Prism structure, visual angle expanding film, backlight module and display device

Abstract

The utility model discloses a prism structure, a visual angle expanding film, a backlight module and a display device, and relates to the technical field of optical films. The prism structure comprises a plurality of first prism parts and a plurality of second prism parts, the top of the second prism part is connected with the bottoms of the first prism parts; wherein the cross sections of the first prism parts are isosceles right triangles, the cross sections of the second prism parts are isosceles trapezoids, and the top width of the second prism parts is the total bottom width of the first prism parts. According to the utility model, the problems that the 1 / 2 light intensity range in the horizontal direction of a general display is within + / -50 degrees, and the 1 / 2 light intensity range in the vertical direction of the general display is within + / -35 degrees due to a single prism sheet, or a diffusion film and prism sheet bonding (DOP) / micro lens film and prism sheet bonding (MOP) and other structures with single prism layers in the current brightness enhancement film technology are solved; if a double-layer prism framework optical film scheme is used, the 1 / 2 light intensity range in the horizontal direction and the 1 / 2 light intensity range in the vertical direction are both lower than + / -35 degrees.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical film technical field especially relates to a prism structure, view angle expansion film, backlight module and display device. BACKGROUND

[0002] Brightness enhancement film is widely used in liquid crystal display industry, and is one of indispensable components in backlight module, which is used to improve the normal viewing angle brightness of display and has the function of saving energy consumption. Figure 1 As shown in the figure, the traditional brightness enhancement film can adjust the light intensity of the uniform surface light source to the normal viewing angle direction.

[0003] The current brightness enhancement film technology, if it is a single prism sheet, or a diffusion film and prism sheet (DOP) / microlens film and prism sheet (MOP) etc. with single prism layer structure, the 1 / 2 light intensity range of general display is within ± 50° horizontally and within ± 35° vertically; if the double-layer prism structure optical film solution is used, the 1 / 2 light intensity range of horizontal and vertical directions will be lower than ± 35°, and the above results cannot meet the problem of high application occasions requiring uniformity of spatial viewing angle light intensity. In view of the above problems, no effective solution has been proposed so far. UTILITY MODEL CONTENT

[0004] The utility model aims to provide a prism structure, view angle expansion film, backlight module and display device, so as to at least solve one of the problems existing in the prior art.

[0005] Technical scheme: a prism structure comprises:

[0006] a plurality of first prism parts; and

[0007] a second prism part, the top of which is connected with the bottom of the plurality of first prism parts;

[0008] Among them, the cross section of the plurality of first prism parts is isosceles right triangle, the cross section of the second prism part is isosceles trapezoid, and the top width of the second prism part is the total bottom width of the plurality of first prism parts, so that the incident light is expanded in viewing angle and improved in brightness by the prism structure.

[0009] As a preferred, the inclination angle of the inclined surface of the second prism part is 0°-90°, and the inclination angle is not equal to 45°, so as to form a right trapezoidal structure, and the inclined surface of the second prism part is not coplanar with the inclined surface of the first prism part.

[0010] As a preferred, the plurality of first prism parts and the second prism part are stacked to form an optical modulation layer.

[0011] As a preference, the height of the first prism portion is 5-20 μm.

[0012] As a preference, the height of the second prism portion is 10-20 μm.

[0013] As a preference, when the number of the first prism portion is one, the bottom width of the first prism portion is equal to the top width of the second prism portion.

[0014] As a preference, when the number of the first prism portion is plural, the total bottom width of the plural first prism portions is equal to the top width of the second prism portion.

[0015] To achieve the above object, according to another aspect of the present application, there is also provided a viewing angle expansion film.

[0016] The viewing angle expansion film according to the present application comprises the prism structure as described above;

[0017] The number of the prism structure is plural, and the plural prism structures are arranged adjacently along a preset direction as a minimum array unit.

[0018] The number of the prism structure is plural, and the plural prism structures are arranged adjacently along a preset direction as a minimum array unit.

[0019] To achieve the above object, according to another aspect of the present application, there is also provided a backlight module.

[0020] The backlight module according to the present application comprises the viewing angle expansion film as described above.

[0021] To achieve the above object, according to another aspect of the present application, there is also provided a display device.

[0022] The display device according to the present application comprises the backlight module as described above.

[0023] Beneficial effects: in the embodiment of the present application, the lower trapezoidal and the upper prism structure are adopted, the cross section of the first prism part is set as an isosceles right triangle, the cross section of the second prism part is set as an isosceles trapezoid, and the top width of the second prism part is the total bottom width of the first prism part, so that the incident light is expanded through the prism structure, the viewing angle is expanded, and the brightness is improved, the purpose of expanding the optical viewing angle under high brightness is achieved, thereby realizing the technical effect of obtaining a wider optical viewing angle, and further solving the technical problems that the current brightness enhancement film technology has a single prism layer structure, and the 1 / 2 light intensity range of the display in the horizontal direction is within ± 50°, and the 1 / 2 light intensity range in the vertical direction is within ± 35°; if the double-layer prism structure optical film scheme is used, the 1 / 2 light intensity range in the horizontal and vertical directions is lower than ± 35°, and the above results cannot meet the technical problems of the application occasions with high requirements for spatial viewing angle light intensity uniformity. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is the optical effect diagram of the traditional brightness enhancement film;

[0025] Figure 2 is the traditional brightness enhancement film prism microstructure for 90° top angle isosceles triangle diagram;

[0026] Figure 3 is the traditional brightness enhancement film prism microstructure for increasing prism top angle diagram;

[0027] Figure 4 is the traditional brightness enhancement film prism microstructure for reducing prism top angle diagram;

[0028] Figure 5 is the optical effect diagram of the traditional brightness enhancement film prism microstructure with different prism top angles;

[0029] Figure 6 is the structure schematic diagram of the viewing angle expansion film of the present application;

[0030] Figure 7 is the structure schematic diagram of another viewing angle expansion film of the present application;

[0031] Figure 8 is the conventional brightness enhancement film microstructure diagram;

[0032] Figure 9 is the brightness enhancement film microstructure diagram adopting the viewing angle expansion film of the present application;

[0033] Figure 10 is another brightness enhancement film microstructure diagram adopting the viewing angle expansion film of the present application; and

[0034] Figure 11It is the label schematic view of the view angle expansion film of the utility model.

[0035] The reference signs are:

[0036] 10, first prism part;

[0037] 20, second prism part;

[0038] 30, base material layer. DETAILED DESCRIPTION

[0039] In order to make the person skilled in the art better understand the scheme of the application, the technical scheme in the embodiments of the application will be clearly and completely described below in conjunction with the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the protection scope of the application.

[0040] It should be noted that the terms "first", "second" and the like in the specification and claims of the application and the above drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0041] In addition, the terms "mount", "set", "provided with", "connected", "connected", "sleeved" should be broadly understood. For example, it can be fixedly connected, detachably connected, or integrally configured; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication between two devices, elements or components. For the person skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0042] It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other without conflict. The application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0043] In order to better understand the technical problems of the application, the following is explained:

[0044] As Figure 2As shown, the conventional brightness enhancement film prism microstructure is an isosceles triangle with a 90° vertex angle, and its optical effect is to transfer the light intensity at large viewing angles to the normal viewing angle direction, thus causing the light intensity in the large viewing angle region to weaken

[0045] As shown, if the prism vertex angle is increased or decreased, the light collection effect at the normal viewing angle will weaken Figures 3-4

[0046] As shown, the actual viewing angle light intensity distribution is as follows, after the vertex angle deviates from 90°, the light intensity at the normal viewing angle decreases, but the light intensity at large viewing angle direction increases, also causing the uniformity of light intensity at spatial viewing angle to improve. Figure 5

[0047] Therefore, directly changing the vertex angle cannot simultaneously provide the increase in light intensity at the normal viewing angle and the improvement in the uniformity of light intensity at spatial viewing angle.

[0048] As shown, the present application relates to a prism structure, a viewing angle expansion film, a backlight module, and a display device. As shown, Figures 6-11 The prism structure comprises: a plurality of first prism portions 10; and a second prism portion 20, the top of which is connected to the bottom of the plurality of first prism portions 10; the prism structure can achieve good light guiding effect and good cooperation effect with other components, thereby achieving multiple functional effects. Figures 6-7

[0049] The second prism portion 20 can achieve good cooperation effect, thereby preliminarily forming a required composite optical structure.

[0050] It should be noted that the prism portion is usually composed of a material with a high refractive index, which causes refraction or reflection of light when passing through, thereby achieving the required optical effect. The refractive index is usually >1.5.

[0051] In optical devices and systems, prism layers are usually used to modulate, separate, or control light. For example, in a liquid crystal display, a prism layer can be used to adjust the propagation direction of light, thereby achieving a display effect of high brightness at the normal viewing angle.

[0052] The cross section of the first prism portion 10 is an isosceles right triangle, the cross section of the second prism portion 20 is an isosceles trapezoid, and the top width of the second prism portion 20 is the total bottom width of the first prism portions 10, so that the incident light is expanded in viewing angle and improved in brightness by the prism structure. By setting the cross section of the first prism portion 10 as an isosceles right triangle, and setting the structure with an isosceles trapezoidal cross section at the bottom of the first prism portion 10, the above structure not only maintains the high brightness effect at the normal viewing angle of the original vertex angle 90° structure, but also provides additional light intensity distribution at large angle region.

[0053] ​​​Specifically, the microstructure unit is divided into two layers, the upper layer is a traditional 90°-angle prism, and the lower layer is a trapezoidal structure, wherein the top width of the trapezoidal structure is the total bottom width of the plurality of prisms in the upper layer.

[0054] Therefore, the new structure of the lower-layer trapezoidal structure + upper-layer multiple prisms in the application maintains the front-view high-brightness effect of the original 90°-angle structure through the upper-layer prism structure, and provides additional light intensity distribution in a large-angle area through the lower-layer non-45°-inclined trapezoidal structure; the light intensity in a large angle can be improved while maintaining the high brightness in the front view, so as to improve the spatial-view-angle light intensity uniformity of the display product.

[0055] The microstructure of the application provides light intensity in a large-view-angle direction, and can effectively improve the 1 / 2 light intensity coverage angle in each direction, that is, the application can meet the application requirements with high spatial-view-angle light intensity uniformity requirements.

[0056] From the above description, it can be seen that the application achieves the following technical effects:

[0057] In the embodiment of the application, the lower-layer trapezoidal structure and the upper-layer multiple prism structure are adopted, the cross section of the first prism part 10 is set as an isosceles right triangle, the cross section of the second prism part 20 is set as an isosceles trapezoid, and the top width of the second prism part 20 is the total bottom width of the first prism part 10, so that the incident light is expanded in view angle and the brightness is improved, the purpose of expanding the optical view angle with high brightness is achieved, the technical effect of obtaining a wider optical view angle is achieved, and the technical problem that the current brightness enhancement film technology has a single prism layer structure, such as a single prism sheet, a diffusion film and a prism sheet (DOP) / a microlens film and a prism sheet (MOP) combination, and the 1 / 2 light intensity range of the display in the horizontal direction is within ± 50°, and the 1 / 2 light intensity range in the vertical direction is within ± 35°; if a double-layer prism structure optical film solution is used, the 1 / 2 light intensity range in the horizontal and vertical directions is lower than ± 35°, and the above results cannot meet the technical problem of the application occasion with high spatial-view-angle light intensity uniformity requirements.

[0058] Further, the inclined angle of the inclined surface of the second prism part 20 is 0°-90°, and the inclined angle is not equal to 45°, so as to form a right trapezoidal structure, and the inclined surface of the second prism part 20 is not coplanar with the inclined surface of the first prism part 10. It can be understood that the inclined angle of the inclined surface of the trapezoidal structure is between 0° and 90°, that is, a rectangle or an inverted trapezoidal structure is not formed, and the inclined angle is not equal to 45°, that is, the inclined surface of the trapezoid is not coplanar with the upper-layer prism.

[0059] From the optical effects of the different vertex angle prisms, it can be seen that when the microstructure bevel inclination angle deviates from 45°, there is better light intensity at large angles, which can ensure good optical performance.

[0060] Further, a plurality of the first prism portions 10 and a second prism portion 20 are stacked to form an optical modulation layer. It can be understood that the formation of the optical modulation layer: the structure formed by stacking the first prism portion 10 and the second prism portion 20 is called an "optical modulation layer", and the function of the modulation layer is to modulate, adjust and guide the path of light when the light passes through. Due to the combination of different slopes of the bevels, the light will produce different deflection and scattering when passing through the entire prism structure.

[0061] The purpose of modulation is to achieve the expansion of viewing angle, the enhancement of brightness and the reduction of light loss. When the light passes through this modulation layer, it can not only be guided to a wider direction, but also to a certain extent, reduce the light loss caused by reflection and refraction, thereby maintaining high brightness and uniformity.

[0062] Further, the height of the first prism portion 10 is 5-20 μm. It can be understood that the prism height directly affects the light refraction path and light field distribution; the use of the above height range can achieve the balance between short-range light diffusion and long-range light guidance, and can optimize the multiple reflections of light in the micron-level structure, and improve the light energy utilization rate.

[0063] Further, the height of the second prism portion 20 is 5-20 μm. It can be understood that a composite light modulation effect can be formed, and by setting the first prism portion 10 and the second prism portion 20 into a height difference structure, interference fringes can be produced to improve the light field uniformity.

[0064] Further, when the number of the first prism portion 10 is one, the bottom width of the first prism portion 10 is equal to the top width of the second prism portion 20. It can be understood that one first prism portion 10 and one second prism portion 20 are matched to form an optical composite microstructure, which can achieve good optical performance.

[0065] Further, when the number of the first prism portion 10 is multiple, the total bottom width of the multiple first prism portions 10 is equal to the top width of the second prism portion 20. It can be understood that multiple first prism portions 10 and one second prism portion 20 are matched to form another optical composite microstructure, which can achieve good optical performance.

[0066] Specifically, combining a second prism with any number of first prisms has its advantages. Since the first prism is a traditional brightness-enhancing film prism structure, it has a good light-gathering effect in the positive viewing angle direction. The effective area of ​​the second prism is its trapezoidal inclined surface; light only has the effect of increasing the light intensity at a wide viewing angle after passing through this inclined surface. Therefore, by combining a trapezoidal lower structure with multiple upper triangular prisms, the viewing angle can be adjusted according to the desired 1 / 2 viewing angle value of the final display. The effect is that when the density of the trapezoidal inclined surface increases, i.e., the number of triangular prisms supported by a single trapezoid decreases, the 1 / 2 viewing angle can be increased. Therefore, the structure of a second prism combined with any number of first prisms improves the controllability of spatial viewing angle uniformity, allowing design values ​​to be changed arbitrarily according to needs, thus improving the convenience of controlling spatial viewing angle uniformity.

[0067] like Figures 8-10 As shown, this application also relates to a viewing angle magnification film, including the prism structure described above;

[0068] The number of prism structures is multiple, and the multiple prism structures are arranged in an adjacent array along a preset direction;

[0069] In this configuration, one of the prism structures serves as the smallest array unit.

[0070] Specifically, by using a prism structure as the smallest array unit and arranging adjacent arrays along a preset direction, the combined effect of multiple prism structures further enhances the field of view expansion. Multiple prism structures can more effectively adjust the direction of light propagation, ensuring a wider field of view expansion. The preset direction can be horizontal.

[0071] Specifically, such as Figures 8-10 As shown, different prism structure brightening films can be obtained by repeating the arrangement of microstructure units. Figure 8 It is a conventional brightness enhancement film microstructure, a simple prism structure, which has the effect of high brightness at the conventional positive viewing angle, but the 1 / 2 light intensity angle is about ±35°. Figure 9 and Figure 10 Featuring a lower trapezoidal structure, it provides additional lateral light at large angles. Therefore, the overall result is high brightness at a positive viewing angle, while also expanding the range of the half-light intensity angle to ±50°.

[0072] The total optical efficiency is the sum of the upper prism structure and the lower trapezoidal structure. The upper prism structure provides light intensity at a positive viewing angle, while the lower trapezoidal structure provides light intensity at a wide viewing angle.

[0073] Furthermore, it also includes a substrate layer 30, which is disposed at the bottom of the second prism portion 20. It is understood that by providing the substrate layer 30, a good fixing and supporting effect can be achieved, thereby ensuring structural stability.

[0074] Preferably, the material of the substrate layer 30 includes, but is not limited to, any one of polyethylene terephthalate (PET), polycarbonate (PC) or polymethyl methacrylate (PMMA), which has excellent mechanical properties, transparency and heat resistance, and serves as the main substrate layer 30 in the composite viewing angle expanding film, providing strength and stability while maintaining the transparency of the material.

[0075] More preferably, the thickness of the substrate layer 30 is 20-250 μm. Understandably, this achieves a good supporting effect.

[0076] The following examples further illustrate this point:

[0077] Example 1

[0078] like Figure 11 As shown, the height H of the first prism section 10 L The height H of the second prism section 20 is 15μm. T The diameter is 10μm, the number S of first prism portions 10 on a single second prism portion 20 is 1, and the inclination angle θ of the inclined surface of the second prism portion 20 is 30°.

[0079] At this point, the test results for the viewing angle expansion film were as follows: 1 / 2 light intensity angle was ±47°, brightness was 4525 nits, and brightness ratio was 91%.

[0080] Example 2

[0081] The difference from Embodiment 1 is that the number S of the first prism portions 10 contained in a single second prism portion 20 is 3.

[0082] At this point, the test results for the viewing angle expansion film were as follows: 1 / 2 light intensity angle was ±40°, brightness was 4628 nits, and brightness ratio was 93%.

[0083] Example 3

[0084] The difference from Embodiment 1 is that the number S of the first prism portions 10 on a single second prism portion 20 is 5.

[0085] At this point, the test results for the viewing angle expansion film are as follows: 1 / 2 light intensity angle is ±38°, brightness is 4643 nits, and brightness ratio is 94%.

[0086] Example 4

[0087] The difference from Embodiment 1 is that the number S of the first prism portions 10 on a single second prism portion 20 is 10.

[0088] At this time, the viewing angle expansion film test results are: 1 / 2 light intensity angle is ± 37°, brightness is 4785 nits, and brightness ratio is 96% after testing.

[0089] Example 5

[0090] The difference from Example 1 is that the inclined angle θ of the inclined surface of the second prism portion 20 is 60°.

[0091] At this time, the viewing angle expansion film test results are: 1 / 2 light intensity angle is ± 43°, brightness is 4530 nits, and brightness ratio is 91% after testing.

[0092] Example 6

[0093] The difference from Example 1 is that the number S of the first prism portion 10 on a single second prism portion 20 is 3, and the inclined angle θ of the inclined surface of the second prism portion 20 is 60°.

[0094] At this time, the viewing angle expansion film test results are: 1 / 2 light intensity angle is ± 38°, brightness is 4790 nits, and brightness ratio is 95% after testing.

[0095] Example 7

[0096] The difference from Example 1 is that the number S of the first prism portion 10 on a single second prism portion 20 is 5, and the inclined angle θ of the inclined surface of the second prism portion 20 is 60°.

[0097] At this time, the viewing angle expansion film test results are: 1 / 2 light intensity angle is ± 37°, brightness is 4861 nits, and brightness ratio is 98% after testing.

[0098] Example 8

[0099] The difference from Example 1 is that the number S of the first prism portion 10 on a single second prism portion 20 is 10, and the inclined angle θ of the inclined surface of the second prism portion 20 is 60°.

[0100] At this time, the viewing angle expansion film test results are: 1 / 2 light intensity angle is ± 36°, brightness is 4813 nits, and brightness ratio is 97% after testing.

[0101] Example 9

[0102] The difference from Example 1 is that the height H of the first prism portion 10 is 5 μm, and the height H of the second prism portion 20 is 20 μm. L T

[0103] At this time, the viewing angle expansion film test results are: 1 / 2 light intensity angle is ± 52°, brightness is 3863 nits, and brightness ratio is 78% after testing. ​​

[0104] Example 10

[0105] The difference from Embodiment 1 is that the height H of the first prism portion 10 is... L The height H of the second prism section 20 is 5μm. T The size is 20μm, and the number S of the first prism portions 10 contained in a single second prism portion 20 is 3.

[0106] At this point, the test results for the viewing angle expansion film are as follows: 1 / 2 light intensity angle is ±46°, brightness is 4248 nits, and brightness ratio is 86%.

[0107] Example 11

[0108] The difference from Embodiment 1 is that the height H of the first prism portion 10 is... L The height H of the second prism section 20 is 5μm. T The size is 20μm, and the number S of the first prism portions 10 contained on a single second prism portion 20 is 5.

[0109] At this point, the test results for the viewing angle expansion film are as follows: 1 / 2 light intensity angle is ±44°, brightness is 4348 nits, and brightness ratio is 88%.

[0110] Example 12

[0111] The difference from Embodiment 1 is that the height H of the first prism portion 10 is... L The height H of the second prism section 20 is 5μm. T The size is 20μm, and the number S of the first prism portions 10 contained in a single second prism portion 20 is 10.

[0112] At this point, the test results for the viewing angle expansion film are as follows: 1 / 2 light intensity angle is ±40°, brightness is 4418 nits, and brightness ratio is 89%.

[0113] Comparative Example 1

[0114] The difference from Embodiment 1 is that the height H of the first prism portion 10 is... L It is 25μm and does not have a second prism section 20.

[0115] At this point, the test results for the viewing angle magnification film are as follows: 1 / 2 light intensity angle is ±35°, brightness is 4960 nits, and brightness ratio is 100%.

[0116] Comparative Example 2

[0117] The difference from Embodiment 1 is that the inclination angle θ of the inclined surface of the second prism part 20 is 45°.

[0118] At this time, the viewing angle expansion film test results were: 1 / 2 light intensity angle ± 35°, brightness 4954 nits, and brightness ratio 100% after testing.

[0119] Comparative Example 3

[0120] The difference from Example 1 was that the height H of the first prism portion 10 was 20 μm, the height H of the second prism portion 20 was 5 μm, and the number S of the first prism portion 10 contained in a single second prism portion 20 was 3. L T The difference from Example 1 was that the height H of the first prism portion 10 was 20 μm, the height H of the second prism portion 20 was 5 μm, and the number S of the first prism portion 10 contained in a single second prism portion 20 was 3.

[0121] At this time, the viewing angle expansion film test results were: 1 / 2 light intensity angle ± 40°, brightness 4590 nits, and brightness ratio 93% after testing.

[0122] Comparative Example 4

[0123] The difference from Example 1 was that the height H of the first prism portion 10 was 20 μm, the height H of the second prism portion 20 was 5 μm, and the number S of the first prism portion 10 contained in a single second prism portion 20 was 3. L T The difference from Example 1 was that the height H of the first prism portion 10 was 20 μm, the height H of the second prism portion 20 was 5 μm, and the number S of the first prism portion 10 contained in a single second prism portion 20 was 3.

[0124] At this time, the viewing angle expansion film test results were: 1 / 2 light intensity angle ± 37°, brightness 4792 nits, and brightness ratio 97% after testing.

[0125] Comparative Example 5

[0126] The difference from Example 1 was that the height H of the first prism portion 10 was 20 μm, the height H of the second prism portion 20 was 5 μm, and the number S of the first prism portion 10 contained in a single second prism portion 20 was 3. L T The difference from Example 1 was that the height H of the first prism portion 10 was 20 μm, the height H of the second prism portion 20 was 5 μm, and the number S of the first prism portion 10 contained in a single second prism portion 20 was 3.

[0127] At this time, the viewing angle expansion film test results were: 1 / 2 light intensity angle ± 36°, brightness 4892 nits, and brightness ratio 99% after testing.

[0128] Comparative Example 6

[0129] The difference from Example 1 was that the height H of the first prism portion 10 was 20 μm, the height H of the second prism portion 20 was 5 μm, and the number S of the first prism portion 10 contained in a single second prism portion 20 was 3. L T The difference from Example 1 was that the height H of the first prism portion 10 was 20 μm, the height H of the second prism portion 20 was 5 μm, and the number S of the first prism portion 10 contained in a single second prism portion 20 was 3.

[0130] At this time, the viewing angle expansion film test results were: 1 / 2 light intensity angle ± 36°, brightness 4888 nits, and brightness ratio 99% after testing.

[0131] Comparative Example 7

[0132] ​​​​The difference from Example 1 is that the number S of the first prism portion 10 contained in the single second prism portion 20 is 3, and the inclination angle θ of the slope of the second prism portion 20 is 45°.

[0133] At this time, the test result of the viewing angle expansion film is that the 1 / 2 light intensity angle is ±39°, the brightness is 4768 nits, and the brightness ratio is 96%.

[0134] Comparative Example 8

[0135] The difference from Example 1 is that the number S of the first prism portion 10 contained in the single second prism portion 20 is 5, and the inclination angle θ of the slope of the second prism portion 20 is 45°.

[0136] At this time, the test result of the viewing angle expansion film is that the 1 / 2 light intensity angle is ±38°, the brightness is 4833 nits, and the brightness ratio is 97%.

[0137] Comparative Example 9

[0138] The difference from Example 1 is that the number S of the first prism portion 10 contained in the single second prism portion 20 is 10, and the inclination angle θ of the slope of the second prism portion 20 is 45°.

[0139] At this time, the test result of the viewing angle expansion film is that the 1 / 2 light intensity angle is ±36°, the brightness is 4873 nits, and the brightness ratio is 98%.

[0140] The results of each example and comparative example are shown in Table 1:

[0141] Table 1

[0142]

[0143]

[0144] From the above test results, it can be seen that:

[0145] 1. From Examples 1-4, it can be seen that the trapezoidal slope density of Example 1 is high, and the brightness is low; the trapezoidal slope density of Example 4 is smaller, and there is no help for large viewing angle light intensity.

[0146] 2. From Examples 5-8, it can be seen that the trapezoidal slope density of Example 5 is high, and the brightness is low; the trapezoidal slope density of Example 8 is smaller, and there is no help for large viewing angle light intensity.

[0147] 3. From Examples 1-8, it can be seen that when the trapezoidal angle becomes larger, the outgoing light enters the adjacent microstructure and is reflected, and the large viewing angle light effect is slightly lower.

[0148] 4. It can be seen from Examples 9-12 that when the prism structure is small, the microstructure function contribution to the brightness at a positive viewing angle is small, and the brightness is poor; the microstructure function contribution to the brightness at a large viewing angle is large, and the viewing angle is large.

[0149] 5. It can be seen from Examples 1-12 and Comparative Example 1 that after the second prism portion is added, there is a large viewing angle light output effect, and the viewing angle is expanded.

[0150] 6. It can be seen from Comparative Example 1 and Comparative Example 2 that the optical performance produced by the structures of the two is consistent.

[0151] 7. It can be seen from Example 1 and Comparative Examples 3-6 that when the trapezoidal structure is small, the large-angle light output effect is poor, and it is of limited help to improve the viewing angle.

[0152] 8. It can be seen from Example 1 and Comparative Examples 7-9 that the trapezoidal slope density of Comparative Example 7 is high, and the brightness is low; the smaller the trapezoidal slope density of Comparative Example 9 is, the less helpful it is to the large viewing angle light intensity.

[0153] 9. It can be seen from Examples 1-4 and Comparative Examples 7-9 that although the 45-degree trapezoidal structure has a compensation effect for the large viewing angle light output brightness, it is slightly poor at a small angle.

[0154] As shown above, it can be seen from the results that by using the structure of the present application, the viewing angle is effectively improved while maintaining the brightness of the brightness enhancement film of 90% or more.

[0155] The present application also relates to a backlight module which can be used in a liquid crystal display device to improve the display quality of the display device. The backlight module of the present embodiment includes a light guide plate and other known structures such as a light emitting unit, which will not be described in detail here. The light emitting surface side of the light guide plate is provided with the viewing angle expansion film described above.

[0156] The present application also relates to a display device which includes a display panel and the backlight module described above, and the backlight module is used to provide a backlight source for the display panel.

[0157] The display device of the present embodiment can be any product or component with display function, such as a liquid crystal panel, electronic paper, a liquid crystal television, a liquid crystal display, a digital photo frame, a mobile phone, a tablet computer, etc.

[0158] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the specific details in the above-described embodiments. Within the technical concept of the present application, the technical solutions of the present application can be variously equivalent, and these equivalent changes all belong to the protection scope of the present application.

Claims

1. A prismatic structure, characterized by, The prism structure comprises: a plurality of first prism portions (10); and a second prism portion (20) connected to the bottom of the plurality of first prism portions (10); wherein the cross section of the plurality of first prism portions (10) is isosceles right triangle, the cross section of the second prism portion (20) is isosceles trapezoid, and the top width of the second prism portion (20) is equal to the total bottom width of the plurality of first prism portions (10), so that the incident light is expanded in viewing angle and improved in brightness by the prism structure.

2. The prismatic structure of claim 1, wherein, The inclined angle of the inclined surface of the second prism portion (20) is 0°-90°, and the inclined angle is not equal to 45°, so as to form a right trapezoidal structure, and the inclined surface of the second prism portion (20) is not coplanar with the inclined surface of the first prism portion (10).

3. The prismatic structure of claim 1, wherein, The plurality of first prism portions (10) and the second prism portion (20) are stacked to form an optical modulation layer.

4. The prismatic structure of claim 1, wherein, The height of the first prism portion (10) is 5-20 μm.

5. The prismatic structure of claim 1, wherein, The height of the second prism portion (20) is 10-20 μm.

6. The prismatic structure of claim 2, wherein, When the number of the plurality of first prism portions (10) is one, the bottom width of the first prism portion (10) is equal to the top width of the second prism portion (20).

7. The prismatic structure of claim 2, wherein, When the number of the plurality of first prism portions (10) is more than one, the total bottom width of the plurality of first prism portions (10) is equal to the top width of the second prism portion (20).

8. An angle-expanding film, characterized by The prism structure comprises any one of claims 1-7. The number of the prism structure is more than one, and the plurality of prism structures are arranged adjacent to each other along a preset direction. The prism structure is used as a minimum array unit.

9. A backlight module characterized by, The viewing angle expansion film comprises the prism structure of claim 8.

10. A display device, characterized by The backlight module comprises the prism structure of claim 9.

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