Display panel, display panel preparation method and display device

Abstract

The invention discloses a display panel, a display panel preparation method and a display device. The display panel comprises a substrate; the light-emitting functional layer is arranged on one side of the substrate, and the light-emitting functional layer comprises a light-emitting structure; the cover plate is arranged on the side, away from the substrate, of the light-emitting functional layer, the cover plate is provided with a first surface and a second surface which are opposite, and the first surface is away from the substrate relative to the second surface; the reflective polaroid is arranged on the second surface of the cover plate; and the quarter-wave plate is arranged on one side, facing the light-emitting functional layer, of the reflective polarizing layer. When the emergent light of the light-emitting structure passes through the reflective polaroid, part of the emergent light is directly emitted through the reflective polaroid, part of the emergent light is reflected by the reflective polaroid, and the polarization direction of the reflected light can be changed by utilizing the quarter-wave plate, so that part of the emergent light which cannot pass through the reflective polaroid originally can pass through the reflective polaroid after being reflected; the light emitting rate of the display panel is improved, and the display effect of the display panel is improved.

Description

Technical Field

[0001] The present application belongs to the field of display technology, and in particular, relates to a display panel, a method for preparing a display panel, and a display device. Background Art

[0002] Organic Light Emitting Diode (OLED) and flat panel display devices based on technologies such as Light Emitting Diode (LED) have been widely used in various consumer electronic products such as mobile phones, televisions, laptops, desktop computers, etc. due to their advantages such as high image quality, power saving, thin body and wide application range, becoming the mainstream in display devices.

[0003] However, the performance of current OLED display products needs to be improved.

[0004] Therefore, there is an urgent need for a new display panel, a method for manufacturing a display panel, and a display device. Summary of the invention

[0005] The embodiments of the present application provide a display panel, a method for preparing a display panel, and a display device. When the light emitted from the light-emitting structure passes through a reflective polarizer, part of it will be directly emitted through the reflective polarizer, and part of it will be reflected by the reflective polarizer. The polarization direction of the reflected light can be changed by using a quarter-wave plate, so that part of the light that originally cannot pass through the reflective polarizer can pass through the reflective polarizer after reflection, thereby improving the light output rate of the display panel, improving the display effect of the display panel, and improving the performance of the display panel.

[0006] On the one hand, an embodiment of the present application provides a display panel, including: a substrate; a light-emitting functional layer, arranged on one side of the substrate, the light-emitting functional layer including a light-emitting structure; a cover plate, arranged on the side of the light-emitting functional layer away from the substrate, the cover plate having a first surface and a second surface opposite to each other, the first surface being arranged away from the substrate relative to the second surface; a reflective polarizer, the reflective polarizer being arranged on the second surface of the cover plate; and a quarter-wave plate, arranged on the side of the reflective polarizer facing the light-emitting functional layer.

[0007] According to one aspect of the present application, the angle between the fast axis or the slow axis of the quarter wave plate and the transmission axis of the reflective polarizer is 45°; preferably, an adhesive layer is provided between the quarter wave plate and the reflective polarizer.

[0008] According to one aspect of the present application, the reflective polarizer includes a first material layer and a second material layer overlapped in a direction perpendicular to the plane of the substrate; the first material layer includes a uniform medium, the second material layer includes a birefringent medium, along the first direction, the refractive index of the second material layer is equal to the refractive index of the first material layer, along the second direction, there is a difference between the refractive index of the second material layer and the refractive index of the first material layer, and the first direction and the second direction intersect; preferably, the reflectivity and transmittance of the reflective polarizer are both 50%.

[0009] According to one aspect of the present application, along a direction perpendicular to the plane where the substrate is located, the minimum distance between the quarter wave plate and the light emitting structure is less than or equal to a preset distance; preferably, the preset distance is greater than or equal to 0.1 μm and less than or equal to 20 μm; preferably, an organic material is provided between the quarter wave plate and the light emitting structure.

[0010] According to one aspect of the present application, a first groove is provided on the second surface of the cover plate, and the reflective polarizer and the quarter wave plate are located in the first groove; preferably, along a direction perpendicular to the plane where the substrate is located, the depth of the first groove is less than or equal to the sum of the thicknesses of the reflective polarizer and the quarter wave plate.

[0011] According to one aspect of the present application, it also includes an encapsulation adhesive layer, which connects the cover plate and the light-emitting functional layer; along a direction perpendicular to the plane where the substrate is located, the orthographic projection of the encapsulation adhesive layer on the substrate and the orthographic projection of the first groove on the substrate do not overlap.

[0012] According to one aspect of the present application, a linear polarizer is further included on the first surface of the cover plate, and the extension direction of the transmission axis of the linear polarizer is the same as the extension direction of the transmission axis of the reflective polarizer.

[0013] According to one aspect of the present application, it also includes an encapsulation adhesive layer, and the edges of the reflective polarizer and the quarter-wave plate are respectively provided with a second groove and a third groove that are connected to each other, and the encapsulation adhesive layer is at least partially located in the second groove and the third groove to connect the light-emitting functional layer and the cover plate; preferably, the orthographic projection of the second groove on the substrate and the orthographic projection of the third groove on the substrate coincide with each other.

[0014] On the other hand, the present invention also provides a method for preparing a display panel, comprising: providing a cover plate, the cover plate having a first surface and a second surface relative to each other; forming a reflective polarizer and a quarter-wave plate in sequence on the second surface of the cover plate; providing a substrate and a light-emitting functional layer arranged on one side of the substrate, and attaching the cover plate having the reflective polarizer and the quarter-wave plate to the side of the light-emitting functional layer facing away from the substrate.

[0015] According to another aspect of the present application, the step of providing a cover plate includes: etching one side of the second surface of the cover plate to form a first groove; the step of sequentially forming a reflective polarizer and a quarter-wave plate on the second surface of the cover plate includes: sequentially forming the reflective polarizer and the quarter-wave plate in the first groove located on the second surface.

[0016] Another aspect of the present invention provides a display device, comprising the display panel in any one of the above embodiments.

[0017] Compared with the prior art, the display panel provided by the embodiment of the present invention includes a substrate, a light-emitting functional layer, a reflective polarizer and a quarter-wave plate. When the light output from the light-emitting structure passes through the reflective polarizer, part of it will be directly emitted through the reflective polarizer, and part of it will be reflected by the reflective polarizer. The quarter-wave plate can be used to change the polarization direction of the reflected light, so that part of the light output that originally could not pass through the reflective polarizer can pass through the reflective polarizer after reflection, thereby improving the light output rate of the display panel, improving the display effect of the display panel, and improving the performance of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 is a schematic structural diagram of a display panel provided by an embodiment of the present invention;

[0020] Figure 2 An embodiment provides Figure 1 Schematic diagram of the cross-sectional structure at A in the middle;

[0021] Figure 3 Another embodiment provides Figure 1 Schematic diagram of the cross-sectional structure at A in the middle;

[0022] Figure 4 Yet another embodiment provides Figure 1Schematic diagram of the cross-sectional structure at A in the middle;

[0023] Figure 5 is a flow chart of a method for preparing a display panel provided by an embodiment of the present invention;

[0024] Figure 6 is a cross-sectional schematic diagram of a structure obtained in step S110 in a method for preparing a display panel provided by an embodiment of the present invention;

[0025] Figure 7 It is a schematic cross-sectional view of a structure obtained in step S120 in a method for preparing a display panel provided in an embodiment of the present invention.

[0026] In the attached figure:

[0027] 1-substrate; 2-light-emitting structure; 21-first electrode layer; 22-light-emitting layer; 23-second electrode layer; 3-cover plate; 4-reflective polarizer; 5-quarter wave plate; 6-encapsulation glue layer; 7-pixel definition layer; 8-support part; F1-first surface; F2-second surface; Y-active layer; G-gate; S-source; D-drain; C-storage capacitor; C1-first plate; C2-second plate; K1-first slot; K2-second slot; K3-third slot. DETAILED DESCRIPTION

[0028] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present application and are not configured to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0029] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0030] It should be understood that when describing the structure of a component, when a layer or a region is referred to as being "on" or "over" another layer or another region, it may mean that it is directly on the other layer or another region, or that other layers or regions are included between it and the other layer or another region. Moreover, if the component is turned over, the layer or a region will be "below" or "beneath" another layer or another region.

[0031] It is obvious to those skilled in the art that various modifications and changes can be made in the present application without departing from the spirit or scope of the present application. Therefore, the present application is intended to cover modifications and changes of the present application that fall within the scope of the corresponding claims (technical solutions for protection) and their equivalents. It should be noted that the implementation methods provided in the embodiments of the present application can be combined with each other without contradiction.

[0032] The embodiments of the present application provide a display panel, a method for manufacturing a display panel, and a display device. Figures 1 to 7 Various embodiments of a display panel, a method for manufacturing a display panel, and a display device are described.

[0033] See also Figure 1 to Figure 2 A display panel provided in an embodiment of the present application includes: a substrate 1; a light-emitting functional layer, which is arranged on one side of the substrate 1, and the light-emitting functional layer includes a light-emitting structure 2; a cover plate 3, which is arranged on the side of the light-emitting functional layer away from the substrate 1, and the cover plate 3 has a first surface F1 and a second surface F2 opposite to each other, and the first surface F1 is arranged away from the substrate 1 relative to the second surface F2; a reflective polarizer 4, which is arranged on the second surface F2 of the cover plate 3; and a quarter-wave plate 5, which is arranged on the side of the reflective polarizer layer facing the light-emitting functional layer.

[0034] The display panel provided by the embodiment of the present invention includes a substrate 1, a light-emitting functional layer, a reflective polarizer 4 and a quarter-wave plate 5. When the light output from the light-emitting structure 2 passes through the reflective polarizer 4, part of it will be directly emitted through the reflective polarizer 4, and part of it will be reflected by the reflective polarizer 4. The quarter-wave plate 5 can be used to change the polarization direction of the reflected light, so that part of the light output that originally cannot pass through the reflective polarizer 4 can pass through the reflective polarizer 4 after reflection, thereby improving the light output rate of the display panel, improving the display effect of the display panel, and improving the performance of the display panel.

[0035] In this embodiment, the reflective polarizer 4 can use APF (Advanced Polarizer Film, multi-layer reflective polarizer). APF is a film layer formed by stacking two organic materials. It is formed by alternating the stacking of two materials. The film layers are overlapped with high and low refractive indices. The thickness is precisely controlled by extrusion and stretching processes, so a high reflectivity can be achieved. In addition, the performance of the polarizer is achieved by stretching the film layer. Only light with the same direction as the film layer stretching direction can pass through. This makes it have the characteristic of light selection in the visible light range, that is, if the light irradiated on its surface is inconsistent with its polarization direction, reflection occurs, and the reflection efficiency is high, while if the polarization direction is consistent, transmission occurs.

[0036] Optionally, the reflectivity and transmittance of the reflective polarizer 4 are both 50%. The light emitted by the light-emitting structure 2 can be disassembled into 50% polarized light parallel to the APF transmission axis (assuming S light) and 50% polarized light perpendicular to the APF transmission axis (assuming P light). Among them, the S light is transmitted by the APF, and the P light will be reflected. This part of the light will become circularly polarized light (assuming left-handed) after passing through the quarter-wave plate 5, and then become right-handed polarized light after reflection from the anode. When passing through the quarter-wave plate 5 again, it will be converted into linearly polarized light. At this time, the polarization direction is reversed and can pass directly through the APF, thereby improving the transmittance of the display panel.

[0037] Specifically, if the reflectivity of the reflected light at the light-emitting functional layer is 50%, the transmittance of the display panel can reach 50% (50% of the light emitted from the light-emitting structure 2 directly from the reflective polarizer 4) + 50% (50% of the light emitted from the light-emitting structure 2 reflected by the reflective polarizer 4) × 50% (the reflectivity of the reflected light at the light-emitting functional layer is 50%) = 75%. Compared with the transmittance of less than 70% in the prior art, the technical solution provided by the present application achieves a significant improvement in the transmittance of the display panel.

[0038] Among them, the quarter wave plate 5 can be used to change the polarization direction of polarized light. The quarter wave plate 5 can produce a phase delay of an odd multiple of π / 2, which can change the incident linear polarized light into elliptically polarized light. If the light vector of the incident linear polarized light is ±45° with the fast and slow axes of the wave plate, circularly polarized light will be obtained.

[0039] Optionally, the angle between the fast axis or the slow axis of the quarter wave plate 5 and the transmission axis of the reflective polarizer 4 is 45°.

[0040] Optionally, the substrate 1 may be a hard substrate, such as a glass substrate, or a flexible substrate, and its material may be polyimide, polystyrene, polyethylene terephthalate, polyparaxylene, polyethersulfone or polyethylene naphthalate. The substrate 1 is mainly used to support the device disposed thereon.

[0041] Optionally, the light emitting structure 2 includes a first electrode layer 21 , a light emitting layer 22 and a second electrode layer 23 which are stacked in a direction away from the substrate 1 .

[0042] Optionally, the light-emitting layer 22 includes one or more of an electron injection layer, an electron transport layer, a light-emitting material layer, a hole blocking layer, an electron blocking layer, a hole transport layer and a hole injection layer. It can be selected according to the specific type of the light-emitting layer 22, and there is no special limitation. The electron injection layer, the electron transport layer, and the hole blocking layer can be arranged between the second electrode layer 23 and the light-emitting material layer. The electron blocking layer, the hole transport layer and the hole injection layer can be arranged between the first electrode layer 21 and the light-emitting material layer.

[0043] The material of the first electrode layer 21 is generally a material with a high work function to improve the hole injection efficiency, and may be gold (Au), platinum (Pt), titanium (Ti), silver (Ag), indium tin oxide (ITO, Indium Tin Oxide), zinc tin oxide (IZO) or a transparent conductive polymer (such as polyaniline), etc. For example, the first electrode layer 21 may be made of an ITO-Ag-ITO composite material, without special limitation.

[0044] The material of the second electrode layer 23 can be one of the metal materials such as silver (Ag), aluminum (Al), lithium (Li), magnesium (Mg), ytterbium (Yb), calcium (Ca) or indium (In), and can also be an alloy of the aforementioned metal materials, such as magnesium-silver alloy (Mg / Ag) and lithium-aluminum alloy (Li / Al), which is not limited in this embodiment.

[0045] Optionally, a pixel definition layer 7 and a support portion 8 disposed on the side of the pixel definition layer 7 facing away from the substrate 1 are further included between the substrate 1 and the light-emitting functional layer. The pixel definition layer 7 includes a pixel opening, and the light-emitting structure 2 is at least partially located in the pixel opening. The support portion 8 can be made of the same material as the pixel definition layer 7 to reduce costs. The sum of the thickness of the support portion 8 and the pixel definition layer 7 can be between 2 μm and 10 μm.

[0046] It can be understood that the cover plate 3 is a film layer made of materials such as glass with high light transmittance, which plays a role in protecting the display panel. Specifically, the cover plate 3 can be made of rigid materials with relatively low cost; it can also be made of flexible materials so that the cover plate 3 can be folded, so that it can be applied to flexible and foldable display panels. Specifically, the cover plate 3 can be made of transparent, soft, and foldable materials such as UTG (Ultra Thin Glass), CPI (Colorless Polyimide), PET (Polyethylene Terephthalate), etc., to achieve the bendability and foldability of the cover plate 3, which is convenient for application in foldable display panels.

[0047] Optionally, the display panel further includes an array layer disposed between the substrate 1 and the pixel definition layer 7, and the array layer may include a first conductive layer, a second conductive layer, and a third conductive layer disposed on one side of the substrate 1 and stacked. An insulating layer is disposed between adjacent conductive film layers. Exemplarily, a pixel driving circuit disposed in the array layer includes a transistor and a storage capacitor C. The transistor includes an active layer Y, a gate G, a source S, and a drain D. The storage capacitor C includes a first plate C1 and a second plate C2. As an example, the gate G and the first plate C1 may be located in the first conductive layer, the second plate C2 may be located in the second conductive layer, and the source S and the drain D may be located in the third conductive layer.

[0048] Optionally, an adhesive layer is provided between the quarter wave plate 5 and the reflective polarizer 4. The adhesive layer may be made of adhesive materials such as OCA (Optically Clear Adhesive) or pressure sensitive adhesive, as long as it does not affect the light transmittance of the display panel.

[0049] In some optional embodiments, the reflective polarizer 4 includes a first material layer and a second material layer which are overlapped in a direction perpendicular to the plane where the substrate 1 is located; the first material layer includes a uniform medium, and the second material layer includes a birefringent medium. Along the first direction, the refractive index of the second material layer is equal to the refractive index of the first material layer, and along the second direction, there is a difference between the refractive index of the second material layer and the refractive index of the first material layer, and the first direction and the second direction intersect.

[0050] In this embodiment, the above-mentioned film layer is set so that when viewed as a whole, the reflective polarizer 4 can be considered as a uniform material in one direction, and in another direction, by controlling the thickness of the film layer, its reflectivity in the visible light range (380-780nm) is 100% (theoretically), thereby achieving the goal that light in one polarization direction can be transmitted and light in another polarization direction can be completely reflected.

[0051] Optionally, the reflectivity and transmittance of the reflective polarizer 4 are both 50%, and the reflective polarizer 4 with a reflectivity and transmittance of 50% can be obtained by adjusting the number of layers, film thickness and refractive index of the reflective polarizer 4.

[0052] In some optional embodiments, in a direction perpendicular to the plane where the substrate 1 is located, the minimum distance between the quarter wave plate 5 and the light emitting structure 2 is less than or equal to a preset distance.

[0053] In this embodiment, the position of the quarter-wave plate 5 can be adjusted to adjust the distance between the quarter-wave plate 5 and the light-emitting structure 2 so that the distance meets the preset distance, thereby avoiding interference and diffraction of reflected light between the quarter-wave plate 5 and the light-emitting structure 2, improving rainbow patterns and moiré patterns, and improving the display effect of the display panel.

[0054] Optionally, the preset distance is greater than or equal to 0.1 μm and less than or equal to 20 μm. For example, the preset distance may be equal to any one of 0.1 μm, 5 μm, 10 μm, 15 μm, and 20 μm.

[0055] Optionally, an organic material is provided between the quarter wave plate 5 and the light emitting structure 2 , that is, the organic material is filled between the quarter wave plate 5 and the light emitting structure 2 to prevent the quarter wave plate 5 from sinking and affecting the light emitting effect.

[0056] In some optional embodiments, a first slot K1 is provided on the second surface F2 of the cover plate 3 , and the reflective polarizer 4 and the quarter-wave plate 5 are located in the first slot K1 .

[0057] By setting the first groove K1 to accommodate the reflective polarizer 4 and the quarter wave plate 5, the influence of the reflective polarizer 4 and the quarter wave plate 5 on the overall film thickness of the display panel can be reduced, which facilitates the realization of lightness and thinness. The shape and size of the first groove K1 can be set according to the thickness and shape of the reflective polarizer 4 and the quarter wave plate 5.

[0058] Optionally, along a direction perpendicular to the plane where the substrate 1 is located, the depth of the first slot K1 is less than or equal to the sum of the thicknesses of the reflective polarizer 4 and the quarter-wave plate 5 .

[0059] When the depth of the first slot K1 is less than the sum of the thicknesses of the reflective polarizer 4 and the quarter-wave plate 5, part of the quarter-wave plate 5 may extend outward in the direction of the light-emitting structure 2 relative to the first slot K1, so as to be closer to the light-emitting structure 2. Alternatively, the depth of the first slot K1 may also be equal to the sum of the thicknesses of the reflective polarizer 4 and the quarter-wave plate 5, that is, the surface of the quarter-wave plate 5 facing the substrate 1 is flush with the surface of the part of the cover plate 3 facing the substrate 1 where the first slot K1 is not formed, thereby improving the flatness of the film layer.

[0060] In some optional embodiments, the display panel also includes an encapsulation adhesive layer 6, which connects the cover plate 3 and the light-emitting functional layer; along a direction perpendicular to the plane where the substrate 1 is located, the orthographic projection of the encapsulation adhesive layer 6 on the substrate 1 and the orthographic projection of the first groove K1 on the substrate 1 do not overlap.

[0061] In this embodiment, since the reflective polarizer 4 and the quarter-wave plate 5 are arranged in the first groove K1, they will not interfere with the encapsulation layer 6. Therefore, the encapsulation layer 6 can be directly connected to the cover plate 3 and the light-emitting functional layer. In the direction perpendicular to the plane where the substrate 1 is located, the orthographic projection of the encapsulation layer 6 on the substrate 1 and the orthographic projection of the first groove K1 on the substrate 1 do not overlap, which means that the encapsulation layer 6 can be correspondingly connected to the cover plate 3 and the light-emitting functional layer that are not provided with the first groove K1. For example, the encapsulation layer 6 can be arranged at the edge portion of the cover plate 3 to achieve encapsulation, so as to ensure that the height of the encapsulation layer 6 is consistent with the existing process.

[0062] Optionally, the packaging glue layer 6 may adopt a packaging method of Frit (glass) packaging, where Frit packaging is performed using glass glue, which is a mixture of glass powder and solvent.

[0063] See also Figure 4 In some optional embodiments, the display panel further includes a packaging adhesive layer 6, and the edges of the reflective polarizer 4 and the quarter-wave plate 5 are respectively provided with a second groove K2 and a third groove K3 that are connected to each other, and the packaging adhesive layer 6 is at least partially located in the second groove K2 and the third groove K3 to connect the light-emitting functional layer and the cover plate 3.

[0064] In this embodiment, there is no need to make grooves on the cover plate 3 to ensure the structural strength of the cover plate 3. Instead, a second groove K2 and a third groove K3 connected to each other are set at the edges of the reflective polarizer 4 and the quarter-wave plate 5 to avoid the encapsulation layer 6 and leave space for the setting of the encapsulation layer 6, so as to facilitate the encapsulation layer 6 to connect the light-emitting functional layer and the cover plate 3.

[0065] Optionally, the orthographic projection of the second groove K2 on the substrate 1 coincides with the orthographic projection of the third groove K3 on the substrate 1 .

[0066] See also Figure 3 In some optional embodiments, the display panel further includes a linear polarizer disposed on the first surface F1 of the cover plate 3 , and the extension direction of the transmission axis of the linear polarizer is the same as the extension direction of the transmission axis of the reflective polarizer 4 .

[0067] It should be noted that the linear polarizer can convert the incoming light at the linear polarizer into outgoing linear polarized light, and the extension direction of the transmission axis of the linear polarizer is the same as the extension direction of the transmission axis of the reflective polarizer 4, so as to ensure that the outgoing light at the reflective polarizer 4 can all be emitted from the linear polarizer without being absorbed. Compared with conventional circular polarizers, linear polarizers have higher light output efficiency.

[0068] See also Figure 5 The embodiment of the present invention further provides a method for preparing a display panel, comprising:

[0069] S110: Provide a cover plate 3, the cover plate 3 having a first surface F1 and a second surface F2 opposite to each other. Figure 6 As shown;

[0070] S120: forming a reflective polarizer 4 and a quarter wave plate 5 on the second surface F2 of the cover plate 3 in sequence, such as Figure 7 As shown;

[0071] S130: providing a substrate 1 and a light-emitting functional layer disposed on one side of the substrate 1, and attaching a cover plate 3 formed with a reflective polarizer 4 and a quarter-wave plate 5 to the side of the light-emitting functional layer away from the substrate 1, such as Figure 4 shown.

[0072] The display panel preparation method provided by the embodiment of the present invention forms a reflective polarizer 4 and a quarter-wave plate 5 on the second surface F2 of the cover plate 3 in sequence, so that when the light output from the light-emitting structure 2 passes through the reflective polarizer 4, part of it will be directly emitted through the reflective polarizer 4, and part of it will be reflected by the reflective polarizer 4. The quarter-wave plate 5 can be used to change the polarization direction of the reflected light, so that part of the light that originally cannot pass through the reflective polarizer 4 can pass through the reflective polarizer 4 after reflection, so as to improve the light output rate of the display panel and improve the display effect of the display panel.

[0073] In step S110, the first surface F1 of the cover plate 3 corresponds to the light emitting side, and the second surface F2 corresponds to the light incident side. The cover plate 3 can be made of a rigid material, such as a rigid glass material, which has a relatively low cost; it can also be made of a flexible material so that the cover plate 3 can be folded, so that it can be applied to a flexible and foldable display panel. The cover plate 3 can be made of transparent, soft, and foldable materials such as UTG, CPI, and PET.

[0074] In step S120 , the reflective polarizer 4 may be prepared by using APF (Advanced Polarizer Film, multi-layer reflective polarizer 4 ).

[0075] In step S130 , the cover plate 3 and the light-emitting functional layer may be bonded and packaged by the packaging adhesive layer 6 .

[0076] In some optional embodiments, the step of providing the cover plate 3 includes: etching one side of the second surface F2 of the cover plate 3 to form a first groove K1; the step of sequentially forming a reflective polarizer 4 and a quarter wave plate 5 on the second surface F2 of the cover plate 3 includes: sequentially forming a reflective polarizer 4 and a quarter wave plate 5 in the first groove K1 located on the second surface F2.

[0077] In this embodiment, the first groove K1 can be formed by at least one of wet etching and dry etching. Etching includes dry etching and wet etching. The difference between dry etching and wet etching is that the wet method uses solvents or solutions for etching. Wet etching is a purely chemical reaction process, which refers to the use of chemical reactions between the solution and the pre-etching material to remove the parts not masked by the masking film material to achieve the purpose of etching. The advantages are good selectivity, good repeatability, high production efficiency, simple equipment and low cost. There are many types of dry etching, including photoevaporation, vapor phase corrosion, plasma corrosion and the like. The advantages of dry etching are: good anisotropy, high selectivity, good controllability, flexibility and repeatability, safe operation of fine lines, easy automation, no chemical waste liquid, no pollution introduced during the treatment process, and high cleanliness.

[0078] After the etching is completed, a deposition process, such as a CVD (Chemical Vapor Deposition) process, is used to form the layer.

[0079] An embodiment of the present invention further provides a display device, comprising the display panel in any of the above embodiments.

[0080] The display device provided by the embodiment of the present invention has the technical effect of the technical solution of the display panel in any of the above embodiments, and the explanation of the structures and terms that are the same as or corresponding to the above embodiments will not be repeated here.

[0081] The display device provided in the embodiment of the present invention may be an organic light-emitting diode (OLED) display device, a quantum dot light-emitting diode (QLED) or a micro flat panel display device (Micro-OLED or Micro-LED).

[0082] The display device provided in the embodiment of the present application can be applied to a mobile phone, or it can be any electronic product with a display function, including but not limited to the following categories: televisions, laptops, desktop displays, tablet computers, digital cameras, smart bracelets, smart glasses, car displays, medical equipment, industrial control equipment, touch interactive terminals, etc. The embodiment of the present application does not make any special limitations on this.

[0083] The above are only specific implementation methods of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

[0084] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

Claims

1. A display panel, characterized in that: include: substrate; A light-emitting functional layer is provided on one side of the substrate, and the light-emitting functional layer includes a light-emitting structure; A cover plate, arranged on a side of the light-emitting functional layer away from the substrate, the cover plate having a first surface and a second surface opposite to each other, the first surface being arranged away from the substrate relative to the second surface; A reflective polarizer, the reflective polarizer is disposed on the second surface of the cover plate; A quarter wave plate is arranged on a side of the reflective polarizing layer facing the light-emitting functional layer.

2. The display panel according to claim 1, characterized in that: The angle between the fast axis or slow axis of the quarter wave plate and the transmission axis of the reflective polarizer is 45°; Preferably, an adhesive layer is provided between the quarter wave plate and the reflective polarizer.

3. The display panel according to claim 1, characterized in that: The reflective polarizer includes a first material layer and a second material layer which are overlapped and arranged in a direction perpendicular to the plane where the substrate is located; The first material layer comprises a homogeneous medium, the second material layer comprises a birefringent medium, along a first direction, the refractive index of the second material layer is equal to the refractive index of the first material layer, along a second direction, there is a difference between the refractive index of the second material layer and the refractive index of the first material layer, and the first direction and the second direction intersect; Preferably, the reflectivity and transmittance of the reflective polarizer are both 50%; Preferably, along a direction perpendicular to the plane where the substrate is located, the minimum distance between the quarter wave plate and the light emitting structure is less than or equal to a preset distance; Preferably, the preset distance is greater than or equal to 0.1 μm and less than or equal to 20 μm; Preferably, an organic material is provided between the quarter wave plate and the light emitting structure.

4. The display panel according to claim 1, characterized in that: A first groove is provided on the second surface of the cover plate, and the reflective polarizer and the quarter-wave plate are located in the first groove; Preferably, along a direction perpendicular to the plane where the substrate is located, the depth of the first groove is less than or equal to the sum of the thicknesses of the reflective polarizer and the quarter-wave plate.

5. The display panel according to claim 4, characterized in that: It also includes a packaging glue layer, wherein the packaging glue layer connects the cover plate and the light-emitting functional layer; Along a direction perpendicular to the plane where the substrate is located, an orthographic projection of the packaging glue layer on the substrate and an orthographic projection of the first groove on the substrate do not overlap.

6. The display panel according to claim 1, characterized in that: It also includes a linear polarizer disposed on the first surface of the cover plate, wherein the extension direction of the light transmission axis of the linear polarizer is the same as the extension direction of the light transmission axis of the reflective polarizer.

7. The display panel according to claim 1, characterized in that: It also includes a packaging glue layer, the edges of the reflective polarizer and the quarter-wave plate are respectively provided with a second groove and a third groove that are connected, and the packaging glue layer is at least partially located in the second groove and the third groove to connect the light-emitting functional layer and the cover plate; Preferably, the orthographic projection of the second groove on the substrate coincides with the orthographic projection of the third groove on the substrate.

8. A method for preparing a display panel, characterized in that: include: Providing a cover plate, the cover plate having a first surface and a second surface opposite to each other; forming a reflective polarizer and a quarter wave plate in sequence on the second surface of the cover plate; A substrate and a light-emitting functional layer arranged on one side of the substrate are provided, and the cover plate formed with the reflective polarizer and the quarter-wave plate is attached to the side of the light-emitting functional layer away from the substrate.

9. The method for preparing a display panel according to claim 8, characterized in that: The step of providing the cover plate includes: etching one side of the second surface of the cover plate to form a first groove; The step of sequentially forming a reflective polarizer and a quarter wave plate on the second surface of the cover plate comprises: The reflective polarizer and the quarter wave plate are sequentially formed in the first groove located on the second surface.

10. A display device, characterized in that: A display panel comprising any one of claims 1 to 7.

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