Antireflection composite film, display panel, and display device

Abstract

The present application provides an anti-reflection composite film, a display panel comprising the anti-reflection composite film and a display device. The anti-reflection composite film comprises a substrate and an anti-reflection composite material layer on at least one side surface of the substrate, wherein the anti-reflection composite material layer comprises at least two reflection material layers with different refractive indexes. The technical scheme of the present application can reduce the reflectivity of the display panel and the damage of short-wavelength ultraviolet rays in the environment to the film layers in the display device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to an anti-reflection composite film, a display panel comprising the anti-reflection composite film and a display device. BACKGROUND

[0002] An organic light emitting diode (OLED) display screen is easily affected by ambient light reflection in the display process, which reduces the display contrast and display quality. Therefore, a circular polarizer or an anti-reflection film is generally attached to the light-emitting surface of the OLED display screen to reduce the reflectivity. However, the light transmittance of the circular polarizer used in the OLED display screen is relatively low, generally about 40%, so that the anti-reflection characteristics of the OLED display screen are improved by attaching the circular polarizer, which greatly sacrifices the light-emitting efficiency of the OLED display screen. If the anti-reflection characteristics of the OLED display screen are improved by attaching the anti-reflection film, since the anti-reflection film layer generally has a relatively high light transmittance, the ultraviolet light in the ambient light enters the interior of the OLED display screen, which directly affects the performance of the OLED device, or makes the OLED encapsulation glue yellow, which affects the light-emitting efficiency of the device, and the anti-reflection film layer is prone to produce bubbles and other defects during the attachment process, which affects the yield of the product. SUMMARY

[0003] The present application provides an anti-reflection composite film, a display panel and a display device to solve or alleviate one or more technical problems in the prior art.

[0004] According to a first aspect of the present application, an anti-reflection composite film is provided, comprising a substrate and an anti-reflection composite material layer located on at least one side surface of the substrate; wherein the anti-reflection composite material layer comprises at least two reflection material layers with different refractive indexes.

[0005] According to one specific embodiment, the anti-reflection composite material layer comprises at least one layer with a transmittance lower than 50% in a short-wavelength ultraviolet region below 325 nm and a transmittance higher than 85% in a visible light wavelength region of 380-780 nm.

[0006] According to one specific embodiment, the two reflection material layers with different refractive indexes comprise a first anti-reflection material layer located on the surface of the substrate, and a second anti-reflection material layer located on the surface of the first anti-reflection material layer away from the substrate, and the refractive index of the first anti-reflection material layer is greater than the refractive index of the second anti-reflection material layer.

[0007] According to one specific embodiment, the refractive index of the first anti-reflection material layer is higher than 1.5, and the refractive index of the second anti-reflection material layer is less than 1.5.

[0008] According to one embodiment, the refractive index of the first anti-reflection material layer and the refractive index of the second anti-reflection material layer satisfy the following condition:

[0009] 1.5≤N1 2 / N2 2 ≤2

[0010] wherein N1 is the refractive index of the first anti-reflection material layer, and N2 is the refractive index of the second anti-reflection material layer.

[0011] According to one embodiment, the first anti-reflection material layer is formed of silicon nitride.

[0012] According to one embodiment, the second anti-reflection material layer is formed of one or more selected from silicon oxide, sodium fluoride, lithium fluoride and potassium fluoride.

[0013] According to one embodiment, the thickness D of the first anti-reflection material layer and the second anti-reflection material layer is 70-120 nm, or (2k+1)D, wherein k is a positive integer.

[0014] According to a second aspect of the present application, there is provided a display panel comprising the above anti-reflection composite film.

[0015] According to a third aspect of the present application, there is provided a display device comprising the above display panel.

[0016] The present application can reduce the reflectivity of the display panel, and can reduce the damage of short-wavelength ultraviolet light in ambient light to the film layers in the display device.

[0017] The above summary is intended to illustrate, but not limit, the present application in any way. Further aspects, embodiments and features of the present application will be readily apparent to those skilled in the art by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0018] In the drawings, like reference numerals refer to same or similar components throughout the several views. These drawings are not necessarily to scale, and the proportions of certain parts have been exaggerated for the sake of clarity. It should be understood that these drawings are only schematic and are intended to provide a general appreciation of the application disclosed herein. It will be readily apparent to those skilled in the art that other embodiments can be made and that the present application is not limited to the embodiments set out below.

[0019] Figure 1 A schematic diagram showing the structure of an anti-reflection film according to the related art;

[0020] Figure 2 A schematic diagram showing the structure of an anti-reflection composite film according to a first embodiment;

[0021] Figure 3 Fig. 2 shows a schematic diagram of a structure of an anti-reflection composite film according to the second embodiment;

[0022] Figure 4 Fig. 3 shows a schematic diagram of a structure of an anti-reflection composite film according to the third embodiment;

[0023] Figure 5 Fig. 4 shows a matching diagram of the transmittance of the silicon nitride film layer and the light emission spectrum of the OLED light emission layer in the anti-reflection composite film according to the first embodiment;

[0024] Figure 6 Fig. 5 shows a simulation result of the anti-reflection effect of the anti-reflection composite film according to the first embodiment;

[0025] Figure 7A and Figure 7B Fig. 6 shows the yellowing effect of different short-wavelength ultraviolet light on the encapsulation filling glue;

[0026] Figure 8 Fig. 7 shows the influence of the thickness of the silicon nitride anti-reflection material layer on the reflectivity.

[0027] BRIEF DESCRIPTION OF DRAWINGS

[0028] 10: cover plate; 20: first anti-reflection composite material layer; 21: first anti-reflection material layer; 22: second anti-reflection material layer; 30: second anti-reflection composite material layer; 31: third anti-reflection material layer; 32: fourth anti-reflection material layer; 40: encapsulation dam glue; 50: encapsulation filling glue; 60: light emission material layer; 70: substrate; A: light emission area of the display panel; B: transparent area of the display panel. DETAILED DESCRIPTION

[0029] In the following, only certain exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present application. Therefore, the drawings and the description are considered to be exemplary in nature rather than limiting.

[0030] In the related art, as shown in CN100383562A, a low-reflectivity brightness-enhancing multilayer optical film is disclosed for enhancing the brightness of an organic light-emitting diode (OLED) display, making the display have an anti-reflection function, the multilayer optical film comprising a transparent substrate, a light-diffusing layer formed on the transparent substrate by a wet coating method, and a light-absorbing layer formed on the light-diffusing layer by a wet coating method, wherein the light-diffusing layer comprises resin and spherical particles, and the light-absorbing layer comprises core-shell structure light-absorbing particles composed of a light-absorbing agent as a core material and a transparent resin as a shell material. The method is complex in process, and there is a risk of increasing the haze of the OLED display and affecting the display quality. Figure 1 Therefore, the present application is proposed.

[0031] The present application provides an anti-reflection composite film, comprising a substrate and an anti-reflection composite material layer on one or both sides of the substrate. The anti-reflection composite material layer comprises at least two layers of reflection materials with different refractive indexes.

[0032] In order to achieve the purpose of anti-reflection and reducing the influence of environmental ultraviolet rays, at least one layer of the anti-reflection composite material layer used in the present application comprises a material layer with a transmittance lower than 50% (preferably lower than 20%) in the short-wavelength ultraviolet region below 325 nm and a transmittance higher than 85% (preferably higher than 90%) in the visible light wavelength region of 380-780 nm.

[0033] According to one specific embodiment, the above-mentioned two layers of reflection materials with different refractive indexes comprise a first anti-reflection material layer on one side of the substrate, and a second anti-reflection material layer on the surface of the first anti-reflection material layer away from the substrate, and the refractive index of the first anti-reflection material layer is greater than the refractive index of the second anti-reflection material layer.

[0034] Specifically, the refractive index of the first anti-reflection material layer can be selected to be higher than 1.5, and the refractive index of the second anti-reflection material layer can be selected to be less than 1.5.

[0035] The refractive index of the first anti-reflection material layer and the refractive index of the second anti-reflection material layer satisfy the following conditions:

[0036] 1.5 ≤ N1 2 / N2 2 ≤ 2

[0037] Wherein, N1 is the refractive index of the first anti-reflection material layer, and N2 is the refractive index of the second anti-reflection material layer.

[0038] According to another specific embodiment, one side of the substrate comprises a first anti-reflection material layer and a second anti-reflection material layer, and the opposite side can comprise a third anti-reflection material layer and a fourth anti-reflection material layer. The refractive index and transmittance of the third anti-reflection material layer and the fourth anti-reflection material layer are as defined above for the first anti-reflection material layer and the second anti-reflection material layer, respectively. Preferably, the third anti-reflection material layer can be the same as or different from the first anti-reflection material layer, and the fourth anti-reflection material layer can be the same as or different from the second anti-reflection material layer.

[0039] The above-mentioned first anti-reflection material layer and third anti-reflection material layer can be formed of silicon nitride (SiN x ). The second anti-reflection material layer and the fourth anti-reflection material layer can be formed of one or more of silicon oxide (SiO x ), sodium fluoride (NaF), lithium fluoride (LiF) and potassium fluoride (KF), preferably SiO xor NaF.

[0040] The thickness D of the first to fourth anti-reflective material layers is 70-120 nm, preferably 75-105 nm, and more preferably 80-100 nm, or (2k+1)D, wherein k is a positive integer.

[0041] The thickness of the anti-reflective material layer has an effect on the reflectivity. Referring to Figure 8 The thickness of the anti-reflective material layer has an effect on the reflectivity. Referring to x The relationship between the thickness of the anti-reflective material layer and the reflectivity and refractive index is explained in detail with the material layer and the glass substrate as examples.

[0042] According to the interference cancellation principle of reflected light, when the reflectivity is zero, according to N 2 = N 玻璃 2 × N0 2 (N is the refractive index of the anti-reflective material layer, N0is the refractive index of air, N 玻璃 is the refractive index of glass) calculation, the closer the refractive index of the single-layer anti-reflective material layer to 1.24, the smaller the reflectivity.

[0043] When the light is vertically incident, N×H=(2k+1)×λ / 4 is calculated according to the optical path difference δ=2×N×H, wherein k is a positive integer, and it can be known that the anti-reflective film thickness increases with the increase of the wavelength and changes periodically. Referring to Table 1 below for details.

[0044] Table 1

[0045]

[0046]

[0047] The anti-reflective composite film of the present application is used for display panels, in particular for OLED display panels.

[0048] Specifically, referring to Figure 2 , the anti-reflective composite film according to one embodiment of the present application comprises a substrate 10, and a first anti-reflective composite material layer 20 and a second anti-reflective composite material layer 30 formed on both sides of the substrate 10, respectively, wherein the first anti-reflective composite material layer 20 comprises a first anti-reflective material layer 21 and a second anti-reflective material layer 22, and the second anti-reflective composite material layer 30 comprises a third anti-reflective material layer 31 and a fourth anti-reflective material layer 32.

[0049] Referring to Figure 3 and Figure 4According to another embodiment of the present application, the anti-reflection composite film comprises a substrate 10, a first anti-reflection composite material layer 20 formed on one side surface of the substrate 10, wherein the first anti-reflection composite material layer 20 comprises a first anti-reflection material layer 21 and a second anti-reflection material layer 22.

[0050] The anti-reflection composite film is used on the light emitting surface of the display panel to reduce the reflectivity of the display panel. According to the display panel applied, the substrate of the anti-reflection composite film can be a cover plate (see Figure 2 、 Figure 3 ) or a substrate of the display panel. Therefore, the anti-reflection composite film of the present application also needs to have a transmittance matching the light emitting spectrum of the display panel, for example, the transmittance of the light emitting region of the display panel comprising a light emitting region A and a transparent region B matches the light emitting spectrum of the light emitting layer.

[0051] Referring to Figure 5 , the transmittance of the SiN x material layer, glass substrate and the relationship between the transmittance of the anti-reflection material layer and the light emitting spectrum of the display panel are described in detail.

[0052] As can be seen from Figure 5 , the SiNx material layer has good transmittance in the visible light band (380-780 nm) and good matching with the light emitting spectrum of the red, green and blue light emitting layers (EL), and has high transmittance in the EL light emitting spectrum band; the transmittance in the ultraviolet light band below 360 nm is low, and the transmittance decreases sharply as the wavelength becomes shorter. Therefore, the material layer can block ultraviolet light.

[0053] The anti-reflection composite film according to the present application can reduce the reflectivity of the display panel and block short-wavelength ultraviolet light in the ambient light from entering the display device to cause damage to the film layers therein.

[0054] The anti-reflection composite material layer can be deposited by conventional methods in the art. For example, the SiN x material layer and the SiO x material layer can be deposited by chemical vapor deposition or sputtering, and the fluorinated salt material layer such as NaF can be deposited by electron beam evaporation, thermal evaporation, sputtering and the like.

[0055] The other configurations of the anti-reflection composite film, the display panel and the display device and the preparation method thereof according to the embodiments described above can be various technical solutions known or to be known to those skilled in the art, which are not described in detail here.

[0056] Embodiments

[0057] Embodiment 1

[0058] 1. For top emission OLED panel, complete the EL film layer and CVD TFE layer, filling glue, dam glue and other necessary packaging film layers on the TFT substrate glass;

[0059] 2. On both sides of the cover glass, sequentially deposit SiN x film layer 105 nm and SiO x film layer 75 nm from inside to outside, and then coat the packaging dam glue and filling glue on one side of the cover glass;

[0060] 3. Bond the above TFT substrate glass and cover glass to complete the OLED panel production.

[0061] Example 2

[0062] 1. For top emission OLED panel, complete the EL film layer and CVD TFE layer, filling glue, dam glue and other necessary packaging film layers on the TFT substrate glass;

[0063] 2. On both sides of the cover glass, sequentially deposit SiN x film layer 120 nm and NaF film layer 85 nm from inside to outside, and SiN x film layer is deposited by chemical vapor deposition, and NaF film layer is deposited by electron beam evaporation process, and then coat the packaging dam glue and filling glue on one side of the cover glass;

[0064] 3. Bond the above TFT substrate glass and cover glass to complete the OLED display panel production.

[0065] Example 3

[0066] Prepare the OLED display panel in the same way as Example 1, except that only SiN x film layer 120 nm and NaF film layer 85 nm are sequentially deposited from inside to outside on one side of the cover glass.

[0067] Example 4

[0068] Prepare the OLED display panel in the same way as Example 2, except that only SiN x film layer 105 nm and SiO x film layer 75 nm are sequentially deposited by chemical vapor deposition from inside to outside on one side of the cover glass.

[0069] Example 5

[0070] 1. For bottom emission OLED display panel, sequentially deposit SiN x film layer 105 nm and SiO x film layer 75 nm from inside to outside on both sides of the TFT substrate glass, and SiN x film layer and SiOx The film layers are deposited by chemical vapor deposition, and then TFT devices and EL devices (including CVD TFT layers, filling glue, dam glue and other necessary packaging film layers) are made on the side of the TFT substrate glass.

[0071] 2. The packaging dam glue and filling glue are coated on the cover glass.

[0072] 3. The TFT substrate glass and the cover glass are laminated to complete the OLED display panel manufacturing.

[0073] The anti-reflection effect of the OLED display panels prepared according to Examples 1 to 4 is tested, that is, the reflectivity of the above display panels under different wavelengths is tested, and the same cover glass is used as a control. The reflectivity curve obtained is shown in Figure 6 .

[0074] Referring to Figure 6 , the display panels prepared according to Example 1 and Example 2 respectively include SiO x / SiN x / glass / SiN x / SiO x or NaF / SiN x / glass / SiN x / NaF structure, which has the best effect on reducing the surface reflectivity of the OLED display panel.

[0075] Experiment on the yellowing influence of ultraviolet light on the packaging filling glue

[0076] The OLED display panel is prepared by the same method as in Example 1, except that the anti-reflection composite film layer is not vapor deposited on the cover glass. The transmittance of different short-wavelength ultraviolet light of the OLED display panel is tested. The test results are shown in Figure 7A . As shown in Figure 7A , the OLED display panel has high transmittance to short-wavelength ultraviolet light below 360 nm.

[0077] A circular cut filter is placed above the OLED display panel, and the appearance and transmittance of the OLED display panel after being blocked are tested respectively. The test results are shown in Figure 7B .

[0078] Referring to Figure 7B , when the short-wavelength cut filter filters out UV light below 325 nm, the packaging filling glue no longer yellows.

[0079] Therefore, the anti-reflection composite film according to the present application contains SiN xThe film layer has a low short-wavelength ultraviolet light transmittance, can prevent ultraviolet light from transmitting, and can prevent the filling glue from yellowing.

[0080] Influence of anti-reflection composite film on display efficiency of display panel

[0081] The OLED display panel prepared according to Embodiment 1 and the OLED display panel (control OLED display panel) having only a corresponding cover glass (thickness 500 nm) were respectively tested for luminous efficiency (cd), color coordinates (CIEx, CIEy), and external quantum efficiency (EQE), and the results are shown in Table 2 below.

[0082] Table 2

[0083] OLED display panel of Example 1 Control OLED display panel cd(A) 5.39 5.52 CIEx 0.1378 0.138 CIEy 0.0631 0.0629 EQE 8.66％ 8.88％

[0084] As can be seen from Table 2 above, the OLED display panel according to Embodiment 1 of the present application has an anti-reflection composite film, and the luminous efficiency, color coordinates (CIEx, CIEy), and external quantum efficiency (EQE) thereof are close to the corresponding performances of the OLED having a blank cover glass. That is, the anti-reflection composite film of the present application has little influence on the luminous efficiency, color coordinates (CIEx, CIEy), and external quantum efficiency (EQE) of the display panel.

[0085] In the description of the present specification, it should be understood that the orientation or positional relationship indicated by the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential” and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0086] In addition, the terms “first” and “second” are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with “first” and “second” can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of “plurality” is two or more, unless otherwise specifically limited.

[0087] In this application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixed", and similar terms should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection, and can also be communication; can be direct connection, can also be indirect connection through intermediate medium, can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0088] In this application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "under" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0089] The above disclosure provides many different implementations or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and arrangements of specific examples are described in the above. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or arrangements discussed.

[0090] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can easily think of various changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An antireflection composite film, characterized by comprising: The anti-reflection composite film comprises a substrate and a first anti-reflection composite layer and a second anti-reflection composite layer formed on two side surfaces of the substrate respectively, wherein the first anti-reflection composite layer comprises a first anti-reflection material layer and a second anti-reflection material layer, and the second anti-reflection composite layer comprises a third anti-reflection material layer and a fourth anti-reflection material layer; One side surface of the substrate comprises the first anti-reflection material layer on the side surface of the substrate and the second anti-reflection material layer on the surface of the first anti-reflection material layer away from the substrate, and the opposite side surface comprises the third anti-reflection material layer and the fourth anti-reflection material layer; The refractive index of the first anti-reflection material layer is greater than the refractive index of the second anti-reflection material layer; The refractive index of the third anti-reflection material layer and the fourth anti-reflection material layer is as defined for the first anti-reflection material layer and the second anti-reflection material layer respectively; The first anti-reflection material layer and the third anti-reflection material layer are formed of silicon nitride (SiNx), and the second anti-reflection material layer and the fourth anti-reflection material layer are formed of sodium fluoride (NaF).

2. The antireflection composite film according to claim 1, wherein The third anti-reflection material layer is the same as or different from the first anti-reflection material layer.

3. The antireflection composite film according to claim 1, wherein The thickness D of the first anti-reflection material layer and the second anti-reflection material layer is 70-120 nm or (2k+1)D, wherein k is a positive integer.

4. The antireflection composite film according to claim 1, wherein The thickness D of the first anti-reflection material layer to the fourth anti-reflection material layer is 70-120 nm or (2k+1)D, wherein k is a positive integer.

5. The antireflection composite film according to claim 4, wherein The thickness D of the first anti-reflection material layer to the fourth anti-reflection material layer is 75-105 nm.

6. The antireflection composite film according to claim 4, wherein The thickness D of the first anti-reflection material layer to the fourth anti-reflection material layer is 80-100 nm.

7. A display panel, characterized by, The anti-reflection composite film according to any one of claims 1 to 6.

8. The display panel according to claim 7, wherein the display panel is an organic electroluminescent display panel.

9. The display panel according to claim 8, wherein the substrate of the anti-reflection composite film is a cover plate or a substrate of the display panel.

10. A display device, characterized by comprising: The display panel according to any one of claims 7 to 9.

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