Brightness enhancement film, backlight module and display device

Abstract

The invention discloses a brightness enhancement film, a backlight module and a display device, and relates to the technical field of optical films. The brightness enhancement film comprises a base material layer and a plurality of first prisms which are arranged on the base material layer in an adjacent array mode in the first direction. The plurality of second prisms are obliquely arranged on the base material layer at intervals along a second direction and are respectively embedded with the plurality of first prisms; wherein the first prisms are higher than the second prisms, the cross section of each first prism is an isosceles triangle, and the vertex angle of each first prism is an arc vertex angle. According to the invention, the technical problems that the vertex angle of the prism is changed from a sharp angle to a round angle, although the scratch resistance of the surface of the brightness enhancement film is favorably improved, the brightness of a product is directly and obviously reduced, and the original intention of using a brightness enhancement film component is lost are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical films, and in particular to a brightness enhancement film, a backlight module and a display device. Background Art

[0002] The brightness enhancement film reflects its light-collecting function through the geometric optical effect of the surface prism microstructure. The traditional microstructure is a sharp-angled isosceles prism with a vertex angle of 90 degrees. The top of the prism is quite fragile and can be easily damaged during operation or transportation, resulting in bright white defects on the film surface, which reduces the yield and increases production costs. In order to solve this problem, a rounded corner prism solution has been proposed. Changing the prism vertex from a sharp angle to a rounded angle does help improve the scratch resistance of the surface of the brightness enhancement film, but it directly causes a significant decrease in the brightness of the product, which loses the original intention of using the brightness enhancement film component. No effective solution has been proposed for the above-mentioned problems. Summary of the invention

[0003] Purpose of the invention: To provide a brightness enhancement film, a backlight module and a display device to solve at least one of the problems existing in the above-mentioned prior art.

[0004] Technical solution: A brightness enhancement film, comprising: Base material layer, A plurality of first prisms are arranged in an adjacent array along a first direction on the substrate layer; and A plurality of second prisms are obliquely arranged on the substrate layer at intervals along a second direction and are respectively embedded with a plurality of the first prisms; The heights of the first prisms are higher than the heights of the second prisms, and the cross-section of the first prism is an isosceles triangle, the vertex angle of which is set as a circular arc vertex angle.

[0005] Preferably, the arc curvature radius r of the arc vertex angle is 0.5-5um.

[0006] Preferably, the bottom width L1 of the first prism is 20-100 um.

[0007] Preferably, the cross section of the second prism is an isosceles right triangle.

[0008] Preferably, the bottom width of the second prism is L2, and the bottom width of the second prism is smaller than the bottom width of the first prism.

[0009] Preferably, the first prisms are distributed in a cross shape.

[0010] Preferably, an angle θ between an extension direction of the first prism and an extension direction of the second prism is 15-165°.

[0011] Preferably, a spacing is provided between adjacent ones of the second prisms.

[0012] In order to achieve the above objective, according to another aspect of the present application, a backlight module is also provided.

[0013] The backlight module according to the present application includes the brightness enhancement film as described above.

[0014] In order to achieve the above objective, according to another aspect of the present application, a display device is also provided.

[0015] The display device according to the present application includes the backlight module as described above.

[0016] Beneficial effect: In the embodiment of the present application, a method of introducing a plurality of second prisms is adopted, and the height of a plurality of first prisms is set to be higher than the height of a plurality of second prisms, and the cross section of the first prism is an isosceles triangle, and its vertex angle is set to a circular arc vertex angle, and the cross section of the second prism is an isosceles triangle, and its vertex angle is set to a pointed vertex angle. Through the height difference of the first prism with a rounded vertex angle, the tip of the pointed second prism is protected from damage caused by friction, and at the same time, through the setting of the second prism, an additional prism focusing function is provided, and the purpose of changing the focusing microstructure is achieved, thereby achieving the technical effect of maintaining high brightness while improving the wear resistance of the brightness enhancement film, and thus solving the technical problem that changing the prism vertex angle from a sharp angle to a rounded angle, although it helps to improve the scratch resistance of the surface of the brightness enhancement film, directly causes a significant decrease in product brightness, and loses the original intention of using the brightness enhancement film component. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the prism structure of the present invention.

[0018] The accompanying drawings are marked as follows: 10. Base material layer; 20. First prism; 30. Second prism. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0020] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0021] In addition, the terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0023] like Figure 1 As shown, the present application relates to a brightness enhancement film, a backlight module and a display device. The brightness enhancement film comprises: a substrate layer 10, which refers to the base material or substrate to which the optical film or coating is attached, and can achieve good fixing and supporting effects; at the same time, it can also cooperate with other film layer structures to achieve multiple functional effects. Preferably, the substrate layer 10 is PET, PC, PMMA, PE, PVC or PS. It can achieve the effect of multiple materials to choose from, so that the effect can be easily achieved.

[0024] A plurality of first prisms 20 are arranged in an adjacent array along a first direction on the substrate layer 10; the first prisms 20 are main optical elements, and are arranged adjacent to each other in sequence along a specific direction (first direction) on the substrate layer 10; wherein the first direction can be the X-axis direction or the Y-axis direction of the substrate layer 10.

[0025] A plurality of second prisms 30 are arranged obliquely on the substrate layer 10 at intervals along the second direction, and are respectively interlocked with a plurality of the first prisms 20; in order to compensate for the lost brightness, the second prisms 30 are introduced in an angle direction; the second prisms 30 are another main optical element, which are arranged obliquely on the upper surface of the substrate layer 10 along the second direction, and are respectively introduced into the first prisms 20, thereby forming a cross-shaped distribution, and then the complete light collection function is doubled by the first prism 20 and the second prism 30, so that the brightness of the rounded wear-resistant brightening film is improved. Among them, the second direction can be the X-axis direction or the Y-axis direction of the substrate layer 10, or any angle direction intersecting with the first direction.

[0026] The prism structure is a conventional prism structure in the field of optical films, and can be used for various optical applications such as light splitting, focusing, and beam splitting; at the same time, these prisms can be arranged into various geometric shapes to achieve different optical functions.

[0027] It should be noted that the first prism 20 and the second prism 30 are formed by methods including but not limited to sputtering, evaporation, spraying, coating or mold imprinting, so as to obtain the desired compound prism structure.

[0028] The height of the first prisms 20 is higher than the height of the second prisms 30, and the cross section of the first prism 20 is an isosceles triangle, and the vertex angle is set to a circular arc vertex, which can improve the wear resistance of the brightness enhancement film. By setting the height of the second prism 30 to be lower than the height of the first prism 20, and the cross section of the second prism 30 is an isosceles right triangle, the lost brightness can be compensated, thereby achieving the effect of improving the brightness.

[0029] This application also has the following beneficial effects: Optimize light propagation efficiency: The height of the first prism 20 is higher than that of the second prism 30, so that the first prism 20 plays a leading role in the optical structure and can more effectively control the light propagation path. It can ensure that the main light is accurately focused or reflected when passing through the first prism 20, while the second prism 30 is used to fine-tune the direction or distribution of light, thereby improving the overall optical efficiency.

[0030] Enhanced mechanical strength and durability: The rounded vertex design not only helps with optical performance, but also reduces damage to the prism due to stress concentration during manufacturing or use; it improves the mechanical strength of the prism, making it more durable, especially in application scenarios that require frequent operation or exposure to harsh environments.

[0031] Achieve uniform light distribution: By cross-setting the first prism and the second prism, the directional regularity of a single prism group is destroyed, which helps to alleviate the display screen interference phenomenon caused by a single group of prisms.

[0032] From the above description, it can be seen that the present application achieves the following technical effects: In the embodiment of the present application, a plurality of second prisms 30 are introduced, and the height of the plurality of first prisms 20 is set to be higher than the height of the plurality of second prisms 30, and the cross section of the first prism 20 is an isosceles triangle, and its vertex angle is set to a circular arc vertex angle, and the cross section of the second prism 30 is an isosceles triangle, and its vertex angle is set to a pointed vertex angle. The height difference of the first prism with a rounded vertex angle protects the tip of the pointed second prism from being damaged by friction, and at the same time, the setting of the second prism provides an additional prism focusing function, achieving the purpose of changing the focusing microstructure, thereby achieving the technical effect of maintaining high brightness while improving the wear resistance of the brightness enhancement film, and thus solving the technical problem that changing the prism vertex angle from a sharp angle to a rounded angle, although it helps to improve the scratch resistance of the surface of the brightness enhancement film, directly causes a significant decrease in the brightness of the product, and loses the original intention of using the brightness enhancement film component.

[0033] Furthermore, the arc curvature radius r of the arc vertex angle is 0.5-5um. It is understandable that setting the fillet radius r to 0.5-5um can improve the wear resistance and achieve the effect of multiple sizes to be selected, thereby meeting the effect of multiple use requirements.

[0034] It should be noted that if the radius of curvature r of the arc of the first prism 20 is too small, sufficient scratch resistance cannot be provided.

[0035] If the half angle r of the arc curvature of the first prism 20 is too large, the contact area will be too large, resulting in inter-film adsorption and obvious stripe marks on the screen. Therefore, setting the fillet radius within the above range can ensure good optical and physical properties.

[0036] Furthermore, the bottom width L1 of the first prism 20 is 20-100 um. It is understandable that a variety of bottom widths can be selected to meet the use requirements of various scenarios.

[0037] Furthermore, the cross section of the second prism 30 is an isosceles right triangle. It is understandable that by adopting the isosceles right triangle structure, the second prism 30 has symmetry and high efficiency in optical function, and can reflect or refract light at a specific angle.

[0038] Further, the bottom width of the second prism 30 is L2, and the bottom width of the second prism 30 is smaller than the bottom width of the first prism 20; Among them, L2 is the size of the general traditional brightness enhancement film prism, which is between 20-100um; It should be noted that if L2 is too large, it will not only be higher than the first prism and fail to meet the protection purpose, but also have a negative effect on the image visible to the naked eye; if L2 is too small, the optical effect is too poor and there is no substantial effect of improving brightness. Among them, L2 is set between 20-100um; it can be understood that it can ensure good mechanical and optical properties, so as to meet the use requirements.

[0039] Furthermore, the first prisms 20 are arranged in a cross shape with the first prisms 20. It can be understood that the overall performance of the optical structure can be enhanced, for example, the uniformity of light can be improved or the viewing angle range can be adjusted.

[0040] Furthermore, the angle θ between the extension direction of the first prism 20 and the extension direction of the second prism 30 is 15-165°. It can be understood that it can ensure that the prism structure has good optical performance, thereby avoiding the situation where the optical effect is poor due to the angle being too large or too small, and reducing the display screen interference phenomenon caused by a single regular prism group.

[0041] Furthermore, a plurality of adjacent second prisms 30 are provided with a spacing. It is understandable that by providing a spacing d between adjacent second prisms 30, the density of the prisms can be adjusted, thereby achieving an effect of improving brightness. The spacing of the spacing can be a fixed spacing or a non-fixed spacing.

[0042] Furthermore, the first prism 20 and the second prism 30 are photocurable hard resins with a refractive index range of 1.5-1.7. It is understandable that by selecting a photocurable hard resin with a higher refractive index, the brightness of the brightness enhancement film can be improved while taking into account the scratch resistance.

[0043] This application also has the following beneficial effects: 1. A second set of cross prisms is introduced. The second set of prisms has a 90-degree sharp angle and is 20 degrees lower in height than the first prism, providing additional optical benefits to compensate for the rounded prisms.

[0044] 2. The spacing of the second prisms 30 is adjustable, which helps to adjust the interference phenomenon.

[0045] 3. This solution is suitable for single brightness enhancement film or laminated brightness enhancement film (POP).

[0046] The specific examples are further described below: The testing items of the brightness enhancement film provided by the present invention include but are not limited to: scratch resistance test and brightness test.

[0047] Scratch test: The brightness enhancement film of the following examples was loaded with a specific weight using a scratch test machine, and the back of the diffusion film was used for a scratch test.

[0048] Brightness test: The brightness enhancement film of the following example was installed in the backlight module, and the brightness was measured using a BM-7AC brightness meter, and the picture condition was observed.

[0049] Example 1 The bottom width L1 of the first prism 20 is 70um, and the arc curvature radius r of the arc vertex angle of the first prism 20 is 2um; the bottom width L2 of the second prism 30 is 60um, and its vertex angle is a sharp angle, and the spacing between adjacent second prisms 30 is 100um; the angle θ between the first prism 20 and the second prism 30 is 30°.

[0050] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness is 8259nits, brightness ratio is 130%, and scratch resistance is 1200g.

[0051] Example 2 The difference from the first embodiment is that the arc curvature radius r of the arc vertex angle of the first prism 20 is 0.5 um.

[0052] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness of 8570nits, brightness ratio of 135%, and scratch resistance of 500g.

[0053] Example 3 The difference from the first embodiment is that the arc curvature radius r of the arc vertex angle of the first prism 20 is 5 um.

[0054] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness of 7811nits, brightness ratio of 123%, and scratch resistance of 2000g.

[0055] Example 4 The difference from the first embodiment is that the bottom width L2 of the second prism 30 is 20 um.

[0056] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness is 8088nits, brightness ratio is 128%, and scratch resistance is 1200g.

[0057] Example 5 The difference from the first embodiment is that the included angle θ between the first prism 20 and the second prism 30 is 90°.

[0058] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness is 8449nits, brightness ratio is 133%, and scratch resistance is 1200g.

[0059] Example 6 The difference from the first embodiment is that the included angle θ between the first prism 20 and the second prism 30 is 165°.

[0060] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness is 8102nits, brightness ratio is 128%, and scratch resistance is 1200g.

[0061] Example 7 The difference from the first embodiment is that the interval between adjacent second prisms 30 is 10 um.

[0062] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness is 10594nits, brightness ratio is 167%, and scratch resistance is 1200g.

[0063] Example 8 The difference from the first embodiment is that the interval between adjacent second prisms 30 is 1000 um.

[0064] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness is 6366nits, brightness ratio is 101%, and scratch resistance is 1200g.

[0065] Comparative Example 1 The difference from the first embodiment is that the first prism 20 has a full rounded corner structure and does not have the second prism 30 structure.

[0066] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness of 6332nits, brightness ratio of 100%, and scratch resistance of 1200g.

[0067] Comparative Example 2 The difference from the first embodiment is that the top angle of the first prism 20 is a sharp angle structure, and the second prism 30 structure is not provided.

[0068] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness of 6758nits, brightness ratio of 107%, and scratch resistance of 50g.

[0069] Comparative Example 3 The difference from the first embodiment is that the arc curvature radius r of the arc vertex angle of the first prism 20 is 0.4 um.

[0070] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness is 8637nits, brightness ratio is 136%, and scratch resistance is 300g.

[0071] Comparative Example 4 The difference from the first embodiment is that the arc curvature radius r of the arc vertex angle of the first prism 20 is 6 um.

[0072] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness of 7606nits, brightness ratio of 120%, and scratch resistance of 2000g.

[0073] Comparative Example 5 The difference from the first embodiment is that the included angle θ between the first prism 20 and the second prism 30 is 170°.

[0074] At this time, after testing, the performance parameters of the brightness enhancement film are: brightness of 7666nits, brightness ratio of 121%, and scratch resistance of 1200g.

[0075] The results of various embodiments and comparative examples are shown in Table 1: From the above test results we can see that: 1. It can be seen from Example 1 and Comparative Examples 1-2 that the brightness enhancement film of the present invention adds the second prism 30, and the vertex angle of the second prism 30 is a sharp angle, which can not only improve the brightness gain effect of the brightness enhancement film, but also have good scratch resistance.

[0076] 2. It can be seen from Examples 1-3 and Comparative Examples 1-4 that as the radius of curvature increases from small to large, the wear resistance is significantly improved. When the radius of curvature of the first prism corner is 0.4um, the top angle is still too sharp and the wear resistance is insufficient. When the radius of curvature of the first prism corner is 6um, the top angle is too rounded, resulting in limited improvement in optical efficiency, and abnormal image adsorption begins to occur. At the same time, due to the introduction of the second group of prisms, an additional light-gathering effect is provided, which significantly improves the brightness of the product and is higher than a single full-point prism.

[0077] 3. It can be seen from Examples 1 and 4 that as the bottom width of the second prism 30 becomes smaller, the light efficiency of the prism decreases. Therefore, the bottom width of the second prism must still follow the conventional brightness enhancement film prism size of 20-100um and cannot be too small.

[0078] 4. It can be seen from Examples 1, 5-6 and Comparative Example 5 that as the angle between the second prism 30 and the first prism 20 deviates from the orthogonal state, the brightness enhancement effect decreases.

[0079] 5. It can be seen from Examples 1, 7-8 that when the density of the second prisms 30 is increased, it is close to the POP architecture and the brightness is greatly improved; when the density of the second prisms 30 is reduced, the brightness improvement effect is greatly reduced.

[0080] In summary, it can be seen from the embodiments and the comparison results that the present invention can improve the brightness of the brightness enhancement film while improving the wear resistance by introducing the second prism 30 .

[0081] The present application also relates to a backlight module, comprising the brightness enhancement film as described above.

[0082] The present application also relates to a POP-type laminating brightness enhancement film, including the brightness enhancement film as described above.

[0083] The scratch-resistant compound staggered prism structure of the present invention can be applied not only to a single brightness enhancement film, but also to a POP type laminated brightness enhancement film as an upper prism structure to improve the surface scratch resistance of the POP product.

[0084] The present application also relates to a display device, comprising the backlight module as described above.

[0085] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical scheme of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. Brightness enhancement film, characterized in that: include: A substrate layer (10), A plurality of first prisms (20) are arranged in an adjacent array along a first direction on the substrate layer (10); and A plurality of second prisms (30) are arranged obliquely on the substrate layer (10) at intervals along a second direction and are respectively embedded with a plurality of the first prisms (20); The height of a plurality of the first prisms (20) is higher than the height of a plurality of the second prisms (30), and the cross section of the first prism (20) is an isosceles triangle, the vertex angle of which is set as a circular arc vertex angle.

2. The brightness enhancement film according to claim 1, characterized in that: The arc curvature radius r of the arc vertex angle is 0.5-5um.

3. The brightness enhancement film according to claim 1, characterized in that: The bottom width L1 of the first prism (20) is 20-100 um.

4. The brightness enhancement film according to claim 1, characterized in that: The cross section of the second prism (30) is an isosceles right triangle.

5. The brightness enhancement film according to claim 3, characterized in that: The bottom width of the second prism (30) is L2, and the bottom width of the second prism (30) is smaller than the bottom width of the first prism (20).

6. The brightness enhancement film according to claim 1, characterized in that: The first prisms (20) are distributed in a cross shape.

7. The brightness enhancement film according to claim 1, characterized in that: The included angle θ between the extension direction of the first prism (20) and the extension direction of the second prism (30) is 15-165°.

8. The brightness enhancement film according to claim 1, characterized in that: A plurality of adjacent second prisms (30) are respectively provided with spacing therebetween.

9. A backlight module, characterized in that: The invention comprises the brightness enhancement film as claimed in any one of claims 1 to 8.

10. A display device, characterized in that Comprising the backlight module as claimed in claim 9.

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