Micro light emitting diode display device

Abstract

The micro-LED display device includes an emissive layer, a color conversion layer disposed on the light-emitting surface of the emissive layer, and a Bragg reflector element disposed on the color conversion layer. The Bragg reflector element comprises multiple layer pairs, each layer pair consisting of alternating stacked first layers and multiple second layers. Each layer pair includes a first layer pair, a last layer pair, and an intermediate layer pair located between the first and last layer pairs. In each intermediate layer pair, the thickness of the first layer is less than the thickness of the second layer. The refractive index of the first layer is greater than the refractive index of the second layer. Therefore, the micro-LED display device can increase visible light transmittance and ultraviolet light filtering effect.

Description

[0001] Case Analysis This invention is a divisional application of the invention patent application filed on August 2, 2022, with application number 202210919481.0 and title "Micro Light Emitting Diode Display Device". Technical Field

[0002] This invention relates to a micro light-emitting diode device. Background Technology

[0003] Micro light-emitting diodes (micro LEDs) are produced by further miniaturizing LEDs to achieve high-resolution displays and meet the high-brightness requirements of virtual reality (VR) for highly immersive experiences and augmented reality (AR) for resisting ambient light. Micro LEDs outperform current LCD and organic light-emitting diode (OLED) technologies in terms of lifespan, response time, color saturation, pixel density, and energy efficiency. However, current micro LEDs suffer from insufficient luminous efficiency. For example, there is a significant difference between the converted light and the original light, leading to reduced brightness in subsequent applications.

[0004] Therefore, providing micro-LED display devices that can overcome the above problems remains one of the goals that the industry is currently striving to research. Summary of the Invention

[0005] The technical form of the present invention is a micro light-emitting diode display device.

[0006] According to some embodiments of the present invention, a micro-light-emitting diode display device includes a light-emitting layer, a color conversion layer, and a Bragg reflector. The color conversion layer is disposed on the light-emitting surface of the light-emitting layer. The Bragg reflector is disposed on the color conversion layer, and the Bragg reflector comprises multiple layer pairs. Each layer pair consists of at least one first layer and at least one second layer alternately stacked, wherein each layer pair includes a first layer pair, a last layer pair, and an intermediate layer pair located between the first and last layer pairs. The thickness of the first layer in each intermediate layer pair is less than the thickness of the second layer. The refractive index of the first layer is greater than the refractive index of the second layer.

[0007] In some embodiments of the present invention, the thickness of the first layer of the intermediate layer pair is less than λ / 4n1 and the thickness of the second layer of the intermediate layer pair is greater than λ / 4n2, where λ is the emission wavelength of the light-emitting layer, n1 is the refractive index of the first layer, and n2 is the refractive index of the second layer.

[0008] In some embodiments of the present invention, the sum of the thickness of the first layer and the thickness of the second layer of the first layer pair is less than the sum of the thickness of the first layer and the thickness of the second layer of each of the intermediate layer pairs.

[0009] In some embodiments of the present invention, the sum of the thicknesses of the first and second layers of the last layer pair is less than the sum of the thicknesses of the first and second layers of each of the intermediate layer pairs.

[0010] In some embodiments of the present invention, the sum of the thickness of the first layer and the thickness of the second layer of the first layer pair is greater than the sum of the thickness of the first layer and the thickness of the second layer of the last layer pair.

[0011] In some embodiments of the present invention, the thickness of the first layer of the first layer pair is greater than the thickness of the first layer of the last layer pair.

[0012] In some embodiments of the present invention, the thickness of the second layer of the first layer pair is greater than the thickness of the second layer of the last layer pair.

[0013] In some embodiments of the present invention, the light-emitting layer includes a plurality of ultraviolet light-emitting micro-diodes, and the ultraviolet light-emitting micro-diodes are configured to emit ultraviolet light respectively. The color conversion layer includes a red wavelength conversion material, a green wavelength conversion material and a blue wavelength conversion material corresponding to the ultraviolet light-emitting micro-diodes respectively, so as to convert ultraviolet light into red light, green light and blue light respectively.

[0014] In some embodiments of the present invention, the micro-light-emitting diode display device further includes another Bragg reflector element disposed on the surface of the light-emitting layer opposite to the light-emitting surface. The other Bragg reflector element comprises multiple layer pairs, each layer pair consisting of alternating stacked first layers and multiple second layers. Each layer pair includes a first layer pair, a last layer pair, and multiple intermediate layer pairs located between the first layer pair and the last layer pair. The refractive index of the first layer is greater than the refractive index of the second layer.

[0015] In some embodiments of the present invention, the layer pairs of another Bragg reflector are the same as the layer pairs of the Bragg reflector.

[0016] In some embodiments of the invention, the thickness of each of the first layers of another Bragg reflector element is the same as that of each of the second layers.

[0017] In some implementations, the first layer of another Bragg reflector is connected to the light-emitting layer.

[0018] In some implementations, the last layer of the Bragg reflector is connected to a color conversion layer.

[0019] In the above embodiments, the micro-light-emitting diode display device of the present invention includes a Bragg reflector element, and by adjusting the thickness of the Bragg reflector element, the visible light transmission efficiency and ultraviolet light filtering effect are increased. In this way, the luminous efficiency of the micro-light-emitting diode display device can be increased. Attached Figure Description

[0020] To make the above and other objects, features, advantages and embodiments of the present invention more apparent and understandable, the accompanying drawings are described below: Figure 1 This is a schematic diagram of a micro-light-emitting diode display device according to an embodiment of the present invention.

[0021] Figure 2 for Figure 1 An enlarged view of the Bragg reflector element.

[0022] Figure 3 This is a graph showing the relationship between transmittance and emission wavelength according to an embodiment of the present invention.

[0023] Figure 4 This is a graph showing the relationship between reflectivity and emission wavelength according to an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram of a micro-light-emitting diode display device according to another embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of a micro-light-emitting diode display device according to another embodiment of the present invention.

[0026] Figure 7 This is a schematic diagram of a micro-light-emitting diode display device according to another embodiment of the present invention. Detailed Implementation

[0027] Several embodiments of the present invention will be described below with reference to the accompanying drawings. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not essential and therefore should not be used to limit the invention. Furthermore, for the sake of simplicity, some conventional structures and elements will be shown in the drawings in a simplified schematic manner. In addition, for the reader's convenience, the dimensions of the elements in the drawings are not drawn to scale.

[0028] As used in this invention, "about," "approximately," or "substantially" generally refers to within 20 percent of a given value or range, preferably within 10 percent, and more preferably within 5 percent. The values ​​given herein are approximate, meaning that unless explicitly stated otherwise, the meaning of the terms "about," "approximately," or "substantially" can be inferred.

[0029] Figure 1 This is a schematic diagram of a micro-light-emitting diode (LED) display device 100 according to an embodiment of the present invention. The LED display device 100 includes a light-emitting layer 110, a color conversion layer 120, and a Bragg reflector element 130. The light-emitting layer 110 includes ultraviolet LEDs 112, 114, and 116. The color conversion layer 120 is disposed on the light-emitting surface 111 of the light-emitting layer 110. The Bragg reflector element 130 is disposed on the color conversion layer 120.

[0030] Figure 2 for Figure 1 An enlarged view of the Bragg reflector 130 is shown. The Bragg reflector 130 comprises multiple layer pairs, each layer pair consisting of alternating stacked first layers and multiple second layers, wherein the refractive index of the first layer is greater than that of the second layer. Specifically, the layer pairs of the Bragg reflector 130 include a first layer pair 130T, a last layer pair 130B, and multiple intermediate layer pairs 130M disposed between the first layer pair 130T and the last layer pair 130B. In some embodiments, the number of intermediate layer pairs 130M may be six, meaning the Bragg reflector 130 comprises a total of eight pairs of alternating stacked first and second layers; however, the aforementioned number is for illustrative purposes only and is not intended to limit the invention. The first layer pair 130T comprises a first layer 132H and a lower second layer 132L, and the last layer pair 130B comprises a first layer 136H and a lower second layer 136L. Each of the intermediate layer pairs 130M comprises a first layer 134H and a lower second layer 134L. The thickness of the first layer 134H of each of the intermediate layers 130M is less than the thickness of the second layer 134L. In some embodiments, the thickness T of the first layer 134H of each of the intermediate layers 130M is... 134H The thickness T of the second layer is less than λ / 4n1 and is 134L. 134L The wavelength of the light-emitting layer 110 is greater than λ / 4n², where λ is the emission wavelength of the light-emitting layer 110, n1 is the refractive index of the first layer (i.e., the high-refractive-index material layer), and n2 is the refractive index of the second layer (i.e., the low-refractive-index material layer), and n1 is greater than n2. Through the aforementioned thickness configuration of the Bragg reflector 130, the standing wave peaks can be moved away from the boundary between the first and second layers, effectively reducing ripples caused by higher-order interference. This increases visible light transmission efficiency and ultraviolet light filtering effect, and improves light purity, thereby increasing the luminous efficiency of the micro-LED display device 100. Furthermore, the micro-LED display device 100 of the present invention includes the Bragg reflector 130, which can replace a filter to achieve a reduction in size. That is, the micro-LED display device 100 does not include a filter.

[0031] The intermediate layers for each of the 130M layers have the same thickness. For example, the thickness T of the first layer 134H of one of the 130M intermediate layers is... 134H The thickness T of the first layer 134H is the same as that of the intermediate layer 130M. 134H The same, and the thickness T of the second layer 134L of the intermediate layer is the same as that of the 130M layer. 134L The thickness T of the second layer is 134L, which is the same as the intermediate layer of 130M. 134L The thicknesses are the same, such that one of the intermediate layers of 130M has the same total thickness as the other. In some embodiments, the thickness T of the first layer 134H of each of the intermediate layers of 130M is... 134H With the second layer of 134L thickness T 134L The sum is essentially equal to the sum of λ / 4n1 and λ / 4n2.

[0032] In some implementations, the thickness of the first layer 130T is less than the thickness of each of the intermediate layers 130M. That is, the thickness T of the first layer 132H of the first layer 130T is less than the thickness of each of the intermediate layers 130M. 132H With the second layer of 132L thickness T 132L The sum of the thicknesses is less than the thickness T of the first layer of 134H for each of the intermediate layers of 130M. 134H With the second layer of 134L thickness T 134L The sum of all additions. Furthermore, the thickness T of the first layer (132H) is equal to the thickness of the first layer (130T). 132H The thickness T of the first layer of each of the intermediate layers is less than 130M and 134H. 134H And the thickness T of the first layer is 130T compared to the second layer of 132L. 132L The thickness T of the second layer of 134L is less than that of the intermediate layer of 130M. 134L Therefore, the Bragg reflector 130 can disrupt the overall reflection of the sideband, thereby maintaining high transmittance of visible light refractive index and improving reflectivity of ultraviolet light. For example, the transmittance of wavelengths greater than 455 nm (e.g., including the visible light band) can be higher than 90%, and the transmittance of wavelengths less than 455 nm (e.g., including the ultraviolet light band) can be lower than 10%. Therefore, ultraviolet light can be effectively filtered. The thickness T of the first layer 132H of the first layer 130T is... 132H It can be in the range of approximately 19 nanometers to 25 nanometers (e.g., 22 nanometers), and the thickness T of the first layer is 130T and the second layer is 132L. 132L It can be in the range of approximately 50 nanometers to 56 nanometers (e.g., 53 nanometers). The thickness of the first layer, T, is 134H for each of the intermediate layers of 130M. 134HIt can be in the range of approximately 37 nanometers to 43 nanometers (e.g., 40 nanometers), and the thickness T of the second layer 134L for each of the intermediate layers is 130M. 134L It can be in the range of approximately 57 nanometers to 63 nanometers (e.g., 60 nanometers). In some embodiments, the thickness T of the first layer 132H is 130T. 132H The thickness T of the first layer of each of the 130M intermediate layers is 134H. 134H The ratio can range from about 0.5 to about 0.6 (e.g., 0.55). The thickness T of the first layer is 130T, and the thickness of the second layer is 132L. 132L The thickness T of the second layer of 134L for each of the intermediate layers is 130M. 134L The ratio can range from about 0.85 to about 0.95 (e.g., 0.89). In some embodiments, the thickness T of the first layer 132H is 130T. 132H The thickness T is less than λ / 4n1 and the first layer is 130T and the second layer is 132L. 132L Less than λ / 4n².

[0033] In some embodiments, the thickness of the final layer pair 130B is less than the thickness of each of the intermediate layers pair 130M. That is, the thickness T of the first layer 136H of the final layer pair 130B is less than the thickness of each of the intermediate layers pair 130M. 136H With the second layer of 136L thickness T 136L The sum of the two layers is less than the thickness T of the first layer 134H for each of the intermediate layers of 130M. 134H With the second layer of 134L thickness T 134L The sum of all additions. Furthermore, the thickness T of the final layer relative to the first layer 136H of 130B. 136H The thickness T of the first layer of each of the intermediate layers is less than 130M and 134H. 134H And the thickness T of the last layer relative to the second layer 136L of 130B. 136L The thickness T of the second layer of 134L is less than that of the intermediate layer of 130M. 134L Therefore, the Bragg reflector 130 can disrupt the overall reflection of the sideband, thereby maintaining high visible light transmittance and improving ultraviolet light reflectivity. The thickness T of the first layer 136H of the final layer 130B is... 136H It can be in the range of approximately 5 nanometers to 10 nanometers (e.g., 7 nanometers), and the thickness T of the second layer is 136L. 136L It can be in the range of approximately 30 nanometers to 35 nanometers (e.g., 33 nanometers). In some embodiments, the thickness T of the last layer relative to the first layer 136H of 130B is... 136H The thickness T of the first layer of each of the 130M intermediate layers is 134H. 134HThe ratio can range from about 0.15 to about 0.25 (e.g., 0.19). The thickness T of the last layer relative to the second layer 136L of 130B. 136L The thickness T of the second layer of 134L for each of the intermediate layers is 130M. 134L The ratio can range from about 0.5 to about 0.6 (e.g., 0.55). In some embodiments, the thickness T of the last layer relative to the first layer 136H of 130B is... 136H The thickness T of the second layer is less than λ / 4n1 and is 136L. 136L Less than λ / 4n².

[0034] In some implementations, the thickness of the first layer pair 130T is greater than the thickness of the last layer pair 130B. That is, the thickness T of the first layer 132H in the first layer pair 130T is... 132H The thickness T of the first layer is 130T and the second layer is 132L. 132L The sum of the two is greater than the thickness T of the first layer 136H of the last layer relative to 130B. 136H The thickness T of the second layer 136L relative to the last layer 130B 136L The sum of all additions. Furthermore, the thickness T of the first layer (132H) is equal to the thickness of the first layer (130T). 132H The thickness T of the first layer 136H of the last layer is greater than that of the last layer of 130B. 136H And the thickness T of the first layer is 130T compared to the second layer of 132L. 132L The thickness T of the second layer 136L is greater than that of the last layer 130B. 136L Therefore, the Bragg reflector 130 can maintain high visible light transmittance and improve ultraviolet light reflectivity. In some embodiments, the thickness T of the first layer 132H of the first layer 130T is... 132H The thickness T of the first layer 136H of the last layer is the same as that of the last layer 130B. 136H The ratio can range from about 2.7 to about 3.3 (e.g., 3). The thickness T of the first layer is 130T, and the thickness of the second layer is 132L. 132L The thickness T of the second layer 136L relative to the last layer 130B 136L The ratio can range from about 1.3 to about 1.9 (e.g., 1.6).

[0035] In some embodiments, the first layer of the Bragg reflector 130 (i.e., comprising first layers 132H, 134H, and 136H) comprises titanium oxide (TiO2) or other suitable materials. The second layer of the Bragg reflector 130 (i.e., comprising second layers 132L, 134L, and 136L) comprises silicon oxide (SiO2) or other suitable materials. In some embodiments, the Bragg reflector 130 comprises a first light-transmitting layer and a second light-transmitting layer (not shown), respectively disposed on the first layer pair 130T and the last layer pair 130B, wherein the first and second light-transmitting layers may be made of glass. In some embodiments, the last layer pair 130B of the Bragg reflector 130 is connected to the color conversion layer 120. Specifically, the second layer 136L of the last layer pair 130B of the Bragg reflector 130 is connected to the color conversion layer 120.

[0036] In some embodiments, the micro-light-emitting diode display device 100 is applied to large-area and / or high-pixel display devices, wearable display devices, augmented reality devices, virtual reality devices, mixed reality devices, automotive display devices, flexible electronic device display devices, and visible light communication devices. In some embodiments of the present invention, the light-emitting layer 110 includes micro-light-emitting diodes (micro LEDs), which comprise aluminum gallium nitride (AlGaN). Micro-light-emitting diodes refer to diodes with wafer sizes miniaturized to the micrometer level (e.g., below 50 micrometers), eliminating the need for a sapphire substrate, and arraying the miniaturized wafers into display pixels that can be individually driven and controlled. In some embodiments, the light-emitting layer 110 includes light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), laser discs, semiconductor lasers, or other suitable light-emitting elements.

[0037] Simultaneously refer to Figure 1 and Figure 2The light-emitting layer 110 includes spaced-apart ultraviolet (UV) micro-LEDs 112, 114, and 116. That is, the light-emitting layer 110 includes a plurality of pixels, each pixel consisting of three UV micro-LEDs 112, 114, and 116, and the UV micro-LEDs 112, 114, and 116 are configured to emit UV light toward the color conversion layer 120. The color conversion layer 120 includes a material capable of changing wavelength. Specifically, the color conversion layer 120 includes a first portion, a second portion, and a third portion spaced-apart, wherein the first portion includes a red wavelength conversion material 122, the second portion includes a green wavelength conversion material 124, and the third portion includes a blue wavelength conversion material 126. The red wavelength conversion material 122 corresponds to the UV micro-LED 112, the green wavelength conversion material 124 corresponds to the UV micro-LED 114, and the blue wavelength conversion material 126 corresponds to the UV micro-LED 116. Red wavelength conversion material 122 comprises red quantum dots or red phosphor, or a mixture of red phosphor and red quantum dots, which can be used to absorb ultraviolet light from ultraviolet micro-light-emitting diode 112 and convert it into red light, which is then emitted towards Bragg reflector element 130. Green wavelength conversion material 124 comprises green quantum dots or green phosphor, or a mixture of green phosphor and green quantum dots, which can be used to absorb ultraviolet light from ultraviolet micro-light-emitting diode 114 and convert it into green light, which is then emitted towards Bragg reflector element 130. Blue wavelength conversion material 126 comprises blue quantum dots or blue phosphor, or a mixture of blue phosphor and blue quantum dots, which can be used to absorb ultraviolet light from ultraviolet micro-light-emitting diode 116 and convert it into blue light, which is then emitted towards Bragg reflector element 130.

[0038] In some embodiments, a portion (e.g., about 90%) of the ultraviolet light from the ultraviolet micro-light-emitting diodes 112, 114, and 116 is converted into visible light by the red wavelength conversion material 122, green wavelength conversion material 124, and blue wavelength conversion material 126 corresponding to the color conversion layer 120, while the remaining portion (e.g., about 10%) of the ultraviolet light remains unconverted and is retained as ultraviolet light. The Bragg reflector element 130 is configured to allow visible light to pass through and reflect ultraviolet light. Furthermore, the ultraviolet light reflected by the Bragg reflector element 130 is directed toward the color conversion layer 120, where the wavelength conversion materials (red wavelength conversion material 122, green wavelength conversion material 124, and blue wavelength conversion material 126) can again convert the ultraviolet light into visible light. Therefore, the Bragg reflector element 130 can simultaneously enhance visible light intensity and reduce ultraviolet light penetration.

[0039] Figure 3 This is a graph showing the relationship between the wavelength of light and the transmittance through the Bragg reflector 130 according to an embodiment of the present invention. (See also...) Figure 1 and Figure 3When visible light (i.e., red, green, and / or blue light) passes through the Bragg reflector 130, if the Bragg reflector 130 has the following properties: Figure 2 The structure shown allows visible light (e.g., wavelengths greater than approximately 455 nanometers as shown in region R) to maintain high transmittance above 90%, as illustrated by curve L1. In contrast, when visible light passes through a Bragg reflector, if the Bragg reflector does not possess the characteristics shown... Figure 2 The structure shown exhibits inconsistent transmittance of visible light (e.g., wavelengths greater than approximately 455 nanometers as shown in region R), resulting in some visible light being unable to pass through, as indicated by curve L2. Therefore, the Bragg reflector element 130 of the present invention achieves the technical effect of increasing visible light transmittance efficiency.

[0040] Figure 4 This is a graph showing the relationship between the wavelength of light and the reflectivity of the Bragg reflector element 130 according to an embodiment of the present invention. (See also...) Figure 1 and Figure 4 When the remaining ultraviolet light passes from the color conversion layer 120 through the Bragg reflector 130, if the Bragg reflector 130 has the following properties... Figure 2 The structure shown allows for high reflectivity of ultraviolet light, as indicated by curve L3. In contrast, when ultraviolet light passes through a Bragg reflector, if the Bragg reflector does not possess the same reflectivity... Figure 2 The structure shown exhibits inconsistent reflectivity of ultraviolet light, which may result in some ultraviolet light not being filtered out, and may also cause unintended reflections (i.e., additional interference ripples), as shown in curve L4. Therefore, the Bragg reflector element 130 of the present invention can achieve the technical effect of reflecting / filtering ultraviolet light.

[0041] Figure 5 This is a schematic diagram of a micro-light-emitting diode display device 100a according to another embodiment of the present invention. Figure 5 Micro LED display device 100a and Figure 1The micro-LED display device 100a is substantially the same as the micro-LED display device 100a, except that it further includes another Bragg reflector element 140. The Bragg reflector element 140 is disposed on the surface 113 of the light-emitting layer 110 opposite to the light-emitting surface 111, such that the light-emitting layer 110 is located between the color conversion layer 120 and the Bragg reflector element 140. The Bragg reflector element 140 prevents light emitted from the light-emitting layer 110 from escaping. The Bragg reflector element 140 includes multiple layer pairs, each layer pair consisting of multiple alternating stacked first layers and multiple second layers. Each layer pair includes a first layer pair, a last layer pair, and multiple intermediate layer pairs located between the first and last layer pairs, wherein the refractive index of the first layer is greater than the refractive index of the second layer. The first layer pair of the Bragg reflector element 140 is connected to the light-emitting layer 110. For example, the first layer of the first layer pair of the Bragg reflector element 140 is connected to the light-emitting layer 110. In some embodiments, the Bragg reflector element 140 and the Bragg reflector element 130 have the same or similar structures (e.g., thickness relationship). Specifically, the layer pairs of the Bragg reflector 140 are identical to those of the layer pairs of the Bragg reflector 130. The Bragg reflector 140 includes the same first layer pair 130T, last layer pair 130B, and multiple intermediate layer pairs 130M (e.g., ...) located between the first layer pair 130T and the last layer pair 130B as the Bragg reflector 130. Figure 2 As shown), the aforementioned detailed structures are the same as or similar to Figure 2 The description is omitted here for simplicity. In some other embodiments, the Bragg reflector 140 and the Bragg reflector 130 have different structures. Specifically, the thickness of each of the first layers of the Bragg reflector 140 is the same as the thickness of each of the second layers. For example, the thickness of each of the first layers is λ / 4n1 and the thickness of each of the second layers is λ / 4n2, where λ is the emission wavelength of the light-emitting layer, n1 is the refractive index of the first layer, n2 is the refractive index of the second layer, and n1 is greater than n2.

[0042] Figure 6 This is a schematic diagram of a micro-light-emitting diode display device 100b according to another embodiment of the present invention. Figure 6 The micro light-emitting diode display device 100b and Figure 1The micro-LED display device 100b is largely the same as the micro-LED display device 100b, the difference being the configuration of the light-emitting layer 110b and the color conversion layer 120b. In other words, the light-emitting layer 110b contains multiple pixels, each pixel consisting of two ultraviolet micro-LEDs 112 and 114 and a blue micro-LED 118. The color conversion layer 120b contains a first portion, a second portion, and a third portion 128 spaced apart. The first portion contains a red wavelength conversion material 122 corresponding to the ultraviolet micro-LED 112, and the second portion contains a green wavelength conversion material 124 corresponding to the ultraviolet micro-LED 114, to convert the ultraviolet light emitted by the ultraviolet micro-LEDs 112 and 114 into red and green light, respectively. The third portion 128 of the color conversion layer 120b corresponds to the blue micro-LED 118 and does not contain a wavelength conversion material, so that the blue light emitted by the blue micro-LED 118 is not converted after passing through the third portion 128 of the color conversion layer 120b. The micro-light-emitting diode display device 100b has the same characteristics as... Figure 1 Similar technical effects to the micro-LED display device 100 include the ability to effectively reduce ripples caused by higher-order interference, and to increase visible light transmission efficiency and ultraviolet light filtering effect.

[0043] Figure 7 This is a schematic diagram of a micro-light-emitting diode display device 100c according to another embodiment of the present invention. Figure 7 Micro LED display device 100c and Figure 6The micro-LED display device 100c is substantially the same as the micro-LED display device 100b, except that the micro-LED display device 100c also includes another Bragg reflector element 150. The Bragg reflector element 150 is disposed on the surface 113 of the light-emitting layer 110b relative to the light-emitting surface 111, such that the light-emitting layer 110b is located between the color conversion layer 120b and the Bragg reflector element 150. The Bragg reflector element 150 prevents light emitted from the light-emitting layer 110b from escaping. The Bragg reflector element 150 includes multiple layer pairs, each layer pair consisting of multiple alternating stacked first layers and multiple second layers. Each layer pair includes a first layer pair, a last layer pair, and multiple intermediate layer pairs located between the first and last layer pairs, wherein the refractive index of the first layer is greater than the refractive index of the second layer. The first layer pair of the Bragg reflector element 150 is connected to the light-emitting layer 110. For example, the first layer of the first layer pair of the Bragg reflector element 150 is connected to the light-emitting layer 110. In some embodiments, the Bragg reflector element 150 and the Bragg reflector element 130 have the same or similar structures (e.g., thickness relationship). Specifically, the layer pairs of the Bragg reflector 150 are identical to those of the layer pairs of the Bragg reflector 130. The Bragg reflector 150 includes the same first layer pair 130T, last layer pair 130B, and multiple intermediate layer pairs 130M located between the first layer pair 130T and the last layer pair 130B as the Bragg reflector 130. Figure 2 As shown), the aforementioned detailed structures are the same as or similar to Figure 2 The description is omitted here for simplicity. In some other embodiments, the Bragg reflector 150 and the Bragg reflector 130 have different structures. Specifically, the thickness of each of the first layers of the Bragg reflector 150 is the same as the thickness of each of the second layers. For example, the thickness of each of the first layers is λ / 4n1 and the thickness of each of the second layers is λ / 4n2, where λ is the emission wavelength of the light-emitting layer, n1 is the refractive index of the first layer, n2 is the refractive index of the second layer, and n1 is greater than n2.

[0044] In summary, the micro-light-emitting diode display device of the present invention includes a Bragg reflector element, and by adjusting the thickness of the Bragg reflector element, the visible light transmission efficiency and ultraviolet light filtering effect are increased. In this way, the luminous efficiency of the micro-light-emitting diode display device can be increased.

[0045] Although the present invention has been described above with reference to embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0046] [Symbol Explanation] 100: Micro LED display device 100a: Micro LED display device 100b: Micro LED display device 100c: Micro LED display device 110: Emissive layer 110b: Emissive layer 111: Light-emitting surface 112: Ultraviolet micro-light-emitting diode 113: Surface 114: Ultraviolet Micro-Light Emitting Diode 116: Ultraviolet Micro-Light Emitting Diode 118: Blue LED 120: Color Conversion Layer 120b: Color Conversion Layer 122: Red Wavelength Conversion Material 124: Green Wavelength Converting Material 126: Blue Wavelength Converting Material 128: Part 130: Bragg reflector element 130B: Last layer pair 130M: Intermediate layer 130T: First floor 132H: First layer 132L: Second layer 134H: First layer 134L: Second layer 136H: First layer 136L: Second layer 140: Bragg reflector element 150: Bragg reflector element L1: Curve L2: Curve L3: Curve L4: Curve R: Region T 132H :thickness T 132L :thickness T 134H :thickness T 134L :thickness T 136H :thickness T 136L :thickness.

Claims

1. A micro-light-emitting diode display device, characterized in that, Include: Emissive layer; A color conversion layer is disposed on the light-emitting surface of the light-emitting layer; and A Bragg reflector element is disposed on the color conversion layer. The Bragg reflector element comprises multiple layer pairs, each layer pair consisting of at least one first layer and at least one second layer alternately stacked, wherein the multiple layer pairs comprise: First floor pair; Last layer pair; as well as Multiple intermediate layer pairs are located between the first layer pair and the last layer pair, wherein the thickness of the first layer in each of the multiple intermediate layer pairs is less than the thickness of the second layer; Wherein, the refractive index of the plurality of first layers is greater than the refractive index of the plurality of second layers. The sum of the thickness of the first layer and the thickness of the second layer in the first layer pair is less than the sum of the thickness of the first layer and the thickness of the second layer in each of the plurality of intermediate layer pairs, and the sum of the thickness of the first layer and the thickness of the second layer in the last layer pair is less than the sum of the thickness of the first layer and the thickness of the second layer in each of the plurality of intermediate layer pairs.

2. The display device according to claim 1, characterized in that, The thickness of the plurality of first layers in the plurality of intermediate layer pairs is less than λ / 4n1 and the thickness of the plurality of second layers in the plurality of intermediate layer pairs is greater than λ / 4n2, where λ is the emission wavelength of the light-emitting layer, n1 is the refractive index of the plurality of first layers, and n2 is the refractive index of the plurality of second layers.

3. The display device according to claim 1, characterized in that, The sum of the thickness of the first layer and the thickness of the second layer in the first layer pair is greater than the sum of the thickness of the first layer and the thickness of the second layer in the last layer pair.

4. The display device according to claim 1, characterized in that, The thickness of the first layer in the first layer pair is greater than the thickness of the first layer in the last layer pair.

5. The display device according to claim 1, characterized in that, The thickness of the second layer in the first layer pair is greater than the thickness of the second layer in the last layer pair.

6. The display device according to claim 1, characterized in that, The light-emitting layer includes multiple ultraviolet micro-light-emitting diodes, and the multiple ultraviolet micro-light-emitting diodes are configured to emit ultraviolet light respectively. The color conversion layer includes red wavelength conversion material, green wavelength conversion material and blue wavelength conversion material corresponding to the multiple ultraviolet micro-light-emitting diodes respectively, so as to convert the multiple ultraviolet light into red light, green light and blue light respectively.

7. The display device according to claim 1, characterized in that, It also includes another Bragg reflector element disposed on the surface of the light-emitting layer opposite to the light-emitting surface, wherein the other Bragg reflector element comprises multiple layer pairs, each layer pair consisting of multiple alternating stacked first layers and multiple second layers, wherein the multiple layer pairs comprise: First floor pair; Last layer pair; as well as Multiple intermediate layer pairs are located between the first layer pair and the last layer pair; The refractive index of the plurality of first layers is greater than the refractive index of the plurality of second layers.

8. The display device according to claim 7, characterized in that, Each of the layer pairs of the other Bragg reflector is the same as each of the layer pairs of the Bragg reflector.

9. The display device according to claim 7, characterized in that, The thickness of each of the plurality of first layers of the other Bragg reflector element is the same as that of each of the plurality of second layers.

10. The display device according to claim 7, characterized in that, The first layer of the other Bragg reflector is connected to the light-emitting layer.

11. The display device according to claim 1, characterized in that, The final layer of the Bragg reflector is connected to the color conversion layer.

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