Pixel circuit and display apparataus including the same

Abstract

A transparent micro-LED unit pixel circuit capable of increasing the transparent area by driving red, green, and blue micro-LED elements with a single driving transistor, and a transparent micro-LED display device including the same are disclosed. The transparent micro-LED unit pixel circuit includes a first micro-LED, a second micro-LED, and a third micro-LED that emit light according to a driving current; a driving transistor that controls the driving current and is coupled between the anode electrodes of the first micro-LED, the second micro-LED, and the third micro-LED and a high potential power line; a storage capacitor coupled between the gate electrode and the source electrode of the driving transistor; and a first transistor that applies a data voltage to the gate electrode of the driving transistor.

Description

Technology Field

[0001] The present specification relates to a display device, and more specifically, to a pixel circuit including a transparent micro LED and a transparent micro LED display device including such a pixel circuit. Background Technology

[0002] In addition to televisions or monitors, display devices are widely used as display screens for laptop computers, tablet computers, smartphones, portable display devices, and portable information devices.

[0003] Recently, research and development on micro-LED display devices using micro-LEDs as light-emitting elements have been underway, and they are gaining attention as next-generation display devices due to their high image quality and high reliability.

[0004] In addition, as the development of display devices is actively progressing, there is a demand for diversity that is differentiated from existing designs, and transparent display devices capable of enhancing aesthetic functions and providing multifunctional usability are being proposed. The problem to be solved

[0005] A transparent display panel may include a light-emitting area and a transmission area within the display region. Multiple pixels may be arranged in the light-emitting area. The areas of the light-emitting and transmission areas may be designed considering light-emitting efficiency and transparency. In the case of a structure in which a single driving transistor drives a single light-emitting element, the increase in the area of ​​the transmission region of the transparent display panel may be limited.

[0006] The embodiments of the present specification may provide a pixel circuit capable of driving red, green, and blue micro LED elements with a single driving transistor to increase the area of ​​the transmission region.

[0007] The embodiments of the present specification provide a transparent micro-LED unit pixel circuit capable of increasing the transparent area by driving red, green, and blue micro-LED elements with a single driving transistor, and a transparent micro-LED display device including the same.

[0008] The problems to be solved according to one embodiment of this specification are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0009] A transparent micro LED unit pixel circuit according to the first embodiment of the present specification comprises: a first micro LED, a second micro LED, and a third micro LED that emit light according to a driving current; a driving transistor that controls the driving current and is coupled between the anode electrodes of the first micro LED, the second micro LED, and the third micro LED and a high potential power line; a storage capacitor coupled between the gate electrode and the source electrode of the driving transistor; and a first transistor that applies a data voltage to the gate electrode of the driving transistor.

[0010] A transparent micro LED unit pixel circuit according to the second embodiment of the present specification comprises: a first micro LED, a second micro LED, and a third micro LED that emit light according to a driving current; a driving transistor that controls the driving current and is coupled between the cathode electrodes of the first micro LED, the second micro LED, and the third micro LED and a low potential power line; a storage capacitor coupled between the gate electrode and the source electrode of the driving transistor; and a first transistor that applies a data voltage to the gate electrode of the driving transistor.

[0011] A transparent micro LED unit pixel circuit according to the third embodiment of the present specification comprises: a first micro LED, a second micro LED, and a third micro LED that emit light according to a driving current; a first scan transistor coupled to the anode electrode of the first micro LED; a second scan transistor coupled to the anode electrode of the second micro LED; a third scan transistor coupled to the anode electrode of the third micro LED; a driving transistor that controls the driving current and is coupled between the first scan transistor, the second scan transistor, and the third scan transistor and a high potential power line; a storage capacitor coupled between the gate electrode and the source electrode of the driving transistor; and a first transistor that applies a data voltage to the gate electrode of the driving transistor.

[0012] A transparent micro LED display device according to another aspect of the present specification comprises: a transparent display panel including a light-emitting region and a transmission region, and a plurality of unit pixel circuits disposed in the light-emitting region; each of the plurality of unit pixel circuits includes a first micro LED, a second micro LED, and a third micro LED that emit light according to a driving current; a driving transistor that controls the driving current and is coupled between the anode electrodes of the first micro LED, the second micro LED, and the third micro LED and a high potential power line; a storage capacitor coupled between the gate electrode and the source electrode of the driving transistor; and a first transistor that applies a data voltage to the gate electrode of the driving transistor. Effects of the invention

[0013] According to the embodiments, the transparent area can be increased by driving red, green, and blue micro LED elements with a single driving transistor.

[0014] In addition, transparency can be improved by increasing the transparent area of ​​the transparent display panel.

[0015] In addition, by improving the transparency of the transparent display panel, aesthetic functions and multifunctional usability can be provided.

[0016] In addition to the effects described above, the specific effects of the present invention are described together with the specific details for implementing the invention below. Brief explanation of the drawing

[0017] FIG. 1 illustrates a transparent micro LED display device according to one embodiment. Figure 2 illustrates a subpixel circuit of the unit pixel circuit of Figure 1. Figure 3 illustrates the layout of the unit pixel circuit of Figure 1. FIG. 4 illustrates a transparent micro LED display device according to another embodiment. FIG. 5 illustrates a unit pixel circuit according to a first embodiment. FIG. 6 illustrates the layout of a unit pixel circuit according to a first embodiment. FIG. 7 illustrates a unit pixel circuit according to a second embodiment. FIG. 8 illustrates the layout of a unit pixel circuit according to a second embodiment. FIG. 9 illustrates a unit pixel circuit according to a third embodiment. FIG. 10 illustrates a timing diagram of a transparent micro LED display device to which a unit pixel circuit according to a first embodiment is applied. Figure 11 is a cross-sectional view shown along one direction in the pixel circuit of Figure 6. Specific details for implementing the invention

[0018] The advantages and features of this specification and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, this specification is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of this specification is complete and to fully inform those skilled in the art of the scope of the invention, and this specification is defined only by the scope of the claims.

[0019] Shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of this specification are exemplary and are not limited to the depicted items. Throughout the specification, the same reference numerals refer to the same components. Furthermore, in describing this specification, if it is determined that a detailed description of related prior art could unnecessarily obscure the essence of this specification, such detailed description is omitted. Where terms such as "includes," "has," or "is made up" are used in this specification, other parts may be added unless "only" is used. Where a component is expressed in the singular, it includes cases where it is included in the plural unless specifically stated otherwise.

[0020] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement.

[0021] In the case of an explanation of a temporal relationship, for example, when a temporal sequence is explained using 'after', 'following', 'next', 'before', etc., it may include cases where the sequence is not continuous unless 'immediately' or 'directly' is used.

[0022] In the case of a description of signal flow relationships, for example, even in the case where 'a signal is transmitted from Node A to Node B,' unless 'immediately' or 'directly' is used, it may include cases where a signal is transmitted from Node A to Node B via another node.

[0023] Although terms such as "first," "second," etc. are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the technical scope of this specification.

[0024] The features of each of the various embodiments of this specification may be combined or combined with one another, either partially or wholly, and may technically enable various interlocking and operation. Each embodiment may be implemented independently of one another or may be implemented together in an associated relationship.

[0025] Hereinafter, a transparent micro-LED unit pixel circuit according to several embodiments and a transparent micro-LED display device including the same will be described.

[0026] FIG. 1 illustrates a transparent micro LED display device according to one embodiment.

[0027] Referring to FIG. 1, a transparent micro LED display device includes a transparent display panel (100) having a plurality of unit pixel circuits (10).

[0028] Each of the plurality of unit pixel circuits (10) includes sub-pixel circuits. A sub-pixel may include red, green, and blue pixels (R, G, B). Or, a sub-pixel may include red, green, blue, and white pixels (R, G, B, W).

[0029] Each subpixel can be coupled (or connected) to a data line to which a data voltage is applied, a detection line to which a reference voltage (VREF) is applied, a scan line to which an initialization signal (INIT) is applied, a scan line to which a scan signal (SCAN) is applied, and a scan line to which a detection signal (SENSE) is applied. In addition, each subpixel can be coupled to a high-potential power line to which a high-potential voltage is applied, a low-potential power line to which a low-potential voltage is applied, and a power line to which an initialization voltage is applied.

[0030] A transparent display panel (100) may include a light-emitting area and a transmission area. Subpixels may be placed in the light-emitting area, and an area where subpixels are not placed may be designated as a transmission area. The areas of the light-emitting area and the transmission area may be designed considering light-emitting efficiency and transparency.

[0031] FIG. 2 illustrates a subpixel circuit of the unit pixel circuit of FIG. 1. The subpixel circuit may be an R, G, B, or W pixel.

[0032] Referring to FIGS. 1 and 2, each sub-pixel circuit of the unit pixel circuit (10) includes a micro LED (uLED), a driving transistor (DR-TFT), a storage capacitor (Cst), a first transistor (T1), a second transistor (T2), and a third transistor (T3).

[0033] A micro LED (uLED) emits light depending on the driving current. The anode electrode of the micro LED (uLED) is coupled to the source electrode of a driving transistor (DR-TFT), and the cathode electrode is coupled to a low-potential power line. A low-potential voltage (EVSS) can be applied to the low-potential power line.

[0034] The driving transistor (DR-TFT) controls the driving current and is coupled between the anode electrode of the micro LED and the high-potential power line. It includes the driving transistor (DR-TFT), a source electrode, a gate electrode, and a drain electrode. The gate electrode corresponds to the node (DTG), and the source electrode corresponds to the node (DTS). The high-potential power line is coupled to the drain electrode. A high-potential voltage (EVDD) is applied to the high-potential power line.

[0035] A storage capacitor (Cst) is coupled between the gate electrode and the source electrode of a driving transistor (DR-TFT). The storage capacitor (Cst) can sample the data voltage (VDATA) when the first transistor (T1) is turned on and can boost the gate electrode of the driving transistor.

[0036] The first transistor (T1) is coupled between the data line and the gate electrode of the driving transistor (DR-TFT). Additionally, the first transistor (T1) is coupled between the data line and one electrode of the storage capacitor (Cst). A data voltage (VDATA) is applied to the data line. The first transistor (T1) transmits the data voltage (VDATA) to the node (DTG) in response to a scan signal (SCAN).

[0037] The second transistor (T2) is coupled between the initialization power line and the node (DTG). An initialization voltage (VINIT) is applied to the initialization power line. The second transistor (T2) can initialize the node (DTG) to the initialization voltage (VINIT) in response to the initialization signal (INIT).

[0038] The third transistor (T3) is coupled between the reference power line and the node (DTS). A reference voltage (VREF) is applied to the reference power line. The third transistor (T3) can precharge the node (DTS) to the reference voltage (VREF) in response to a sensing signal (SENSE).

[0039] According to an embodiment, at least one of the driving transistor (DR-TFT), the first transistor (T1), the second transistor (T2), and the third transistor (T3) may be implemented as a Low Temperature Polycrystalline Oxide (LTPS) transistor or an oxide semiconductor transistor. However, it is not limited thereto. For example, at least one of the driving transistor (DR-TFT), the first transistor (T1), the second transistor (T2), and the third transistor (T3) may be configured as a P-type oxide thin film transistor comprising a P-type oxide semiconductor layer. Alternatively, at least one of the driving transistor (DR-TFT), the first transistor (T1), the second transistor (T2), and the third transistor (T3) may be configured as an N-type oxide thin film transistor comprising an N-type oxide semiconductor layer.

[0040] When the transparent micro LED display device is configured with unit pixel circuits (10) as R, G, and B subpixels, each subpixel requires four thin-film transistors and one storage capacitor, and each unit subpixel (10) requires 12 thin-film transistors and three storage capacitors.

[0041] This places a limit on increasing the area of ​​the transparent display panel's transmittance to the target area.

[0042] Figure 3 illustrates the layout of the unit pixel circuit of Figure 1.

[0043] Referring to FIGS. 1 to 3, each subpixel requires four thin-film transistors and one storage capacitor, each unit subpixel (10) requires 12 thin-film transistors and three storage capacitors, and each subpixel requires power lines, so there is a limit to the increase in the area of ​​the transparent region (TA) of the transparent display panel, and it is difficult to achieve a transparency of 70% or more.

[0044] FIG. 4 illustrates a transparent micro LED display device according to another embodiment.

[0045] Referring to FIG. 4, the transparent micro LED display device includes a transparent display panel (100) having a plurality of unit pixel circuits (20).

[0046] Each of the plurality of unit pixel circuits (20) can drive red, green, and blue micro LEDs (R, G, B) with a single driving transistor. Alternatively, each of the plurality of unit pixel circuits (20) can drive red, green, blue, and white micro LEDs (R, G, B, W) with a single driving transistor.

[0047] The unit pixel circuit (20) can be coupled (or connected) to a data line to which a data voltage is applied, a detection line to which a reference voltage (VREF) is applied, a scan line to which an initialization signal (INIT) is applied, a scan line to which a scan signal (SCAN) is applied, and a scan line to which a detection signal (SENSE) is applied.

[0048] Additionally, the unit pixel circuit (20) may be coupled to a high-potential power line to which a high-potential voltage is applied, a low-potential power line to which a low-potential voltage is applied, and a power line to which an initialization voltage is applied. For example, the cathode electrodes of the red, green, and blue micro LEDs (R, G, B) of the unit pixel circuit (20) may be coupled to a first low-potential power line to a third low-potential power line. As another example, the anode electrodes of the red, green, and blue micro LEDs (R, G, B) of the unit pixel circuit (20) may be coupled to a first high-potential power line to a third high-potential power line.

[0049] FIG. 5 illustrates a unit pixel circuit according to a first embodiment.

[0050] Referring to FIGS. 4 and 5, the unit pixel circuit (20) according to the first embodiment includes a first micro LED (uLED_R), a second micro LED (uLED_G), a third micro LED (uLED_B), a driving transistor (DR-TFT), a storage capacitor (Cst), a first transistor (T1), a second transistor (T2), and a third transistor (T3).

[0051] The first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B) emit light according to the driving current.

[0052] The anode electrode of the first micro LED (uLED_R) is coupled to the source electrode of the driving transistor (DR-TFT), and the cathode electrode is coupled to the first low-potential power line (EVSS_R).

[0053] The anode electrode of the second micro LED (uLED_G) is coupled to the source electrode of the driving transistor (DR-TFT), and the cathode electrode is coupled to the second low-potential power line (EVSS_G).

[0054] The anode electrode of the third micro LED (uLED_B) is coupled to the source electrode of the driving transistor (DR-TFT), and the cathode electrode is coupled to the third low-potential power line (EVSS_B).

[0055] A low potential voltage (EVSS) or a high potential voltage (EVDD) may be applied to the first low potential power line (EVSS_R) to the third low potential power line (EVSS_B).

[0056] For example, when emitting light from the first micro LED (uLED_R), a low potential voltage (EVSS) can be applied to the first low potential power line (EVSS_R), and a high potential voltage (EVDD) can be applied to the second low potential power line (EVSS_G) and the third low potential power line (EVSS_B).

[0057] For example, when emitting light from the second micro LED (uLED_G), a low potential voltage (EVSS) can be applied to the second low potential power line (EVSS_G), and a high potential voltage (EVDD) can be applied to the first low potential power line (EVSS_R) and the third low potential power line (EVSS_B).

[0058] For example, when emitting light from the third micro LED (uLED_B), a low potential voltage (EVSS) can be applied to the third low potential power line (EVSS_B), and a high potential voltage (EVDD) can be applied to the first low potential power line (EVSS_R) and the second low potential power line (EVSS_G).

[0059] The driving transistor (DR-TFT) controls the driving current and is coupled between the anode electrodes of the first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B) and a high potential power line to which a high potential voltage (EVDD) is applied. The driving transistor (DR-TFT) includes a source electrode corresponding to a node (DTS), a gate electrode corresponding to a node (DTG), and a drain electrode to which a high potential voltage (EVDD) is applied.

[0060] A storage capacitor (Cst) is coupled between the gate electrode and the source electrode of a driving transistor (DR-TFT). The storage capacitor (Cst) can sample the data voltage (VDATA) when the first transistor (T1) is turned on and can boost the gate electrode of the driving transistor (DR-TFT).

[0061] The first transistor (T1) is coupled between the data line to which the data voltage (VDATA) is applied and the gate electrode of the driving transistor (DR-TFT). Additionally, the first transistor (T1) is coupled between the data line and one electrode of the storage capacitor (Cst). The first transistor (T1) transmits the data voltage (VDATA) to the node (DTG) in response to the scan signal (SCAN).

[0062] The second transistor (T2) is coupled between the initialization power line to which the initialization voltage (VINIT) is applied and the node (DTG). The second transistor (T2) initializes the node (DTG) corresponding to the gate electrode of the driving transistor (DR-TFT) in response to the initialization signal (INIT).

[0063] The third transistor (T3) is coupled between the reference power line to which the reference voltage (VREF) is applied and the node (DTS). In response to the detection signal (SENSE), the third transistor (T3) precharges the node (DTS) corresponding to the source electrode of the driving transistor (DR-TFT) to the reference voltage (VREF).

[0064] The driving transistor (DR-TFT), the first transistor (T1), the second transistor (T2), and the third transistor (T3) may be composed of NMOS transistors.

[0065] In this way, the transparent micro LED pixel circuit according to the first embodiment can control the voltage applied to the first low-potential power line (EVSS_R), the second low-potential power line (EVSS_G), and the third low-potential power line (EVSS_B) to emit light from the first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B) with a single driving transistor (DR-TFT).

[0066] Since the transparent micro LED pixel circuit according to the first embodiment can drive the first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B) using a single driving transistor (DR-TFT), the area of ​​the transparent display panel's transmission region can be increased and the transparency can be improved.

[0067] The first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B) may each be a Light Emitting Diode (LED) device made of inorganic materials, etc. Since LED devices have high light conversion efficiency, they consume very little energy, have a semi-permanent lifespan, and are environmentally friendly devices.

[0068] FIG. 6 illustrates the layout of a unit pixel circuit according to a first embodiment.

[0069] Referring to FIGS. 4 to 6, with the idea of ​​increasing the area of ​​the transmission region (TA), three microLED (uLED) elements are driven by a single driving transistor (DR-TFT), and each pixel can drive the R, G, and B microLED (uLED) elements in time division, for example, 33%, by controlling the voltage applied to the power line.

[0070] The unit pixel circuit according to the first embodiment requires a first low-potential power line (EVSS_R), a second low-potential power line (EVSS_G), and a third low-potential power line (EVSS_B), but the thin-film transistors of the unit pixel circuit can be reduced from 12 to 4, and the data lines can be reduced from 3 to 1, thereby increasing the area of ​​the transmission region (TA). Through this, transparency can also be improved from 65% to 72%.

[0071] Referring to FIG. 6, a first micro LED (uLED_R) may be placed on a pixel circuit. A second micro LED (uLED_G) may be placed on the first low-potential power line (EVSS_R) such that at least a portion overlaps with the first low-potential power line (EVSS_R). A third micro LED (uLED_B) may be placed independently on one side of the first low-potential power line (EVSS_R). The third micro LED (uLED_B) may not overlap with the driving transistor (DR-TFT).

[0072] In an embodiment, the first low-potential power line (EVSS_R), the second low-potential power line (EVSS_G), and the third low-potential power line (EVSS_B) may be arranged in the Y-axis direction with respect to the plane of the display panel. For example, the third low-potential power line (EVSS_B) may be arranged in a manner that surrounds at least three sides of the pixel circuit. The sides of the pixel circuit that are not adjacent to the third low-potential power line (EVSS_B) may be adjacent to the data lines.

[0073] Additionally, the high potential power line, initialization power line, reference voltage power line, and data line may be arranged in the Y-axis direction with respect to the plane of the display panel. For example, the high potential power line, initialization power line, reference voltage power line, and data line (DATA) may be arranged to overlap with at least one of the first low potential power line (EVSS_R), the second low potential power line (EVSS_G), and the third low potential power line (EVSS_B). Alternatively, the high potential power line, initialization power line, reference voltage power line, and data line may be arranged parallel to the first low potential power line (EVSS_R), the second low potential power line (EVSS_G), and the third low potential power line (EVSS_B).

[0074] In addition, a first scan line to which an initialization signal (INIT) is applied, a second scan line to which a scan signal (SCAN) is applied, and a third scan line to which a detection signal (SENSE) is applied may be arranged in the X-axis direction with respect to the plane of the display panel. For example, the first scan line may be arranged parallel to the second scan line and the third scan line, spaced apart from each other with the driving transistor (DR-TFT) in the center.

[0075] In the embodiment, the pixel circuit and micro LED (uLED) elements (R, G, B) may be placed in a circuit area (A1) and an auxiliary area (A2). Within the circuit area (A1), a driving transistor (DR-TFT), a first transistor (T1), a second transistor (T2), and a third transistor (T3) are placed, and a data line (DATA) may be placed in at least a portion of a first low-potential power line (EVSS_R), a second low-potential power line (EVSS_G), and a third low-potential power line (EVSS_B). Within the circuit area (A1), a first micro LED (R) and a second micro LED (G) may be placed. In this case, the first micro LED (R) and the second micro LED (G) may be placed on other components within the circuit area (A1), for example, the driving transistor (DR-TFT), the first transistor (T1), and the first low-potential power line (EVSS_R). However, this is merely an example and is not limited to it.

[0076] A third micro LED (B) may be placed within the auxiliary region (A2). The third micro LED (B) may be placed within the auxiliary region (A2) but may be electrically connected to other components included in the circuit region (A1). The third micro LED (B) may be placed on the same layer as the first micro LED (R) and the second micro LED (G), but is not limited thereto.

[0077] In the embodiments, the sizes of the first micro LED (R), the second micro LED (G), and the third micro LED (B) may be distinct from one another. For example, the size of the first micro LED (R) may be larger than the size of the second micro LED (G). As another example, the size of the second micro LED (G) may be larger than the size of the third micro LED (B).

[0078] In the embodiment, a first auxiliary micro LED (R'), a second micro LED (G'), and a third micro LED (B') may be further disposed within the pixel area (A1) and the auxiliary area (A2). The first auxiliary micro LED (R'), the second micro LED (G'), and the third micro LED (B') may be LED elements for replacement in the event that the first micro LED (R), the second micro LED (G), and the third micro LED (B) fail.

[0079] For example, the first auxiliary micro LED (R') is positioned on the same y-axis line as the first micro LED (R) so that it can be connected to the pixel circuit in place of the first micro LED (R) in the event that the first micro LED (R) fails. The first auxiliary micro LED (R') may have the same configuration as the first micro LED (R). For example, the first auxiliary micro LED (R') may have the same size and configuration as the first micro LED (R).

[0080] The second auxiliary micro LED (G') is positioned on the same y-axis line as the second micro LED (G) so that if the first micro LED (G) fails, the second micro LED (G) can be connected to the pixel circuit instead. The second auxiliary micro LED (G') may have the same configuration as the second micro LED (G). For example, the second auxiliary micro LED (G') may have the same size and configuration as the second micro LED (G).

[0081] The third auxiliary micro LED (B') is positioned on the same y-axis line as the third micro LED (B) so that it can be connected to the pixel circuit in place of the third micro LED (B) in the event that the third micro LED (B) fails. The third auxiliary micro LED (B') may have the same configuration as the third micro LED (B). For example, the third auxiliary micro LED (B') may have the same size and configuration as the third micro LED (B).

[0082] FIG. 6 illustrates an example in which the first auxiliary micro LED (R'), the second micro LED (G'), and the third micro LED (B') are positioned on the same y-axis line as the first micro LED (R), the second micro LED (G), and the third micro LED (B), but is not limited thereto and may be positioned on the same x-axis line (see FIG. 8) or positioned in other ways.

[0083] FIG. 7 illustrates a unit pixel circuit according to a second embodiment. FIG. 8 illustrates the layout of a unit pixel circuit according to a second embodiment. In the description of FIG. 8, content that overlaps with FIG. 6 may be omitted.

[0084] Referring to FIGS. 7 and 8, the unit pixel circuit (20) according to the second embodiment includes a first micro LED (uLED_R), a second micro LED (uLED_G), a third micro LED (uLED_B), a driving transistor (DR-TFT), a storage capacitor (Cst), a first transistor (T1), a second transistor (T2), and a third transistor (T3).

[0085] The first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B) emit light according to the driving current.

[0086] The cathode electrode of the first micro LED (uLED_R) is coupled to the drain electrode of the driving transistor (DR-TFT), and the anode electrode is coupled to the first high-potential power line (EVDD_R).

[0087] The cathode electrode of the second micro LED (uLED_G) is coupled to the drain electrode of the driving transistor (DR-TFT), and the anode electrode is coupled to the second high-potential power line (EVDD_G).

[0088] The cathode electrode of the third micro LED (uLED_B) is coupled to the drain electrode of the driving transistor (DR-TFT), and the anode electrode is coupled to the third high-potential power line (EVDD_B).

[0089] A low potential voltage (EVSS) or a high potential voltage (EVDD) may be applied to the first high potential power line (EVDD_R) to the third high potential power line (EVDD_B).

[0090] For example, when emitting light from the first micro LED (uLED_R), a high potential voltage (EVDD) can be applied to the first high potential power line (EVDD_R), and a low potential voltage (EVSS) can be applied to the second high potential power line (EVDD_G) and the third high potential power line (EVDD_B).

[0091] For example, when emitting light from the second micro LED (uLED_G), a high potential voltage (EVDD) can be applied to the second high potential power line (EVDD_G), and a low potential voltage (EVSS) can be applied to the first high potential power line (EVDD_R) and the third high potential power line (EVDD_B).

[0092] For example, when emitting light from the third micro LED (uLED_B), a high potential voltage (EVDD) can be applied to the third high potential power line (EVDD_B), and a low potential voltage (EVSS) can be applied to the first high potential power line (EVDD_R) and the second high potential power line (EVDD_G).

[0093] The driving transistor (DR-TFT) controls the driving current and is coupled between the cathode electrodes of the first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B) and a low potential power line to which a low potential voltage (EVSS) is applied. The driving transistor (DR-TFT) includes a source electrode corresponding to a node (DTS), a gate electrode corresponding to a node (DTG), and a drain electrode coupled to the cathode electrodes of the first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B).

[0094] A storage capacitor (Cst) is coupled between the gate electrode and the source electrode of a driving transistor (DR-TFT). The storage capacitor (Cst) can sample the data voltage (VDATA) when the first transistor (T1) is turned on and can boost the gate electrode of the driving transistor (DR-TFT).

[0095] The first transistor (T1) is coupled between the data line to which the data voltage (VDATA) is applied and the gate electrode of the driving transistor (DR-TFT). Additionally, the first transistor (T1) is coupled between the data line and one electrode of the storage capacitor (Cst). The first transistor (T1) transmits the data voltage (VDATA) to the node (DTG) in response to the scan signal (SCAN).

[0096] The second transistor (T2) is coupled between the initialization power line to which the initialization voltage (VINIT) is applied and the node (DTG). The second transistor (T2) initializes the node (DTG) corresponding to the gate electrode of the driving transistor (DR-TFT) in response to the initialization signal (INIT).

[0097] The third transistor (T3) is coupled between the reference power line to which the reference voltage (VREF) is applied and the node (DTS). In response to the detection signal (SENSE), the third transistor (T3) precharges the node (DTS) corresponding to the source electrode of the driving transistor (DR-TFT) to the reference voltage (VREF).

[0098] The driving transistor (DR-TFT), the first transistor (T1), the second transistor (T2), and the third transistor (T3) may be composed of NMOS transistors.

[0099] In this way, the transparent micro LED pixel circuit according to the second embodiment can control the voltage applied to the first high potential power line (EVDD_R), the second high potential power line (EVDD_G), and the third high potential power line (EVDD_B) to emit light from the first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B) with a single driving transistor (DR-TFT).

[0100] Since the transparent micro LED pixel circuit according to the second embodiment can drive the first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B) using a single driving transistor (DR-TFT), the area of ​​the transparent display panel's transmission region can be increased and the transparency can be improved.

[0101] Referring to FIG. 8, a first micro LED (uLED_R) may be placed on a pixel circuit. A second micro LED (uLED_G) may be placed on the pixel circuit spaced apart from the first micro LED (uLED_R). A third micro LED (uLED_B) may be placed so as to overlap with a third scan signal to which a detection signal (SENSE) is applied.

[0102] In an embodiment, the first high-potential power line (EVDD_R), the second high-potential power line (EVDD_G), and the third high-potential power line (EVDD_B) may be arranged in the Y-axis direction with respect to the plane of the display panel. For example, the first high-potential power line (EVDD_R), the second high-potential power line (EVDD_G), and the third high-potential power line (EVDD_B) may be spaced apart from each other and arranged parallel to each other.

[0103] Additionally, the high potential power line, initialization power line, reference voltage power line, and data line may be arranged in the Y-axis direction with respect to the plane of the display panel. For example, the low potential power line, initialization power line, reference voltage power line, and data line may be arranged parallel to the first high potential power line (EVDD_R), the second high potential power line (EVDD_G), and the third high potential power line (EVDD_B). Alternatively, the low potential power line, initialization power line, reference voltage power line, and data line may be arranged to overlap with at least one of the first high potential power line (EVDD_R), the second high potential power line (EVDD_G), and the third high potential power line (EVDD_B).

[0104] In addition, a first scan line to which an initialization signal (INIT) is applied, a second scan line to which a scan signal (SCAN) is applied, and a third scan line to which a detection signal (SENSE) is applied may be arranged in the X-axis direction with respect to the plane of the display panel. For example, the first scan line may be arranged parallel to the second scan line and the third scan line, spaced apart from each other with the driving transistor (DR-TFT) in the center.

[0105] In the embodiment, FIG. 8 may show an example where the auxiliary region (A1) of FIG. 6 is omitted. In this case, the pixel circuit and micro LEDs (R, G, B) may be placed on the pixel area.

[0106] FIG. 9 illustrates a unit pixel circuit according to a third embodiment.

[0107] Referring to FIG. 9, the unit pixel circuit (20) according to the third embodiment includes a first micro LED (uLED_R), a second micro LED (uLED_G), a third micro LED (uLED_B), a first scan transistor (T4), a second scan transistor (T5), a third scan transistor (T6), a driving transistor (DR-TFT), a storage capacitor (Cst), a first transistor (T1), a second transistor (T2), and a third transistor (T3).

[0108] The first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B) emit light according to the driving current.

[0109] The first scan transistor (T4) is coupled between the anode electrode of the first micro LED (uLED_R) and the source electrode of the driving transistor (DR-TFT). The first scan transistor (T4) forms a current path between the driving transistor (DR-TFT) and the first micro LED (uLED_R) in response to the first scan signal (SCAN_R).

[0110] The second scan transistor (T5) is coupled between the anode electrode of the second micro LED (uLED_G) and the source electrode of the driving transistor (DR-TFT). The second scan transistor (T5) forms a current path between the driving transistor (DR-TFT) and the second micro LED (uLED_G) in response to the second scan signal (SCAN_G).

[0111] The third scan transistor (T6) is coupled between the anode electrode of the third micro LED (uLED_B) and the source electrode of the driving transistor (DR-TFT). The third scan transistor (T6) forms a current path between the driving transistor (DR-TFT) and the third micro LED (uLED_B) in response to the third scan signal (SCAN_B).

[0112] The first micro LED (uLED_R) is coupled between the first scan transistor (T4) and a low-potential power line to which a low-potential voltage (EVSS) is applied. The second micro LED (uLED_G) is coupled between the second scan transistor (T5) and a low-potential power line to which a low-potential voltage (EVSS) is applied. The third micro LED (uLED_B) is coupled between the third scan transistor (T6) and a low-potential power line to which a low-potential voltage (EVSS) is applied.

[0113] For example, if you want to emit light from the first micro LED (uLED_R), you can enable the first scan signal (SCAN_R); if you want to emit light from the second micro LED (uLED_G), you can enable the second scan signal (SCAN_G); and if you want to emit light from the third micro LED (uLED_B), you can enable the third scan signal (SCAN_B).

[0114] The driving transistor (DR-TFT) controls the driving current and is coupled between the first scan transistor (T4), the second scan transistor (T5), and the third scan transistor (T5) and the high potential power line to which the high potential voltage (EVDD) is applied.

[0115] A storage capacitor (Cst) is coupled between the gate electrode and the source electrode of a driving transistor (DR-TFT). The storage capacitor (Cst) can sample the data voltage (VDATA) when the first transistor (T1) is turned on and can boost the gate electrode of the driving transistor (DR-TFT).

[0116] The first transistor (T1) is coupled between the data line to which the data voltage (VDATA) is applied and the gate electrode of the driving transistor (DR-TFT). Additionally, the first transistor (T1) is coupled between the data line and one electrode of the storage capacitor (Cst). The first transistor (T1) transmits the data voltage (VDATA) to the node (DTG) in response to the scan signal (SCAN).

[0117] The second transistor (T2) is coupled between the initialization power line to which the initialization voltage (VINIT) is applied and the node (DTG). The second transistor (T2) initializes the node (DTG) corresponding to the gate electrode of the driving transistor (DR-TFT) in response to the initialization signal (INIT).

[0118] The third transistor (T3) is coupled between the reference power line to which the reference voltage (VREF) is applied and the node (DTS). In response to the detection signal (SENSE), the third transistor (T3) precharges the node (DTS) corresponding to the source electrode of the driving transistor (DR-TFT) to the reference voltage (VREF).

[0119] In this way, the transparent micro LED pixel circuit according to the third embodiment can control the first scan signal (SCAN_R), the second scan signal (SCAN_G), and the third scan signal (SCAN_B) applied to the first scan transistor (T4), the second scan transistor (T5), and the third scan transistor (T5) to emit light from the first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B) with a single driving transistor (DR-TFT).

[0120] Since the transparent micro LED pixel circuit according to the third embodiment can drive the first micro LED (uLED_R), the second micro LED (uLED_G), and the third micro LED (uLED_B) using a single driving transistor (DR-TFT), the area of ​​the transparent display panel's transmission region can be increased and the transparency can be improved.

[0121] FIG. 10 illustrates a timing diagram of a transparent micro LED display device to which a unit pixel circuit according to a first embodiment is applied.

[0122] Referring to FIGS. 5 and FIGS. 10, the transparent micro LED display can operate by dividing it into an initialization period, a sensing period, a lighting period, a boosting period, and an emission period.

[0123] During the initialization period, the second transistor (T2) applies an initialization voltage (VINI) to the gate electrode of the driving transistor (DR-TFT) in response to the initialization signal (INIT). The third transistor (T3) applies a reference voltage (VREF) to the source electrode of the driving transistor (DR-TFT) in response to the detection signal (SENSE).

[0124] During the sensing period, the third transistor (T3) is turned off, and the source electrode of the driving transistor (DR-TFT) rises according to the threshold voltage (Vth) of the driving transistor. For example, the sensing period can be set to 200 µs or more.

[0125] During the writing period, the first transistor (T1) responds to the scan signal (SCAN) to transmit the data voltage (VDATA) to the storage capacitor (Cst) and writes the data voltage (VDATA).

[0126] During the boosting period, the first transistor (T1) is turned off, and the gate electrode and source electrode of the driving transistor (DR-TFT) are boosted to levels according to the gate-source voltage (VGS1). For example, the characteristics of the driving transistor can be compensated in real time during the boosting period. For example, the threshold voltage difference of the driving transistor between unit pixel circuits can be compensated.

[0127] During the emission period, a low potential voltage (EVSS) is applied to the first low potential power line (EVSS_R), and a high potential voltage (EVDD) is applied to the second low potential power line (EVSS_G) and the third low potential power line (EVSS_B) to emit light from the first micro LED (uLED_R).

[0128] Additionally, during the emission period, a low potential voltage (EVSS) is applied to the second low potential power line (EVSS_G), and a high potential voltage (EVDD) is applied to the first low potential power line (EVSS_R) and the third low potential power line (EVSS_B) to emit light from the second micro LED (uLED_G).

[0129] Additionally, during the emission period, a low potential voltage (EVSS) is applied to the third low potential power line (EVSS_B), and a high potential voltage (EVDD) is applied to the first low potential power line (EVSS_R) and the second low potential power line (EVSS_G) to emit light from the third micro LED (uLED_B).

[0130] Figure 11 is a cross-sectional view shown along one direction in the pixel circuit of Figure 6.

[0131] Referring to FIG. 11, a thin-film transistor (TFT) is disposed on a substrate (105). The thin-film transistor (TFT) may include a semiconductor layer (110) formed on the substrate (105), a gate electrode (115) located on the semiconductor layer (110), and a gate insulating layer (113) located between the semiconductor layer (110) and the gate electrode (115), formed over the entire area of ​​the substrate (105) to cover the semiconductor layer (110). A buffer insulating layer (107) may be disposed between the substrate (105) and the semiconductor layer (110). A light-blocking layer (BSM) is disposed on the buffer insulating layer (107). The light-blocking layer (BSM) can reduce leakage current by blocking light incident on the semiconductor layer (110) of the thin-film transistor (TFT) from the bottom of the substrate (105). For example, when light is irradiated onto the semiconductor layer (110), leakage current may occur, which may reduce the reliability of the thin-film transistor (TFT). Therefore, the reliability of the thin-film transistor (TFT) can be improved by placing a light-blocking layer (BSM) on the substrate (105). The light-blocking layer (BSM) may include an opaque conductive material.

[0132] The substrate (105) may be composed of a transparent material including glass or plastic. The semiconductor layer (110) may include an active region (110a) that forms a channel by overlapping with the gate electrode (115), and source regions (110b) and drain regions (110c) located on both sides with the active region (110a) in between.

[0133] A first interlayer insulating film (119a) is disposed on the gate electrode (115). A capacitor electrode (TM) may be disposed on the first interlayer insulating film (119a) in an overlapping position corresponding to the gate electrode (115). A storage capacitor (Cst) may be configured using the first interlayer insulating film (119a) disposed between the capacitor electrode (TM) and the gate electrode (115) as a dielectric. A second interlayer insulating film (119b) may be disposed on the first interlayer insulating film (119a) to form an interlayer insulating film (119) comprising the first and second interlayer insulating films (119a, 119b).

[0134] The interlayer insulating film (119) may include a drain contact hole (120) that penetrates the second interlayer insulating film (119b), the first interlayer insulating film (119a), and the gate insulating layer (113) to partially expose the drain region (110c) of the semiconductor layer (110). The drain contact hole (120) is filled with a conductive material or a metallic material and has a drain contact (123) that is electrically connected to the drain region (110c). Additionally, it may include a source contact hole (126a) that penetrates the second interlayer insulating film (119b) to expose a portion of the surface of the capacitor electrode (TM). The source contact hole (126a) may be filled with a conductive material or a metallic material and has a source contact (126b) that is electrically connected to the capacitor electrode (TM). The capacitor electrode (TM) may be connected to another switching thin-film transistor.

[0135] A drain electrode (124a) and a source electrode (124b) may be disposed on the second interlayer insulating film (119b). The drain electrode (124a) may be electrically connected to a thin-film transistor (TFT) through a drain contact (123). The source electrode (124b) may be electrically connected to a capacitor electrode (TM) through a source contact (126b). The drain electrode (124a) and the source electrode (124b) may be located on the same plane.

[0136] A first protective layer (129) may be disposed on a second interlayer insulating film (119b) comprising a drain electrode (124a) and a source electrode (124b). The first protective layer (129) may include an insulating material. A first insulating layer (130) is disposed on the first protective layer (129). The first insulating layer (130) may be composed of a positive type photoactive compound (PAC). The positive type photoactive compound includes a material in which a decomposition reaction occurs in the exposed portion, thereby increasing the solubility of the exposed portion.

[0137] The first insulating layer (130) and the first protective layer (129) may include an opening (131a) that selectively exposes the upper surface of the drain electrode (124a) while covering the source electrode (124b). A second protective layer (132) containing an insulating material may be disposed on the exposed surface of the first insulating layer (130) and the opening (131a). A via contact (131b) that fills the opening (131a) may be disposed.

[0138] A connection electrode (125), a reflection layer (137), and a common voltage line (127) may be disposed on the via contact (131b) and the second protection layer (132). The common voltage line (127) may be disposed parallel to and spaced apart from the data line and extended. The connection electrode (125), the reflection layer (137), and the common voltage line (127) may be disposed on the same plane, but are not limited thereto. The connection electrode (125), the reflection layer (137), and the common voltage line (127) may be disposed on different layers.

[0139] Conductive pad portions (133, 135) connected to a common voltage line (127) and a connecting electrode (125), respectively, may be arranged. The conductive pad portions (133, 135) may include a conductive material or a metal material. The conductive pad portions (133, 135) may include a first conductive pad portion (133) connected to the common voltage line (127) and a second conductive pad portion (135) connected to the connecting electrode (125).

[0140] The reflective layer (137) is located on the second protective layer (132) and has a flat plate shape. The reflective layer (137) serves to reflect light emitted from the microLED (150) towards the substrate (105) towards the light-emitting region (EA1). The reflective layer (137) may include a metal material that reflects well, but is not limited thereto.

[0141] An adhesive layer (AD) may be disposed on the connecting electrode (125), the reflective layer (137), and the common voltage line (127). The adhesive layer (AD) is a layer for attaching a microLED (150) to the reflective layer (137). The adhesive layer (AD) may insulate the reflective layer (137), which is made of a metallic material, from the microLED (150). The adhesive layer (AD) may be made of a thermal curing material or a photocuring material, but is not limited thereto. Meanwhile, although FIG. 3 shows the adhesive layer (AD) disposed on the front surface of the substrate (105), it may be partially disposed only in a portion of the area overlapping with the reflective layer (137), and is not limited thereto.

[0142] A microLED (150) is disposed on the adhesive layer (AD). The microLED (150) may be positioned corresponding to the position where the plate-shaped reflective layer (137) is disposed. The microLED (150) may include a first semiconductor layer (140), an active layer (143) disposed on one side of the first semiconductor layer (140), a second semiconductor layer (145), a first pad electrode (147) disposed on the first semiconductor layer (140) where the active layer (143) is not located, and a second pad electrode (149) disposed on the second semiconductor layer (145).

[0143] The first semiconductor layer (140) is a layer for supplying electrons to the active layer (143) and may include a nitride semiconductor containing a first conductivity type impurity. For example, the first conductivity type impurity may include an N-type impurity. The nitride semiconductor may be a GaN-based semiconductor material including GaN, AlGaN, InGaN, or AlInGaN. The N-type impurity included in the first semiconductor layer (140) may include silicon (Si), germanium (Ge), selenium (Se), or carbon (C). The first semiconductor layer (140) may further include an undoped nitride semiconductor layer (undoped GaN) underneath.

[0144] An active layer (143) disposed on one side of a first semiconductor layer (140) is a layer for emitting light and may include a multi-quantum well (MQW) structure having a well layer and a barrier layer having a band gap higher than that of the well layer. For example, the active layer (143) may be composed of InGaN as the well layer and an AlGaN layer as the barrier layer.

[0145] The second semiconductor layer (145) is formed on the active layer (143) and is a layer for injecting holes into the active layer (143). The second semiconductor layer (145) may include a nitride semiconductor containing a second conductivity type impurity. For example, the second conductivity type impurity may include a P-type impurity. The nitride semiconductor may be a GaN-based semiconductor material including GaN, AlGaN, InGaN, or AlInGaN. The P-type impurity included in the second semiconductor layer (145) may be manganese (Mg), zinc (Zn), or beryllium (Be), etc. Meanwhile, in the embodiments of this specification, the first semiconductor layer (140) and the second semiconductor layer (145) are described as a nitride semiconductor containing an N-type impurity and a nitride semiconductor containing a P-type impurity, respectively, but are not limited thereto. In one example, the first semiconductor layer (140) and the second semiconductor layer (145) may each be a nitride semiconductor containing P-type impurities and a nitride semiconductor containing N-type impurities.

[0146] The first pad electrode (147) and the second pad electrode (149) may each be made of a material including one or more of the metal materials such as Au, W, Pt, Si, Ir, Ag, Cu, Ni, Ti, or Cr and their alloys.

[0147] The active layer (143) can emit light from the combination of electrons and holes supplied from the first semiconductor layer (140) and the second semiconductor layer (145), respectively.

[0148] The microLED (150) may be covered with a second insulating layer (153) and a third insulating layer (155). The second insulating layer (153) and the third insulating layer (155) are composed of the same material and, for example, may include a positive type photosensitive material.

[0149] In the adhesive layer (AD), the second insulating layer (153), and the third insulating layer (155), a first contact hole (156) and a second contact hole (157) are formed, each including a first via hole (153a, 153b) and a second via hole (155a, 155b), so as to expose the first conductive pad portion (133) and the second conductive pad portion (135). Additionally, on the third insulating layer (155) above the first pad electrode (147) and the second pad electrode (149) of the microLED (150), a first pad contact hole (155c) and a second pad contact hole (155d) are formed, respectively, so as to expose a portion of the upper surface of the first pad electrode (147) and the second pad electrode (149) to the outside.

[0150] A first electrode (160) and a second electrode (165) are positioned on the third insulating layer (155) and can be electrically connected to the drain electrode (124a) and common voltage line (127) of the thin film transistor (TFT). The first electrode (160) is connected to the first pad electrode (147) exposed by the first pad contact hole (155c), and can be electrically connected to the thin film transistor (TFT) through the connecting electrode (125) and the drain electrode (124a), which extend along the exposed surface of the first contact hole (156) and are connected to the second conductive pad portion (135). Here, the first electrode (160) may also be referred to as the cathode electrode.

[0151] The second electrode (165) is connected to the second pad electrode (149) exposed by the second pad contact hole (155d) and can be electrically connected to a common voltage line (127) connected to the first conductive pad portion (135) by extending along the exposed surface of the second contact hole (157). The second electrode (165) may also be referred to as an anode electrode.

[0152] The first electrode (160) and the second electrode (165) may be composed of the same material and may include a transparent metal oxide such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO).

[0153] A bank (170) having a bank hole (170a) is disposed on a third insulating layer (155) on which a first electrode (160) and a second electrode (165) are formed. The bank (170) serves to separate each subpixel into a boundary area that defines a light-emitting region (EA1). Additionally, the bank (170) serves as a barrier to prevent light of different colors from adjacent pixels from mixing and being output. The first contact hole (156) and the second contact hole (157), on which the first electrode (160) and the second electrode (165) are formed respectively, may be filled with a material constituting the bank (170). A black bank (BB) containing an opaque material may be disposed on the bank (170).

[0154] The microLED (150) can be electrically connected to a driving thin-film transistor (TFT) through a first electrode (160) and electrically connected to a common voltage line (127) through a second electrode (165) to emit light.

[0155] The unit pixel circuit of the transparent micro LED according to the embodiments can emit red, green, and blue micro LEDs using a single driving transistor, so the area of ​​the transparent display panel can be increased and transparency can be improved.

[0156] A transparent micro LED unit pixel circuit according to the first embodiment of the present specification comprises: a first micro LED, a second micro LED, and a third micro LED that emit light according to a driving current; a driving transistor that controls the driving current and is coupled between the anode electrodes of the first micro LED, the second micro LED, and the third micro LED and a high potential power line; a storage capacitor coupled between the gate electrode and the source electrode of the driving transistor; and a first transistor that applies a data voltage to the gate electrode of the driving transistor.

[0157] A first power line can be coupled to the cathode electrode of a first micro LED, a second power line can be coupled to the cathode electrode of a second micro LED, and a third power line can be coupled to the cathode electrode of a third micro LED.

[0158] A low potential voltage can be applied to the power line corresponding to the micro LED to be emitted among the first to third power lines, and a high potential voltage can be applied to the remaining power lines.

[0159] It may further include a second transistor that applies an initialization voltage to the gate electrode of the driving transistor.

[0160] It may further include a third transistor that applies a reference voltage to the source electrode of the driving transistor.

[0161] A transparent micro LED unit pixel circuit according to the second embodiment of the present specification comprises: a first micro LED, a second micro LED, and a third micro LED that emit light according to a driving current; a driving transistor that controls the driving current and is coupled between the cathode electrodes of the first micro LED, the second micro LED, and the third micro LED and a low potential power line; a storage capacitor coupled between the gate electrode and the source electrode of the driving transistor; and a first transistor that applies a data voltage to the gate electrode of the driving transistor.

[0162] A transparent micro LED unit pixel circuit according to the third embodiment of the present specification comprises: a first micro LED, a second micro LED, and a third micro LED that emit light according to a driving current; a first scan transistor coupled to the anode electrode of the first micro LED; a second scan transistor coupled to the anode electrode of the second micro LED; a third scan transistor coupled to the anode electrode of the third micro LED; a driving transistor that controls the driving current and is coupled between the first scan transistor, the second scan transistor, and the third scan transistor and a high potential power line; a storage capacitor coupled between the gate electrode and the source electrode of the driving transistor; and a first transistor that applies a data voltage to the gate electrode of the driving transistor.

[0163] A transparent micro LED display device according to another aspect of the present specification comprises: a transparent display panel including a light-emitting region and a transmission region, and a plurality of unit pixel circuits disposed in the light-emitting region; each of the plurality of unit pixel circuits includes a first micro LED, a second micro LED, and a third micro LED that emit light according to a driving current; a driving transistor that controls the driving current and is coupled between the anode electrodes of the first micro LED, the second micro LED, and the third micro LED and a high potential power line; a storage capacitor coupled between the gate electrode and the source electrode of the driving transistor; and a first transistor that applies a data voltage to the gate electrode of the driving transistor.

[0164] According to the embodiments, the transparent area can be increased by driving red, green, and blue micro LED elements with a single driving transistor.

[0165] In addition, transparency can be improved by increasing the transparent area of ​​the transparent display panel.

[0166] In addition, by improving the transparency of the transparent display panel, aesthetic functions and multifunctional usability can be provided.

[0167] Although the present invention has been described above with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention were not explicitly described while explaining the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized.

Claims

Claim 1 A transparent micro-LED display device comprising: a transparent display panel including a light-emitting region, wherein the light-emitting region includes a plurality of unit pixel circuits, and at least one of the plurality of unit pixel circuits is configured to emit light, comprising a plurality of micro-LEDs; and a single driving member coupled in common to the plurality of micro-LEDs and configured to control a driving current so that a selected micro-LED among the micro-LEDs emits light, wherein the first electrodes of the plurality of micro-LEDs are connected in common to the single driving member, and the second electrodes of the plurality of micro-LEDs are individually connected to each power line having an individually controlled voltage level, and the selected micro-LED is determined by the voltage levels applied to each power line. Claim 2 A transparent micro LED display device according to claim 1, wherein a first voltage is applied to a second electrode of the selected micro LED, and a second voltage having a level different from the first voltage is applied to the second electrodes of the unselected micro LEDs. Claim 3 A transparent micro LED display device according to claim 1, wherein the single driving member is configured to supply a constant current to the first electrodes of the commonly connected micro LEDs. Claim 4 A transparent micro LED display device according to claim 1, wherein the micro LEDs within the unit pixel circuit emit light of different colors. Claim 5 A transparent micro LED display device according to claim 1, wherein the power lines are arranged parallel to each other and extend in a direction intersecting the row direction of the unit pixel circuits. Claim 6 A transparent micro LED display device according to claim 1, wherein a bank is disposed in a boundary region defining the light-emitting region, and a black bank containing an opaque material is disposed on the bank. Claim 7 A transparent micro LED display device according to claim 1, wherein the display panel further includes a transparent area, and the single driving member is not disposed in the transparent area. Claim 8 A transparent micro LED display device according to claim 1, wherein, within the light-emitting region, the ratio of the number of the single driving member to the number of the micro LEDs is less than 1. Claim 9 A transparent micro LED display device according to claim 1, wherein two or more of the micro LEDs coupled to the single driving member are configured to emit the same color. Claim 10 A transparent micro LED display device according to claim 1, wherein two or more of the micro LEDs coupled to the single driving member are configured to emit a red color.

Images