Display panel and display device

Abstract

The utility model embodiment provides a kind of display panel and display device, display panel includes: array substrate, the array substrate includes drive substrate and is arranged on the drive substrate and the multiple miniature light emitting devices of electric connection drive substrate;Intermediate layer includes: encapsulation layer, covers on the array substrate;Light efficiency layer, it is arranged on the side of the encapsulation layer away from the array substrate, the multiple lens structures are arranged in the light efficiency layer;Wherein, the lens structure satisfies: in the light path of visible light by the lens structure, the phase difference caused by material birefringence is less than 5 °;Circular polaroid, it is located in the side of the intermediate layer away from the array substrate.The display panel provided in the utility model embodiment has the characteristics of lower reflection, higher contrast and high brightness.

Description

Technical Field

[0001] This utility model relates to the field of display technology, and in particular to a display panel and a display device. Background Technology

[0002] For non-transparent Micro LED (Micro Light Emitting Diode) displays, a relatively high ambient contrast and a relatively low reflectivity are required to achieve better image quality. This requires reducing the reflected light from the metal on the display panel. Existing technologies use BM (Black Matrix) to reduce reflected light. However, in VR or wearable displays, which have high pixel density, light leakage from the chip electrodes and metal reflections between BM steps have a significant impact on the display contrast, making it difficult to achieve low reflectivity.

[0003] Therefore, there is an urgent need to provide a new display panel structure to improve the problem of difficulty in reducing reflection in existing technologies. Utility Model Content

[0004] Therefore, in order to overcome at least some of the defects in the prior art, the present invention provides a display panel and display device that have the effects of lower reflection, higher contrast and higher brightness.

[0005] This utility model provides a display panel comprising: an array substrate, the array substrate including a driving substrate and a plurality of micro light-emitting devices disposed on and electrically connected to the driving substrate; an intermediate layer including: an encapsulation layer covering the array substrate; a light-efficiency layer disposed on the side of the encapsulation layer away from the array substrate, the light-efficiency layer having a plurality of lens structures disposed therein; wherein the lens structures satisfy the following condition: in the optical path of visible light passing through the lens structures, the phase difference caused by material birefringence is less than 5°; and a circular polarizer disposed on the side of the intermediate layer opposite to the array substrate.

[0006] In some embodiments, the lens structure is a single refractive index material or has a refractive index that satisfies ,in, The ordinary refractive index of the lens structure is given. is the unusual refractive index of the lens structure.

[0007] In some embodiments, the optical effect layer further includes a low-refractive-index material layer disposed between the plurality of lens structures and the circular polarizer, wherein the refractive index of the low-refractive-index material layer is lower than the refractive index of the lens structures, and the low-refractive-index material layer is a single-refractive-index material or has a refractive index that satisfies... ,in, The ordinary refractive index of the low refractive index material layer is given. is the unusual optical refractive index of the low refractive index material layer.

[0008] In some embodiments, the refractive index of the low-refractive-index material layer is less than the refractive index of the encapsulation layer.

[0009] In some embodiments, the optical effect layer further includes a substrate layer disposed between the encapsulation layer and the plurality of lens structures, wherein the substrate layer is a single refractive index material or has a refractive index that satisfies ,in, The ordinary refractive index of the substrate layer is _____. The unusual optical refractive index of the substrate layer.

[0010] In some embodiments, the refractive index of the substrate layer is less than the refractive index of the lens structure; and the refractive index of the encapsulation layer is less than the refractive index of the substrate layer.

[0011] In some embodiments, the encapsulation layer is a single refractive index material or has a refractive index that satisfies ,in, The ordinary refractive index of the encapsulation layer is... The unusual optical refractive index of the encapsulation layer.

[0012] In some embodiments, the phase difference caused by material birefringence in the optical path of visible light passing through the intermediate layer is less than 5°.

[0013] In some embodiments, the ratio of the maximum width of the bottom surface of the lens structure to the maximum width of the micro light-emitting device is 0.2 to 2.

[0014] Another embodiment of the present invention provides a display device, including the display panel described in any one of the foregoing claims.

[0015] The above embodiments of this utility model have at least one or more of the following beneficial effects: by setting a circular polarizer and a lens structure in the display panel, and by designing the lens structure to meet the requirement of a phase difference of less than 5°, the reflected light can be better intercepted, thereby ensuring a significant reduction in ambient light reflection and improving contrast, which can have the effect of reducing ambient light reflection and improving brightness. Attached Figure Description

[0016] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the structure of a display panel provided in an embodiment of the present utility model.

[0018] Figure 2This is a schematic diagram of another display panel provided in an embodiment of the present utility model.

[0019] Figure 3 This is a schematic diagram of the structure of a display device provided in an embodiment of the present utility model.

[0020] [Explanation of Labels in the Attached Image] 1000: Display device; 100: Display panel; 10: Array substrate; 11: Driving substrate; 12: Micro light-emitting device; 20: Intermediate layer; 21: Encapsulation layer; 22: Optical effect layer; 221: Lens structure; 222: Low refractive index material layer; 223: Substrate layer; 30: Circular polarizer; 31: Quarter-wave plate; 32: Linear polarizer. Detailed Implementation

[0021] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0022] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0023] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0024] It should also be noted that the division of multiple embodiments in this utility model is only for the convenience of description and should not constitute a special limitation. Features in various embodiments can be combined and referenced in each other without contradiction.

[0025] [First Embodiment] The first embodiment of this utility model provides a display panel 100, see reference. Figure 1 The display panel 100 includes an array substrate 10, an intermediate layer 20, and a circular polarizer 30. The array substrate 10 includes a driving substrate 11 and a plurality of micro-light-emitting devices 12 disposed on and electrically connected to the driving substrate 11. The intermediate layer 20 includes: an encapsulation layer 21 covering the array substrate 10, i.e., the encapsulation layer 21 covers the driving substrate 11 and the plurality of micro-light-emitting devices 12; and a light-efficiency layer 22 disposed on the side of the encapsulation layer 21 away from the driving substrate 11, wherein the light-efficiency layer 22 contains a plurality of lens structures 221; wherein the lens structures 221 satisfy the condition that the phase difference (hereinafter referred to as "phase difference") caused by material birefringence in the optical path of visible light passing through the lens structures 221 is less than 5°. The circular polarizer 30 is disposed on the side of the intermediate layer 20 facing away from the array substrate 10.

[0026] Among them, the micro-light-emitting device 12 is, for example, a Micro LED chip. In a color display panel, multiple micro-light-emitting devices 12 include Micro LED chips of different colors corresponding to different color sub-pixels, such as red, green, and blue chips corresponding to RGB sub-pixels respectively. A single micro-light-emitting device 12 includes, for example, an N-doped layer, a P-doped layer, an active layer (e.g., multiple quantum well, MQW) located between the N-doped layer and the P-doped layer, an N-electrode connected to the N-doped layer, and a P-electrode connected to the P-doped layer. Taking a blue Micro-LED chip as an example, the N-doped conductor layer is, for example, an N-type GaN (gallium nitride) layer, the P-doped layer is, for example, a P-type GaN layer, and the active layer is, for example, an InGaN / GaN multiple quantum well layer.

[0027] The driving substrate 11 has, for example, multiple pad pairs, each pad pair including two electrode pads corresponding to the N-electrode and P-electrode of the micro-light-emitting device 12, respectively. Specifically, the micro-light-emitting device 12 is electrically connected to the driving substrate 11 through its N-electrode and P-electrode to the corresponding pad pairs. The driving substrate 11 is provided with circuitry for driving the micro-light-emitting device 12. The driving substrate 11 may be, for example, a complementary metal-oxide-semiconductor (CMOS) substrate, a liquid crystal on silicon (LCOS) substrate, a thin film transistor (TFT) substrate, or other substrates with operating circuitry, and is not limited thereto.

[0028] The encapsulation layer 21 is used to isolate the micro-light-emitting device 12 and the circuitry on the driving substrate 11 from the external environment, achieving water and oxygen barrier functions. It can be made of a transparent adhesive material with good sealing and thermal conductivity. In this embodiment, the encapsulation layer 21 also serves to support the light-emitting layer 22.

[0029] The circular polarizer 30 specifically includes a quarter-wave plate 31 and a linear polarizer 32. The circular polarizer 30 reduces reflected light, and its principle for reducing reflected light is as follows: Ambient light is unpolarized. When ambient light enters the display panel 100, it first passes through the linear polarizer 32. After passing through the linear polarizer 32, only linearly polarized light remains, aligned with the transmission axis of the linear polarizer. It then passes through the quarter-wave plate 31 and is converted into circularly polarized light. When the light is reflected, the rotation direction of the circularly polarized light is reversed. The reversed circularly polarized light passes through the quarter-wave plate 31 and is converted back into linearly polarized light. However, at this point, the direction of the linearly polarized light has rotated by 90° compared to the direction of the polarized light that initially passed through the linear polarizer 32, and it is completely blocked by the linear polarizer 32 and cannot escape.

[0030] In actual production, the inventors discovered that while only a circular polarizer 30 is used, although reflected light is reduced, the brightness loss of the display panel also increases. Therefore, this embodiment also includes a light-efficiency layer 22 with multiple lens structures 221. The lens structure 221 can be hemispherical, semi-ellipsoidal, triangular pyramidal, or pyramidal, etc., and this embodiment is not limited to these shapes. The lens structure 221 can concentrate the light emitted by multiple micro-light-emitting devices 12 to improve the emitted brightness. In actual production tests, the inventors found that traditional lenses have birefringence due to material and other factors. The reflected light, after passing through the lens, generates a large phase difference. Therefore, the reflected light returning to the linear polarizer 32 is not exactly 90° from the polarized light that initially passes through the linear polarizer 32, and the difference is significant. This results in the light not being completely blocked by the linear polarizer 32 and still escaping outside the panel. Although brightness is increased, reflected light also increases, thus creating a problem where high contrast and high brightness cannot be simultaneously achieved. Therefore, in this embodiment, the lens structure 221 is designed to satisfy a phase difference of less than 5°, so that the reflected light returning to the linear polarizer 32 is closer to 90° to the polarized light that begins to pass through the linear polarizer 32. This allows the reflected light returning to the linear polarizer 32 to be better intercepted, thereby greatly reducing the reflection of ambient light and improving contrast.

[0031] In summary, by providing a circular polarizer 30 and a lens structure 221 with a phase difference of less than 5° in the display panel 100, this embodiment of the present invention can achieve both the effect of reducing ambient light reflection and improving brightness.

[0032] In this embodiment, "visible light" refers to light with a wavelength of 380~780nm. In this embodiment, the phase difference θ1 caused by material birefringence in the optical path of visible light passing through lens structure 221 can be calculated by the following formula (1):

[0033] in, The ordinary refractive index of lens structure 221, For the unusual refractive index of lens structure 221, refer to Figure 1 In the annotation, H1 represents the maximum height of lens structure 221. In this embodiment, the wavelength is the same as that corresponding to the quarter-wave plate 31. We choose 550nm. Light at 550nm is relatively bright and represents the average wavelength from blue to red light. Using this wavelength as the design wavelength for calculations results in lower reflectivity while still accommodating both red and blue light. A single refractive index material can be understood as... =0. According to the above formula (1), the corresponding phase difference requirements can be met by designing the maximum height of the lens structure 221 and selecting a material with a suitable refractive index. For example, with Substituting 25μm into formula (1) yields the following result: hour, <5°.

[0034] In some embodiments, the lens structure 221 is a single refractive index material or has a refractive index that satisfies When lens structure 221 is made of a single refractive index material, it can be understood as... =0, according to the above formula (1), θ1 is also 0° at this time. The smaller the diameter, the closer the reflected light returning to the linear polarizer 32 is to the polarization direction of the light that initially passed through the linear polarizer 32 (approximately 90°), thus allowing for better interception of the reflected light returning to the linear polarizer 32. For example, the lens structure 221 can be made of a single-refractive-index material such as epoxy, silicone, or acrylic, and can be fabricated using dispensing, photolithography, or nanoimprinting processes. The maximum height H1 of the lens structure 221 can be 10~200 μm. Specifically, H1 can be 15~80 μm. In some embodiments, the refractive index of the lens structure 221 can be 1.6~2.0. If the lens structure 221 is made of a low birefringence material... All are between 1.6 and 2.0.

[0035] In some embodiments, the light-effect layer 22 further includes a low-refractive-index material layer 222 disposed between the plurality of lens structures 221 and the circular polarizer 30. The refractive index of the low-refractive-index material layer 222 is less than that of the lens structures 221. The low-refractive-index material layer 222 fills the gaps between the tops of the plurality of lens structures 221, providing a flat support for the arrangement of structures such as the circular polarizer 30, and reducing bubbles or optical defects caused by surface unevenness. Furthermore, since the refractive index of the low-refractive-index material layer 222 is smaller than that of the lens structures 221, light emitted from the lens structures 221 first passes through the low-refractive-index material layer 222, reducing the problem of total internal reflection of light emitted from the micro-light-emitting device 12 within the display panel 100, and also expanding the viewing angle. In some embodiments, the low-refractive-index material layer 222 is a single-refractive-index material or has a refractive index that satisfies… .in, The ordinary refractive index of the low refractive index material layer 222 is given by [the value of the material]. The unusual optical refractive index of the low refractive index material layer 222 is given. Similarly to formula (1) above, setting the material of the low refractive index material layer 222 to a single refractive index or low birefringence material can effectively reduce the phase difference caused by light passing through the low refractive index material layer 222, thereby better reducing reflection and improving contrast. Specifically, the low refractive index material layer 222 can be made of single refractive index materials such as epoxy resin, silicone, and acrylic materials, and can be manufactured using processes such as IJP, dispensing, and slot coating. Specifically, the thickness H2 of the low refractive index material layer 222 (refer to...) Figure 1 Specifically, the thickness of the low-refractive-index material layer 222 located above the highest point of the lens structure 221 can be 10~100μm, specifically 15~80μm. The refractive index of the low-refractive-index material layer 222 can be selected between 1.3 and 1.5. If a low birefringence material is used, then... All are between 1.3 and 1.5.

[0036] In some embodiments, the light effect layer 22 further includes a substrate layer 223 disposed between the encapsulation layer 21 and the plurality of lens structures 221, wherein the substrate layer 223 is a single refractive index material or has a refractive index that satisfies ,in, The ordinary refractive index of substrate layer 223 is given by [reference to substrate layer 223]. The substrate layer 223 has an unusual refractive index. The substrate layer 223 provides a flat base for the lens structure 221, facilitating the fabrication of the lens structure 221 and ensuring its stable fixation within the display panel 100. Similarly to formula (1) above, selecting a single refractive index or low birefringence material for the substrate layer 223 can effectively reduce the phase difference caused by light passing through the substrate layer 223, thereby better reducing reflection and improving contrast. The substrate layer 223 can be fabricated using processes such as IJP, dispensing, and slot coating. Specifically, the thickness H3 of the substrate layer 223 (refer to...) Figure 1 The thickness can range from 5 to 500 μm, specifically from 50 to 200 μm. The refractive index of the substrate layer 223 can be selected between 1.4 and 2.0. If a low birefringence material is chosen, then... All are between 1.4 and 2.0.

[0037] In some embodiments, the encapsulation layer 21 is a single refractive index material or a material whose refractive index satisfies ,in, The ordinary refractive index of the encapsulation layer 21, The unusual refractive index of the encapsulation layer 21. Similarly to formula (1) above, selecting a single refractive index or low birefringence material can effectively reduce the phase difference caused by light passing through the encapsulation layer 21, thus better reducing reflection and improving contrast. The encapsulation layer 21 can be fabricated using processes such as IJP, dispensing, and slot coating. In some embodiments, the thickness H4 of the encapsulation layer 21 is 5~50 μm, specifically 15~30 μm. The thickness of the encapsulation layer 21 can be selected between 1.4 and 2.0 μm. If a low birefringence material is selected...

[0038] In some embodiments, the refractive index of the substrate layer 223 is less than that of the lens structure 221. In some embodiments, the refractive index of the encapsulation layer 21 is less than that of the substrate layer 223. This can create a gentle refractive index gradient, which helps reduce interface reflection and further improves light extraction efficiency. In some embodiments, the refractive index of the low-refractive-index material layer 222 is less than that of the encapsulation layer 21, that is, the order of refractive index in the display panel 100 from smallest to largest is: low-refractive-index material layer 222, encapsulation layer 21, substrate layer 223, and lens structure 221.

[0039] In some embodiments, the phase difference θ2 caused by material birefringence in the optical path of visible light passing through the optical effect layer 22 is less than 5°. θ2 can be calculated using the following formula (2):

[0040] For low birefringence materials | d is the optical path. According to the above formula (2), the requirements of the corresponding phase difference θ2 can be met by comprehensively designing the maximum height of the lens structure 221, the thickness of the low refractive index material layer 222 and the thickness of the substrate layer 223, and the selection of the refractive indices of the lens structure 221, the low refractive index material layer 222 and the substrate layer 223.

[0041] In some embodiments, the phase difference θ3 caused by material birefringence in the visible light path passing through the intermediate layer 20 is less than 5°. θ3 can be calculated using the following formula (3):

[0042] According to the above formula (3), the requirements of the corresponding phase difference θ3 can be met by comprehensively designing the maximum height of the lens structure 221, the thickness of the low refractive index material layer 222, the thickness of the substrate layer 223, the thickness of the encapsulation layer 21, and the selection of the refractive indices of the lens structure 221, the low refractive index material layer 222, the substrate layer 223 and the encapsulation layer 21.

[0043] In the above embodiments of this application, the lens structure 221 may be aligned with or not aligned with the micro-light-emitting device 12. In some embodiments, the ratio of the maximum width of the bottom surface of a single lens structure 221 to the maximum width of a single micro-light-emitting device 12 is 0.2 to 2. For example, when the shape of the lens structure 221 is hemispherical or ellipsoidal, the maximum width of the bottom surface of a single lens structure 221 is the diameter of the bottom circle. When the shape of the lens structure 221 is a square pyramid, the maximum width of the bottom surface of the lens structure 221 is the length of the long side of the bottom rectangle; when the shape of the lens structure 221 is a triangular pyramid, the maximum width of the bottom surface of the lens structure 221 is the side length of the bottom triangle. If the micro-light-emitting device 12 is, for example, a rectangular chip, then the maximum width of the micro-light-emitting device 12 refers to the length of the long side of the micro-light-emitting device 12. (Refer to...) Figure 1 In some embodiments, the multiple lens structures 221 are not aligned with the multiple micro-light-emitting devices 12, and the multiple lens structures 221 are arranged continuously. (Refer to...) Figure 2 In some embodiments, each micro-light-emitting device 12 may have a corresponding set of lens structures 221, and each set of lens structures 221 may include one or more lens structures 221, for example... Figure 2One set of lens structures 221 includes three lens structures 221. In some embodiments, adjacent sets of lens structures 221 can be spaced apart. In this embodiment, due to the phase difference setting of the lens structures 221, even the light-effect layer 22, and even the intermediate layer 20, the ambient light reflected from the driving substrate 11 back to the linear polarizer 32 can be better blocked, thus reducing reflection and improving contrast. Therefore, the lens structures 221 do not need to be aligned with the micro light-emitting device 12, so that precise alignment is not required when forming or assembling the lens structures 221 on the array substrate 10, making the fabrication process simpler and the cost lower.

[0044] [Second Embodiment] like Figure 3 As shown, the second embodiment of this utility model also provides a display device 1000, including the display panel 100 in the first embodiment. It has the same beneficial effects as the first embodiment. The display device 1000 can be, for example, an electronic device with display function such as a mobile phone, computer, tablet, smartwatch, or VR display device. The display device 1000 also includes necessary structures such as a control circuit board for controlling the operation of the display panel 100. The configuration of these necessary structures can be referenced to the configuration of conventional display devices, and will not be described in detail in this embodiment.

[0045] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A display panel, characterized in that, include: An array substrate, the array substrate including a driving substrate and a plurality of micro light-emitting devices disposed on the driving substrate and electrically connected to the driving substrate; The intermediate layer includes: an encapsulation layer covering the array substrate; and a light-efficiency layer disposed on the side of the encapsulation layer away from the array substrate, wherein the light-efficiency layer contains a plurality of lens structures; wherein the lens structures satisfy the following condition: in the optical path of visible light passing through the lens structures, the phase difference caused by material birefringence is less than 5°. A circular polarizer is disposed on the side of the intermediate layer facing away from the array substrate.

2. The display panel as described in claim 1, characterized in that, The lens structure is made of a single refractive index material or has a refractive index that satisfies... ,in, The ordinary refractive index of the lens structure is given. is the unusual refractive index of the lens structure.

3. The display panel as described in claim 1, characterized in that, The optical effect layer further includes a low-refractive-index material layer disposed between the plurality of lens structures and the circular polarizer. The refractive index of the low-refractive-index material layer is lower than that of the lens structures, and the low-refractive-index material layer is a single-refractive-index material or has a refractive index that satisfies... ,in, The ordinary refractive index of the low refractive index material layer is given. is the unusual optical refractive index of the low refractive index material layer.

4. The display panel as described in claim 3, characterized in that, The refractive index of the low-refractive-index material layer is less than that of the encapsulation layer.

5. The display panel as described in claim 1, characterized in that, The optical effect layer further includes a substrate layer disposed between the encapsulation layer and the plurality of lens structures, wherein the substrate layer is a single refractive index material or has a refractive index that satisfies... ,in, The ordinary refractive index of the substrate layer is _____. The unusual optical refractive index of the substrate layer.

6. The display panel as described in claim 5, characterized in that, The refractive index of the substrate layer is less than that of the lens structure, and the refractive index of the encapsulation layer is less than that of the substrate layer.

7. The display panel as described in claim 1, characterized in that, The encapsulation layer is a single refractive index material or has a refractive index that satisfies... ,in, The ordinary refractive index of the encapsulation layer is... The unusual optical refractive index of the encapsulation layer.

8. The display panel as described in any one of claims 1 to 7, characterized in that, The phase difference caused by material birefringence in the optical path of visible light passing through the intermediate layer is less than 5°.

9. The display panel as described in any one of claims 1 to 7, characterized in that, The ratio of the maximum width of the bottom surface of the lens structure to the maximum width of the micro light-emitting device is 0.2 to 2.

10. A display device, characterized in that, Includes the display panel as described in any one of claims 1 to 9.

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