Viewing angle expansion film, method for manufacturing the same, and display panel

Abstract

The present application relates to a view angle expanding film and a preparation method thereof, and a display panel. The present application first prepares an expanding material layer, then injects an expanding unit material into the expanding material layer by printing to form a first semi-finished product, and then prepares the view angle expanding film by applying pressure and curing treatment, which can avoid the problems of long mold manufacturing cycle, low yield of the view angle expanding film and inability to mass-produce the view angle expanding film in the prior art, shortens the preparation cycle of the view angle expanding film and improves the yield of the view angle expanding film.

Description

Technical Field

[0001] This application relates to the field of display technology, specifically to viewing angle widening films and their preparation methods, and display panels. Background Technology

[0002] Liquid crystal display (LCD) devices generally consist of a liquid crystal display screen and polarizing plates positioned on either side of the screen. Because the light leakage state of the liquid crystal material in the LCD screen varies at different viewing angles, generally more light leakage occurs with a wider viewing angle. Therefore, the display effect of an LCD device significantly deteriorates as the viewing angle increases. To improve the display effect at wide viewing angles and make it more consistent with the display effect at normal viewing angles, the industry typically uses viewing angle expanders (GABs). These GABs adjust the emitted light from both normal and wide viewing angles to improve the display effect at wide viewing angles. GABs have two functions: one is to refract light emitted from the front into the wide viewing angle, and the other is to refract light emitted from the wide viewing angle back into the front. Through these two simultaneous actions, the light emitted from the front and the wide viewing angle mixes, thus achieving consistency in the display effect between normal and wide viewing angles. A GAB consists of a substrate layer, a high-refractive-index resin layer, and a low-refractive-index resin layer. The light control function of the GAB is mainly achieved through the high-refractive-index resin, the low-refractive-index resin, and the cross-sectional shape between them.

[0003] The current method for manufacturing viewing angle magnifying films is as follows: First, a high-refractive resin layer with a pattern is formed on a substrate by imprinting, and then the pattern is cured to form the high-refractive resin layer. Next, a low-refractive resin layer is filled and coated on top of the high-refractive resin layer to complete the manufacturing of the viewing angle magnifying film. When using the imprinting method to create the patterned high-refractive resin layer, a high-precision mold is required. Since the pattern size is at the micrometer level, mold making is difficult and time-consuming, typically requiring several months. Furthermore, after the pattern is formed by imprinting, it is easily damaged during demolding, leading to functional defects. Therefore, it is difficult to guarantee product yield, which seriously affects the mass production of viewing angle magnifying films. Summary of the Invention

[0004] The purpose of this invention is to provide a viewing angle enhancement film and its preparation method, as well as a display panel, which can solve the problems of long mold manufacturing cycle, low yield of viewing angle enhancement film, and inability to mass-produce viewing angle enhancement film in the prior art using mold imprinting method.

[0005] To address the aforementioned problems, the present invention provides a viewing angle magnification film, comprising: a magnification layer having a first surface and a second surface disposed opposite to each other; and at least one magnification unit disposed within the magnification layer, wherein the refractive index of the magnification unit is greater than the refractive index of the magnification layer; wherein the acute angle between each magnification unit and the first surface is α, where 90°>α≥0°.

[0006] Furthermore, the difference between the refractive index of the enlarged unit and the refractive index of the enlarged layer is greater than 0.02.

[0007] Furthermore, each of the enlarged units extends along a first direction, the length of the enlarged unit in the first direction is L1, the length of the enlarged unit in a second direction intersecting the first direction is L2, and 30 > L1 / L2 > 1.

[0008] Furthermore, the viewing angle magnification film further includes: a substrate disposed on the second surface of the magnification layer; an adhesive layer disposed on the first surface of the magnification layer; and a functional coating disposed on the side of the substrate away from the magnification layer.

[0009] Furthermore, the functional coating includes one or more of a surface-hardening coating, an anti-glare coating, and a low-reflection coating.

[0010] To address the aforementioned problems, this invention provides a method for preparing a viewing angle magnification film, comprising the following steps: preparing a magnifying material layer; injecting magnifying unit material into the magnifying material layer by printing to form a first semi-finished product; applying pressure to the first semi-finished product to form a second semi-finished product; and curing the second semi-finished product. The magnifying material layer forms a magnifying layer, the magnifying layer having a first surface and a second surface disposed opposite to each other, the magnifying unit material forming a magnifying unit, the refractive index of the magnifying unit being greater than the refractive index of the magnifying layer, and the acute angle between each magnifying unit and the first surface being α, where 90°>α≥0°.

[0011] Furthermore, the method for preparing the viewing angle magnification film further includes: after the step of curing the second semi-finished product, providing an adhesive layer on the first surface of the magnification layer; or before the step of applying pressure to the first semi-finished product to form the second semi-finished product, providing an adhesive layer on the magnification material layer.

[0012] To address the aforementioned problems, the present invention provides a display panel comprising a viewing angle-enhancing polarizing plate, the viewing angle-enhancing polarizing plate comprising: the viewing angle-enhancing film of the present invention; and a polarizing plate disposed on the side of the adhesive layer of the viewing angle-enhancing film away from the widening layer; the polarizing plate comprising a polarizing layer and a first protective layer disposed on the side of the polarizing layer away from the viewing angle-enhancing film.

[0013] Furthermore, the polarizing plate also includes a second protective layer disposed between the polarizing layer and the viewing angle widening film.

[0014] Furthermore, the display panel further includes: a backlight module having a light-emitting side; a first polarizing plate disposed on the light-emitting side of the backlight module; and a liquid crystal display screen disposed on the side of the first polarizing plate away from the backlight module; wherein the viewing angle widening polarizing plate is disposed on the side of the liquid crystal display screen away from the backlight module.

[0015] The advantages of this invention are: First, an enlarging material layer is prepared, and then the enlarging unit material is injected into the enlarging material layer by printing to form a first semi-finished product; then, the viewing angle enlarging film is prepared by applying pressure and curing treatment. This can avoid the problems of long mold making cycle, low yield of viewing angle enlarging film and inability to mass produce viewing angle enlarging film in the prior art by using mold imprinting method, thus shortening the preparation cycle of viewing angle enlarging film and improving the yield of viewing angle enlarging film.

[0016] Each of the enlargement units of the present invention extends along a first direction, the length of the enlargement unit in the first direction is L1, the length of the enlargement unit in the second direction intersecting the first direction is L2, 30>L1 / L2>1, which can make more effective use of light, directionally improve the viewing angle performance of the projection of the enlargement unit on the first surface in the extension direction, avoid too much loss of the viewing angle enlargement film in frontal view brightness, and improve the light utilization rate. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the display panel structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the viewing angle-enlarging polarizing plate in Example 1;

[0020] Figure 3 This is a schematic diagram of the expanded unit in Embodiment 1;

[0021] Figure 4 This is a schematic diagram of the light amplification of the viewing angle magnification film in Example 1;

[0022] Figure 5 This is a schematic diagram of the preparation of the first semi-finished product;

[0023] Figure 6 This is a schematic diagram of the preparation of the second semi-finished product;

[0024] Figure 7 This is a schematic diagram of the preparation of the adhesive layer;

[0025] Figure 8 This is a schematic diagram of the structure of the viewing angle-enlarging polarizing plate in Example 2;

[0026] Figure 9 This is a schematic diagram of the structure of the viewing angle-enlarging polarizing plate in Example 3;

[0027] Figure 10 This is a schematic diagram of the structure of the viewing angle-enhancing polarizing plate in Example 4.

[0028] Explanation of reference numerals in the attached figures:

[0029] 100. Display panel;

[0030] 1. Backlight module; 2. First polarizing plate;

[0031] 3. LCD screen; 4. Polarizing plate for wider viewing angle;

[0032] 11. Light-emitting side;

[0033] 41. Viewing angle expanding film; 42. Polarizing plate;

[0034] 411. Expanded layer; 412. Expanded unit;

[0035] 413. Substrate; 414. Adhesive layer;

[0036] 415. Functional coating;

[0037] 421. Polarizing layer; 422. First protective layer;

[0038] 423. Second protective layer;

[0039] 4111, First surface; 4112, Second surface. Detailed Implementation

[0040] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings to fully introduce the technical content of the present invention to those skilled in the art, and to demonstrate that the present invention can be implemented, making the disclosed technical content of the present invention clearer and enabling those skilled in the art to more easily understand how to implement the present invention. However, the present invention can be embodied in many different forms of embodiments, and the scope of protection of the present invention is not limited to the embodiments mentioned herein. The following description of the embodiments is not intended to limit the scope of the present invention.

[0041] The directional terms used in this invention, such as "up", "down", "front", "back", "left", "right", "inner", "outer", and "side", are only for the directions shown in the accompanying drawings. The directional terms used herein are for the purpose of explaining and illustrating this invention, and not for limiting the scope of protection of this invention.

[0042] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. Furthermore, for ease of understanding and description, the dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component.

[0043] like Figure 1 As shown, this application provides a display panel 100. The display panel 100 includes: a backlight module 1, a first polarizing plate 2, a liquid crystal display screen 3, and a viewing angle widening polarizing plate 4.

[0044] The backlight module 1 has a light-emitting side 11. Specifically, the backlight module 1 may include structures such as a light source, a reflective sheet, and an optical film, which will not be described in detail here.

[0045] The first polarizing plate 2 is disposed on the light-emitting side 11 of the backlight module 1.

[0046] The liquid crystal display screen 3 is disposed on the side of the first polarizing plate 2 away from the backlight module 1. Specifically, the liquid crystal display screen 3 includes structures such as an array substrate, a color filter substrate, and a liquid crystal layer, which will not be described in detail here.

[0047] The viewing angle widening polarizing plate 4 is located on the side of the liquid crystal display screen 3 away from the backlight module 1.

[0048] Example 1

[0049] like Figure 2 As shown, the viewing angle widening polarizer 4 in this embodiment includes: a viewing angle widening film 41 and a polarizer 42.

[0050] like Figure 2 As shown, the viewing angle magnification film 41 in this embodiment includes: magnification layer 411, at least one magnification unit 412, substrate 413, and adhesive layer 414.

[0051] The enlarged layer 411 has a first surface 4111 and a second surface 4112 disposed opposite to each other. The material of the enlarged layer 411 includes one or more of polyethylene, polypropylene, polyvinyl alcohol, polycarbonate, polyacrylic acid and polyethylene terephthalate.

[0052] In this embodiment, all expanding units 412 are disposed within the expanding layer 411, and the refractive index of the expanding unit 412 is greater than the refractive index of the expanding layer 411. To ensure the expanding effect of the viewing angle expanding film 41, the difference between the refractive index of the expanding unit 412 and the refractive index of the expanding layer 411 is greater than 0.02. In this embodiment, the difference between the refractive index of the expanding unit 412 and the refractive index of the expanding layer 411 is greater than 0.1.

[0053] In this embodiment, the acute angle between each of the expanding units 412 and the first surface 4111 is α, where 90° > α ≥ 0°. In this embodiment, α = 45°. The light emitted from the backlight module 1 passes through the first polarizing plate 2 and the liquid crystal display screen 3, and is then refracted by the expanding layer 411 and the expanding units 412 before exiting. Since the refractive index of the expanding unit 412 is greater than that of the expanding layer 411, the exit angle of the light can be increased, thereby improving the viewing angle of the display panel 100.

[0054] like Figure 3 As shown, each of the enlargement units 412 extends along a first direction M. The length of the enlargement unit 412 in the first direction M is L1, and the length of the enlargement unit 412 in a second direction N intersecting the first direction M is L2, where 30 > L1 / L2 > 1. Where L2 > 0.8 μm, in this embodiment, L2 = 3 μm. The second direction N is perpendicular to the first direction M, and L1 / L2 = 5. In this embodiment, the enlargement unit 412 is cylindrical, where L1 is the height of the cylinder and L2 is the length of the cylinder.

[0055] Due to the inherent characteristics of the display panel 100 (mainly the characteristics of the liquid crystal material), the display effect is best when viewed from the front. The effect is worse when viewed from the side at a wider viewing angle. Therefore, one method to widen the viewing angle is to refract the light emitted from the front through an optical structure to the side, essentially viewing the light that would otherwise be emitted from the front from the side. This improves the viewing angle. Because the light from the front is refracted to the side, less light is emitted from the front, meaning the brightness of the front panel decreases.

[0056] like Figure 4As shown, in this embodiment, 30 > L1 / L2 > 1, which allows for more effective use of light and a more directional enhancement of the viewing angle performance of the projection of the magnifying unit 412 onto the first surface 4111 in the extended direction, avoiding excessive loss of brightness when viewed directly from the viewing angle magnifying film and improving light utilization.

[0057] In real life, we only need vertical or horizontal viewing angle diffusion (for example, a home television only needs a large horizontal viewing angle). If the shape of the expanding unit 412 is spherical, the viewing angle expanding film will diffuse the light from the front to the left and right as well as vertically. In this case, there is a lot of light loss. However, the structure of this application can direct and expand the light to the required large angle, avoid too much loss of brightness when viewed directly from the front of the viewing angle expanding film, and improve the light utilization rate.

[0058] The substrate 413 is disposed on the second surface 4112 of the expanded layer 411. Considering that actual production is carried out in continuous roll form, the substrate 413 is preferably made of flexible, rollable optical film or optical glass. In fact, the substrate 413 can also be made of commonly used optical films, such as cellulose acetate film (TAC), acrylic film (PMMA), polyethylene terephthalate film (PET), and carbonate film (PC).

[0059] The adhesive layer 414 is disposed on the first surface 4111 of the widening layer 411. The adhesive layer 414 is mainly used to attach the viewing angle widening film 41 to the polarizing plate 42.

[0060] The polarizing plate 42 is disposed on the side of the adhesive layer 414 of the viewing angle magnification film 41 away from the magnification layer 411.

[0061] In this embodiment, the polarizing plate 42 includes: a polarizing layer 421, a first protective layer 422, and a second protective layer 423.

[0062] Among them, the polarizing layer 421 is made of PVA (polyvinyl alcohol).

[0063] The first protective layer 422 is disposed on the side of the polarizing layer 421 away from the viewing angle expanding film 41. In this embodiment, the material of the first protective layer 422 is TAC (cellulose triacetate).

[0064] The second protective layer 423 is disposed between the polarizing layer 421 and the viewing angle expanding film 41. In this embodiment, the material of the second protective layer 423 is TAC (cellulose triacetate).

[0065] like Figure 5As shown, this application also provides a method for preparing the viewing angle magnification film 41 of this application, which includes: S1, preparing a magnifying material layer 4011, and injecting magnifying unit material 4012 into the magnifying material layer 4011 by printing to form a first semi-finished product. The angle between the magnifying unit material 4012 and the lower surface of the magnifying material layer 4011 is β, 90°≥β>0°. In this application, the magnifying material layer 4011 is prepared on a substrate, and the magnifying unit material 4012 is injected into the magnifying material layer 4011 by inkjet printing to form a first semi-finished product, β=90°.

[0066] like Figure 6 As shown, the method for preparing the viewing angle magnification film 41 further includes: S2, applying pressure to the first semi-finished product to form a second semi-finished product. In this embodiment, pressure is applied to the first semi-finished product by a roller, causing the magnification material layer 4011 to deform, wherein the magnification unit material 4012 is oriented in the direction of deformation of the magnification material layer 4011.

[0067] The preparation method of the viewing angle magnification film 41 further includes: S3, curing the second semi-finished product. The magnified material layer 4011 and magnified unit material 4012, which are deformed under pressure, are cured and shaped using methods such as heating or light irradiation, maintaining the tilt orientation and angle of the magnified unit material 4012 within the magnified material layer 4011. It is worth noting that if the magnified unit material 4012 selected for printing injection is liquid, it also needs to be cured to stabilize its shape and prevent material deformation.

[0068] like Figure 7 As shown, the method for preparing the viewing angle magnification film 41 in this embodiment further includes: S4, providing an adhesive layer on the first surface of the magnification layer. In other embodiments, an adhesive layer may also be provided on the magnification material layer 4011 in S2.

[0069] In this embodiment, an enlarging material layer 40111 is first prepared, and then the enlarging unit material 4012 is injected into the enlarging material layer 4011 by printing to form a first semi-finished product. Then, the viewing angle enlarging film 41 is prepared by applying pressure and curing. This can avoid the problems of long mold manufacturing cycle, low yield of viewing angle enlarging film and inability to mass-produce viewing angle enlarging film in the prior art using mold imprinting method. It shortens the preparation cycle of viewing angle enlarging film and improves the yield of viewing angle enlarging film.

[0070] Example 2

[0071] like Figure 8 As shown, this embodiment includes most of the technical features of embodiment 1. The difference between this embodiment and embodiment 1 is that the viewing angle expanding film 41 in this embodiment does not require a substrate 413.

[0072] By removing the substrate 413, the thickness of the display panel 100 can be reduced, which is beneficial to achieving a thinner and lighter display panel 100.

[0073] Example 3

[0074] like Figure 9 As shown, this embodiment includes most of the technical features of embodiment 1. The difference between this embodiment and embodiment 1 is that the viewing angle magnification film 41 in this embodiment also includes a functional coating 415.

[0075] The functional coating 415 is disposed on the side of the substrate 413 away from the expanded layer 411. The functional coating 415 includes one or more of a surface-hardening coating, an anti-glare coating, and a low-reflection coating. The surface-hardening coating, through surface hardening treatment (HC), prevents scratches on the material surface during handling and cleaning, thus affecting the viewing experience. The anti-glare coating, through anti-glare treatment (AG), prevents ambient light interference that could cause viewers to have difficulty seeing the screen content or experience dizziness or discomfort; this is generally achieved through surface roughening. The low-reflection coating, through low-reflection treatment (LR), reduces the impact of ambient light reflection, improving the viewing experience.

[0076] Example 4

[0077] like Figure 10 As shown, this embodiment includes most of the technical features of embodiment 3. The difference between this embodiment and embodiment 3 is that the second protective layer 423 in the polarizing plate 42 is removed in this embodiment, and the polarizing layer 421 is protected by the viewing angle expanding film 41.

[0078] This embodiment can reduce the thickness of the display panel 100 by removing the second protective layer 423, which is beneficial to achieving a thinner and lighter display panel 100.

[0079] Furthermore, the above provides a detailed description of the viewing angle expansion film, its preparation method, and the display panel provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for preparing a viewing angle-enlarging film, characterized in that, Includes the following steps: An enlarged material layer is prepared, and enlarged unit material is injected into the enlarged material layer by printing to form a first semi-finished product; Pressure is applied to the first semi-finished product to form the second semi-finished product. Pressure is applied to the first semi-finished product through a roller to deform the enlarged material layer. The enlarged unit materials in the enlarged material layer are oriented in the direction of deformation of the enlarged material layer. The second semi-finished product is cured, the expanded material layer forms an expanded layer, the expanded layer has a first surface and a second surface disposed opposite to each other, the expanded unit material forms an expanded unit, the refractive index of the expanded unit is greater than the refractive index of the expanded layer, and the acute angle between each expanded unit and the first surface is α, 90°>α≥0°.

2. The method for preparing the viewing angle-enlarging film according to claim 1, characterized in that, Also includes: After the step of curing the second semi-finished product, an adhesive layer is provided on the first surface of the expanded layer; or Before the step of applying pressure to the first semi-finished product to form the second semi-finished product, an adhesive layer is provided on the expanded material layer.

3. A viewing angle magnifying film, characterized in that, The viewing angle expanding film is prepared by the method described in claim 1 or 2, wherein the viewing angle expanding film comprises: An enlarged layer having a first surface and a second surface disposed opposite to each other; and At least one enlarging unit is disposed within the enlarging layer, and the refractive index of the enlarging unit is greater than the refractive index of the enlarging layer; Wherein, the acute angle between each of the enlarged units and the first surface is α, where 90°>α≥0°.

4. The viewing angle expanding film according to claim 3, characterized in that, The difference between the refractive index of the enlarged unit and the refractive index of the enlarged layer is greater than 0.

02.

5. The viewing angle expanding film according to claim 3, characterized in that, Each of the enlarged units extends along a first direction, the length of the enlarged unit in the first direction is L1, the length of the enlarged unit in a second direction intersecting the first direction is L2, and 30 > L1 / L2 > 1.

6. The viewing angle magnifying film according to claim 3, characterized in that, Also includes: The substrate is disposed on the second surface of the enlarged layer; An adhesive layer is disposed on the first surface of the enlarged layer; as well as A functional coating is disposed on the side of the substrate away from the enlarged layer.

7. The viewing angle magnifying film according to claim 6, characterized in that, The functional coating includes one or more of the following: surface-hardening coating, anti-glare coating, and low-reflection coating.

8. A display panel, characterized in that, Including a polarizing plate that expands the viewing angle; The angle-enhancing polarizing plate includes: The viewing angle-enlarging film according to any one of claims 3-7; and A polarizing plate is disposed on the side of the adhesive layer of the viewing angle magnification film away from the magnification layer; The polarizing plate includes a polarizing layer and a first protective layer disposed on the side of the polarizing layer away from the viewing angle magnification film.

9. The display panel according to claim 8, characterized in that, The polarizing plate also includes: The second protective layer is disposed between the polarizing layer and the viewing angle expanding film.

10. The display panel according to claim 8, characterized in that, Also includes: A backlight module having a light-emitting side; A first polarizing plate is disposed on the light-emitting side of the backlight module; A liquid crystal display screen is disposed on the side of the first polarizing plate away from the backlight module; The viewing angle widening polarizing plate is located on the side of the liquid crystal display screen away from the backlight module.

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