Display panel and its manufacturing method

Abstract

This invention discloses a display panel and its fabrication method. The display panel includes a substrate, a light-emitting device layer, and a viewing angle adjustment film. The light-emitting device layer has a first viewing angle curve, which includes a point of maximum luminous efficiency. The film thickness of the light-emitting device layer is the thickness corresponding to the point of maximum luminous efficiency, which is located at a side viewing angle. The viewing angle adjustment film is disposed on the side of the light-emitting device layer away from the substrate, and is used to adjust the point of maximum luminous efficiency from the side viewing angle to the main viewing angle to obtain a second viewing angle curve. The normal direction of the side viewing angle is inclined to the normal direction of the main viewing angle. Compared with the prior art's method of sacrificing the luminous brightness at the front viewing angle to achieve a large viewing angle, this invention can obtain a large viewing angle without reducing the luminous brightness at the front viewing angle, achieving a balance between luminous efficiency and viewing angle under a fixed light color.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a display panel and its manufacturing method. Background Technology

[0002] Increasing panel size and resolution is one of the main development directions for displays such as OLEDs (Organic Light-Emitting Diodes). Since most OLED devices currently use a top-emitting structure, large-size and high-resolution displays suffer from poor viewing angles. Viewing angle issues are typically addressed by adjusting the OLED optical resonator or adding viewing angle improvement components external to the panel. However, according to the law of conservation of energy, since the number of photons emitted under a fixed color of light is constant, emitting photons at other angles to improve the viewing angle inevitably leads to energy loss at the positive viewing angle, resulting in reduced brightness at that angle. Therefore, a large viewing angle and high brightness at the positive viewing angle are mutually exclusive. Summary of the Invention

[0003] This invention provides a display panel and its manufacturing method to solve the technical problem of reduced brightness at the normal viewing angle when improving the viewing angle of existing display panels.

[0004] To solve the above problems, the technical solution provided by the present invention is as follows:

[0005] This invention provides a display panel, comprising:

[0006] substrate;

[0007] A light-emitting device layer is disposed on the substrate. The light-emitting device layer has a first viewing angle curve, the first viewing angle curve including a point of maximum luminous efficiency, and the film thickness of the light-emitting device layer is the film thickness corresponding to the point of maximum luminous efficiency, the point of maximum luminous efficiency being located at a side viewing angle; and

[0008] A viewing angle adjustment film is disposed on the side of the light-emitting device layer away from the substrate;

[0009] The viewing angle adjustment film is used to adjust the maximum luminous efficiency point from the side viewing angle to the main viewing angle and obtain a second viewing angle curve, wherein the normal direction of the side viewing angle is inclined to the normal direction of the main viewing angle.

[0010] According to the display panel provided by the present invention, the tilt angle between the viewing angle corresponding to the maximum luminous efficiency point on the first viewing angle curve and the normal direction of the main viewing angle is 20 degrees to 40 degrees.

[0011] According to the display panel provided by the present invention, the viewing angle adjustment film includes:

[0012] Multiple dimming microstructures; and

[0013] A filling layer is applied to the side of the plurality of dimming microstructures away from the substrate;

[0014] The refractive index of the filling layer is greater than that of the dimming microstructure.

[0015] According to the display panel provided by the present invention, the dimming microstructure is a combination of one or more of a single-refractive lens, a birefractive lens, and a multirefractive lens.

[0016] According to the display panel provided by the present invention, the light-emitting device layer includes a first electrode, a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, an electron injection layer, and a second electrode, which are sequentially stacked along a direction away from the substrate.

[0017] The hole injection layer has a film thickness ranging from 20 nanometers to 30 nanometers, the hole transport layer has a film thickness ranging from 20 nanometers to 30 nanometers, and the organic light-emitting layer has a film thickness ranging from 20 nanometers to 30 nanometers.

[0018] According to the display panel provided by the present invention, the display panel further includes:

[0019] An encapsulation layer is applied to the side of the light-emitting device layer away from the substrate.

[0020] A cover plate is disposed on the side of the encapsulation layer away from the substrate; and

[0021] A polarizer is disposed on the side of the cover plate away from the substrate;

[0022] The viewing angle adjustment film is located on the side of the polarizer away from the substrate.

[0023] This invention provides a method for manufacturing a display panel, comprising the following steps:

[0024] S10: Provides a substrate;

[0025] S20: A light-emitting device layer is formed on the substrate, the light-emitting device layer having a first viewing angle curve, the first viewing angle curve including a point of maximum luminous efficiency; the film thickness of the light-emitting device layer is adjusted so that the point of maximum luminous efficiency is located at a side viewing angle; and

[0026] S30: A viewing angle adjustment film is formed on the side of the light-emitting device layer away from the substrate. The viewing angle adjustment film is used to adjust the maximum luminous efficiency point from the side viewing angle to the main viewing angle and obtain a second viewing angle curve.

[0027] According to the preparation method provided by the present invention, step S20 includes:

[0028] S201: Import the parameters of the light-emitting device layer into physical optics simulation software to obtain the first viewing angle curve; and

[0029] S202: Adjust the film thickness parameter of the light-emitting device layer so that the maximum luminous efficiency point on the first viewing angle curve is located at the side viewing angle.

[0030] According to the preparation method provided by the present invention, step S30 includes:

[0031] S301: An encapsulation layer is formed on the side of the light-emitting device layer away from the substrate;

[0032] S302: Sequentially attach the cover plate and polarizer to the side of the encapsulation layer away from the substrate; and

[0033] S303: Provide a viewing angle adjustment film, and attach the viewing angle adjustment film to the side of the polarizer away from the substrate.

[0034] According to the preparation method provided by the present invention, in step S30, the first viewing angle curve is imported into geometric optics simulation software, and the parameters of the dimming microstructure and the filling layer are adjusted so that the maximum luminous efficiency point is adjusted from the side viewing angle to the main viewing angle and the second viewing angle curve is obtained.

[0035] The beneficial effects of this invention are as follows: The display panel and its manufacturing method provided by this invention have a first viewing angle curve in the light-emitting device layer of the display panel. The first viewing angle curve includes a point of maximum luminous efficiency. By adjusting the film thickness of the light-emitting device layer to the thickness corresponding to the maximum luminous efficiency, the luminous efficiency of the light-emitting device layer can be adjusted to the highest level within the allowable color range, and the point of maximum luminous efficiency is located at the side viewing angle. In addition, a viewing angle adjustment film is applied to the side of the light-emitting device layer away from the substrate. The viewing angle adjustment film adjusts the point of maximum luminous efficiency from the side viewing angle to the main viewing angle and obtains a second viewing angle curve. Compared with the prior art's method of sacrificing the luminous brightness at the front viewing angle to achieve a large viewing angle, this invention can obtain a large viewing angle without reducing the luminous brightness at the front viewing angle, achieving a balance between luminous brightness and viewing angle under a fixed color. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0037] Figure 1 This is a schematic diagram of a cross-sectional structure of a display panel provided in an embodiment of the present invention;

[0038] Figure 2 This is a comparison diagram of the first viewing angle curve and the second viewing angle curve in the display panel provided in the embodiment of the present invention;

[0039] Figure 3A This is a schematic diagram of the first cross-sectional structure of the dimming microstructure in the display panel provided in the embodiment of the present invention;

[0040] Figure 3B This is a schematic diagram of the second cross-sectional structure of the dimming microstructure provided in the embodiments of the present invention;

[0041] Figure 3C This is a schematic diagram of the third cross-sectional structure of the dimming microstructure provided in the embodiments of the present invention;

[0042] Figure 4 This is a flowchart of a method for manufacturing a display panel according to an embodiment of the present invention;

[0043] Figures 5A to 5D This is a schematic diagram of the process structure of a method for manufacturing a display panel according to an embodiment of the present invention.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1. Substrate; 2. Light-emitting device layer; 21. First electrode; 22. Hole injection layer; 23. Hole transport layer; 24. Organic light-emitting layer; 25. Electron transport layer; 26. Electron injection layer; 27. Second electrode; 3. Encapsulation layer; 4. Cover plate; 5. Polarizer; 6. Viewing angle adjustment film; 61. Dimming microstructure; 62. Filler layer; 7. Pixel definition layer. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present invention and are not intended to limit the present invention. In the present invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0047] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of a cross-sectional structure of a display panel provided in an embodiment of the present invention; Figure 2This is a comparison diagram of the first viewing angle curve and the second viewing angle curve in the display panel provided in the embodiment of the present invention; the display panel provided in the embodiment of the present invention includes a substrate 1, a light-emitting device layer 2 and a viewing angle adjustment film 6.

[0048] The light-emitting device layer 2 is disposed on the substrate 1. The light-emitting device layer 2 has a first viewing angle curve, which includes a maximum luminous efficiency point. The film thickness of the light-emitting device layer 2 is the film thickness corresponding to the maximum luminous efficiency point, which is located in the side viewing angle. The viewing angle adjustment film 6 is disposed on the side of the light-emitting device layer 2 away from the substrate 1. The viewing angle adjustment film 6 adjusts the maximum luminous efficiency point from the side viewing angle to the main viewing angle and obtains a second viewing angle curve. The normal direction of the side viewing angle is inclined to the normal direction of the main viewing angle.

[0049] It is understood that the display panel provided in this embodiment of the invention, by adjusting the film thickness of the light-emitting device layer 2 to the thickness corresponding to the maximum luminous efficiency, can adjust the luminous efficiency of the light-emitting device layer 2 to the highest level within the allowable light color range, and make the maximum luminous efficiency point located at the side viewing angle; in addition, a viewing angle adjustment film 6 is provided on the side of the light-emitting device layer 2 away from the substrate 1. The viewing angle adjustment film 6 adjusts the maximum luminous efficiency point from the side viewing angle to the main viewing angle and obtains a second viewing angle curve. Compared with the prior art's method of sacrificing the luminous brightness at the front viewing angle to achieve a large viewing angle, the present invention can obtain a large viewing angle without reducing the luminous brightness at the front viewing angle, and achieves a balance between luminous brightness and viewing angle under a fixed light color.

[0050] Specifically, the light-emitting device layer 2 includes a first electrode 21, a hole injection layer 22, a hole transport layer 23, an organic light-emitting layer 24, an electron transport layer 25, an electron injection layer 26, and a second electrode 27, sequentially stacked along the direction away from the substrate 1. The display panel also includes a pixel definition layer 7, which defines a plurality of pixel openings. The first electrode 21 is disposed on the substrate 1, and the pixel definition layer 7 covers the substrate 1 and a portion of the first electrode 21. The pixel openings expose a portion of the surface of the first electrode 21 away from the substrate 1. The hole injection layer 22, the hole transport layer 23, the organic light-emitting layer 24, the electron transport layer 25, and the electron injection layer 26 are stacked on the side of the first electrode 21 away from the substrate 1 and located within the pixel openings. The second electrode 27 covers the pixel electrode layer and the electron injection layer 26 on the side away from the substrate 1.

[0051] It should be noted that in the light-emitting device layer 2, the first electrode 21 is the anode, which is a reflective electrode, and the second electrode 27 is the cathode, which is a semi-reflective, semi-transparent electrode or a fully transparent electrode. The light-emitting device layer 2 forms a resonant cavity due to the presence of the first electrode 21 and the second electrode 27. Taking the cathode as a transparent electrode as an example, a portion of the light emitted from the organic light-emitting layer 24 passes directly through the first electrode 21 and is emitted to the outside. The remaining portion of the light emitted from the organic light-emitting layer 24 passes sequentially through the hole transport layer 23 and the hole injection layer 22 before entering the first electrode 21. After being reflected by the first electrode 21, it passes sequentially through the hole injection layer 22, the hole transport layer 23, the organic light-emitting layer 24, and the second electrode 27 before being emitted to the outside. Therefore, by adjusting the distance between the first electrode 21 and the second electrode 27, the phase difference between the two portions of light can satisfy the interference condition, thereby increasing their intensity and improving the luminous efficiency of the light-emitting device layer 2, thus adjusting the luminous efficiency of the light-emitting device layer 2 to its maximum value.

[0052] In other words, by adjusting the thickness of any one or more of the films in the first electrode 21, the hole injection layer 22, the hole transport layer 23, the organic light-emitting layer 24, the electron transport layer 25, the electron injection layer 26, and the second electrode 27, the luminous efficiency of the light-emitting device layer 2 can be improved because the thickness of each film in the light-emitting device layer 2 is adjusted to be comparable to the thickness of the film at the maximum luminous efficiency. This embodiment of the invention does not limit which specific layer's thickness is adjusted, as long as the thickness of the light-emitting device layer 2 is adjusted until the luminous efficiency of the light-emitting device layer 2 reaches the maximum luminous efficiency.

[0053] Furthermore, from an optical perspective, the hole injection layer 22, the hole transport layer 23, and the organic light-emitting layer 24 have a significant effect on the resonant cavity and absorb less light. Therefore, in this embodiment of the invention, the luminous efficiency of the light-emitting device layer 2 can be adjusted to the maximum value by adjusting the film thickness of the hole injection layer 22, the hole transport layer 23, and the organic light-emitting layer 24.

[0054] Furthermore, since the first electrode 21 and the second electrode 27 are generally formed by vapor deposition or sputtering, while the hole injection layer 22, the hole transport layer 23, and the organic light-emitting layer 24 are generally formed by inkjet printing, inkjet printing, compared to vapor deposition or sputtering, only requires adjusting the number of ink droplets to adjust the film thickness, making it easier to adjust the film thickness of each layer. Therefore, by adjusting the film thickness of the hole injection layer 22, the hole transport layer 23, and the organic light-emitting layer 24, this embodiment of the invention can easily and precisely fine-tune the film thickness of the light-emitting device layer 2, further improving its optical properties.

[0055] Specifically, the hole injection layer 22 has a film thickness ranging from 20 nanometers to 30 nanometers, the hole transport layer 23 has a film thickness ranging from 20 nanometers to 30 nanometers, and the organic light-emitting layer 24 has a film thickness ranging from 20 nanometers to 30 nanometers.

[0056] Specifically, the thickness of the first electrode 21 is in the range of 10 nanometers to 15 nanometers, the thickness of the electron transport layer 25 is in the range of 10 nanometers to 15 nanometers, the thickness of the electron injection layer 26 is in the range of 10 nanometers to 15 nanometers, and the thickness of the second electrode 27 is in the range of 10 nanometers to 15 nanometers.

[0057] It should be noted that, in the embodiments of the present invention, "the film thickness of the light-emitting device layer 2 is the film thickness corresponding to the maximum luminous efficiency point" refers to the film thickness within ±10% of the film thickness corresponding to the maximum luminous efficiency point.

[0058] In this embodiment of the invention, the tilt angle between the viewing angle corresponding to the maximum luminous efficiency point on the first viewing angle curve and the normal direction of the main viewing angle is 20 degrees to 40 degrees. It should be noted that if the tilt angle is too small, since the maximum luminous efficiency point is close to the main viewing angle, adjusting the viewing angle of the maximum luminous efficiency point through the viewing angle adjustment film 6 is not very meaningful and will not achieve the aforementioned beneficial effect; if the tilt angle is too large, it will be difficult for the viewing angle adjustment film 6 to adjust the large-angle maximum luminous efficiency point to the main viewing angle. Therefore, the tilt angle should be avoided to be too large or too small.

[0059] It should be noted that the first viewing angle curve is the relationship curve between the viewing angle and brightness of the light emitted from the light-emitting device layer 2 to the outside when the viewing angle adjustment film 6 is not set; the second viewing angle curve is the relationship curve between the viewing angle and brightness of the light emitted from the light-emitting device layer 2 to the outside when the viewing angle adjustment film 6 is set, wherein the frontal viewing angle is 0 degrees and the side viewing angle is between 0 and 90 degrees.

[0060] The viewing angle adjustment film 6 includes multiple dimming microstructures 61 and a filling layer 62. The multiple dimming microstructures 61 are correspondingly arranged with multiple light-emitting pixels so that the light emitted from the light-emitting device layer 2 can pass through the dimming microstructures 61. The filling layer 62 covers the side of the multiple dimming microstructures 61 away from the substrate 1. The refractive index of the filling layer 62 is greater than that of the dimming microstructures 61, so that the light emitted from the light-emitting device layer 2 is refracted at the junction of the dimming microstructures 61 and the filling layer 62. On the one hand, this adjusts the maximum luminous efficiency point from the side viewing angle to the main viewing angle and obtains a second viewing angle curve. On the other hand, it causes the light to diverge in the side viewing angle direction, which is beneficial to improving the viewing angle of the display panel and obtaining a wide viewing angle.

[0061] Specifically, the dimming microstructure 61 is made of resin; the filling layer 62 is also made of resin. This embodiment of the invention controls the relationship between the refractive indices of the dimming microstructure 61 and the filling layer 62 to cause light to refract at the interface between them. Specifically, the refractive index of the dimming microstructure 61 ranges from 1.2 to 1.4, for example, 1.2, 1.25, 1.3, 1.35, 1.4; the refractive index of the filling layer 62 ranges from 1.6 to 1.7, for example, 1.6, 1.65, 1.7.

[0062] Specifically, the dimming microstructure 61 is a trapezoidal prism microstructure; the dimming microstructure 61 is a combination of one or more of a single-refractive lens, a birefractive lens, and a multi-refractive lens, for example, such as... Figure 1 and Figure 3A As shown, Figure 3A This is a schematic diagram of a first cross-sectional structure of the dimming microstructure in the display panel provided in an embodiment of the present invention, wherein the dimming microstructure 61 is a single-refractive lens; for example, as... Figure 3B As shown, Figure 3B This is a schematic diagram of a second cross-sectional structure of the dimming microstructure provided in an embodiment of the present invention, wherein the dimming microstructure 61 is a birefringent lens; or, for example, Figure 3C As shown, Figure 3C This is a schematic diagram of a third cross-sectional structure of the dimming microstructure provided in this embodiment of the invention. The dimming microstructure 61 is a multi-refractive lens. Furthermore, the dimming microstructure 61 can be one-dimensional, strip-shaped, or a two-dimensional array. In this case, the dimming microstructure 61 corresponds one-to-one with multiple light-emitting pixels in the light-emitting device layer 2. It should be noted that this embodiment of the invention does not limit the specific structural form of the dimming microstructure 61. To achieve a better improvement in viewing angle, the structure of the dimming microstructure 61 needs to be designed to be more complex.

[0063] It should be noted that for the first viewing angle curves of different types of light-emitting device layers 2, from the frontal viewing angle to the side viewing angle, the dimming microstructure 61 with different parameters should be designed according to factors such as the degree of brightness attenuation, so as to adjust the maximum luminous efficiency point located at the side viewing angle to the main viewing angle.

[0064] In one embodiment, the display panel further includes an encapsulation layer 3, a cover plate 4, and a polarizer 5. The encapsulation layer 3 covers the side of the light-emitting device layer 2 away from the substrate 1, and the encapsulation layer 3 is thin-film encapsulated to prevent external water and oxygen from interfering with the light-emitting device layer 2. The cover plate 4 is disposed on the side of the encapsulation layer 3 away from the substrate 1. In this embodiment, the cover plate 4 is a rigid cover plate 4, or optionally, a transparent glass cover plate 4. The polarizer 5 is disposed on the side of the cover plate 4 away from the substrate 1; wherein, the viewing angle adjustment film 6 is located on the side of the polarizer 5 away from the substrate 1.

[0065] It should be noted that in other embodiments, the viewing angle adjustment film 6 can also be disposed on the side of the cover plate 4 closer to the substrate 1. However, in this case, the refractive index of the cover plate 4 is usually less than 1.5, that is, the refractive index of the cover plate 4 is less than the refractive index of the viewing angle adjustment film 6. Light is prone to total internal reflection at the junction of the viewing angle adjustment film 6 and the cover plate 4, thereby affecting the luminous efficiency and hindering the viewing angle improvement effect. Therefore, by disposing the viewing angle adjustment film 6 on the side of the cover plate 4 away from the substrate 1, the influence of the cover plate 4 on the luminous efficiency can be avoided.

[0066] Furthermore, the display panel also includes an anti-reflection layer, which is disposed on the side of the viewing angle adjustment layer away from the substrate 1, in order to reduce light reflection and improve light extraction efficiency.

[0067] Please refer to it again. Figure 2 As shown in Table 1, the inventors conducted experimental verification of the technical solution of this invention. Figure 2In the diagram, the solid curve Q-LV represents the first viewing angle curve, the dashed curve H-LV represents the second viewing angle curve, and the solid straight line LV is the standard line for 50% of the single-sided viewing angle, where 50% of the single-sided viewing angle refers to 50% of the brightness of the positive viewing angle on one side. Taking the dimming microstructure 61 as a birefringent lens as an example, in the first viewing angle curve, the maximum luminous efficiency point is located at 30 degrees, the maximum luminous efficiency is 130%, and when the brightness reaches 50% of the positive viewing angle brightness, that is, when the brightness reaches 1000 nits, the viewing angle is 60 degrees; in the second viewing angle curve, the maximum luminous efficiency point is located at 0 degrees (positive viewing angle), the maximum luminous efficiency is 100%, and when the brightness reaches 50% of the positive viewing angle brightness, that is, when the brightness reaches 1000 nits, the viewing angle is greater than 70 degrees. Therefore, it can be seen that when the brightness reaches 50% of the positive viewing angle brightness in the first and second viewing angle curves, the difference in the corresponding viewing angles is greater than 10 degrees. It is understood that, in the embodiments of the present invention, for the same brightness, the viewing angle after setting the viewing angle adjustment layer is larger than that before setting the viewing angle adjustment layer; for the same viewing angle, the brightness after setting the viewing angle adjustment layer is larger than that before setting the viewing angle adjustment layer; therefore, the display panel provided in the embodiments of the present invention can obtain a larger viewing angle and improve the brightness of the side viewing angle.

[0068] Brightness / nits 50% unilateral view Before applying the screen protector 1000 60 After applying the screen protector 1000 70

[0069] Table 1

[0070] Furthermore, the positive viewing angle brightness in the second viewing angle curve is comparable to that in the first viewing angle curve, both reaching 100%. The positive viewing angle brightness in the second viewing angle curve is not significantly lower than that in the first viewing angle curve. Therefore, the embodiments of the present invention can obtain a large viewing angle without reducing the positive viewing angle brightness, which is a significant improvement over the prior art method of sacrificing positive viewing angle brightness to obtain a large viewing angle. Moreover, compared with the first viewing angle curve, the brightness decay of the second viewing angle curve from the positive viewing angle to the side viewing angle is relatively slow, which is beneficial to improving the brightness uniformity of the display panel at different viewing angles, thereby improving the display effect.

[0071] Please see Figure 4 and Figures 5A to 5D This invention also provides a method for manufacturing a display panel, comprising the following steps:

[0072] S10: Provide a substrate 1.

[0073] Specifically, please refer to Figure 5AThe substrate 1 is an array substrate, and the substrate 1 includes a pixel driving circuit layer. The pixel driving circuit layer includes multiple pixel driving circuits, and the multiple pixel driving circuits are used to drive one or more corresponding light-emitting pixels to emit light.

[0074] S20: A light-emitting device layer 2 is formed on the substrate 1. The light-emitting device layer 2 has a first viewing angle curve, which includes a maximum luminous efficiency point. The film thickness of the light-emitting device layer 2 is adjusted so that the maximum luminous efficiency point is located at the side viewing angle.

[0075] Specifically, please refer to Figure 5B Step S20 includes:

[0076] S201: Import the parameters of the light-emitting device layer 2 into physical optics simulation software to obtain the first viewing angle curve; and

[0077] S202: Adjust the film thickness parameter of the light-emitting device layer 2 so that the maximum luminous efficiency point on the first viewing angle curve is located at the side viewing angle.

[0078] In this embodiment of the invention, the light-emitting device layer 2 includes a hole injection layer 22, a hole transport layer 23, and an organic light-emitting layer 24 stacked sequentially. The thickness of the hole injection layer 22 is adjusted to be 20 nanometers to 30 nanometers, the thickness of the hole transport layer 23 is 20 nanometers to 30 nanometers, and the thickness of the organic light-emitting layer 24 is 20 nanometers to 30 nanometers.

[0079] Optionally, in this embodiment of the invention, the physical optics simulation software in step S201 can be a finite-difference time-domain simulation software.

[0080] S30: A viewing angle adjustment film 6 is formed on the side of the light-emitting device layer 2 away from the substrate 1. The viewing angle adjustment film 6 is used to adjust the maximum luminous efficiency point from the side viewing angle to the main viewing angle and obtain a second viewing angle curve.

[0081] Specifically, please refer to Figure 5C and Figure 5D When the viewing angle adjustment film 6 is located on the side of the polarizer 5 away from the substrate 1, step S30 includes:

[0082] S301: An encapsulation layer 3 is formed on the side of the light-emitting device layer 2 away from the substrate 1;

[0083] S302: The cover plate 4 and the polarizer 5 are sequentially attached to the side of the encapsulation layer 3 away from the substrate 1; and

[0084] S303: Provide a viewing angle adjustment film 6, and attach the viewing angle adjustment film 6 to the side of the polarizer 5 away from the substrate 1.

[0085] S301: A plurality of dimming microstructures 61 are formed on the side of the light-emitting device layer 2 away from the substrate 1, and the dimming microstructures 61 are disposed corresponding to a plurality of light-emitting pixels of the light-emitting device layer 2.

[0086] S302: Form a filling layer 62 covering the side of the plurality of dimming microstructures 61 away from the substrate 1.

[0087] Specifically, after the overall formation, the viewing angle adjustment film 6 is attached to the side of the polarizer 5 away from the substrate 1, and the preparation steps of the viewing angle adjustment film 6 include:

[0088] Provide a substrate;

[0089] A plurality of dimming microstructures 61 are formed on one side of the substrate;

[0090] A filling layer 62 is formed on the side of the plurality of dimming microstructures 61 away from the substrate; and

[0091] The substrate is peeled off.

[0092] In other embodiments, when the viewing angle adjustment film 6 can also be disposed on the side of the cover plate 4 near the substrate 1, the viewing angle adjustment film 6 can be directly fabricated on the encapsulation layer 3 after the encapsulation layer 3 is formed. Specifically, in this case, step S30 includes:

[0093] S301: An encapsulation layer 3 is formed on the side of the light-emitting device layer 2 away from the substrate 1;

[0094] S302: A plurality of dimming microstructures 61 are formed on the side of the encapsulation layer 3 away from the substrate 1; and

[0095] S303: Forming a filling layer 62 covering the side of the plurality of dimming microstructures 61 away from the substrate 1; and

[0096] S304: The cover plate 4 and the polarizer 5 are sequentially attached to the side of the filling layer 62 away from the substrate 1. Specifically, the refractive index of the filling layer 62 is greater than the refractive index of the dimming microstructure 61. The refractive index of the dimming microstructure 61 is in the range of 1.2 to 1.4, for example, 1.2, 1.25, 1.3, 1.35, 1.4; the refractive index of the filling layer 62 is in the range of 1.6 to 1.7, for example, 1.6, 1.65, 1.7.

[0097] Optionally, the material of the dimming microstructure 61 is resin; the material of the filling layer 62 is resin.

[0098] Further, in step S30, the first viewing angle curve is imported into geometric optics simulation software, and the parameters of the dimming microstructure 61 and the filling layer 62 are adjusted so that the maximum luminous efficiency point is adjusted from the side viewing angle to the main viewing angle and the second viewing angle curve is obtained.

[0099] Optionally, in this embodiment of the invention, the geometric optics simulation software in step S301 can be Demax simulation software.

[0100] Beneficial Effects: The display panel and its manufacturing method provided by this invention have a first viewing angle curve in the light-emitting device layer, which includes a maximum luminous efficiency point. By adjusting the film thickness of the light-emitting device layer to correspond to the maximum luminous efficiency, the luminous efficiency of the light-emitting device layer can be adjusted to the highest level within the allowable color range, and the maximum luminous efficiency point is located at the side viewing angle. Furthermore, a viewing angle adjustment film is applied to the side of the light-emitting device layer away from the substrate. This film adjusts the maximum luminous efficiency point from the side viewing angle to the main viewing angle, thus obtaining a second viewing angle curve. Compared to the prior art's method of sacrificing luminous brightness at the front viewing angle to achieve a large viewing angle, this invention can obtain a large viewing angle without reducing luminous brightness at the front viewing angle, achieving a balance between luminous brightness and viewing angle under a fixed color.

[0101] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. Those 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 scope defined in the claims.

Claims

1. A display panel, characterized in that, include: substrate; A light-emitting device layer is disposed on the substrate. The light-emitting device layer has a first viewing angle curve. The first viewing angle curve includes a point of maximum luminous efficiency. The film thickness of the light-emitting device layer is the film thickness corresponding to the point of maximum luminous efficiency. The point of maximum luminous efficiency is located at a side viewing angle. as well as A viewing angle adjustment film is disposed on the side of the light-emitting device layer away from the substrate; The viewing angle adjustment film is used to adjust the maximum luminous efficiency point from the side viewing angle to the main viewing angle and obtain a second viewing angle curve, wherein the normal direction of the side viewing angle is inclined to the normal direction of the main viewing angle. The tilt angle between the viewing angle corresponding to the maximum luminous efficiency point on the first viewing angle curve and the normal direction of the main viewing angle is 20 degrees to 40 degrees. The viewing angle adjustment film includes multiple dimming microstructures and a filling layer. The filling layer covers the side of the multiple dimming microstructures away from the substrate. The refractive index of the filling layer is greater than the refractive index of the dimming microstructures.

2. The display panel according to claim 1, characterized in that, The dimming microstructure is a combination of one or more of the following: a single-refractive lens, a birefractive lens, and a multirefractive lens.

3. The display panel according to claim 1, characterized in that, The light-emitting device layer includes a first electrode, a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, an electron injection layer, and a second electrode, which are sequentially stacked along the direction away from the substrate. The hole injection layer has a film thickness ranging from 20 nanometers to 30 nanometers, the hole transport layer has a film thickness ranging from 20 nanometers to 30 nanometers, and the organic light-emitting layer has a film thickness ranging from 20 nanometers to 30 nanometers.

4. The display panel according to claim 1, characterized in that, The display panel also includes: An encapsulation layer is applied to the side of the light-emitting device layer away from the substrate. A cover plate is disposed on the side of the encapsulation layer away from the substrate; and A polarizer is disposed on the side of the cover plate away from the substrate; The viewing angle adjustment film is located on the side of the polarizer away from the substrate.

5. A method for manufacturing a display panel, characterized in that, Includes the following steps: S10: Provides a substrate; S20: A light-emitting device layer is formed on the substrate. The light-emitting device layer has a first viewing angle curve. The first viewing angle curve includes a point of maximum luminous efficiency. The film thickness of the light-emitting device layer is adjusted so that the point of maximum luminous efficiency is located at the side viewing angle. as well as S30: A viewing angle adjustment film is formed on the side of the light-emitting device layer away from the substrate. The viewing angle adjustment film is used to adjust the maximum luminous efficiency point from the side viewing angle to the main viewing angle and obtain a second viewing angle curve. The viewing angle adjustment film includes a plurality of dimming microstructures and a filling layer. The filling layer covers the side of the plurality of dimming microstructures away from the substrate. The refractive index of the filling layer is greater than the refractive index of the dimming microstructures. The tilt angle between the viewing angle corresponding to the maximum luminous efficiency point on the first viewing angle curve and the normal direction of the main viewing angle is 20 degrees to 40 degrees.

6. The preparation method according to claim 5, characterized in that, Step S20 includes: S201: Import the parameters of the light-emitting device layer into physical optics simulation software to obtain the first viewing angle curve; and S202: Adjust the film thickness parameter of the light-emitting device layer so that the maximum luminous efficiency point on the first viewing angle curve is located at the side viewing angle.

7. The preparation method according to claim 5 or 6, characterized in that, Step S30 includes: S301: An encapsulation layer is formed on the side of the light-emitting device layer away from the substrate; S302: Sequentially attach the cover plate and polarizer to the side of the encapsulation layer away from the substrate; and S303: Provide a viewing angle adjustment film, and attach the viewing angle adjustment film to the side of the polarizer away from the substrate.

8. The preparation method according to claim 7, characterized in that, In step S30, the first viewing angle curve is imported into the geometric optics simulation software, and the parameters of the dimming microstructure and the filling layer are adjusted so that the maximum luminous efficiency point is adjusted from the side viewing angle to the main viewing angle and the second viewing angle curve is obtained.

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