Display device

Abstract

The invention discloses a display device. The display device comprises a first substrate, a second substrate, an adhesive layer, at least one light-emitting unit and an intermediate layer, the second substrate is opposite to the first substrate; the adhesive layer is arranged between the first substrate and the second substrate; the light-emitting unit is arranged between the adhesive layer and the first substrate, the light-emitting unit comprises at least one light-emitting assembly, and the surface, facing the adhesive layer, of the light-emitting assembly is provided with a plurality of microstructures; the interposer is disposed between the adhesive layer and the plurality of microstructures, and the refractive index of the interposer is greater than 1 and less than the refractive index of the adhesive layer.

Description

Technical Field

[0001] The present disclosure relates to a display device, and particularly to a display device having light-emitting diode units. Background Art

[0002] With the development of digital technology, display devices have been widely used in various aspects of daily life, such as modern information products like televisions, computers, mobile phones, etc. At the same time, display devices are continuously developing towards being light, thin, short, small, and fashionable. Among existing display devices, light-emitting diode display devices (LED display devices), especially micro light-emitting diode display devices (Micro LED display devices), have become one of the mainstream display devices due to their advantages such as low power consumption, high contrast ratio, wide color gamut, high brightness, small size, thin and light, and energy saving.

[0003] Among them, micro light-emitting diodes (Micro LEDs) utilize the recombination of electron-hole pairs in a p-n junction (p-n junction) to generate electromagnetic radiation (such as light). For example, in a forward-biased p-n junction formed of a direct bandgap material such as gallium arsenide or gallium nitride, the recombination of electron-hole pairs injected into the depletion region generates electromagnetic radiation. The above electromagnetic radiation can be in the visible light region or the non-visible light region, and materials with different energy gaps will result in micro light-emitting diodes that can generate different colors of light. Summary of the Invention

[0004] The present disclosure provides a display device that can effectively improve the light extraction efficiency.

[0005] A display device according to the present disclosure includes a first substrate, a second substrate, an adhesive layer, at least one light-emitting unit, and an intermediate layer. Among them, the second substrate is opposite to the first substrate; the adhesive layer is disposed between the first substrate and the second substrate; the light-emitting unit is disposed between the adhesive layer and the first substrate, the light-emitting unit includes at least one light-emitting component, and the surface of the light-emitting component facing the adhesive layer has a plurality of microstructures; the intermediate layer is disposed between the adhesive layer and these microstructures, and the refractive index of the intermediate layer is greater than 1 and less than the refractive index of the adhesive layer.

[0006] A display device according to the present disclosure includes: a first substrate, a second substrate, an adhesive layer, and at least one light-emitting unit. The first substrate faces the second substrate; the adhesive layer is disposed between the first substrate and the second substrate; the light-emitting unit is disposed between the adhesive layer and the first substrate, and the light-emitting unit includes at least one light-emitting component, and a surface of the light-emitting component facing the adhesive layer has a plurality of microstructures; the refractive index of the adhesive layer is greater than 1 and less than or equal to 1.4. Description of the Drawings

[0007] Figure 1 FIG. is a partial cross-sectional schematic view of the display device according to the first embodiment of the present disclosure.

[0008] Figures 2 to 5 As shown in Figure 1 FIG. is a cross-sectional schematic view of different embodiments of the display device shown.

[0009] Figure 6 FIG. is a partial cross-sectional schematic view of the display device according to the second embodiment of the present disclosure.

[0010] Figures 7 to 10 As shown in Figure 6 FIG. is a cross-sectional schematic view of different embodiments of the display device shown. Detailed Description of the Embodiments

[0011] Hereinafter, a display device according to a preferred embodiment of the present disclosure will be described with reference to the relevant drawings, and the same components will be described with the same reference numerals. It should be understood that the following description provides many different embodiments for implementing different implementation modes of some embodiments of the present disclosure. The specific components and arrangements described below are only for simply and clearly describing some embodiments of the present disclosure. Of course, these embodiments are only used for illustration and not for limiting the scope of the present disclosure. In addition, repeated reference numerals or signs may be used in different embodiments, and these repetitions are only for simply and clearly describing some embodiments of the present disclosure, and do not represent any association between the different embodiments and / or structures discussed. Furthermore, when it is mentioned that a certain film layer is on or above another film layer, it includes the case where a certain film layer is in direct contact with another film layer; or, there may also be a case where one or more other film layers are interposed therebetween. In this case, a certain film layer and another film layer may not be in direct contact.

[0012] Relative terms may be used in the embodiments, such as "lower" or "bottom" and "higher" or "top", to describe the relative relationship of one component of the drawing to another component. It can be understood that if the device in the drawing is turned upside down, the component described on the "lower" side will become the component on the "higher" side.

[0013] Here, the terms "about", "approximately", and "substantially" generally mean within 20% of a given value or range, preferably within 10%, more preferably within 5%, or 3%, or 2%, or 1%, or 0.5%. The quantities given herein are approximate quantities, that is, the meaning of "about", "approximately", or "substantially" may still be implied even without specifically stating "about", "approximately", or "substantially".

[0014] It is understood that although the terms "first", "second", "third", etc. may be used herein to describe various components, ingredients, regions, layers, and / or parts, these components, ingredients, regions, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, ingredients, regions, layers, and / or parts. Therefore, a first component, ingredient, region, layer, and / or part discussed below may be referred to as a second component, ingredient, region, layer, and / or part without departing from the teachings of some embodiments of the present disclosure.

[0015] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present disclosure pertains. It is understood that these terms, such as those defined in a commonly used dictionary, should be interpreted to have a meaning consistent with the relevant technology and the background or context of the present disclosure, and should not be interpreted in an idealized or overly formal manner, unless specifically defined in the embodiments of the present disclosure.

[0016] Some embodiments of the present disclosure may be combined with the attached Figure 1 It is understood that the drawings of the embodiments of the present disclosure are also regarded as part of the description of the embodiments of the present disclosure. It should be noted that the drawings of the embodiments of the present disclosure are not drawn to the scale of actual devices and components. The shapes and thicknesses of the embodiments may be exaggerated in the drawings for clarity to show the features of the embodiments of the present disclosure. In addition, the structures and devices in the drawings are shown in a schematic manner for clarity to show the features of the embodiments of the present disclosure.

[0017] In some embodiments of the present disclosure, relative terms such as "lower", "upper", "parallel", "perpendicular", "beneath", "above", "top", "bottom", etc. should be understood as the orientations shown in this paragraph and the relevant drawings. Such relative terms are only for convenience of description and do not represent that the devices described need to be manufactured or operated in a specific orientation. And terms regarding joining and connecting, such as "connected" and "coupled", unless specifically defined, may mean that two structures are in direct contact, or may also mean that two structures are not in direct contact and there are other structures disposed between these two structures. And such terms regarding joining and connecting may also include the cases where both structures are movable or both structures are fixed.

[0018] It should be noted that in the present disclosure, the term "substrate" may include components formed on a transparent substrate and various film layers covering the substrate, and any required plurality of active components (such as transistors) may have been formed thereon. However, for the sake of simplifying the drawings herein, only a flat substrate is shown.

[0019] Please refer to Figure 1 as shown Figure 1 which is a partial cross-sectional schematic view of a display device 10 according to a first embodiment of the present disclosure. As Figure 1 shown, the display device 10 of this embodiment includes a first substrate 11, a second substrate 12, an adhesive layer 13, at least one light-emitting unit 14, and an intermediate layer 15.

[0020] In this embodiment, the first substrate 11 may be a substrate including a circuit layer (not shown in the figure) electrically connected to the light-emitting unit 14. This circuit layer may include, for example, a microprocessor, a storage element, and / or other components. The circuit layer may also include different passive components and / or active components, such as thin-film resistors, capacitors (such as metal-insulator-metal capacitors (MIMCAPs)), inductors, diodes, Metal-Oxide-Semiconductor field-effect transistors (MOSFETs), Complementary Metal-Oxide-Semiconductor (CMOS) transistors, bipolar junction transistors (BJTs), laterally diffused metal oxide semiconductor transistors, high-power metal oxide semiconductor transistors, thin-film transistors (TFTs), or other types of transistors. Additionally, the first substrate 11 may have a bonding surface, such as the upper surface of the first substrate 11. The first substrate 11 is a driving substrate for driving the light-emitting unit 14 to emit light, and may be, for example, a complementary metal-oxide-semiconductor substrate, a Liquid Crystal on Silicon (LCOS) substrate, a thin-film transistor substrate, or other circuit boards with working circuits, without limitation. In some embodiments, the display device 10 is a Micro LED Display Device, suitable for AR (augmented reality) or VR (virtual reality) applications. The side length of the first substrate 11 may be, for example but not limited to, less than or equal to 1 inch, and the Pixels Per Inch (PPI) may be greater than 1,000 or 2,500, and the brightness may exceed 10,000 nits. Of course, the side length of the first substrate 11 may also be greater than 1 inch, and the PPI is not limited either.

[0021] Such as Figure 1As shown, the second substrate 12 is relative to the first substrate 11, and the adhesive layer 13, the light-emitting unit 14, and the intermediate layer 15 are disposed between the first substrate 11 and the second substrate 12. In this embodiment, the second substrate 12 can be, for example, a light-transmissive substrate, so that the light emitted by the light-emitting unit 14 can directly pass through the second substrate 12 and emit; alternatively, the second substrate 12 can also be a filter substrate, that is, a filter layer is formed on one surface of the second substrate 12. Therefore, the light emitted by the light-emitting unit 14 can pass through the filter layer and then pass through the second substrate 12 and emit. It should be noted that the above description is only for example and is not intended to limit the scope of the present disclosure.

[0022] Please refer to Figure 1 As shown, the adhesive layer 13 is disposed between the first substrate 11 and the second substrate 12, the light-emitting unit 14 is disposed between the adhesive layer 13 and the first substrate 11, and the intermediate layer 15 is disposed between the adhesive layer 13 and the light-emitting unit 14.

[0023] In this embodiment, the material of the adhesive layer 13 may include optical clear adhesive (OCA), optical clear resin (OCR), or other suitable transparent adhesive materials, and the present disclosure is not limited thereto. Among them, the refractive index of the adhesive layer 13 is about 1.5.

[0024] In addition, the light-emitting unit 14 includes at least one light-emitting component 141, and the surface of the light-emitting component 141 facing the adhesive layer 13 (or the intermediate layer 15) has a plurality of microstructures 142. For example, the light-emitting component 141 can include, for example, an organic light emitting diode (OLED), a mini light emitting diode (mini LED), a micro light emitting diode (micro LED), or a quantum dot light emitting diode (quantum dot LED), but the present disclosure is not limited thereto. In this embodiment, the light-emitting unit 14 includes a plurality of light-emitting components 141, and the light-emitting component 141 can be a micro light emitting diode component, such as a red micro light emitting diode component, a green micro light emitting diode component, and / or a blue micro light emitting diode component. In addition, the surface of each light-emitting component 141 connected to the intermediate layer 15 has a plurality of microstructures 142; for example, Figure 1As shown, in some embodiments, each light-emitting component 141 includes a light-emitting portion 143 and a plurality of microstructures 142 formed on one side of the light-emitting portion 143. Generally, the light-emitting portion 143 includes two semiconductor layers and a light-emitting layer sandwiched between the two semiconductor layers. The semiconductor layer can be an elemental semiconductor, a compound semiconductor, an alloy semiconductor, a metal oxide, an organic semiconductor, or a combination of the above materials. Elemental semiconductors include amorphous silicon (amorphous-Si), polycrystalline silicon (poly-Si), germanium, etc.; compound semiconductors include gallium nitride (GaN), silicon carbide, gallium arsenide, gallium phosphide, indium phosphide, indium arsenide, and / or indium antimonide, etc.; alloy semiconductors include silicon-germanium alloy (SiGe), gallium arsenide phosphide (GaAsP), aluminum indium arsenide (AlInAs), aluminum gallium arsenide (AlGaAs), gallium indium arsenide (GaInAs), gallium indium phosphide (GaInP), and / or gallium indium arsenide phosphide (GaInAsP), etc.; metal oxides include indium gallium zinc oxide (IGZO), indium zinc oxide (IZO), indium gallium tin zinc oxide (IGZTO), etc.; organic semiconductors include polycyclic aromatic compounds; of course, it can also be a combination of the above materials. It should be noted that the above materials are only examples and are not used to limit the scope of the present disclosure.

[0025] The light-emitting layer can include a homojunction, a heterojunction, a single-quantum well (SQW), a multiple-quantum well (MQW), or other similar structures. In some embodiments, the light-emitting layer can include undoped n-type In x Ga (1-x) N, Al x In y Ga (1-x-y)N, or any other suitable material. Additionally, the light-emitting layer may be a multiple quantum well structure including alternating multiple well layers (e.g., InGaN) and barrier layers (e.g., GaN). Furthermore, the light-emitting layer may be formed by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE), liquid phase epitaxy (LPE), or other suitable chemical vapor deposition methods. In this embodiment, the light-emitting part 143 is a multiple quantum well structure.

[0026] Additionally, in this embodiment, the microstructure 142 can be directly formed by applying an etching process to a surface of the light-emitting part 143. Therefore, the semiconductor layer of the microstructure 142 and the light-emitting part 143 can be formed of the same material, such as gallium nitride (n-GaN). Additionally, in other embodiments, the microstructure 142 on a surface of the light-emitting part 143 and the light-emitting part 143 can be different material layers; herein, a material layer can be first deposited on the light-emitting part 143, and then the microstructure 142 can be formed by applying an etching process to this material layer. It should be noted that although the spacing of the microstructures 142 shown in Figure 1 is fixed, the present disclosure is not limited thereto. In other embodiments, the spacing of the microstructures 142 can be non-fixed or irregular.

[0027] In this embodiment, as Figure 1 shown, in a cross-sectional view, these microstructures 142 have recessed portions R, the depth of each recessed portion R is H and its width is W, and H and W satisfy the following relationship:

[0028] 15° ≤ tan -1 ((1 / 2W) / H) ≤ 40°.

[0029] Wherein, H and W can further satisfy the following relationship:

[0030] 15° ≤ tan -1 ((1 / 2W) / H) ≤ 30°.

[0031] Specifically, in this embodiment, each recessed portion R is an inverted triangle, the depth H of the recessed portion R defines the height of the inverted triangle, and the width of the recessed portion R defines the base of the inverted triangle. At this time, the included angle θ between the hypotenuse of the inverted triangle (recessed portion R) and the vertical direction is between 15 degrees and 40 degrees, preferably between 15 degrees and 30 degrees, where the included angle θ = tan -1 ((1 / 2W) / H).

[0032] In this embodiment, the refractive index of the microstructures 142 is approximately between 2.35 and 2.60 (2.35 ≤ refractive index of the microstructures 142 ≤ 2.60). The material thereof can be a transparent material, such as indium tin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), antimony tin oxide (ATO), antimony zinc oxide (AZO), a combination of the above materials, or any other suitable transparent conductive oxide material, or any suitable semiconductor material (such as n-GaN) or polymer material (such as optical resin, epoxy resin, silicone resin), etc., but the present disclosure is not limited thereto.

[0033] As Figure 1 shown, the intermediate layer 15 is disposed between the adhesive layer 13 and these microstructures 142. The refractive index of the intermediate layer 15 is greater than 1 and less than the refractive index of the adhesive layer 13. In this embodiment, the refractive index of the intermediate layer 15 is greater than 1 and less than or equal to 1.4. In other words, the refractive index of the intermediate layer 15 is less than the refractive index of these microstructures 142 and less than the refractive index of the adhesive layer 13. At this time, the ratio of the refractive index of the intermediate layer 15 to the refractive index of these microstructures 142 is between (1.0 / 2.60) and (1.4 / 2.35). In addition, in this embodiment, the material of the intermediate layer 15 may include optical clear adhesive (OCA), optical clear resin (OCR), or other suitable transparent adhesive materials (such as photoresist materials), but the present disclosure is not limited thereto.

[0034] It should be particularly noted that in this embodiment, by the refractive index of the intermediate layer 15 being less than the refractive index of these microstructures 142 and less than the refractive index of the adhesive layer 13, and in cooperation with the design that the included angle θ is between 15 degrees and 40 degrees (especially the included angle θ is between 15 degrees and 30 degrees), etc., the light L emitted from the light-emitting part 143 sequentially passes through these microstructures 142, the intermediate layer 15, the adhesive layer 13, and the second substrate 12, so that the light extraction efficiency when the light L is emitted outward can be effectively improved, thereby improving the overall light-emitting efficiency of the display device 10. During actual testing, when the included angle θ is between 15 degrees and 40 degrees, the overall luminous brightness of the display device 10 will have different degrees of improvement. In particular, when the included angle θ is between 15 degrees and 30 degrees, the overall luminous brightness of the display device 10 will have an optimal value, which is close to the case where the light directly enters the air medium from the light-emitting component.

[0035] In addition, the display device according to other embodiments of the present disclosure may be, for example, a color display device, which may be defined with a plurality of pixels, and each pixel includes a plurality of sub-pixels, such as a red photon sub-pixel, a green photon sub-pixel, and a blue photon sub-pixel. In the present disclosure, each light-emitting unit corresponds to a defined pixel, and a plurality of light-emitting components in the light-emitting unit define a plurality of sub-pixels in the corresponding pixel, where each sub-pixel may be constituted by the corresponding light-emitting component, or may be constituted by the corresponding light-emitting component in combination with at least one of the corresponding light-filtering layer (or light-filtering portion), light-conversion layer (or light-conversion portion), diffusion layer (or diffusion portion), etc., or a combination thereof. The present disclosure is not limited thereto.

[0036] The structural configurations of the display devices in different embodiments of the first embodiment of the present disclosure will be described below with reference to the accompanying drawings. It should be noted that the following embodiments are only examples, and the present disclosure is not limited thereto.

[0037] Figure 2 As shown in Figure 1 FIG. 9 is a cross-sectional schematic view of an embodiment of the display device 10. In this embodiment, the display device 10a includes a first substrate 11, a second substrate 12, an adhesive layer 13, at least one light-emitting unit 14, and an intermediate layer 15. The second substrate 12 is opposite to the first substrate 11, the adhesive layer 13 is disposed between the first substrate 11 and the second substrate 12, and the light-emitting unit 14 is disposed between the adhesive layer 13 and the first substrate 11. The light-emitting unit 14 includes three light-emitting components, such as a red light-emitting component 141R, a green light-emitting component 141G, and a blue light-emitting component 141B, which may be a red light-emitting diode, a green light-emitting diode, and a blue light-emitting diode, respectively. Therefore, the display device 10a can emit colored light to output a color image. Each of the light-emitting components 141R, 141G, or 141B has a plurality of microstructures 142 on the surface facing the adhesive layer 13, and the intermediate layer 15 is disposed between the adhesive layer 13 and these microstructures 142; the refractive index of the intermediate layer 15 is greater than 1, for example, may be between 1 and 1.4, and the refractive index of the intermediate layer 15 is less than the refractive index of the adhesive layer 13 and less than the refractive index of these microstructures 142.

[0038] In addition, in the present embodiment, a pixel definition layer 111 (Pixel Define Layer, PDL) and an underfill layer 112 are further formed on the first substrate 11. The pixel definition layer 111 is formed with a plurality of accommodating spaces, and these light-emitting components 141R, 141G, and 141B are respectively disposed in these accommodating spaces. The underfill layer 112 is respectively filled in these accommodating spaces and surrounds these light-emitting components 141R, 141G, and 141B disposed in the accommodating spaces. In some embodiments, a material layer of the pixel definition layer 111, such as an organic photoresist material layer, can be first formed on the first substrate 11 by a coating process, and then this material layer can be patterned by, for example, a photolithography process to form a structure including a plurality of accommodating spaces as shown in Figure 2 ; wherein, a reflective layer (not shown in the figure) can be further formed on the pixel definition layer 111 to improve the light extraction efficiency, but the present disclosure is not limited thereto. After the light-emitting components 141R, 141G, and 141B are respectively disposed in these accommodating spaces, an underfill can be further filled around the light-emitting components 141R, 141G, and 141B. The material thereof can be, for example, silicone, epoxy resin, polymethyl methacrylate, polycarbonate, or other suitable materials, so as to form the underfill layer 112. It should be noted that the above description is only an example and is not intended to limit the scope of the present disclosure. The present disclosure is not limited thereto.

[0039] Figure 3 As shown in Figure 1A cross-sectional schematic diagram of another embodiment of the display device 10 shown. The component composition and the connection relationship of each component of the display device 10b in this embodiment are substantially the same as those of the display device 10a in the foregoing embodiment. The difference is that the display device 10b in this embodiment further includes a light filtering layer 16, and the light filtering layer 16 is disposed on the side of the second substrate 12 facing the light emitting unit 14. In this embodiment, the light filtering layer 16 includes a red light filtering portion 161R, a green light filtering portion 161G, and a blue light filtering portion 161B, and the red light filtering portion 161R, the green light filtering portion 161G, and the blue light filtering portion 161B respectively overlap the red light emitting component 141R, the green light emitting component 141G, and the blue light emitting component 141B. Specifically, in order to form the light filtering layer 16 on the second substrate 12, a layer of bank material, such as an organic photoresist material layer, can be first formed on the second substrate 12 by using a coating process, and then this bank material layer is patterned by using, for example, a photolithography process to define the pattern structures of the respective light filtering portions to be formed, and then the red light filtering portion 161R, the green light filtering portion 161G, and the blue light filtering portion 161B are respectively formed by using the coating process and the photolithography process in sequence. At this time, the remaining bank material forms a bank 162 between these light filtering portions 161R, 161G, and 161B. In one embodiment, the bank 162 can be a black matrix layer (BM layer). It should be noted that the above description is only an example and is not intended to limit the scope of the present disclosure, and the present disclosure is not limited thereto.

[0040] Figure 4 As Figure 1Cross-sectional schematic diagram of another embodiment of the display device 10 shown. The component composition and the connection relationship of each component of the display device 10c in this embodiment are substantially the same as those of the display device 10b in the foregoing embodiment. The difference lies in that the display device 10c in this embodiment further includes an optical layer 17, and the optical layer 17 is disposed on the side of the light filtering layer 16 facing the light emitting unit 14. In addition, the light emitting unit 14 of the display device 10c includes three light emitting components that can emit light of the same color, such as three blue light emitting components 141B; in this embodiment, the first blue light emitting component 141B corresponds to a first light conversion portion 171R of the optical layer 17 and corresponds to the red light filtering portion 161R of the light filtering layer 16. The first light conversion portion 171R can convert the blue light emitted by the first blue light emitting component 141B into red light, and then emit it outward through the red light filtering portion 161R and the second substrate 12; the second blue light emitting component 141B corresponds to a second light conversion portion 171G of the optical layer 17 and corresponds to the green light filtering portion 161G of the light filtering layer 16. The second light conversion portion 171G can convert the blue light emitted by the second blue light emitting component 141B into green light, and then emit it outward through the green light filtering portion 161G and the second substrate 12; the third blue light emitting component 141B corresponds to a light diffusion portion 171D of the optical layer 17 and corresponds to the blue light filtering portion 161B of the light filtering layer 16. The blue light emitted by the third blue light emitting component 141B is emitted outward through the light diffusion portion 171D, the blue light filtering portion 161B and the second substrate 12 in sequence. Specifically, in order to form the optical layer 17 on the light filtering layer 16, a layer of damascene material, such as an organic photoresist material layer, can be first formed on the light filtering layer 16 of the second substrate 12 by using a coating process, and then this damascene material layer is patterned by using, for example, a photolithography process to define the pattern structures of the light conversion portion and the light diffusion portion to be formed, and then the first light conversion portion 171R, the second light conversion portion 171G and the light diffusion portion 171D are formed by using the coating process and the photolithography process in sequence. At this time, the remaining damascene material forms a dam 172 between the first light conversion portion 171R, the second light conversion portion 171G and the light diffusion portion 171D. It should be noted that the above description is only an example and is not intended to limit the scope of the present disclosure. The present disclosure is not limited thereto. In addition, the light conversion portions in this embodiment, such as the first light conversion portion 171R and the second light conversion portion 171G described above, for example, include particulate quantum dots, and the materials of the quantum dots may include CdSe, InP, SiO 2 、ZrO 2 、TiO 2 、Al 2 O 3 、In 2 O 3 、ZnO、SnO 2 、Sb 2 O 3, or other suitable materials, or combinations of the above materials, but the present disclosure is not limited thereto; the light diffusing portion of this embodiment, such as the above-mentioned light diffusing portion 171D, for example, includes light diffusing particles, and the material of the light diffusing particles, for example, includes TiO 2 , but the present disclosure is not limited thereto.

[0041] Figure 5 is a cross-sectional schematic view of another embodiment of the display device 10 as shown in Figure 1 . The component composition and the connection relationship of each component of the display device 10d in this embodiment are substantially the same as those of the display device 10c in the foregoing embodiment. The difference is that the light emitting unit 14 of the display device 10d in this embodiment includes two blue light emitting components 141B and one green light emitting component 141G; in this embodiment, the first blue light emitting component 141B corresponds to a light conversion portion 171R of the optical layer 17 and corresponds to the red light filtering portion 161R of the filter layer 16. The light conversion portion 171R can convert the blue light emitted by the first blue light emitting component 141B into red light, and then emit it outward through the red light filtering portion 161R and the second substrate 12; the green light emitting component 141G corresponds to a first light diffusing portion 171D of the optical layer 17 and corresponds to the green light filtering portion 161G of the filter layer 16. The green light emitted by the green light emitting component 141G is sequentially emitted outward through the first light diffusing portion 171D, the green light filtering portion 161G and the second substrate 12; the second blue light emitting component 141B corresponds to a second light diffusing portion 171D of the optical layer 17 and corresponds to the blue light filtering portion 161B of the filter layer 16. The blue light emitted by the second blue light emitting component 141B is sequentially emitted outward through the second light diffusing portion 171D, the blue light filtering portion 161B and the second substrate 12. It should be noted that the above description is only for example and is not intended to limit the scope of the present disclosure. The present disclosure is not limited thereto.

[0042] In summary, the display device of this embodiment includes a first substrate, a second substrate, an adhesive layer, a light-emitting unit, and an intermediate layer. The second substrate faces the first substrate; the adhesive layer is disposed between the first substrate and the second substrate; the light-emitting unit is disposed between the adhesive layer and the first substrate, and the light-emitting unit includes at least one light-emitting component, and the surface of the light-emitting component facing the adhesive layer has a plurality of microstructures; the intermediate layer is disposed between the adhesive layer and these microstructures, the refractive index of the intermediate layer is greater than 1 and less than the refractive index of the adhesive layer, and the angle θ between the hypotenuse of the concave portion of the microstructure and the vertical direction is between 15 degrees and 40 degrees. The display device of this embodiment has the refractive index of the intermediate layer less than the refractive index of these microstructures and less than the refractive index of the adhesive layer, and can cooperate with the design that the angle θ is between 15 degrees and 40 degrees, etc., so that the light emitted from each light-emitting component sequentially passes through these microstructures, the intermediate layer, the adhesive layer, and the second substrate and then emits outwards. In some cases, it further passes through a filter layer, or a filter layer and an optical layer, which can effectively improve the light extraction efficiency when the light emits outwards, so as to improve the overall light output efficiency of the display device.

[0043] It should be noted that even if the display device of this embodiment only has the design that the refractive index of the intermediate layer is less than the refractive index of these microstructures and less than the refractive index of the adhesive layer (without cooperating with the limiting condition of the angle θ), when the light emitted from each light-emitting component sequentially passes through these microstructures, the intermediate layer, the adhesive layer, and the second substrate and then emits outwards, in some cases, it further passes through a filter layer, or a filter layer and an optical layer, and it can still effectively improve the light extraction efficiency when the light emits outwards, so as to improve the overall light output efficiency of the display device.

[0044] In addition, if the display device only has the design that the angle θ is between 15 degrees and 40 degrees, but does not have the above intermediate layer, and if the refractive index of the adhesive layer is adjusted to be equivalent to the refractive index of the intermediate layer 15 in the foregoing embodiment, then this limitation of the angle θ plus the design of the refractive index of the adhesive layer still has the effect of improving the overall light output efficiency of the display device.

[0045] Please refer to Figure 6 shown in Figure 6 is a partial cross-sectional schematic diagram of the display device 20 according to the second embodiment of the present disclosure. As Figure 6 shown, the display device 20 of this embodiment includes a first substrate 21, a second substrate 22, an adhesive layer 23, and at least one light-emitting unit 24.

[0046] In this embodiment, the first substrate 21 may be a substrate including a circuit layer (not shown in the figure) electrically connected to the light-emitting unit 24. For a detailed description, reference may be made to the first substrate 11 in the foregoing embodiment, which will not be elaborated here.

[0047] As Figure 6As shown, the second substrate 22 is relative to the first substrate 21, and the adhesive layer 23 and the light-emitting unit 24 are disposed between the first substrate 21 and the second substrate 22. For a detailed description of the second substrate 22, reference may be made to the second substrate 12 of the foregoing embodiment, which will not be elaborated herein.

[0048] Please refer again to Figure 6 As shown, the adhesive layer 23 is disposed between the first substrate 21 and the second substrate 22, and the light-emitting unit 24 is disposed between the adhesive layer 23 and the first substrate 21. It should be noted that in this embodiment, the display device 20 is not provided with an interlayer, so the adhesive layer 23 is directly disposed on the light-emitting unit 24; wherein, the refractive index of the adhesive layer 23 can be adjusted to be equivalent to the refractive index of the interlayer 15 of the foregoing embodiment, for example, greater than 1 and less than or equal to 1.4, so as to achieve the effect of improving the light extraction efficiency. Among them, for a detailed description of the adhesive layer 23 and the light-emitting unit 24, reference may be made to the adhesive layer 13 and the light-emitting unit 14 of the foregoing embodiment, which will not be elaborated herein.

[0049] It should be particularly noted that the light-emitting unit 24 includes at least one light-emitting component 241, and the surface of the light-emitting component 241 facing the adhesive layer 23 has a plurality of microstructures 242. For example, the light-emitting component 241 may include, for example, an organic light emitting diode (OLED), a mini light emitting diode (mini LED), a micro light emitting diode (micro LED), or a quantum dot light emitting diode (quantum dot LED), but the present disclosure is not limited thereto. In this embodiment, the light-emitting unit 24 includes a plurality of light-emitting components 241, and the light-emitting component 241 may be a micro light emitting diode component, for example, a red micro light emitting diode component, a green micro light emitting diode component, and / or a blue micro light emitting diode component. In this embodiment, each light-emitting component 241 includes a light-emitting portion 243 and a plurality of microstructures 242 formed on one side of the light-emitting portion 243. As Figure 6 shown, in a cross-sectional view, these microstructures 242 have recessed portions R, and the depth of each recessed portion R is H and its width is W, and H and W satisfy the following relationship:

[0050] 15° ≤ tan -1 ((1 / 2W) / H) ≤ 40°.

[0051] Among them, H and W may further satisfy the following relationship:

[0052] 15° ≤ tan -1 ((1 / 2W) / H) ≤ 30°.

[0053] Specifically, in the present embodiment, each recessed portion R is an inverted triangle. The depth H of the recessed portion R defines the height of the inverted triangle, and the width of the recessed portion R defines the base of the inverted triangle. At this time, the included angle θ between the hypotenuse of the inverted triangle (recessed portion R) and the vertical direction is between 15 degrees and 40 degrees, preferably between 15 degrees and 30 degrees, where the included angle θ = tan -1 ((1 / 2W) / H). In the present embodiment, the refractive index of the microstructure 242 is approximately between 2.35 and 2.60 (2.35 ≤ refractive index of the microstructure 242 ≤ 2.60).

[0054] It should be particularly noted that in the present embodiment, through the design where the included angle θ is between 15 degrees and 40 degrees, the light L emitted from the light-emitting portion 243 can sequentially pass through these microstructures 242, the adhesive layer 23, and the second substrate 22, effectively improving the light extraction efficiency when the light L is emitted outward, so as to improve the overall light output efficiency of the display device 20.

[0055] Hereinafter, the structural configurations of display devices in different embodiments of the second embodiment of the present disclosure will be illustrated with reference to the accompanying drawings. It should be noted that the following embodiments are only examples, and the present disclosure is not limited thereto.

[0056] Figure 7 As shown in Figure 6 a schematic cross-sectional view of an embodiment of the display device 20. In the present embodiment, the display device 20a includes a first substrate 21, a second substrate 22, an adhesive layer 23, and at least one light-emitting unit 24. The second substrate 22 is opposite to the first substrate 21. The adhesive layer 23 is disposed between the first substrate 21 and the second substrate 22. The light-emitting unit 24 is disposed between the adhesive layer 23 and the first substrate 21. The light-emitting unit 24 includes three light-emitting components, such as a red light-emitting component 241R, a green light-emitting component 241G, and a blue light-emitting component 241B, which can be a red light-emitting diode, a green light-emitting diode, and a blue light-emitting diode respectively. Therefore, the display device 20a can emit colored light to output a color image. The surfaces of the respective light-emitting components 241R, 241G, or 241B facing the adhesive layer 23 have a plurality of microstructures 242. These microstructures 242 have recessed portions R. The depth of each recessed portion R is H and its width is W. The included angle θ ( = tan -1 ((1 / 2W) / H)) between the hypotenuse of the recessed portion R and the vertical direction is between 15 degrees and 40 degrees, preferably between 15 degrees and 30 degrees.

[0057] In addition, in this embodiment, a pixel definition layer 211 and a filling layer 212 are further formed on the first substrate 21. The pixel definition layer 211 is formed with a plurality of accommodation spaces, and these light-emitting components 241R, 241G, and 241B are respectively disposed in these accommodation spaces. The filling layer 212 is respectively filled in these accommodation spaces and surrounds these light-emitting components 241R, 241G, and 241B disposed in the accommodation spaces. In some embodiments, a material layer of the pixel definition layer 211, such as an organic photoresist material layer, can be first formed on the first substrate 21 by a coating process, and then this material layer can be patterned by, for example, a photolithography process to form a structure including a plurality of accommodation spaces as shown in Figure 7 ; wherein, a reflective layer (not shown in the figure) can be further formed on the pixel definition layer 211 to improve the light extraction efficiency, but the present disclosure is not limited thereto. After the light-emitting components 241R, 241G, and 241B are respectively disposed in these accommodation spaces, an underfill can be further filled around the light-emitting components 241R, 241G, and 241B. The material thereof can be, for example, silicone, epoxy resin, polymethyl methacrylate, polycarbonate, or other suitable materials, so as to form the filling layer 212. It should be noted that the above description is only an example and is not intended to limit the scope of the present disclosure. The present disclosure is not limited thereto.

[0058] Figure 8 As shown in Figure 6 is a schematic cross-sectional view of another embodiment of the display device 20. The component composition and the connection relationship of each component of the display device 20b in this embodiment are substantially the same as those of the display device 20a in the foregoing embodiment. The difference lies in that the display device 20b in this embodiment further includes a filter layer 26. The filter layer 26 is disposed on the side of the second substrate 22 facing the light-emitting unit 24. In this embodiment, the filter layer 26 includes a red light filter portion 261R, a green light filter portion 261G, and a blue light filter portion 261B. The red light filter portion 261R, the green light filter portion 261G, and the blue light filter portion 261B respectively overlap the red light-emitting component 241R, the green light-emitting component 241G, and the blue light-emitting component 241B. Specifically, in order to form the filter layer 26 on the second substrate 22, a layer of barrier material, such as an organic photoresist material layer, can be first formed on the second substrate 22 by a coating process, and then this barrier material layer can be patterned by, for example, a photolithography process to define the pattern structure of each filter portion to be formed. Then, the red light filter portion 261R, the green light filter portion 261G, and the blue light filter portion 261B are respectively formed by a coating process and a photolithography process in sequence. At this time, the remaining barrier material is located between these filter portions 261R, 261G, and 261B to form a barrier 262. In one embodiment, the barrier 262 can be a black matrix layer. It should be noted that the above description is only an example and is not intended to limit the scope of the present disclosure. The present disclosure is not limited thereto.

[0059] Figure 9 Another cross-sectional schematic diagram of an embodiment of the display device 20 as shown Figure 6 The display device 20c of this embodiment has substantially the same component composition and connection relationship of each component as the display device 20b of the foregoing embodiment. The difference lies in that the display device 20c of this embodiment further includes an optical layer 27, and the optical layer 27 is disposed on the side of the filter layer 26 facing the light-emitting unit 24. In addition, the light-emitting unit 24 of the display device 20c includes three light-emitting components that can emit light of the same color, such as three blue light-emitting components 241B; in this embodiment, the first blue light-emitting component 241B corresponds to a first light conversion portion 271R of the optical layer 27 and corresponds to the red light filter portion 261R of the filter layer 26. The first light conversion portion 271R can convert the blue light emitted by the first blue light-emitting component 241B into red light, and then emit it outward through the red light filter portion 261R and the second substrate 22; the second blue light-emitting component 241B corresponds to a second light conversion portion 271G of the optical layer 27 and corresponds to the green light filter portion 261G of the filter layer 26. The second light conversion portion 271G can convert the blue light emitted by the second blue light-emitting component 241B into green light, and then emit it outward through the green light filter portion 261G and the second substrate 22; the third blue light-emitting component 241B corresponds to a light diffusion portion 271D of the optical layer 27 and corresponds to the blue light filter portion 261B of the filter layer 26. The blue light emitted by the third blue light-emitting component 241B is sequentially emitted outward through the light diffusion portion 271D, the blue light filter portion 261B, and the second substrate 22. Specifically, in order to form the optical layer 27 on the filter layer 26, a layer of barrier material, such as an organic photoresist material layer, can be first formed on the filter layer 26 of the second substrate 22 by using a coating process, and then this barrier material layer can be patterned by using, for example, a photolithography process to define the pattern structures of the light conversion portion and the light diffusion portion to be formed, and then the first light conversion portion 271R, the second light conversion portion 271G, and the light diffusion portion 271D are respectively formed by using a coating process and a photolithography process in sequence. At this time, the remaining barrier material forms a barrier 272 between the first light conversion portion 271R, the second light conversion portion 271G, and the light diffusion portion 271D. It should be noted that the above description is only an example and is not used to limit the scope of the present disclosure. The present disclosure is not limited thereto. In addition, the light conversion portions of this embodiment, such as the first light conversion portion 271R and the second light conversion portion 271G described above, for example, include particulate quantum dots, and the materials of the quantum dots can include CdSe, InP, SiO 2 、ZrO 2 、TiO 2 、Al 2 O 3 、In 2 O 3 、ZnO, SnO 2 、Sb 2 O3 , or other suitable materials, or combinations of the above materials, but the present disclosure is not limited thereto; the light diffusing portion of this embodiment, such as the light diffusing portion 271D described above, includes, for example, light diffusing particles, and the material of the light diffusing particles includes, for example, TiO 2 , but the present disclosure is not limited thereto.

[0060] Figure 10 is as Figure 6 is a schematic cross-sectional view of another embodiment of the display device 20 as shown. The component composition and the connection relationship of each component of the display device 20d in this embodiment are substantially the same as those of the display device 20c in the foregoing embodiment. The difference is that the light emitting unit 24 of the display device 20d in this embodiment includes two blue light emitting components 241B and one green light emitting component 241G; in this embodiment, the first blue light emitting component 241B corresponds to a light conversion portion 271R of the optical layer 27 and corresponds to the red light filtering portion 261R of the filter layer 26. The light conversion portion 271R can convert the blue light emitted by the first blue light emitting component 241B into red light, and then emit it outward through the red light filtering portion 261R and the second substrate 22; the green light emitting component 241G corresponds to a first light diffusing portion 271D of the optical layer 27 and corresponds to the green light filtering portion 261G of the filter layer 26. The green light emitted by the green light emitting component 241G is sequentially emitted outward through the first light diffusing portion 271D, the green light filtering portion 261G, and the second substrate 22; the second blue light emitting component 241B corresponds to a second light diffusing portion 271D of the optical layer 27 and corresponds to the blue light filtering portion 261B of the filter layer 26. The blue light emitted by the second blue light emitting component 241B is sequentially emitted outward through the second light diffusing portion 271D, the blue light filtering portion 261B, and the second substrate 22. It should be noted that the above description is only for example and is not intended to limit the scope of the present disclosure. The present disclosure is not limited thereto.

[0061] In summary, the display device of this embodiment includes a first substrate, a second substrate, an adhesive layer, and a light emitting unit. The second substrate is relative to the first substrate; the adhesive layer is disposed between the first substrate and the second substrate, and the refractive index of the adhesive layer is, for example, greater than 1 and less than or equal to 1.4; the light emitting unit is disposed between the adhesive layer and the first substrate, and the light emitting unit includes at least one light emitting component. The surface of the light emitting component facing the adhesive layer has a plurality of microstructures, and the included angle θ between the hypotenuse of the concave portion of the microstructure and the vertical direction is between 15 degrees and 40 degrees. By the design that the included angle θ is between 15 degrees and 40 degrees and the refractive index of the adhesive layer is greater than 1 and less than or equal to 1.4, the light emitted from each light emitting component is sequentially emitted outward through these microstructures, the adhesive layer, and the second substrate, and in some cases, it further passes through the filter layer or the filter layer and the optical layer, which can effectively improve the light extraction efficiency when the light is emitted outward, so as to improve the overall light output efficiency of the display device.

[0062] The above is only illustrative and not restrictive. Any equivalent modifications or changes made without departing from the spirit and scope of the present invention shall be included in the appended claims.

Claims

1. A display device, characterized in that, comprising: a first substrate; a second substrate, relative to the first substrate; an adhesive layer disposed between the first substrate and the second substrate; at least one light-emitting unit disposed between the adhesive layer and the first substrate, wherein the light-emitting unit includes at least one light-emitting component, and a surface of the light-emitting component facing the adhesive layer has a plurality of microstructures; and an intermediate layer disposed between the adhesive layer and the plurality of microstructures; wherein the refractive index of the intermediate layer is greater than 1 and less than the refractive index of the adhesive layer.

2. The display device according to claim 1, characterized in that, the refractive index of the intermediate layer is greater than 1 and less than or equal to 1.

4.

3. The display device according to claim 1, characterized in that, in a cross-sectional view, at least one of the plurality of microstructures is a recess, the depth of the recess is H, the width of the recess is W, and H and W satisfy the following relationship: 15° ≤ tan -1 ((1 / 2W) / H) ≤ 40°.

4. The display device according to claim 3, characterized in that, H and W further satisfy the following relationship: 15° ≤ tan -1 ((1 / 2W) / H) ≤ 30°.

5. The display device according to claim 3, characterized in that, the recess is an inverted triangle, the depth of the recess defines the height of the inverted triangle, and the width of the recess defines the base of the inverted triangle.

6. The display device according to claim 1, characterized in that, the first substrate includes a pixel definition layer and a filling layer, the pixel definition layer is formed with at least one accommodation space, the light-emitting component is disposed in the accommodation space, and the filling layer fills the accommodation space and surrounds the light-emitting component.

7. The display device according to claim 1, characterized in that, the second substrate includes at least one light filtering layer, at least one light conversion layer, and / or at least one diffusion layer, and the light filtering layer, the light conversion layer or the diffusion layer correspondingly overlaps the light-emitting component.

8. The display device according to claim 1, characterized in that, the light-emitting unit at least includes a red light-emitting component, a green light-emitting component and a blue light-emitting component, the second substrate includes a light filtering layer, the light filtering layer is disposed on a side of the second substrate facing the light-emitting unit and includes a red light filtering portion, a green light filtering portion and a blue light filtering portion, and the red light filtering portion, the green light filtering portion and the blue light filtering portion correspondingly overlap the red light-emitting component, the green light-emitting component and the blue light-emitting component respectively.

9. The display device according to claim 1, characterized in that, The light-emitting unit at least includes a first blue light-emitting component, a second blue light-emitting component, and a third blue light-emitting component. The second substrate includes a light-filtering layer and an optical layer. The light-filtering layer and the optical layer are disposed on a side of the second substrate facing the light-emitting unit. The optical layer is located between the light-filtering layer and the light-emitting unit. The light-filtering layer includes a red light-filtering portion, a green light-filtering portion, and a blue light-filtering portion. The optical layer includes a first light-converting portion, a second light-converting portion, and a diffusion portion. The red light-filtering portion and the first light-converting portion correspondingly overlap the first blue light-emitting component. The green light-filtering portion and the second light-converting portion correspondingly overlap the second blue light-emitting component. The blue light-filtering portion and the diffusion portion correspondingly overlap the third blue light-emitting component.

10. The display device according to claim 1, wherein, the light-emitting unit at least includes a first blue light-emitting component, a green light-emitting component, and a second blue light-emitting component. The second substrate includes a light-filtering layer and an optical layer. The light-filtering layer and the optical layer are disposed on a side of the second substrate facing the light-emitting unit. The optical layer is located between the light-filtering layer and the light-emitting unit. The light-filtering layer includes a red light-filtering portion, a green light-filtering portion, and a blue light-filtering portion. The optical layer includes a light-converting portion, a first diffusion portion, and a second diffusion portion. The red light-filtering portion and the light-converting portion correspondingly overlap the first blue light-emitting component. The green light-filtering portion and the first diffusion portion correspondingly overlap the green light-emitting component. The blue light-filtering portion and the second diffusion portion correspondingly overlap the second blue light-emitting component.

11. A display device, comprising: a first substrate; a second substrate, relative to the first substrate; an adhesive layer disposed between the first substrate and the second substrate; and at least one light-emitting unit disposed between the adhesive layer and the first substrate, wherein the light-emitting unit includes at least one light-emitting component, and a surface of the light-emitting component facing the adhesive layer has a plurality of microstructures; wherein, the refractive index of the adhesive layer is greater than 1 and less than or equal to 1.4.

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