VDDh. The region between the upper horizontal current line VDDh and the horizontal sensing line REFh is defined as the emission region. The region between the horizontal sensing line REFh and the lower horizontal current line VDDh is defined as the non-emission region. An organic light-emitting diode (OLED) is positioned in the emission region. Thin-film transistors ST, DT, and ET, as well as a storage capacitor Cst, are positioned in the non-emission region.

[0084] A switching thin-film transistor ST includes: a switching source electrode SS branching from or connected to a data line DL; a switching gate electrode SG defining a first portion of a scan line SL; a switching semiconductor layer SA; and a switching drain electrode SD. A channel region is defined at the overlap region between the switching semiconductor layer SA and the switching gate electrode SG. The switching semiconductor layer SA extends from the switching source electrode SS disposed above the scan line SL to the switching drain electrode SD disposed below the scan line SL. Since the switching semiconductor layer SA is configured to intersect with the switching gate electrode SG, a switching thin-film transistor ST is formed.

[0085] The sensing thin-film transistor ET includes: a sensing source electrode ES branching from or connected to a horizontal sensing line REFh; a sensing gate electrode EG defined at a second portion of a scan line SL; a sensing semiconductor layer EA; and a sensing drain electrode ED. A channel region is defined at the overlap region between the sensing semiconductor layer EA and the sensing gate electrode EG. The sensing semiconductor layer EA extends from the sensing source electrode ES, which is disposed above the scan line SL, to the sensing drain electrode ED, which is disposed below the scan line SL. Since the sensing semiconductor layer EA is configured to intersect with the sensing gate electrode EG, the sensing thin-film transistor ET is formed.

[0086] The driving thin-film transistor DT includes: a driving source electrode DS defined at a portion of a lower horizontal current line VDDh, a driving gate electrode DG connected to a switching drain electrode SD, a driving semiconductor layer DA, and a driving drain electrode DD. The driving drain electrode DD faces the driving source electrode DS with the driving gate electrode DG located in the middle. The driving semiconductor layer DA extends from the lower horizontal current line VDDh to the scan line SL and intersects with the driving gate electrode DG. A channel region is defined at the overlap region of the driving semiconductor layer DA and the driving gate electrode DG. The driving drain electrode DD is simultaneously connected to one end of the driving semiconductor layer DA and one end of the sensing semiconductor layer EA.

[0087] The storage capacitor Cst includes a first electrode and a second electrode. The first electrode is formed as an extension of the switching drain electrode SD. The second electrode is formed as an extension of the driving semiconductor layer DA extending toward the scan line SL across the driving gate electrode DG.

[0088] The driving thin-film transistor DT and the storage capacitor Cst are positioned between the lower horizontal current line VDDh and the scan line SL. The driving element, including the thin-film transistors ST, DT, and ET, and the storage capacitor Cst, is positioned between the lower horizontal current line VDDh and the horizontal sensing line REFh. This region is defined as a non-emitting region.

[0089] The anode electrode ANO of the organic light-emitting diode (OLED) is connected to the driving drain electrode DD through the pixel contact hole PH. The opening area of ​​the dam BA is defined as the maximum area exposing the anode electrode ANO. While ensuring the maximum area, the anode electrode ANO occupies the emission area and some portion extends into the non-emission area. Specifically, it is preferable that the anode electrode ANO extends into the driving drain electrode DD. Furthermore, the anode electrode ANO may overlap with the storage capacitor Cst. When it is difficult to form a second electrode of the storage capacitor Cst using the driving semiconductor layer DA, the second electrode of the storage capacitor Cst can be formed by extending the anode electrode ANO to overlap with the first electrode.

[0090] Most of the anode electrode ANO is exposed through the dam BA. An organic light-emitting diode (OLED) is formed by stacking an organic light-emitting layer and a cathode electrode on the dam BA. Preferably, the OLED is formed to have the maximum emission area within the pixel region.

[0091] Figure 8 The illustrated organic light-emitting diode (OLED) display has a structure that includes a compensation element. Using this structure, when any pixel is defective, the connection between the anode electrode ANO and the thin-film transistor (TFT) is cut off or disconnected. For example, the anode electrode ANO can be selectively disconnected from the driving TFT DT. Furthermore, to prevent the sensing voltage caused at the defective pixel from affecting other adjacent normal pixels, the sensing gate electrode EG of the sensing TFT ET is selectively disconnected from the horizontal sensing line REFh.

[0092] To darken any defective pixels upon detection, it is preferable to provide an anode bottleneck PCN between the anode electrode ANO and the driving thin-film transistor DT, and a sensing bottleneck ECN between the sensing source electrode ES and the horizontal sensing line REFh. Preferably, these bottleneck PCNs and ECNs are spaced at least 6 μm apart from all adjacent elements. Therefore, a certain area within the pixel region is needed for providing these bottleneck PCNs and ECNs.

[0093] However, in the organic light-emitting diode display according to the third embodiment of this disclosure, the anode bottleneck portion PCN is disposed in the same area as the sensing bottleneck portion ECN. Specifically, these bottleneck portions PCN and ECN are disposed in the area between the horizontal sensing line REFh and the scan line SL. That is, according to the third embodiment, the bottleneck portions PCN and ECN are disposed in the non-emission area. Therefore, the aperture ratio is not affected by the bottleneck portion.

[0094] Furthermore, although not shown in the figure, the switching thin-film transistor ST can also be disconnected from the data line DL. For this purpose, a switching bottleneck SCN can be provided between the data line DL and the switching source electrode SS. Figure 8 In this design, the connection between the switching source electrode SS and the data line DL is located between the horizontal sensing line REFh and the scan line SL. Therefore, the switching bottleneck SCN is located in the same region as the anode bottleneck PCN and the sensing bottleneck ECN. Since all bottlenecks are located in the non-emission region, the aperture ratio is not affected (or reduced) by the bottlenecks.

[0095] The organic light-emitting diode (OLED) display according to the third embodiment of this disclosure includes a compensation element that maintains the maximum aperture ratio. Utilizing the key features of the third embodiment, this disclosure proposes an ultra-high density (above 4K level) OLED display with a high aperture ratio.

[0096] For example, this disclosure can also be configured as follows:

[0097] Option 1. A display device, comprising:

[0098] Upper horizontal current line, horizontal sensing line, scan line and lower horizontal current line, these lines extend in the horizontal direction and are arranged in the vertical direction from the top to the bottom on the substrate in the order described above;

[0099] The emission region is defined between the horizontal sensing line and the upper horizontal current line;

[0100] The non-emission region is defined between the horizontal sensing line and the lower horizontal current line;

[0101] Switching thin-film transistors and sensing thin-film transistors are disposed between the horizontal sensing line and the scan line;

[0102] A driving thin-film transistor is disposed between the scan line and the lower horizontal current line;

[0103] An anode electrode extending from the emitting region to the non-emitting region and connected to the driving thin-film transistor; and

[0104] An anode bottleneck, disposed between the horizontal sensing line and the scan line, is used to selectively disconnect the anode electrode from the driving thin-film transistor.

[0105] Option 2. The display device according to Option 1, wherein the sensing thin-film transistor comprises:

[0106] Sensing source electrodes branching from the horizontal sensing line;

[0107] A sensing gate electrode is defined at a first portion of the scan line;

[0108] The sensing drain electrode faces the sensing source electrode with the sensing gate electrode located in the middle;

[0109] A sensing semiconductor layer extending from the sensing source electrode to the sensing drain electrode and overlapping with the sensing gate electrode; and

[0110] A sensing bottleneck is provided between the horizontal sensing line and the scan line to selectively disconnect the sensing source electrode from the horizontal sensing line.

[0111] Solution 3. The display device according to Solution 1, wherein the anode bottleneck extends vertically between the horizontal sensing line and the scan line, and a first portion of the anode electrode disposed in the emission region is connected to a second portion of the anode electrode disposed in the non-emission region.

[0112] Option 4. The display device according to Option 2, wherein the sensing bottleneck has a segment shape that is spaced at least 6 μm apart from the horizontal sensing line and the anode bottleneck.

[0113] Option 5. The display device according to Option 1, wherein the horizontal sensing line is connected to the vertical sensing line through a sensing contact hole that exposes a portion of the sensing line.

[0114] Solution 6. The display device according to Solution 1 further includes:

[0115] Data lines, drive current lines, and vertical sensing lines extending vertically on the substrate.

[0116] Option 7. The display device according to Option 6, wherein the switching thin-film transistor comprises:

[0117] Switch source electrodes branching from the data line;

[0118] A switching gate electrode is defined at the second portion of the scan line;

[0119] A switch drain electrode, which faces the switch source electrode with the switch gate electrode positioned in the middle; and

[0120] A switching semiconductor layer that extends from the switching source electrode to the switching drain electrode and overlaps with the switching gate electrode.

[0121] Option 8. The display device according to Option 7, wherein the switching thin-film transistor further includes:

[0122] The bottleneck of the switch is located between the data line and the switch source electrode.

[0123] Option 9. The display device according to Option 6, wherein the driving thin-film transistor comprises:

[0124] A drive gate electrode, which is connected to the switching thin-film transistor;

[0125] A drive drain electrode is defined at a portion of the drive current line;

[0126] A driving source electrode, which faces the driving drain electrode with the driving gate electrode positioned in the middle; and

[0127] A driving semiconductor layer extends from the driving source electrode to the driving drain electrode and overlaps with the driving gate electrode.

[0128] Option 10. The display device according to Option 6, wherein the upper horizontal current line and the lower horizontal current line are connected to the drive current line through a current contact hole that exposes a portion of the drive current line.

[0129] Option 11. A display device, comprising:

[0130] Upper horizontal sensing line, horizontal current line, scan line and lower horizontal sensing line, these lines extend in the horizontal direction and are arranged in the vertical direction from the top to the bottom on the substrate in the order described above;

[0131] The emission region is defined between the upper horizontal sensing line and the horizontal current line;

[0132] The non-emission region is defined between the lower horizontal sensing line and the horizontal current line;

[0133] Switching thin-film transistors and sensing thin-film transistors are disposed between the lower horizontal sensing line and the scan line;

[0134] A driving thin-film transistor is disposed between the scan line and the horizontal current line;

[0135] An anode electrode extends from the emitting region to the non-emitting region and is connected to the driving thin-film transistor;

[0136] A sensing bottleneck, disposed between the lower horizontal sensing line and the source electrode of the sensing thin-film transistor, is used to selectively disconnect the lower horizontal sensing line from the source electrode of the sensing thin-film transistor; and

[0137] A switch bottleneck is disposed between the vertical data line and the source electrode of the switching thin-film transistor, for selectively disconnecting the vertical data line from the source electrode of the switching thin-film transistor.

[0138] Solution 12. The display device according to Solution 11 further includes:

[0139] An anode bottleneck, disposed between the upper horizontal sensing line and the horizontal current line, is used to selectively disconnect the anode electrode from the driving thin-film transistor.

[0140] Although embodiments of the invention have been described in detail with reference to the accompanying drawings, those skilled in the art will understand that the invention can be implemented in other specific forms without altering its technical spirit or essential characteristics. Therefore, it should be noted that the foregoing embodiments are merely illustrative in all respects and should not be construed as limiting the invention. The scope of the invention is defined by the appended claims rather than the detailed description thereof. All changes or modifications or equivalents made within the meaning and scope of the claims should be understood to fall within the scope of the invention.

Claims

1. A display device, comprising: Upper horizontal current line, horizontal sensing line, scan line and lower horizontal current line, these lines extend in the horizontal direction and are arranged vertically on the substrate in the order of the upper horizontal current line, the horizontal sensing line, the scan line and the lower horizontal current line from the top to the bottom; The emission region is defined between the horizontal sensing line and the upper horizontal current line; The non-emission region is defined between the horizontal sensing line and the lower horizontal current line; A sensing thin-film transistor is disposed between the horizontal sensing line and the scan line; A driving thin-film transistor is disposed between the scan line and the lower horizontal current line; An anode electrode extends from the emitting region to the non-emitting region and is connected to the driving thin-film transistor; as well as An anode bottleneck, disposed between the horizontal sensing line and the scan line, is used to selectively disconnect the anode electrode from the driving thin-film transistor.

2. The display device according to claim 1, wherein The sensing thin-film transistor includes: Sensing source electrodes branching from the horizontal sensing line; A sensing gate electrode is defined at a first portion of the scan line; The sensing drain electrode faces the sensing source electrode with the sensing gate electrode located in the middle; A sensing semiconductor layer extending from the sensing source electrode to the sensing drain electrode and overlapping with the sensing gate electrode; and A sensing bottleneck is provided between the horizontal sensing line and the scan line to selectively disconnect the sensing source electrode from the horizontal sensing line.

3. The display device according to claim 1, wherein, The anode bottleneck extends vertically between the horizontal sensing line and the scan line, and connects a first portion of the anode electrode disposed in the emission region to a second portion of the anode electrode disposed in the non-emission region.

4. The display device according to claim 2, wherein, The sensing bottleneck has a segment shape that is at least 6 μm apart from the horizontal sensing line and the anode bottleneck.

5. The display device according to claim 1, wherein, The horizontal sensing line is connected to the vertical sensing line through a sensing contact hole that exposes a portion of the vertical sensing line.

6. The display device according to claim 1, further comprising: Data lines, drive current lines, and vertical sensing lines extending vertically on the substrate.

7. The display device according to claim 6, further comprising a switching thin-film transistor, wherein, The switching thin-film transistor includes: Switch source electrodes branching from the data line; A switching gate electrode is defined at the second portion of the scan line; A switch drain electrode, which faces the switch source electrode with the switch gate electrode positioned in the middle; and A switching semiconductor layer that extends from the switching source electrode to the switching drain electrode and overlaps with the switching gate electrode.

8. The display device according to claim 7, wherein, The switching thin-film transistor further includes: The bottleneck of the switch is located between the data line and the switch source electrode.

9. The display device according to claim 7, wherein, The driving thin-film transistor includes: A drive gate electrode, which is connected to the switching thin-film transistor; A drive drain electrode is defined at a portion of the drive current line; A driving source electrode, which faces the driving drain electrode with the driving gate electrode positioned in the middle; and A driving semiconductor layer extends from the driving source electrode to the driving drain electrode and overlaps with the driving gate electrode.

10. The display device according to claim 6, wherein, The upper horizontal current line and the lower horizontal current line are connected to the drive current line through a current contact hole that exposes a portion of the drive current line.

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