Display device including low luminance region

Abstract

A display device is disclosed. The display device includes a substrate and a plurality of light emitting diode (LED) elements arranged in a matrix on the substrate, wherein: the plurality of LED elements respectively include: a first LED element having a first light emitting layer, a second LED element having a second light emitting layer, and a third LED element having a third light emitting layer; the first LED element, the second LED element, and the third LED element are arranged along a column direction of the plurality of LED elements and constitute a single pixel; and the first light emitting layer, the second light emitting layer, and the third light emitting layer respectively include first, second, and third low brightness regions arranged in a row.

Description

Technical Field

[0001] This disclosure relates to a display device, and more specifically, to a display device comprising a plurality of light-emitting diode (LED) elements, the plurality of LED elements including a weak light-emitting region. Background Technology

[0002] Display devices have evolved to feature high brightness, high efficiency, and low power consumption, along with large screen sizes and high image resolution. LED displays are intended to replace liquid crystal displays (LCDs), but due to issues such as high cost and large size in LED display production, micro-LEDs have recently attracted widespread attention to overcome these problems.

[0003] Micro LEDs are ultra-small inorganic light-emitting materials that can emit light on their own without color filters or backlights. Micro LEDs can refer to ultra-small LEDs with micrometer (μm) unit sizes that are smaller than those of conventional LED chips.

[0004] Micro-LEDs are fabricated by growing multiple micro-LEDs in the form of chips on a wafer (growth substrate) using epitaxial processes. The micro-LEDs are then transferred onto a target substrate to form a display module.

[0005] In related technologies, when transferring micro-LEDs to a target substrate, side moldings may be added to increase contrast. However, this can result in reduced brightness at certain angles or a failure to maintain white balance. Therefore, a technique is needed to reduce or eliminate the adverse effects of side moldings that may affect the image quality of the display module. Summary of the Invention

[0006] [Technical Issues]

[0007] The purpose of this disclosure is to provide a display device that improves brightness and white balance by changing the arrangement of the weak light-emitting areas of the LED elements and the structure of the crystal layer, thereby preventing image quality degradation.

[0008] [Technical Solution]

[0009] According to one aspect of this disclosure, a display device may include: a substrate; and a plurality of light-emitting diode (LED) elements arranged in a matrix on the substrate, wherein the plurality of LED elements includes: a first LED element including a first light-emitting layer and configured to emit a first light of a first color through the first light-emitting layer; a second LED element including a second light-emitting layer and configured to emit a second light of a second color through the second light-emitting layer; and a third LED element including a third light-emitting layer and configured to emit a third light of a third color through the third light-emitting layer, wherein the first LED element, the second LED element, and the third LED element are arranged along a column direction of the plurality of LED elements and together constitute a pixel, wherein the first light-emitting layer includes a first weak light-emitting region, the second light-emitting layer includes a second weak light-emitting region, and the third light-emitting layer includes a third weak light-emitting region, wherein the first weak light-emitting region, the second weak light-emitting region, and the third weak light-emitting region are aligned along a line in the column direction, and wherein the first weak light-emitting region, the second weak light-emitting region, and the third weak light-emitting region each have a brightness lower than the average brightness of the first LED element, the second LED element, and the third LED element.

[0010] The first LED element may further include: a terminal layer disposed at the lower part of the first light-emitting layer and connected to the substrate; and a sapphire layer disposed on the upper part of the first light-emitting layer, wherein the sapphire layer may have two facing surfaces extending from the first light-emitting layer in a vertical direction and two inclined surfaces extending from the first light-emitting layer in an inclined direction at a predetermined angle.

[0011] The two inclined surfaces can extend in the opposite direction to the direction in which the first weak luminescent region is formed.

[0012] In the first LED element, the distances from the first weak light-emitting region to the two sides of the first LED element parallel to the row direction of the first light-emitting layer can be different from each other. The first side surface of the sapphire layer parallel to the column direction can extend in the vertical direction, and the second side surface of the sapphire layer parallel to the row direction can extend in the inclined direction.

[0013] The terminal layer may include anode terminals and cathode terminals. The substrate may include anode terminal coupling portions and cathode terminal coupling portions. The arrangement of the anode terminal coupling portions coupled to one or more of the plurality of LED elements may be the opposite of the arrangement of the anode terminal coupling portions coupled to another of the plurality of LED elements.

[0014] The first LED element, the second LED element, and the third LED element can be spaced apart from each other at a predetermined interval.

[0015] The display device may also include: a side molding portion disposed in the gap between a plurality of LED elements on a substrate.

[0016] The side molding may include a light-transmitting material that allows light to pass through.

[0017] The display device may further include a bonding layer disposed on the upper part of the substrate to bond a plurality of LED elements and side molding portions to the substrate.

[0018] The bonding layer may include a light-absorbing bonding material that absorbs light transmitted through the light-transmitting material.

[0019] The display device may include a transparent molding layer disposed on the upper surface of a plurality of LED elements and side molding portions.

[0020] The transparent molding layer includes a light-transmitting material that allows light to pass through.

[0021] The display device may further include: an optical film disposed on a transparent molding layer, wherein the optical film may be a neutral density (ND) film having neutral characteristics for color.

[0022] The second LED element can be a green LED element, the first LED element can be any one of a red (R) LED element or a blue (B) LED element, and the third LED element can be an LED element that is different from the first LED element among the R LED element and the B LED element.

[0023] [Invention Effects]

[0024] According to various embodiments, a display device can improve brightness and white balance by changing the arrangement of the weak light-emitting areas of the LED elements and the structure of the crystal layer, thereby preventing image quality degradation. Attached Figure Description

[0025] The above and other aspects, features, and advantages of some embodiments of this disclosure will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0026] Figure 1 This is a diagram illustrating a display device according to an embodiment;

[0027] Figure 2 This is a diagram illustrating a display module included in a display device according to an embodiment;

[0028] Figure 3 This is a block diagram illustrating a display device according to an embodiment;

[0029] Figure 4 This is a diagram illustrating a display device comprising a plurality of display modules in a 4×3 array according to an embodiment;

[0030] Figure 5 This is a diagram illustrating a display device according to an embodiment;

[0031] Figure 6 This is a perspective view of an LED element according to an embodiment;

[0032] Figure 7 This is a diagram showing the arrangement of a plurality of LED elements according to an embodiment;

[0033] Figure 8a and Figure 8b It is a graph showing the brightness of the field of view of each of a plurality of LED elements according to an embodiment;

[0034] Figure 9 This is a cross-sectional view of an LED element according to an embodiment;

[0035] Figure 10 It is a graph showing the brightness of the field of view of a plurality of LED elements based on an embodiment; and

[0036] Figure 11 yes Figure 7 A cross-sectional view of the display device along the A-A' direction. Detailed Implementation

[0037] The embodiments are described in more detail below with reference to the accompanying drawings.

[0038] In the following description, the same reference numerals are used for the same elements, even in different figures. The definitions in the description (e.g., detailed constructions and elements) are provided to aid in a comprehensive understanding of the exemplary embodiments. However, it should be understood that the exemplary embodiments can be practiced even in the absence of these specific definitions. Furthermore, well-known functions or constructions are not described in detail because unnecessary detail would obscure the description.

[0039] The terminology used in this disclosure and claims is general terminology determined with respect to the functionality of embodiments of this disclosure. However, these terms may be changed based on the intent of those skilled in the art, legal or technical interpretations, the emergence of new technologies, etc. Additionally, in some cases, the applicant may choose the terms, in which case the term will be described in detail in the description of the corresponding disclosure. Therefore, the terms used in this disclosure should be defined based on their meaning and throughout the content of this disclosure, rather than their simple names.

[0040] One or more specific embodiments of the present disclosure are shown in the accompanying drawings and described in detail in the specific embodiments. However, it should be understood that the present disclosure is not limited to the one or more specific embodiments, but includes all modifications, equivalents, and substitutions without departing from the scope and spirit of the present disclosure. Furthermore, well-known functions or constructions have not been described in detail, as they would obscure the present disclosure with unnecessary detail.

[0041] Terms such as “first” and “second” used in various example embodiments can modify a variety of elements and do not limit the corresponding elements. These terms can be used to distinguish one element from another.

[0042] Unless otherwise specified, singular expressions include plural expressions. It should be understood that terms such as "comprising" can be used, for example, to indicate the presence of features, quantities, steps, operations, elements, components, or combinations thereof, without excluding the possibility of the presence or addition of one or more other features, quantities, steps, operations, elements, components, or combinations thereof.

[0043] Terms such as “module,” “unit,” and “component” are used to refer to an element that performs at least one function or operation, and such an element can be implemented as hardware or software, or a combination of hardware and software. Furthermore, except when it is necessary to implement each of multiple “modules,” “units,” “components,” etc., in a single piece of hardware, these components can be integrated into at least one module or chip, and can be implemented in at least one processor.

[0044] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings to enable those skilled in the art to readily implement the disclosure. However, the present disclosure may be implemented in several different forms and is not limited to the embodiments described herein. Furthermore, for clarity in the accompanying drawings, components unrelated to the description have been omitted, and identical components are given the same reference numerals throughout the disclosure.

[0045] Expressions such as "at least one of..." modify the entire list of components when they follow a list of components, rather than individual components in the list. For example, the expression "at least one of a, b, and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, all a, b, and c, or any variation of the above examples.

[0046] Figure 1 This is a diagram illustrating a display device 100 according to an embodiment.

[0047] According to an embodiment, the display device 100 may include one display module or multiple display modules 110.

[0048] Figure 2 This is a diagram illustrating a display module according to an embodiment.

[0049] refer to Figure 2 Each of the multiple display modules 110-1 to 110-12 can be implemented as an LED display module including inorganic LEDs.

[0050] Each LED display module may include multiple pixels, which include red (R) LED elements, green (G) LED elements, and blue (B) LED elements.

[0051] refer to Figure 2 Multiple display modules 110-1 to 110-12 are coupled into a 4×3 array. The LED display modules arranged in a 4×3 array are merely an example, and the number and type of the LED display modules can be varied. For example, the number of pixels included in the display module 110 can be varied according to the manufacturer's purpose, manufacturing process, etc., and the arrangement and number of the display modules 110 constituting the display device 100 can be varied according to the manufacturer's purpose, manufacturing process, etc.

[0052] For example, the display device 100 can be implemented as a large display device coupled to multiple display modules 110, such as a digital signage, wall display or video wall installed in a public or commercial place.

[0053] The display device 100, which includes multiple display modules 110-1 to 110-12, can be collectively referred to as a cabinet or sub-screen. The number of display modules 110 constituting the cabinet or sub-screen can be variable and can be widely changed.

[0054] Figure 3 This is a block diagram illustrating a display device 100 according to an embodiment.

[0055] refer to Figure 3 The display device 100 according to the embodiment may include a display module 110 and a processor 120.

[0056] The display device 100 can be implemented as a television (TV), but is not limited to this, and can be applied to any device that includes display functions, such as video walls, large-format displays (LFDs), digital signage, digital information displays (DIDs), projector displays, etc. Furthermore, the display device 100 can be implemented as various types of displays, such as liquid crystal displays (LCDs), organic light-emitting diodes (OLEDs), liquid crystal on silicon (LCoS), digital light processing (DLP), quantum dot (QD) display panels, quantum dot light-emitting diodes (QLEDs), micro light-emitting diodes (μLEDs), or mini LEDs. The display device 100 can be implemented as a touch screen coupled to a touch sensor, a flexible display, a rollable display, a three-dimensional (3D) display, or a display with multiple display modules physically connected, etc.

[0057] The display device 100 according to the embodiment may be one of a plurality of display devices constituting a modular display device, and may include a plurality of display modules 110.

[0058] Display module 110 can display various images. These images can include still images and moving images, and display module 110 can display various images such as broadcast content, multimedia content, etc. Display module 110 can display user interface (UI) and icons.

[0059] Display module 110 may include an integrated circuit (IC) chip, which can display an image based on an image signal received from processor 120. For example, the IC chip can generate an LED driving signal based on the image signal received from processor 120, and display an image by controlling the emission of a plurality of pixels included in display module 110 based on the LED driving signal. According to an embodiment, the IC chip may be an LED driver IC chip.

[0060] The display module 110 according to the embodiment can be implemented as a display including a self-emissive element. For example, the display module 110 can be implemented as various types of displays, such as, but not limited to: liquid crystal display (LCD), organic light-emitting diode (OLED) display, light-emitting diode (LED), micro LED, mini LED, plasma display panel (PDP), quantum dot (QD) display, quantum dot light-emitting diode (QLED), etc. The display module 110 may also include a backlight unit and a driving circuit that can be implemented as a-si TFT, low-temperature polycrystalline silicon (LTPS) TFT, organic TFT (OTFT), etc. The display module 110 can be implemented as a touch screen coupled to a touch sensor, a flexible display, a rollable display, a three-dimensional (3D) display, or a display in which multiple display modules 110-1 to 110-12 are physically connected, etc.

[0061] Processor 120 can control the overall operation of display device 100. Processor 120 may be configured with one or more processors. For example, processor 120 can execute the operation of electronic device 100 according to various embodiments of the present disclosure by executing at least one instruction stored in memory.

[0062] The processor 120 according to the embodiment can be implemented using, for example (but not limited to), a digital signal processor (DSP), microprocessor, graphics processing unit (GPU), artificial intelligence (AI) processor, neural processor or neural processing unit (NPU), time controller (TCON), etc., for image processing of digital image signals, but the processor is not limited thereto. The processor 120 may include, for example (but not limited to), one or more of a central processing unit (CPU), microcontroller unit (MCU), microprocessor (MPU), controller, application processor (AP), communication processor (CP), advanced reduced instruction set computing (RISC) machine (ARM) processor, or may be defined by the corresponding term. The processor 120 can be implemented using a system-on-a-chip (SoC) type or a large-scale integration (LSI) type, an application-specific integrated circuit (ASIC) type or a field-programmable gate array (FPGA) type with built-in processing algorithms.

[0063] The processor 120 can drive an operating system or application to control hardware or software components connected to the processor 120, and can perform various data processing and operations. The processor 120 can load commands or data received from at least one of the other components into volatile memory and process them, and can store various data in non-volatile memory.

[0064] refer to Figure 4 and Figure 5 The following describes the display device 100 and the display module 110 according to an embodiment.

[0065] Figure 4 This is a diagram illustrating a display device comprising multiple display modules in a 4×3 array according to an embodiment.

[0066] The display device 100 according to an embodiment may include a plurality of display modules 110-1 to 110-12. For example, the plurality of display modules 110-1 to 110-12 may be arranged in a matrix format (e.g., M×N, where M and N are natural numbers). The matrix may be a square arrangement (e.g., M=N, where M and N are natural numbers, a 16×16 array, a 24×24 array, etc.), or it may be a different arrangement (e.g., M≠N, where M and N are natural numbers).

[0067] The LEDs in the LED display module according to the embodiment can be implemented using micro-LEDs. Micro-LEDs can be LEDs ranging in size from 5 to 100 micrometers, and can refer to ultra-small self-emitting light-emitting elements without color filters.

[0068] However, the LED display module is merely an example, and the display module can be implemented as a liquid crystal display (LCD) panel (i.e., a flat panel display), an organic LED (OLED) panel, an active-matrix OLED (AMOLED) panel, a plasma display panel (PDP), etc. In the following description, for ease of description, the display module according to the embodiment is illustrated as an LED display module.

[0069] refer to Figure 4 The display device 100 according to the embodiment may include a plurality of display modules 110-1 to 110-12 arranged in a 4×3 array. This is merely an example, and the embodiment is not limited thereto.

[0070] The display module 110 according to an embodiment may include a plurality of pixels arranged in a matrix. (See reference...) Figure 4 For ease of description, the display module 110 may include 21,600 pixels arranged in a 120×180 array, but this is only an example and the embodiments are not limited thereto.

[0071] For example, display module 110 may include 43,200 pixels arranged in a 240×180 array. The size and aspect ratio of display module 110 may vary depending on the number of pixels included in display module 110 and the distance between adjacent pixels (e.g., pixel pitch).

[0072] Figure 5 This is a diagram illustrating a display device 100 according to an embodiment.

[0073] refer to Figure 5 According to the embodiment, the display device 100' can be implemented as a modular display device 100' in which a plurality of display modules 110 or a plurality of cabinets are coupled.

[0074] refer to Figure 5 For ease of description, twelve (12) display modules 110 are referred to as a sub-rack, and a modular display device 100' including a full HD (FHD) screen implemented with four sub-racks is shown, but is not limited thereto. For example, the display device 100 can be implemented as a modular display device 100' including multiple display modules 110, racks, or sub-screens, thereby including various resolutions such as 4K (e.g., 3840×2160) and 8K.

[0075] refer to Figures 6 to 11The description will cover the array of multiple LED elements included in the display module 110 and the structure of the LED elements.

[0076] Figure 6 This is a perspective view of the LED element 130 according to an embodiment.

[0077] refer to Figure 6 The display device 100 according to the embodiment may include a substrate 15 and an LED element 130.

[0078] The substrate 15 may be a printed circuit board and may supply power to a plurality of LED elements 130 mounted on the surface of the substrate 15.

[0079] The LED element 130 can emit light on its own. In an embodiment, the micro LED element 130 can be a semiconductor chip made of inorganic light-emitting material with a width, length, and height of less than or equal to 10 μm to 100 μm, and can emit light on its own when powered. However, the size and structure of the LED element 130 are not limited to a specific size or structure.

[0080] Each of the plurality of LED elements 130 may include a light-emitting layer 132, a terminal layer 134, and a sapphire layer 137.

[0081] The plurality of LED elements 130 may include a first LED element 130-1 that emits light of a first color, a second LED element 130-2 that emits light of a second color, and a third LED element 130-3 that emits light of a third color. The first LED element 130-1, the second LED element 130-2, and the third LED element 130-3 may be spaced apart from each other at a predetermined interval and may constitute a pixel 10-1.

[0082] The light-emitting layer 132 can emit light in the direction of the light-emitting surface, which is the upper surface, and can be formed to have a weak light-emitting region 133. The weak light-emitting region 133 can refer to a region whose brightness is lower than the average brightness of the light-emitting layer 132 by a preset value. The weak light-emitting region 133 can also be referred to as a low brightness region.

[0083] A light-emitting layer 132 without weak light-emitting regions 133 could be ideal, but according to the characteristics of an LED element 130 that emits light through the current flow generated by the cathode terminal 134-2 and the anode terminal 134-1, some areas of the light-emitting layer 132 may not emit light, or may emit weak light. Because terminals are connected to the upper side of the light-emitting layer 132 during the manufacturing process of the micro-LED element 130, and vias pass through some areas of the light-emitting layer 132, weak light-emitting regions 133 are formed. Current can be supplied to the upper part of the light-emitting layer 132 through the vias, but the areas with vias may have degraded light-emitting performance compared to other areas, and it may be difficult to completely eliminate the weak light-emitting regions 133 in the ultra-small micro-LED element 130; therefore, weak light-emitting regions 133 are formed.

[0084] Weakly emitting regions 133 may be formed in at least some regions of the light-emitting layer 132, and at least a portion of the weakly emitting regions 133 may include non-emitting regions, and may consist of only one non-emitting region. Although the weakly emitting regions 133 are shown as black dots for convenience, the boundaries of the weakly emitting regions 133 may be larger or smaller than black dots. The weakly emitting regions 133 may be defined as regions with lower brightness than other adjacent regions, or regions with brightness lower than a preset value than the average brightness of the light-emitting layer 132.

[0085] The location where the weakly emitting region 133 is formed can be varied, and reference... Figure 6 The weak light-emitting area 133 can be formed at a position adjacent to the left (L) or right (R) of the central portion of the LED element 130.

[0086] The LED element 130, which has a weak light-emitting region 133 including a side molding portion 135 that blocks light transmission, may cause brightness deviations depending on the field of view. As a result, a pixel 10-1 may cause white balance degradation depending on the field of view.

[0087] refer to Figure 6 In the embodiment where the weak light-emitting region 133 is formed on the upper part of the terminal layer 134 along the left (L) direction, the weak light-emitting region 133 may not be a problem for the viewer's line of sight at the left (L). However, in the viewer's line of sight at the right (R), in addition to the weak light-emitting region 133, light transmission is also blocked by the side molding portion 135, making the light-emitting layer 132 of the weak light-emitting region 133 the main focus of the view. Therefore, the brightness of the LED element 130 may be reduced in the viewer's line of sight at the right (R), and brightness deviation may occur as the field of view changes according to the viewer's position.

[0088] In a pixel 10-1 structure comprising a first LED element 130-1 emitting light of a first color, a second LED element 130-2 emitting light of a second color, and a third LED element 130-3 emitting light of a third color, one LED element 130 can be formed to the left of the weak light-emitting area 133. When the weak light-emitting area 133 is formed on the right, a particular color may appear less bright in the left or right view due to the weak light-emitting area 133. Because the position of the weak light-emitting area 133 of each LED element 130 constituting a pixel 10-1 is different, white balance may deteriorate when the field of view changes.

[0089] The side molding portion 135 can be disposed in the gap among the plurality of LED elements 130 on the substrate 15, and can block the light emitted from the LED elements 130 from being transmitted.

[0090] The side molding portion 135 can improve coupling reliability during the coupling of multiple LED elements 130 and substrate 15, and can improve contrast by blocking light reflection, thereby improving the image quality of the display device 100, and can minimize the deviation between multiple display modules 110.

[0091] Figure 7 This is a diagram showing the arrangement of a plurality of LED elements 130 according to an embodiment.

[0092] refer to Figure 7 A pixel 10-1 of the display module 110 may include a first LED element 130-1, a second LED element 130-2, and a third LED element 130-3. For example, the second LED element 130-2 may be a G LED element 130, the first LED element 130-1 may be any one of an R LED element 130 or a B LED element 130, and the third LED element 130-3 may be implemented as an LED element that is different from the first LED element 130-1 among the R LED element 130 and B LED elements 130.

[0093] According to the embodiment, a plurality of LED elements 130 can be arranged in a matrix on the substrate 15, and the first to third LED elements 130-1, 130-2, and 130-3 constituting a pixel 10-1 can be arranged in the column direction (i.e., the y-axis direction shown in Figure 7). In the following description, for ease of explanation, Figure 7 The x-axis direction shown is called the row direction, and the y-axis direction is called the column direction.

[0094] The first LED element 130-1, the second LED element 130-2, and the third LED element 130-3 constituting a pixel 10-1 can be aligned in the column direction and can be disposed on the substrate 15. The first LED element 130-1, the second LED element 130-2, and the third LED element 130-3 constituting another pixel 10-2 can be arranged in the same column direction as a pixel 10-1.

[0095] Figure 8a It is a graph showing the brightness variation based on the field of view of each of the multiple LED elements in the comparative example. Figure 8b It is a graph showing the brightness varying according to the field of view of each of the plurality of LED elements 130 in the embodiment.

[0096] Figure 8a This is a graph showing the brightness of the field of view of the first LED element to the third LED elements 130-1, 130-2 and 130-3 in a comparative example where the low-light-emitting region 133 is misaligned. Figure 8b This is a diagram showing the brightness of the field of view of the first LED element to the third LED elements 130-1, 130-2 and 130-3 in an embodiment where the weak light-emitting region 133 is aligned on a line.

[0097] refer to Figure 8a In the first LED element 130-1, the brightness in the left field of view at approximately 50 degrees can be maintained at or above the brightness in the central field of view at 0 degrees, but the brightness in the right field of view can gradually decrease as it moves away from the center.

[0098] In the second LED element 130-2 and the third LED element 130-3, the brightness in the right field of view at approximately 50 degrees can be kept the same or similar to the brightness in the central field of view at 0 degrees, but the brightness in the left field of view can gradually decrease as it moves away from the center.

[0099] In having such Figure 8a In a pixel 10-1 with the brightness shown, the first LED element 130-1 has a weak light-emitting region 133 formed on its left side, and the second LED element 130-2 and the third LED element 130-3 may have weak light-emitting regions 133 formed on their right sides. Based on a comparative example where the weak light-emitting regions 133 are not aligned in a line along the same direction, the brightness of the LED element emitting one of the R, G, and B colors may decrease with increasing viewing angle, thereby reducing white balance.

[0100] refer to Figure 8bThe brightness of the first LED element 130-1, the second LED element 130-2, and the third LED element 130-3 in the right field of view at approximately 50 degrees remains the same or similar to the brightness in the central field of view, but the brightness in the left field of view can gradually decrease as it moves away from the center.

[0101] Even if the brightness decreases according to the field of view, the brightness of each of the first LED element 130-1, the second LED element 130-2, and the third LED element 130-3 decreases to a similar degree, so that each LED element 130 can prevent the white balance from deteriorating according to the field of view.

[0102] Because the corresponding weak light-emitting areas 133 are aligned in the column direction, the first LED element 130-1, the second LED element 130-2, and the third LED element 130-3 can prevent the white balance from deteriorating according to the field of view and can improve the image quality of the display device 100.

[0103] Figure 9 This is a cross-sectional view of the LED element 130 according to an embodiment.

[0104] refer to Figure 9 According to the embodiment, the LED element 130 may include a sapphire layer 137.

[0105] A sapphire layer 137 may be disposed on the upper part of the light-emitting layer 132. During the cutting process in the manufacturing process, the sapphire layer 137 may include a shape inclined along the cutting direction. Of the four side surfaces extending to the upper part of the light-emitting layer 132, two opposing side surfaces 137a may extend vertically from the light-emitting layer 132 (i.e., as shown in the image). Figure 9 The light-emitting layer has two sides (i.e., the z-axis direction shown in the diagram), while the other two sides (also referred to as "tilted sides") 137b can be tilted from the light-emitting layer at a predetermined angle (θ) along the cutting direction. The two tilted sides 137b can be parallel to each other. One of the tilted sides 137b can form an acute angle with the light-emitting layer 132, while the other tilted side 137b can form an obtuse angle with the light-emitting layer 132.

[0106] Because the two sides 137b are tilted, light emitted from the light-emitting layer 132 can be transmitted at a wider angle toward the tilt direction of the sapphire layer 137. (Reference) Figure 9 The sapphire layer 137 is tilted to the right (relative to the direction perpendicular to the light-emitting layer 132), and the light propagates wider to the right than to the left.

[0107] In the sapphire layer 137, the two inclined side surfaces 137b can extend in a direction opposite to the direction in which the weak luminescent region 133 is formed. For example, when the weak luminescent region 133 is formed on the left side of the luminescent layer 132, the inclined side surface 137b is inclined to the right (relative to the vertical direction). On the other hand, when the weak luminescent region 133 is formed on the right side of the luminescent layer 132, the inclined side surface 137b is inclined to the left (relative to the vertical direction). (Refer to...) Figure 10 The results of the embodiments will be described below.

[0108] Terminal layer 134 can be disposed below light-emitting layer 132 and can connect LED element 130 and substrate 15. Terminal layer 134 may include anode terminal 134-1 and cathode terminal 134-2, and substrate 15 may include anode terminal coupling portion 19-1 and cathode terminal coupling portion 19-2. Anode terminal coupling portion 19-1 can be connected to anode terminal 134-1 of terminal layer 134, and cathode terminal coupling portion 19-2 can be connected to cathode terminal 134-2 of terminal layer 134, so that substrate 15 can supply power to LED element 130.

[0109] The weak light-emitting region 133 of one of the LED elements 130-1, 130-2, and 130-3 can be formed adjacent to the cathode terminal 134-2, and the weak light-emitting region 133 of the other LED element 130-1, 130-2, and 130-3 can be formed adjacent to the anode terminal 134-1. In a comparative example, when the anode terminal coupling portion 19-1 and the cathode terminal coupling portion 19-2 of the substrate 15 have the same arrangement, it may be difficult to align the weak light-emitting regions 133 on a straight line.

[0110] According to one embodiment, the arrangement direction of the anode terminal coupling portion 19-1 and the cathode terminal coupling portion 19-2 of the first type of LED (e.g., red LED) coupled to the plurality of LED elements 130 can be opposite to the arrangement direction of the anode terminal coupling portion 19-1 and the cathode terminal coupling portion 19-2 of the second type of LED (e.g., green LED) among the plurality of LED elements 130. Therefore, the direction in which the weak light-emitting region 133 of the LED element 130 is arranged can be set during the process of setting the LED element 130 on the substrate 15.

[0111] For example, in the substrate 15 according to the embodiment, the arrangement direction of the anode terminal coupling portion 19-1 and the cathode terminal coupling portion 19-2 for mounting a plurality of LED elements 130 on the substrate 15 can have a uniform direction.

[0112] The position where the weak light-emitting area 133 is formed on the LED element 130 can be adjacent to the anode terminal 134-1 or the cathode terminal 134-2. The first LED element 130-1 can form the weak light-emitting area 133 in the direction of the anode terminal 134-1, and the other LED elements 130-2 and 130-3 can form the weak light-emitting area in the direction of the cathode terminal 134-2.

[0113] Because the arrangement direction of the anode terminal coupling portion 19-1 and cathode terminal coupling portion 19-2 coupled to the first LED element 130-1 can be opposite to the arrangement direction of the anode terminal coupling portion 19-1 and cathode terminal coupling portion 1902 coupled to other LED elements 130-2 and 130-3, the first LED element 130-1, the second LED element 130-2 and the third LED element 130-3 can align the corresponding weak light-emitting areas 133 in the column direction.

[0114] On the substrate 15 according to the embodiment, the arrangement direction of the anode terminal coupling portion 19-1 and the cathode terminal coupling portion 19-2 of at least one of the plurality of LED elements 130 is opposite to the arrangement direction of the anode terminal coupling portion 19-1 and the cathode terminal coupling portion 19-2 of at least another of the plurality of LED elements 130, such that the weak light-emitting regions 133 of the plurality of LED elements 130 can be arranged in a line, without being limited by the position of forming the weak light-emitting regions 133 of the plurality of LED elements 130.

[0115] Figure 10 This is a graph showing the brightness of the field of view of a plurality of LED elements 130 according to an embodiment.

[0116] refer to Figure 10 Line I represents the brightness of the ideal field of view of the plurality of LED elements 130, line E1 represents the brightness of the field of view of the plurality of LED elements 130 having a weak light-emitting region 133, wherein the cutting direction of the sapphire layer 137 is not tilted, and line E2 represents the brightness of the field of view of the plurality of LED elements 130 having a weak light-emitting region 133, wherein the cutting direction of the sapphire layer 137 is tilted.

[0117] Line I represents the brightness of the ideal field of view of the plurality of LED elements 130, and more specifically, the brightness of the field of view of the plurality of LED elements including the light-emitting layer 132 in which a weak light-emitting region 133 is not formed. Reference line I can provide stable brightness within a field of view of 50 degrees, while at a field of view of 50 degrees or greater, the brightness value is reduced due to the side molding portion 135.

[0118] Line E1 represents the brightness of the field of view according to the embodiment, wherein in the plurality of LED elements 130 including the light-emitting layer 132 having the weak light-emitting region 133, the cutting direction of the sapphire layer 137 is not adjusted (e.g., not tilted). As the field of view expands to the right, the brightness gradually decreases, and it can be confirmed that the brightness at a position 50 degrees to the right is about 70% or lower. However, as the field of view expands to the left, the brightness gradually increases, and it can be confirmed that the brightness at a position 50 degrees to the left is about 110%.

[0119] In the online E1 implementation, there is a significant difference in brightness values ​​between the left and right fields of view, which means that depending on the observer's position, the display may appear darker to some observers and brighter to others.

[0120] In a plurality of LED elements 130 including a light-emitting layer 132 on which a weak light-emitting region 133 is formed, line E2 represents the brightness of the field of view according to the embodiment, wherein the tilt direction of the two sides of the sapphire layer 137 is opposite to the direction in which the weak light-emitting region 133 is formed, and the brightness at a position 50 degrees to the right in the right direction is identified as approximately 90%, and the brightness at a position 50 degrees to the left is approximately 90%.

[0121] In the embodiment of line E2, the brightness changes as the field of view widens in the left or right direction, but it can provide a brightness distribution similar to that of line I, which is more ideal than line E1.

[0122] In the display device 100 according to the embodiment, the tilting direction of the two sides along the middle direction (half direction) of the sapphire layer 137 is opposite to the direction of forming the weak light-emitting region 133, and stable brightness can be provided even when the field of view widens.

[0123] In one embodiment, the weak light-emitting region 133 is formed at the center of the light-emitting layer 132 in the vertical direction. However, in other embodiments, the light-emitting layer 132 may have different distances from the weak light-emitting region 133 to the upper or lower side.

[0124] Therefore, in one of the multiple LED elements 130, where the distance from the weak light-emitting region 133 to the two sides parallel to the row direction of the light-emitting layer 132 is the same (e.g., when the weak light-emitting region 133 is located at the center of the light-emitting layer 132), the sapphire layer 137 may include a side surface that is parallel to the row direction and extends in the vertical direction (e.g., the normal direction of the light-emitting layer 132), and the side surface that is parallel to the column direction may extend in the inclined direction.

[0125] In multiple LED elements 130 where the distances from the weak light-emitting region 133 to two sides parallel to the row direction of the light-emitting layer 132 differ (e.g., when the weak light-emitting region 133 is not located at the center of the light-emitting layer 132), the sapphire layer 137 may include a side surface extending vertically parallel to the column direction, and the side surface parallel to the row direction may extend in an inclined direction. The side surface parallel to the row direction of the sapphire layer 137 may include an inclination in a direction opposite to the direction in which the weak light-emitting region 133 is formed, thereby minimizing brightness changes based on the observer's viewing height.

[0126] Figure 11 It is along Figure 7 A cross-sectional view of the display device 100 along the A-A' direction.

[0127] refer to Figure 11 The display device 100 according to the embodiment may further include a bonding layer 138, a transparent molding layer 17, and an optical film 18.

[0128] The bonding layer 138 can be disposed on the upper part of the substrate 15 to bond multiple LED elements 130 and side molding portions 135 to the substrate 15, and can be formed by an anisotropic conductive film, or the bonding layer 138 can be formed by a welding process.

[0129] A transparent molding layer 17 can be disposed on the upper surface of the plurality of LED elements 130 and the side molding portion 135 to transmit light. The transparent molding layer 17 may include transparent materials such as epoxy resin, silicone, and UV, and may also be referred to as a transparent molding layer. An optical film 18 can be disposed on the upper surface of the transparent molding layer 17, and may be a neutral density (ND) film with neutral characteristics relative to color.

[0130] In the above embodiment, the side molding portion 135 provided in the gaps spaced apart from the plurality of LED elements 130 has the effect of increasing contrast by blocking light emitted from the LED elements 130, but may limit the field of view of the LED elements 130.

[0131] In another embodiment, the side molding portion 135 may transmit light. The bonding layer 138 may include a light-absorbing bonding material to absorb light that penetrates the side molding portion 135.

[0132] The side molding portion 135 allows 10% to 100% of the incident light to pass through, and does not completely block the light emitted from the side LED element 130, thereby effectively improving the field of view.

[0133] Because the bonding layer 138 is made of a light-absorbing material, the bonding layer 138 disposed below the side molding portion 135 can absorb light without reflecting light, and therefore, as in the embodiment where the side molding portion 135 blocks light, the side molding portion 135 can have the effect of increasing contrast.

[0134] In this example, when the bonding layer 138 covers the entire surface of the substrate 15 and completely blocks light, errors may occur during the arrangement of electrodes on the substrate 15, and the bonding layer 138 may be made of a bonding material that includes a predetermined level of light absorption.

[0135] The bonding layer 138 can maintain contrast by absorbing emitted light, and the side molding portion 135 can improve white balance by allowing light to pass through and reducing brightness deviation according to the field of view.

[0136] Although exemplary embodiments of the present disclosure have been shown and described, the present disclosure is not limited to the specific embodiments described above. Those skilled in the art will understand that various changes in form and detail may be made without departing from the true spirit and full scope of the present disclosure, including the appended claims and their equivalents.

Claims

1. A display device, comprising: Substrate; as well as Multiple light-emitting diode (LED) elements are arranged in a matrix on the substrate. Among them, multiple LED components include: A first LED element includes a first light-emitting layer and is configured to emit a first light of a first color through the first light-emitting layer. The second LED element includes a second light-emitting layer and is configured to emit second light of a second color through the second light-emitting layer. A third LED element includes a third light-emitting layer and is configured to emit a third light of a third color through the third light-emitting layer. The first LED element, the second LED element, and the third LED element are arranged along the column direction of the plurality of LED elements and together constitute a pixel. The first light-emitting layer includes a first weak light-emitting region, the second light-emitting layer includes a second weak light-emitting region, and the third light-emitting layer includes a third weak light-emitting region. Wherein, the first weak light-emitting region, the second weak light-emitting region, and the third weak light-emitting region are aligned along a line in the column direction, and The first weak light-emitting region, the second weak light-emitting region, and the third weak light-emitting region each have a brightness lower than the average brightness of the first LED element, the second LED element, and the third LED element, respectively. The first LED element further includes: A sapphire layer is disposed on top of the first light-emitting layer. The sapphire layer has two opposing surfaces extending vertically from the first light-emitting layer, and two inclined surfaces extending at a predetermined angle from the first light-emitting layer in an inclined direction. The two inclined surfaces extend in a direction opposite to the direction in which the first weak luminescent region is formed.

2. The display device according to claim 1, wherein, The first LED element further includes: A terminal layer is disposed at the lower part of the first light-emitting layer and connected to the substrate.

3. The display device according to claim 1, wherein, In the first LED element, the distances from the first weak light-emitting region to both sides of the first LED element parallel to the row direction of the first light-emitting layer are equal to each other. The first side surface of the sapphire layer, parallel to the row direction, extends in the vertical direction, and The second side surface of the sapphire layer, which is parallel to the column direction, extends in the inclined direction.

4. The display device according to claim 1, wherein, In the first LED element, the distances from the first weak light-emitting region to the two sides of the first LED element parallel to the row direction of the first light-emitting layer are different from each other. The first side surface of the sapphire layer, parallel to the column direction, extends in the vertical direction, and The second side surface of the sapphire layer, which is parallel to the row direction, extends in the inclined direction.

5. The display device according to claim 2, wherein, The terminal layer includes an anode terminal and a cathode terminal. The substrate includes an anode terminal coupling portion and a cathode terminal coupling portion, and The arrangement of the anode terminal coupling portion and the cathode terminal coupling portion coupled to one or more of the plurality of LED elements is opposite to the arrangement of the anode terminal coupling portion and the cathode terminal coupling portion coupled to another of the plurality of LED elements.

6. The display device according to claim 1, wherein, The first LED element, the second LED element, and the third LED element are spaced apart from each other at a predetermined interval.

7. The display device according to claim 1, further comprising: A side molding portion is disposed on the substrate at the gap between the plurality of LED elements.

8. The display device according to claim 7, wherein, The side molding portion includes a light-transmitting material that allows light to pass through.

9. The display device according to claim 8, further comprising: A bonding layer is disposed on the upper part of the substrate to bond the plurality of LED elements and the side molding portion to the substrate.

10. The display device according to claim 9, wherein, The bonding layer includes a light-absorbing bonding material that absorbs light transmitted through the light-transmitting material.

11. The display device according to claim 7, further comprising: A transparent molding layer is disposed on the upper surface of the side molding portion and on the plurality of LED elements.

12. The display device according to claim 11, wherein, The transparent molding layer includes a light-transmitting material that allows light to pass through.

13. The display device according to claim 11, further comprising: An optical film is disposed on the transparent molding layer. The optical film is a neutral density ND film with neutral characteristics for color.

14. The display device according to claim 1, wherein, The second LED element is a green LED element. Wherein, the first LED element is either a red LED element or a blue LED element, and The third LED element is either a red LED element or a blue LED element that is different from the first LED element.

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