Patent Publication Number: US-2022238846-A1

Title: Display panel, preparation method of display panel, and display device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Chinese patent application No. 202110739070.9 filed with the China National Intellectual Property Administration (CNIPA) on Jun. 30, 2021, the disclosure of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     Embodiments of the present disclosure relate to the technical field of display, and in particular, a display panel, a preparation method of a display panel, and a display device. 
     BACKGROUND 
     The lithographic technology forms an exposed region and an unexposed region by exposing a surface coated with a photosensitive material in a certain pattern, and an exposed region pattern or an unexposed region pattern is retained. The lithographic technology is mainly used for manufacturing semiconductor elements, printed circuit boards, display panels, and the like. 
     An existing film layer of a display panel generally includes a display function layer and an anti-reflective function layer, the anti-reflective function layer is manufactured by adopting the lithographic technology, and the anti-reflective effect of the display panel is affected, since phenomena of holes, undercuts and the like are easily generated at the bottom of the anti-reflective function layer during exposure and development of the lithographic process. 
     SUMMARY 
     The present disclosure provides a display panel, a preparation method of a display panel, and a display device, so as to avoid the phenomena of undercuts and the like generated at the bottom of a low refractive layer after lithographic exposure and development and further improve the anti-reflective effect of the display panel. 
     The present disclosure provides a display panel. The display panel includes a display function layer, an anti-reflective function layer and a base material layer. The display function layer includes multiple light-emitting elements and a pixel definition structure surrounding the multiple light-emitting elements. The anti-reflective function layer is disposed on the light emitting side of the display function layer and includes a first refractive index pattern, and the first refractive index pattern overlaps with the pixel definition structure. The base material layer is disposed between the anti-reflective function layer and the display function layer and includes a light uniformizing structure, the light uniformizing structure includes a first inclined sidewall, and in a light emitting direction of the multiple light-emitting elements, the first inclined sidewall is inclined towards a direction away from a light-emitting element adjacent to the first inclined sidewall, and the first refractive index pattern covers the first inclined sidewall. 
     The present disclosure further provides a display device. The display device includes the display panel described above. 
     The present disclosure further provides a preparation method of a display panel. The preparation method includes the steps described below. A display function layer is formed, the display function layer includes multiple light-emitting elements and a pixel definition structure surrounding the multiple light-emitting elements; a base material layer is formed on a light emitting side of the display function layer, the base material layer includes a light uniformizing structure, the light uniformizing structure includes a first inclined sidewall, and in a light emitting direction of the multiple light-emitting elements, the first inclined sidewall is inclined towards a direction away from a light-emitting element adjacent to the first inclined sidewall; and an anti-reflective function layer is formed on a light emitting side of the base material layer, the anti-reflective function layer includes a first refractive index pattern, the first refractive index pattern overlaps with the pixel definition structure, and the first refractive index pattern covers the first inclined sidewall. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a structural schematic view of a display panel in the related art; 
         FIG. 2  is a schematic top view of a structure of a display panel provided in an embodiment of the present disclosure; 
         FIG. 3  is a schematic cross-sectional view of  FIG. 1  taken along a dashed line AA′; 
         FIG. 4  is a flowchart of a preparation method of a display panel provided in an embodiment of the present disclosure; 
         FIGS. 5A to 5F  are diagrams illustrating a flow of a process preparation of a display panel provided in an embodiment of the present disclosure; 
         FIG. 6  is a partial schematic view of exposure light incident on a light uniformizing structure in a display panel provided in an embodiment of the present disclosure; 
         FIG. 7  is an enlarged schematic view of a dashed box Bb of  FIG. 3 ; 
         FIG. 8  is a structural schematic view of a light uniformizing structure in a display panel provided in an embodiment of the present disclosure; 
         FIG. 9  is a structural schematic view of a light uniformizing structure in another display panel provided in an embodiment of the present disclosure; 
         FIG. 10  is a structural schematic view of a base material layer in a display panel provided in an embodiment of the present disclosure; 
         FIG. 11  is a structural schematic view of a base material layer in another display panel provided in an embodiment of the present disclosure; 
         FIG. 12  is a structural schematic view of a light-emitting element in a display panel provided in an embodiment of the present disclosure; and 
         FIG. 13  is a structural schematic view of a display device provided in an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure will be further described in detail in conjunction with the drawings and embodiments below. It should be understood that the specific embodiments described herein are merely used for explaining the present disclosure and are not intended to limit the present disclosure. It should also be noted that, for ease of description, only some, but not all, of the structures related to the present disclosure are shown in the drawings. 
     Embodiments of the present disclosure provide a display panel, a preparation method of a display panel, and a display device. The display panel includes a display function layer, an anti-reflective function layer and a base material layer. The display function layer includes multiple light-emitting elements and a pixel definition structure surrounding the multiple light-emitting elements. The anti-reflective function layer is disposed on a light emitting side of the display function layer and includes a first refractive index pattern, and the first refractive index pattern overlaps with the pixel definition structure. The base material layer is disposed between the anti-reflective function layer and the display function layer and includes a light uniformizing structure, the light uniformizing structure includes a first inclined sidewall, and in a light emitting direction of the multiple light-emitting elements, the first inclined sidewall is inclined towards a direction away from a light-emitting element adjacent to the first inclined sidewall, and the first refractive index pattern covers the light uniformizing structure. 
     According to the display panel provided in the embodiments of the present disclosure, the base material layer including the light uniformizing structure is arranged between the display function layer and the anti-reflective function layer, so that the first refractive index pattern in the anti-reflective function layer coats the light uniformizing structure, and the light uniformizing structure forms the first inclined sidewall with a light emitting surface of the multiple light-emitting elements. Then, exposure light incident on the first inclined sidewall is scattered, sensitivity of light incident by the photoresist on the bottom layer of the first refractive index pattern is enhanced, and the degree of curing the bottom layer of the first refractive index pattern in the anti-reflective function layer is improved. When the sensitivity of the bottom layer of the first refractive index pattern is enhanced, the phenomena of holes, undercuts and the like caused by relatively weak light sensitivity at the bottom of the first refractive index pattern can be effectively avoided. 
     The above is the core idea of the present disclosure, and the technical schemes of the embodiments of the present disclosure will be described clearly and completely in connection with the accompanying drawings in the embodiments of the present disclosure below. All other embodiments obtained by those skilled in the art based on the embodiments of the present disclosure without requiring creative efforts shall all fall in the scope of protection of the present disclosure. 
       FIG. 1  is a structural schematic view of a display panel in the related art. As shown in  FIG. 1 , an existing display panel film layer includes a display function layer  012  and an anti-reflective function layer  013 , and the anti-reflective function layer  013  is manufactured by adopting the lithographic technology. When the lithographic process is used for exposure and development, an exposure light source is vertically incident on the anti-reflective function layer  013  from top to bottom, so that light incident on the bottom of the anti-reflective function layer  013  has relatively weak light sensitivity. In a preparation process of the display panel, the anti-reflective function layer  013  is usually made of a negative tone photoresist material, and this kind of negative tone photoresist material is poor in the curing effect, so that the bottom with a poor curing effect of a non-exposure region is easy to be washed off when the lithographic technology is adopted for exposure and development, thereby an undercut phenomenon as shown in  FIG. 1  occurs at the bottom of the anti-reflective function layer  013  (as shown by the dashed box Cc in  FIG. 1 ). 
     Based on the above problems existing in the related art, an embodiment of the present disclosure provides a display panel, which can effectively solve the phenomena of undercuts, holes, pattern edge warpings and the like caused by the relatively low photosensitivity of the bottom of the anti-reflective function layer, and further improve the anti-reflective effect of the display panel. 
       FIG. 2  is a schematic top view of a structure of a display panel provided in an embodiment of the present disclosure.  FIG. 3  is a schematic cross-sectional view of  FIG. 1  taken along a dashed line AN. Referring to  FIG. 2  and  FIG. 3 , the display panel  10  includes a display function layer  12 , an anti-reflective function layer  13  and a base material layer  14 . The display function layer  12  includes multiple light-emitting elements  120  and a pixel definition structure  122  surrounding the light-emitting elements  120 . The anti-reflective function layer  13  is disposed on a light emitting side of the display function layer  12  and includes a first refractive index pattern  131 , and the first refractive index pattern  131  overlaps with the pixel definition structure  122 . The base material layer  14  is disposed between the anti-reflective function layer  13  and the display function layer  12  and includes a light uniformizing structure  141 , and the light uniformizing structure  141  includes a first inclined sidewall Aa. In a light emitting direction of the multiple light-emitting elements  120 , the first inclined sidewall Aa is inclined towards a direction away from a light-emitting element  120  adjacent to the first inclined sidewall Aa, and the first refractive index pattern  131  covers the light uniformizing structure  141 . 
     The pixel definition structure  122  is used for defining a light emitting region, being conducive to improving the color mixing problem. In this embodiment, the anti-reflective function layer  13  is used for improving the light transmittance and display efficiency. The first refractive index pattern  131  in the anti-reflective function layer  13  is manufactured by exposure and development through the lithographic process. Because an exposure light source is incident on the display panel from top to bottom, light on the surface of the first refractive index pattern  131  in the anti-reflective function layer has relatively strong light sensitivity while light on the bottom of the first refractive index pattern  131  has relatively weak light sensitivity, therefore, the degree of curing of the bottom of the first refractive index pattern  131  obtained after lithographic is relatively low, and a relatively low degree of curing may further cause the phenomena of undercuts, holes or the like at the bottom of the first refractive index pattern  131  which is in the anti-reflective function layer  13  and close to the base material layer  14 . In order to avoid such situations, in the embodiments of the present disclosure, multiple light uniformizing structures  141  are designed on the base material layer  14  between the anti-reflective function layer  13  and the display function layer  12 , each light uniformizing structure  141  is arranged at the bottom of each first refractive index pattern  131  close to the display function layer  12 , and each light uniformizing structure  141  is covered by each first refractive index pattern  131 . The principle that the light uniformizing structure  141  improves the degree of curing of the bottom of the first refractive index pattern  131  is explained in detail below. 
     Firstly, the first refractive index pattern  131  is manufactured after exposure and development through the lithographic technology, the first refractive index pattern  131  is a convex structure in the anti-reflective function layer  13 , and when each first refractive index pattern  131  covers each light uniformizing structure  141 , this kind of light uniformizing structure  141  is also a convex structure on the base material layer. In this embodiment, as shown in the cross-sectional view in  FIG. 3 , the first refractive index pattern  131  formed after the exposure and development by using the lithographic technology is a regular-trapezoid structure with a narrower upper surface and a wider lower surface, and each light uniformizing structure  141  is coated inside the corresponding first refractive index pattern  131  and is also a regular-trapezoid structure with a narrower upper surface and a wider lower surface. In some other embodiments, the shape of the first refractive index pattern  131  may also be other shapes and may be determined by the patterning design before lithographic by those skilled in the art, which is not limited herein. 
     Referring to the cross-sectional view shown in  FIG. 3 , each light uniformizing structure  141  has an upwardly protruding regular-trapezoid structure on the base material layer  14 , therefore, an angle less than 90° is formed between the first inclined sidewall Aa and the surface of a side of the base material layer  14  away from the display function layer  12 . In this embodiment, when the lithographic technology is used for the exposure and development, each light uniformizing structure  141  in the base material layer  14  is located in an exposure region, therefore, when the exposure light irradiates the first inclined sidewall Aa of the light uniformizing structure  141 , a lot of exposure light on the first inclined sidewall Aa is scattered, so that the sensitivity of light incident by the photoresist on the bottom layer of the first refractive index pattern  131  is enhanced, the degree of curing of the bottom layer of the first refractive index pattern  131  in the anti-reflective function layer  13  is improved. When the sensitivity of the bottom layer of the first refractive index pattern  131  close to the base material layer  14  is enhanced, the phenomena of holes, undercuts and the like caused by the relatively weak light sensitivity at the bottom of the first refractive index pattern  131  can be effectively avoided. 
     After the structure of the display panel provided in this embodiment is described, a flow of a process preparation of the display panel in this embodiment is set forth immediately. 
       FIG. 4  is a flowchart of a preparation method of a display panel provided in an embodiment of the present disclosure. As shown in  FIG. 4 , the method includes the following steps. 
     In S 110 , a display function layer is formed, and the display function layer includes multiple light-emitting elements and a pixel definition structure surrounding the multiple light-emitting elements. 
     In S 120 , a base material layer is formed on a light emitting side of the display function layer, the base material layer includes a light uniformizing structure, the light uniformizing structure includes a first inclined sidewall, and in a light emitting direction of the multiple light-emitting elements, the first inclined sidewall is inclined towards a direction away from a light-emitting element adjacent to the first inclined sidewall. 
     In S 130 , an anti-reflective function layer is formed on a light emitting side of the base material layer, the anti-reflective function layer includes a first refractive index pattern, the first refractive index pattern overlaps with the pixel definition structure, and the first refractive index pattern covers the light uniformizing structure. 
     The preparation method of the display panel provided in this embodiment is described in detail below from the perspective of process preparation. 
       FIGS. 5A to 5F  show a flowchart of a process preparation of a display panel provided in an embodiment of the present disclosure. Referring to  FIG. 4 , the process preparation method includes the following steps. 
     Referring to  FIG. 5A , an array substrate  11  is provided. 
     Referring to  FIG. 5B , a display function layer  12  is formed on the array substrate  11 , and the display function layer  12  includes multiple light-emitting elements  120  and a pixel definition structure  122  surrounding the light-emitting elements  120 . 
     The preparation method for forming the display function layer  12  on the array substrate  11  may adopt technical means commonly used by those skilled in the art, which is not limited here. 
     Referring to  FIG. 5C , a base material layer  14  is formed on a light emitting side of the display function layer  12 , the base material layer  14  includes a light uniformizing structure  141 , the light uniformizing structure  141  includes a first inclined sidewall, and in a light emitting direction of the multiple light-emitting elements  120 , the first inclined sidewall is inclined towards a direction away from a light-emitting element  120  adjacent to the first inclined sidewall. 
     Exemplarily, in this embodiment, the base material layer may be formed by depositing a layer of material on a light emitting layer of the display function layer through a deposition method. The light uniformizing structure on the base material layer may be integrally designed, or after the base material layer is deposited, the light uniformizing structure is formed on the base material layer by designing a structure made of the same material as the base material layer in a patterning manner through the lithographic technology. 
     It should be noted that the photoresist may also be patterned by those skilled in the art using other patterning processes, such as nanoimprinting, which is not limited in this embodiment. 
     In addition, it should be noted that if a second insulating layer and a second electrode layer in a touch function layer provided in the above embodiments are directly also used as the base material layer, the process of independently preparing the base material layer may be omitted. 
     Referring to  FIG. 5D , an anti-reflective function layer  13  is formed on the light emitting side of the base material layer  14 , and the anti-reflective function layer  13  includes a low-refractive layer  130  close to the base material layer. 
     Similarly, with reference to the process steps in forming the base material layer described above, the low-refractive layer  130  is formed on the base material layer  12  to improve the light transmittance. 
     Next, referring to  FIG. 5E , exposure is performed by using the lithographic process. 
     In this embodiment, a film layer where the low-refractive layer  130  is located is also used as negative tone photoresist, and the thickness of the photoresist may be adjusted through a spin coating process or a spray coating process. Next, the low-refractive layer  130  is exposed using the lithographic technology, where the exposure light source is incident at an open region of a photomask  15 . 
     Referring to  FIG. 5F , a wet etching process may be adopted for pattern transfer, and the low-refractive layer  130  with a photoresist mask body is cleaned to obtain first refractive index patterns  131  periodically arranged in the low-refractive layer  1311 . 
     It should be noted that the photoresist in this embodiment is the negative tone photoresist, and the negative tone photoresist is a mixed liquid which is generally composed of three main components of a photosensitive resin, a sensitizer and a solvent and has the light sensitization. After the photosensitive resin is illuminated, a photocuring reaction quickly occurs in the exposure region, so that the physical property of the photoresist is obviously changed, and then the soluble part is dissolved away through a proper solvent treatment to obtain the required pattern, namely the first refractive index pattern finally obtained in the embodiment. The negative tone photoresist material has a poor curing effect, and when the lithographic technology is adopted for the exposure and development, the negative tone photoresist material in a development and non-exposure region of the bottom with the poor curing effect is easy to be washed away. 
     With continued reference to  FIG. 3 , an included angle γ between the first inclined sidewall Aa and the light emitting surface may be greater than or equal to 45°. 
     As described above, the first inclined sidewall Aa may be understood to form an included angle less than 90° with the surface of a side of the base material layer  14  away from the display function layer  12 , and this included angle, i.e., the included angle between the first inclined sidewall Aa and the light emitting surface, is denoted by γ. In order to cure the bottom layer of the first refractive index pattern  131 , incident light is reflected after hitting the first inclined sidewall Aa, and a direction of the reflected light needs to be kept in a direction of irradiating the bottom of the first refractive index pattern  131  as much as possible.  FIG. 6  is a partial schematic view of exposure light incident on a light uniformizing structure in a display panel provided in an embodiment of the present disclosure. Referring to  FIG. 6 , after light is incident on the first inclined sidewall Aa, a light path diagram of the reflected light to the bottom of the first refractive index pattern  131  is shown by the arrow, and 2θ≥90°, i.e., θ≥45°. On the basis of the above, when the included angle γ between the first inclined sidewall Aa and the light emitting surface is set to be greater than or equal to 45°, it can effectively guarantee that the bottom of the first refractive index pattern is prevented from being undercut in a controllable range. 
     With continued reference to  FIG. 6 , a height H of the light uniformizing structure  141  in the light emitting direction may be greater than or equal to 0.5 μm. 
     Referring to  FIG. 3 , since the light uniformizing structure  141  is coated inside the first refractive index pattern  131 , the light uniformizing structure  141  is mainly configured to scatter exposure light when the exposure light is incident, so that the photosensitive effect irradiated on the bottom of the first refractive index pattern  131  is increased. When the height of the light uniformizing structure  141  is less than 0.5 μm, a light attachment area of the first inclined sidewall Aa of the light uniformizing structure  141  is reduced, when the light is incident on the first inclined sidewall Aa, the exposure light is less scattered, and the problem of relatively weak light sensitivity at the bottom of the first refractive index pattern  131  cannot be improved. On the basis that the included angle γ between the first inclined sidewall Aa and the light emitting surface is greater than or equal to 45° in the above embodiments, when the height H of the light uniformizing structure  141  is determined to be greater than or equal to 0.5 μm, the light attachment area of the first inclined sidewall Aa of the light uniformizing structure  141  is increased, the number of exposure light scattered on the first inclined sidewall Aa is increased, thereby the photosensitive intensity reflected onto the bottom of the first refractive index pattern  131  is improved, thus increasing the degree of curing of the bottom of the first refractive index pattern  131 . 
     The display panel provided in this embodiment includes the display function layer, the anti-reflective function layer and the base material layer. The display function layer includes the multiple light-emitting elements and the pixel definition structure surrounding the multiple light-emitting elements. The anti-reflective function layer is disposed on the light emitting side of the display function layer and includes the first refractive index pattern, and the first refractive index pattern overlaps with the pixel definition structure. The base material layer is disposed between the anti-reflective function layer and the display function layer and includes a light uniformizing structure, the light uniformizing structure includes the first inclined sidewall, and in the light emitting direction of the multiple light-emitting elements, the first inclined sidewall is inclined towards the direction away from the light-emitting element adjacent to the first inclined sidewall, and the first refractive index pattern covers the light uniformizing structure. According to the technical scheme of this embodiment, the base material layer including the light uniformizing structure is arranged between the display function layer and the anti-reflective function layer, so that the first refractive index pattern in the anti-reflective function layer coats the light uniformizing structure, and the light uniformizing structure forms the first inclined sidewall with the light emitting surface. Then, exposure light incident on the first inclined sidewall is scattered, the sensitivity of light incident by the photoresist on the bottom layer of the first refractive index pattern is enhanced, and the degree of curing of the first refractive index pattern in the anti-reflective function layer is improved. When the sensitivity of the bottom layer of the first refractive index pattern close to the base material layer is enhanced, the phenomena of holes, undercuts and the like caused by the relatively weak light sensitivity at the bottom of the first refractive index pattern can be effectively avoided. 
     In an embodiment, the light uniformizing structures may be arranged to surround the light-emitting elements or may be arranged to be discretely around the light-emitting elements. 
     In an embodiment, the first refractive index pattern may be made of a negative tone photoresist material. 
     The negative tone photoresist material is an organic solution containing a cyclized rubber-based resin and a compound having photosensitive properties, and the negative tone photoresist material generates a crosslinking reaction by light irradiation and has the insolubility through superposition and hardening by a developer, that is, since a difference in solubility exists between an exposed portion and a non-exposed portion formed after exposure, an image may be formed by using this characteristic. When the lithographic technology is adopted for the exposure and development, the negative tone photoresist material has the characteristics of high chemical stability, sensitivity and wet etching resistance. 
     In this embodiment, when the lithographic technology is used for exposure and development, an exposure region and a non-exposure region exist, the first refractive index pattern is easy to be prepared after patterning design and the exposure and development by utilizing the high-quality characteristic of the negative tone photoresist material described above, and the formation and size of the first refractive index pattern can be easily controlled. 
     With continued reference to  FIG. 3 , the first refractive index pattern  131  includes a second inclined sidewall Ab, and in the light emitting direction of the light-emitting elements  120 , the second inclined sidewall Ab is inclined towards a direction away from a light-emitting element  120  adjacent to the second inclined sidewall. 
     As described above, the first refractive index pattern  131  has the convex regular-trapezoid structure and covers the light uniformizing structure  141 , therefore, the second inclined sidewall Ab of the first refractive index pattern  131  and the first inclined sidewall Aa of the light uniformizing structure  141  face the same direction and are both inclined in the direction away from the light-emitting element  120  adjacent to the first inclined sidewall Aa and the second inclined sidewall Ab, thereby facilitating scattering of exposure light incident on the sidewall. 
     It should be noted that an included angle between the second inclined sidewall Ab and the light emitting surface in this embodiment is different from the included angle between the first inclined sidewall Aa and the light emitting surface in the above embodiments. 
     In this embodiment, referring to  FIG. 3 , the included angle between the light emitting surface and the second inclined sidewall Ab of the first refractive index pattern  131  is denoted by δ, and the larger the included angle γ between the light emitting surface and the first inclined sidewall Aa of the light uniformizing structure  141  is, the larger the included angle δ between the light emitting surface and the second inclined sidewall Ab of the first refractive index pattern  131  is. For example, during manufacture of the display panel in this embodiment, when the included angle γ between the first inclined sidewall Aa and the light emitting surface is set to be 45°, the included angle δ between the second inclined sidewall Ab and the light emitting surface is 70°; when the included angle gamma between the first inclined sidewall Aa and the light emitting surface is set to be 50°, the included angle δ between the second inclined sidewall Ab and the light emitting surface is 73°; when the included angle γ between the first inclined sidewall Aa and the light emitting surface is set to be 55°, the included angle δ between the second inclined sidewall Ab and the light emitting surface is 75°; and when the included angle γ between the first inclined sidewall Aa and the light emitting surface is set to be 60°, the included angle δ between the second inclined sidewall Ab and the light emitting surface is 78°. By setting different included angles, the length of a light scattering path exposure light after being incident on the inclined sidewall can be effectively controlled, and the photosensitive intensity of the light incident by the photoresist on the bottom layer of the first refractive index pattern  131  is enhanced, and the degree of curing between the bottom layer of the first refractive index pattern  131  in the anti-reflective function layer  13  and the surface of the side of the base material layer  14  away from the display function layer  12  is further improved. 
       FIG. 7  is an enlarged schematic view of a dashed box Bb of  FIG. 3 . As shown in  FIG. 7 , in a direction parallel to the light emitting surface, in the first inclined sidewall Aa and the second inclined sidewall Ab that are adjacent to the same light-emitting element  120 , a distance between the first inclined sidewall Aa and the first light-emitting element  120  is a first distance L 1 , a distance between the second inclined sidewall Ab and the light-emitting element  120  is a second distance L 2 , and a difference between the first distance L 1  and the second distance L 2  is 2 μm to 3 μm. 
     The first refractive index pattern  131  overlaps with the pixel definition structure  122 , and one light-emitting element  120  is disposed within an opening of the pixel definition structure  122 , so that the color mixing phenomenon can be effectively avoided. 
     As shown in  FIG. 7 , an opening of the first refractive index pattern  131  is larger than the opening of the pixel definition structure  122 . In other embodiments, it may be provided that the opening of the first refractive index pattern is smaller than the opening of the pixel definition structure, i.e., the first refractive index pattern has an overlapping portion with the light-emitting element. 
     Referring to  FIG. 7 , a distance from the first inclined sidewall Aa of the light uniformizing structure  141  to the elongated direction of the light-emitting element  120  in the figure is L 1 , and a distance from the second inclined sidewall Ab of the first refractive index pattern  131  to the elongated direction of the light-emitting element  120  in the figure is L 2 . In order to effectively control the exposure light to be scattered after being incident on the inclined sidewall, the light hitting the first refractive index pattern  131  may effectively reach the bottom of the first refractive index pattern  131 , so that the bottom of the first refractive index pattern  131  also has relatively high photosensitivity, so as to increase the degree of curing of the anti-reflective function layer. When the difference between the first distance L 1  and the second distance L 2  is less than 2 μm, the light reflected after the exposure light is incident on the inclined sidewall reaches a side of the bottom of the to-be-formed first refractive index pattern  131  away from the inclined sidewall; and when the difference between the first distance L 1  and the second distance L 2  is larger than 3 μm, the light reflected after the exposure light is incident on the inclined sidewall cannot reach the bottom of the to-be-formed first refractive index pattern  131 , such that it may easily cause holes on the bottom layer of the first refractive index pattern  131 . 
     With continued reference to  FIG. 3 , the anti-reflective function layer further includes a second refractive index layer  132 , the second refractive index layer  132  is located on a side of the first refractive index pattern  131  away from the display function layer  12 , and the refractive index of the second refractive index layer  132  is greater than the refractive index of the first refractive index pattern  131 . 
     The anti-reflective function layer  13  in this embodiment is used for increasing the light transmittance, the arrangement of the second refractive index layer  132  on the basis that the first refractive index pattern  131  is formed through the lithographic technology further facilitates the guide for light emitting, so that the light is prevented from being reflected and sealed in the film layer when the light directly reaches a refractive layer with a relatively high refractive index, thus achieving the anti-reflective effect. 
       FIG. 8  is a structural schematic view of a light uniformizing structure in a display panel provided in an embodiment of the present disclosure.  FIG. 9  is a structural schematic view of a light uniformizing structure in another display panel provided in an embodiment of the present disclosure. Referring to  FIG. 8 , the light uniformizing structure is a convex structure  142 , and referring to  FIG. 9 , the light uniformizing structure is a first concave structure  143 . 
     Referring to  FIG. 8 , the convex structure  142  is formed on the inner side of the edge of the exposure region  151 , and when exposure light is incident, a sudden light change occurs in the exposure region  151  and the non-exposure region  152 , so that the convex structure  142  formed on the base material layer  14  is used to scatter the light as much as possible, disperse the photosensitive amount at the bottom, improve the degree of photocuring at the bottom of the first refractive index pattern  131 , and avoid the phenomenon of holes, undercuts and the like at the bottom of the first refractive index pattern  131 . 
     In this embodiment, the manner for forming the convex structure  142  may be referred to the manner for forming the light uniformizing structure of an upwardly protruding regular trapezoid in the above embodiments. When exposure light is incident, the light hits the convex structure  142  formed on the substrate layer  14 , and the incident exposure light is subjected to multi-angle scattering along the surface of the convex structure  142  according to protruding features of the convex structure, so that the scattered light at the bottom is dispersed, the light sensitivity of the bottom is improved, and thus the degree of curing of the anti-reflective function layer is further improved. 
     In addition, when the light uniformizing structure is the convex structure  142 , the arrow in  FIG. 8  represents the light path diagram of light, and it can be found by observing  FIG. 8  that part of the light originally subjected to total reflection may be emitted, so that the light efficiency is further improved. 
     Referring to  FIG. 9 , a first concave structure  143  is also formed at a boundary of the exposure region  151 , and when exposure light is incident, the exposure light reaches the first concave structure  143  formed on the base material layer  14 , so that the incident exposure light is scattered at multiple angles along the surface of the first concave structure  143 , the scattered light at the bottom may also be dispersed, and the degree of curing of the anti-reflective function layer is further improved. 
     Due to the scattering effect of the exposure light, the light sensitivity of the incident light on the bottom layer of the anti-reflective function layer  13  is relatively high, therefore, when the light uniformizing structure is concave on the base material layer  14 , the degree of curing of the anti-reflective function layer  13  on the base material layer  14  can still be ensured, and the occurrence of the phenomena of holes, undercuts and the like at the whole bottom of the anti-reflective function layer cannot be affected by a volume shrinkage. 
     In an embodiment, the base material layer may include a second concave structure, the second concave structure includes a part overlapping with the light-emitting element, and the second concave structure includes the first inclined sidewall. 
     Arrows in  FIG. 3  represent a light path diagram of light, and it can be found by observing  FIG. 3  that vertically-emitted light is directly emitted, light with a relatively large inclination angle is transmitted through the base material layer  14 , the first refractive index pattern  131  and the second refractive index layer  132  in sequence, and the first refractive index pattern  131  and the second refractive index layer  132  are configured to improve the light transmittance, so as to improve the lighting effect. 
       FIG. 10  is a structural schematic view of a base material layer in a display panel provided in an embodiment of the present disclosure. Referring to  FIG. 10 , the base material layer may include a touch function layer  17 , the touch function layer  17  is disposed between the display function layer  12  and the anti-reflective function layer  13 , the touch function layer  17  includes a first electrode layer  171 , a first insulating layer  172 , a second electrode layer  173 , and a second insulating layer  174  sequentially stacked in the light emitting direction, and the second insulating layer  174  is also used as the base material layer. 
     The first insulating layer  172  insulates the first electrode layer  171  and the second electrode layer  173  to avoid an electric leakage phenomenon. When the second insulating layer  174  is directly also used as the base material layer, a preparation process of the original base material layer is reduced, and thus the overall thickness of the display panel is reduced. 
     In addition, since the base material layer is located between the display function layer  12  and the anti-reflective function layer  13 , using the metal electrode layer as the light uniformizing structure, the light reflection can be greatly improved.  FIG. 11  is a structural schematic view of a base material layer in another display panel provided in an embodiment of the present disclosure. Referring to  FIG. 11 , the touch function layer  17  is also disposed between the display function layer  12  and the anti-reflective function layer  13  and includes a first electrode layer  171 , a first insulating layer  172 , and a second electrode layer  173  that are sequentially stacked in the light emitting direction, the second electrode layer  173  includes a second electrode  1731 , and the second electrode layer  173  is also used as the base material layer  14  in the above embodiments, and the second electrode  1731  is also used as the light uniformizing structure  141  in the above embodiments. 
     Similarly, an additional base material layer is not required in this embodiment, and the second electrode layer  173  is also used as the base material layer on the basis of the original touch function layer  17 , so that the process of manufacturing the base material layer is also reduced, and the manufacturing cost is further reduced. 
       FIG. 12  is a structural schematic view of a light-emitting element in a display panel provided in an embodiment of the present disclosure. As shown in  FIG. 12 , the light-emitting elements  120  include first light-emitting elements  121  and second light-emitting elements  122 , the first light-emitting elements  121  and the second light-emitting elements  122  have the same light emitting color, the first light-emitting elements  121  and the second light-emitting elements  122  are alternately arranged, an included angle between the light emitting surface and the first inclined sidewall Aa adjacent to a first light-emitting element  121  is a first included angle α 1 , and an included angle between the light emitting surface and the first inclined sidewall Aa adjacent to a second light-emitting element  122  is a second included angle α 2 , and α 2 &gt;α 1 . 
     Exemplarily, in this embodiment, the first light-emitting elements  121  and the second light-emitting elements  122  as red light-emitting elements emitting the red light are taken as an example, and the first light-emitting elements  121  and the second light-emitting elements  122  are labeled here as the first red light-emitting elements  121  and the second red light-emitting elements  122 . 
     Referring to  FIG. 12 , the light-emitting elements  120  may further include first color light-emitting elements  1201  and second color light-emitting elements  1202 , the light emitting color of the first color light-emitting elements  1201  is different from the light emitting color of the second color light-emitting elements  1202 , and the first color light-emitting element  1201  includes the first light-emitting elements  121  and the second light-emitting elements  122 , an included angle between the light emitting surface and the first inclined sidewall Aa adjacent to a second color light-emitting element  1202  is an included angle β, and α 1 &lt;β≤α 2 . 
     Exemplarily, in this embodiment, the first color light-emitting elements  1201  are red light-emitting elements emitting the red light, and the second color light-emitting elements  1202  are green light-emitting elements emitting the green light. 
     In this embodiment, the first included angle α 1  of 70° and the second included angle α 2  of 75° are taken as an example. In the manufacturing process of the display panel, the light-emitting elements  120  may have a process error, so that an included angle between the light emitting surface and the first inclined sidewall Aa of the first red light-emitting element  121  deviates from the included angle between the light emitting surface and the first inclined sidewall Aa of the second red light-emitting element  122 , and the deviation may directly influence the light emitting of the light-emitting elements, even a color cast phenomenon may be generated. In this embodiment, the light-emitting elements with the same light emitting color are arranged to be alternated and have different included angles with the light emitting surface, the influence of color cast caused by the process error of different light-emitting elements can be balanced, and the fluctuation of the color cast is further improved. 
       FIG. 13  is a structural schematic view of a display device provided in an embodiment of the present disclosure. Referring to  FIG. 13 , the display device  100  includes the display panel  10  provided in any one of the above embodiments. 
     Since the display device  100  provided in this embodiment includes the display panel  10  provided in any of the above-described embodiments, it has the same or corresponding beneficial effects as the display panel  10 , which is not repeated here. 
     After the display function layer is formed and before the anti-reflective function layer is formed, the touch function layer is formed on the light emitting side of the display function layer, the touch function layer includes a first electrode layer, a first insulating layer, a second electrode layer and a second insulating layer which are sequentially stacked in the light emitting direction, and the second insulating layer is also used as the base material layer 
     Another situation that the touch function layer is formed on the light emitting side of the display function layer is that: the touch function layer includes a first electrode layer, a first insulating layer and a second electrode layer which are sequentially stacked in the light emitting direction, the second electrode layer includes a second electrode, the second electrode layer is also used as the base material layer, and the second electrode is also used as the light uniformizing structure. 
     The preparation method of the touch function layer is a technique well known to those skilled in the art, which is not repeated here. 
     It should be noted that the above are merely alternative embodiments of the present disclosure and the technical principles applied herein. It should be understood by those skilled in the art that the present disclosure is not limited to the particular embodiments described herein. For those skilled in the art, various apparent modifications, adaptations, combinations and substitutions may be made without departing from the scope of the present disclosure. Therefore, although the present disclosure has been described in detail through the above embodiments, the present disclosure is not limited to the above embodiments and may include more other equivalent embodiments without departing from the concept of the present disclosure. The scope of the present disclosure is determined by the scope of the appended claims.