Optical film assembly, backlight module and display device

Abstract

The invention discloses an optical film assembly, a backlight module and a display device, which are used for reducing the thickness of the optical film assembly. The embodiment of the invention provides an optical film assembly. The optical film assembly comprises a substrate, a first prism layer located on one side of the substrate, a second prism layer located on the side, away from the substrate, of the first prism layer, and a first bonding layer located between the first prism layer and the second prism layer. The first prism layer comprises a plurality of first prisms which are arranged along a first direction and extend along a second direction; the second prism layer comprises a plurality of second prisms which are arranged along a third direction and extend along a fourth direction; the first direction intersects with the third direction; the second direction intersects the fourth direction.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to an optical film assembly, a backlight module and a display device. Background Art

[0002] Displays have been widely used in various fields and are inseparable from our work, study and life. In the prior art, the backlight module of the display usually needs to be provided with a double-layer prism sheet to improve the light utilization rate, but this will result in a thicker product. Summary of the invention

[0003] The embodiments of the present application provide an optical film assembly, a backlight module and a display device, which are used to reduce the thickness of the optical film assembly.

[0004] An optical film assembly provided in an embodiment of the present application includes: a substrate, a first prism layer located on one side of the substrate, a second prism layer located on a side of the first prism layer away from the substrate, and a first bonding layer located between the first prism layer and the second prism layer;

[0005] The first prism layer includes a plurality of first prisms arranged along a first direction and extending along a second direction; the second prism layer includes a plurality of second prisms arranged along a third direction and extending along a fourth direction; the first direction intersects with the third direction; and the second direction intersects with the fourth direction.

[0006] In some embodiments, the angle between the fourth direction and the first direction is greater than or equal to 20° and less than or equal to 40°; the angle between the second direction and the first direction is greater than or equal to 50°.

[0007] In some embodiments, the non-obtuse angle between the fourth direction and the first direction is greater than or equal to 25° and less than or equal to 33°.

[0008] In some embodiments, the non-obtuse angle between the second direction and the first direction is greater than or equal to 65° and less than or equal to 80°.

[0009] In some embodiments, at least one of the substrate and the first bonding layer includes a plurality of scattering particles.

[0010] In some embodiments, the volume of the scattering particles in the film layer is greater than or equal to 5% and less than or equal to 45%.

[0011] In some embodiments, the haze of the first bonding layer is greater than or equal to 15% and less than or equal to 30%.

[0012] In some embodiments, the substrate has a haze greater than or equal to 25% and less than or equal to 45%.

[0013] In some embodiments, the diameter of the scattering particles is greater than or equal to 2 microns and less than or equal to 3 microns.

[0014] In some embodiments, the cross-section of the first prism along the first direction is a first triangle, the first triangle includes a first vertex angle away from the substrate; the cross-section of the second prism along the third direction is a second triangle, the second triangle includes a second vertex angle away from the substrate;

[0015] The first vertex angle is 90°, or the first vertex angle is a rounded angle, and the central angle corresponding to the rounded angle is 90°;

[0016] The second vertex angle is 90°, or the second vertex angle is a rounded angle, and the center angle corresponding to the rounded angle is 90°.

[0017] In some embodiments, the refractive index of the substrate, the refractive index of the first prism layer, the refractive index of the second prism layer, and the refractive index of the first bonding layer are greater than or equal to 1.5 and less than or equal to 1.6.

[0018] A backlight module provided in an embodiment of the present application includes: a light source, and an optical film assembly provided in an embodiment of the present application located on one side of the light source.

[0019] In some embodiments, the backlight module further includes: a brightness enhancement film located on the light emitting side of the optical film assembly.

[0020] A display device provided in an embodiment of the present application includes: a backlight module provided in an embodiment of the present application, and a display panel located on a light emitting side of the backlight module.

[0021] In the optical film assembly, backlight module and display device provided by the embodiments of the present application, two prism layers are bonded by a first bonding layer, that is, the two prism layers are integrated into one structure, and there is no need to set up an additional substrate to support the second prism layer located on the upper layer. The thickness of the first bonding layer is much smaller than the thickness of the substrate, that is, compared with the case where the two prism layers are independently set in the prior art, the total thickness of the optical film assembly can be reduced. The optical film assembly is applied to the backlight module of the display product, which can reduce the thickness of the backlight module, thereby reducing the thickness of the display product. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of the structure of an optical film assembly provided in an embodiment of the present application;

[0024] Figure 2 A schematic diagram of the structure of another optical film assembly provided in an embodiment of the present application;

[0025] Figure 3 A schematic diagram of the structure of another optical film assembly provided in an embodiment of the present application;

[0026] Figure 4 A full-viewing angle brightness diagram of an optical film assembly provided for related technology;

[0027] Figure 5 A full-viewing angle distribution brightness diagram of a second prism of an optical film assembly provided in an embodiment of the present application when the extension direction is rotated;

[0028] Figure 6 A full-viewing angle distribution brightness diagram of a first prism of an optical film assembly provided in an embodiment of the present application when the extension direction is rotated;

[0029] Figure 7 A schematic diagram of the relationship between the angle between the fourth direction X" and the first direction X, the angle between the second direction X' and the first direction X, and brightness provided in an embodiment of the present application;

[0030] Figure 8 A schematic diagram of the relationship between the angle between the second direction X' and the first direction X and TCO when the angle between the fourth direction X" and the first direction X is fixed, provided in an embodiment of the present application;

[0031] Fig. 9 A full-viewing angle brightness diagram of another optical film assembly provided in an embodiment of the present application;

[0032] Fig.10 A graph showing the relationship between horizontal viewing angle and brightness in an optical film assembly provided in an embodiment of the present application;

[0033] Fig.11 A schematic diagram of the structure of another optical film assembly provided in an embodiment of the present application;

[0034] Fig.12 A full-viewing angle brightness diagram of another optical film assembly provided in an embodiment of the present application;

[0035] Fig.13 A graph showing the relationship between angle and brightness of the first optical film assembly and the second optical film assembly provided in an embodiment of the present application;

[0036] Fig.14 A schematic diagram of the structure of a first prism provided in an embodiment of the present application;

[0037] Fig.15 A schematic diagram of the structure of a second prism provided in an embodiment of the present application;

[0038] Fig.16 A schematic diagram of the structure of another first prism provided in an embodiment of the present application;

[0039] Fig.17 A schematic diagram of the structure of another second prism provided in an embodiment of the present application;

[0040] Fig.18 A schematic diagram of the structure of a backlight film assembly provided in an embodiment of the present application;

[0041] Fig.19 A schematic diagram of the structure of a display device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be clearly and completely described below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. And in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. Based on the described embodiments of the present application, all other embodiments obtained by ordinary technicians in the field without creative work belong to the scope of protection of this application.

[0043] Unless otherwise defined, the technical terms or scientific terms used in this application should be understood by people with ordinary skills in the field to which this application belongs. "First", "second" and similar words used in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and other similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and other similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0044] It should be noted that the sizes and shapes of the figures in the accompanying drawings do not reflect the actual proportions, but are only intended to illustrate the content of the present application. The same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions.

[0045] It should be noted that in the related art, the backlight module of the display product needs to be provided with two layers of prism sheets, and each layer of prism sheets needs to be provided with a prism structure on a substrate and supported by the substrate, that is, the prism sheet includes a substrate and a prism structure located on one side of the substrate. The double-layer substrate and double-layer prism structure included in the two-layer prism sheet will result in a thick backlight module.

[0046] The present application embodiment provides an optical film assembly, such as Figure 1 , Figure 2 , Figure 3 As shown, the optical film assembly includes: a substrate 1, a first prism layer 2 located on one side of the substrate 1, a second prism layer 3 located on the side of the first prism layer 2 away from the substrate 1, and a first bonding layer 4 located between the first prism layer 2 and the second prism layer 3;

[0047] The first prism layer 2 includes a plurality of first prisms 201 arranged along a first direction X and extending along a second direction X'; the second prism layer 3 includes a plurality of second prisms 301 arranged along a third direction Y and extending along a fourth direction X''; the first direction X intersects with the third direction Y; the second direction X' intersects with the fourth direction X''.

[0048] In the optical film assembly provided by the embodiment of the present application, the two prism layers are bonded by the first bonding layer, that is, the two prism layers are integrated into one structure, and there is no need to set up an additional substrate to support the second prism layer located on the upper layer. The thickness of the first bonding layer is much smaller than the thickness of the substrate, that is, compared with the case where the two prism layers are independently set in the prior art, the total thickness of the optical film assembly can be reduced. The optical film assembly is applied to the backlight module of the display product, which can reduce the thickness of the backlight module, thereby reducing the thickness of the display product.

[0049] It should be noted that Figure 1 For along Figure 3 The cross-sectional view of AA', Figure 2 For along Figure 3 Cross-sectional view of BB'.

[0050] In some embodiments, Figure 1 As shown, the thickness h1 of the substrate is greater than or equal to 50 micrometers and less than or equal to 400 micrometers, and the maximum thickness h2 of the first bonding layer is greater than or equal to 5 micrometers and less than or equal to 100 micrometers.

[0051] In a specific implementation, a plurality of first prisms in the first prism layer are closely arranged, that is, adjacent first prisms are in contact with each other; a plurality of second prisms in the second prism layer are closely arranged, that is, adjacent second prisms are in contact with each other.

[0052] It should be noted that Figure 1 Take the first prism 201 and the second prism 301 as an example, both of which are triangular prisms, that is, the shape of the first prism in a cross section perpendicular to the substrate and perpendicular to the second direction is a triangle, and the shape of the second prism in a cross section perpendicular to the substrate and perpendicular to the fourth direction is a triangle. Figure 3 The different dashed lines in the figure represent the edge 2011 of the first prism 201 away from the substrate and the edge 3011 of the second prism 301 away from the substrate.

[0053] It should be noted that when the optical film assembly is applied to the backlight module of a display product, the display product has a fixed horizontal direction, which is parallel to the direction in which the human eyes are arranged. Figure 3 The first direction X corresponds to the horizontal direction of the display product when the optical film assembly is applied to the display product, wherein the direction extending to the right of the first direction X is defined as the positive direction of the first direction X, and the direction extending to the left of the first direction X is defined as the negative direction of the first direction X. Figure 3 In the embodiment, the third direction Y is perpendicular to the fourth direction X″.

[0054] It should be noted that one of the certification standards for display products is TCO. TCO needs to meet the following requirements for the uniformity of viewing angle brightness of display products: (1) TCO in the horizontal direction of the display product: [(L max+30° / L min+30° )+(L max-30° / L min-30° )] / 2≤1.73; where L max+30° L is the brightness value corresponding to the viewing angle of +30° with the maximum brightness in the horizontal direction. min+30° L is the brightness value corresponding to the viewing angle of +30° with the minimum brightness in the horizontal direction. max-30° L is the brightness value corresponding to the viewing angle of -30° with the maximum brightness in the horizontal direction. min-30° The brightness value corresponding to the viewing angle of -30°, which is the minimum brightness in the horizontal direction. (2) TCO of the display product in the vertical direction: L max+15° / L min+15° ≤1.73, L max-15° / L min-15° ≤1.73; where L max+15° L is the brightness value corresponding to the viewing angle of maximum brightness in the vertical direction + 15°. min+15° L is the brightness value corresponding to the viewing angle of minimum brightness in the vertical direction +15°. max-15° L is the brightness value corresponding to the viewing angle of -15° with the maximum brightness in the vertical direction. min-15° The brightness value corresponding to the viewing angle of -15°, which is the minimum brightness in the vertical direction. The related technology includes a backlight module with a double-layer prism sheet applied to display products, which cannot meet the viewing angle requirements of TCO for brightness uniformity of display products.

[0055] It should be noted that in the related art, in the double-layer prism sheet, the lower prism sheet corresponds to the first prism layer of the present application, and the extension direction of the prism structure included in the lower prism sheet is perpendicular to the first direction involved in the embodiment of the present application, and the upper prism sheet corresponds to the second prism layer of the present application, and the extension direction of the prism structure included in the upper prism sheet is parallel to the first direction involved in the embodiment of the present application. When the optical film assembly is applied to the backlight module, the full-viewing angle image of the light emitted by the backlight module is related to the extension direction of the prism. In the related art, when the extension direction of the prism structure included in the upper prism sheet is parallel to the first direction involved in the embodiment of the present application, and the extension direction of the prism structure included in the lower prism sheet is perpendicular to the first direction involved in the embodiment of the present application, the setting method of the double-layer prism in the related art makes the light converge more in the 0° direction perpendicular to the picture, while sacrificing the viewing angle. The full-viewing angle brightness diagram of the backlight module is shown as follows. Figure 4 As shown, from Figure 4 It can be seen that there are two brightness gaps in the horizontal direction, namely Figure 4 In the middle F region, the backlight module including the double-layer prism sheet is applied to display products and cannot meet the viewing angle requirements of TCO for brightness uniformity of display products.

[0056] It should be noted that, for the full-viewing angle brightness diagram of the backlight module, the extension direction of the second prism in the upper prism layer, i.e., the second prism layer, is rotated, such as Figure 5 As shown, the central axis X'' in the full viewing angle distribution brightness diagram also rotates accordingly, and the extension direction of the second prism rotates 45°. Figure 5 The central axis X'' in the lower prism layer, that is, the extension direction (ie, the second direction X') of the first prism in the first prism layer, is rotated. Figure 6 As shown, the bright areas Y1 and Y2 in the full viewing angle distribution brightness diagram also rotate accordingly, and the extension direction of the first prism (ie, the fourth direction X") rotates 45°. Figure 6 The middle bright areas Y1 and Y2 in the image are also rotated 45° and gradually darkened. That is, once the angle between the second direction X' and the first direction X and the angle between the fourth direction X" and the first direction X are determined, the size of the gap in the full viewing angle brightness distribution is determined. However, the brightness distribution at the horizontal viewing angle and the vertical viewing angle of the display product will be determined by the angle between the fourth direction X" and the first direction X.

[0057] It should be noted that when the relationship between the angle between the fourth direction X" and the first direction X, the angle between the second direction X' and the first direction X, and the brightness is as follows: Figure 7 When the angle between the fourth direction X' and the first direction X is fixed, the relationship between the angle between the second direction X' and the first direction X and TCO is as follows: Figure 8 As shown, Figure 8In the figure, curve b1 is: when the angle between the fourth direction X" and the negative direction of the first direction X is 30° and the second direction X' changes clockwise, the relationship between the angle between the second direction X' and the first direction X and the horizontal direction (i.e., the first direction X) TCO; curve b2 is: when the angle between the fourth direction X" and the negative direction of the first direction X is 150° and the second direction X' changes counterclockwise, the relationship between the angle between the second direction X' and the first direction X and the horizontal direction (i.e., the first direction X) TCO; curve b3 is: when the angle between the fourth direction X" and the negative direction of the first direction X is 30° and the second direction X' changes clockwise, the relationship between the angle between the second direction X' and the first direction X and the vertical direction (i.e., perpendicular to the first direction X) TCO; curve b4 is: when the angle between the fourth direction X" and the negative direction of the first direction X is 150° and the second direction X' changes counterclockwise, the relationship between the angle between the second direction X' and the first direction X and the vertical direction (i.e., perpendicular to the first direction X) TCO. In specific implementation, the angle between the fourth direction X″ and the first direction X and the angle between the second direction X′ and the first direction X may be determined by comprehensively considering the brightness gain and TCO requirements.

[0058] The optical film assembly provided in the embodiment of the present application designs the extension direction of each layer of the prism structure so that the backlight module applied to the display product can meet the viewing angle requirement of TCO for the brightness uniformity of the display product. In order to improve the display effect when the optical film assembly is applied to the display product, in some embodiments, the non-obtuse angle a2 between the fourth direction X" and the first direction X is greater than or equal to 20° and less than or equal to 40°, and the non-obtuse angle a1 between the second direction X' and the first direction X is greater than or equal to 50°.

[0059] In a specific implementation, the non-obtuse angle between the fourth direction X" and the first direction X can be the non-obtuse angle between the fourth direction X" and the positive direction of the first direction X, or the non-obtuse angle between the fourth direction X" and the negative direction of the first direction X.

[0060] Furthermore, the non-obtuse angle a2 between the fourth direction X" and the first direction X is greater than or equal to 25° and less than or equal to 33°. Thus, the backlight module can meet the brightness and TCO viewing angle requirements when applied to display products.

[0061] Furthermore, the angle a1 between the second direction X' and the first direction X is greater than or equal to 65° and less than or equal to 80°. This can avoid serious brightness loss when the optical film assembly is applied to the backlight module when a1 is less than 65°. It can also avoid the backlight module being unable to meet the TCO viewing angle requirements when applied to display products when a1 is greater than 80°.

[0062] In some embodiments, a2 = 30°, a1 = 80°. When the optical film assembly is applied to a backlight module, the full viewing angle brightness of the backlight module is as follows: Fig. 9 As shown. It can be seen that Fig. 9 and Figure 4 In comparison, the arrangement of the first prism and the second prism in the optical film assembly provided in the embodiment of the present application eliminates the two small gaps in the horizontal direction, and the overall brightness trend becomes smooth, which is conducive to improving the uniformity of viewing angle brightness. The horizontal viewing angle brightness curve A2 when the optical film assembly with a2 = 30° and a1 = 80° is applied to the backlight module is compared with the horizontal viewing angle brightness curve A1 when the double-layer prism arrangement method of the related art is applied to the backlight module. Fig.10 It can be seen that when the optical film assembly provided in the embodiment of the present application is applied to the backlight module, the horizontal viewing angle brightness is significantly improved.

[0063] In some embodiments, Fig.11 As shown, at least one of the substrate 1 and the first bonding layer 4 includes a plurality of scattering particles 5 .

[0064] That is, only the substrate may include a plurality of scattering particles, only the first bonding layer may include a plurality of scattering particles, or both the substrate and the first bonding layer may include a plurality of scattering particles. Fig.11 In the description, it is taken as an example that both the substrate 1 and the first bonding layer 4 include a plurality of scattering particles 5 , the plurality of scattering particles 5 included in the substrate 1 are a plurality of first scattering particles 501 , and the plurality of scattering particles 5 included in the first bonding layer 4 are a plurality of second scattering particles 502 .

[0065] The optical film assembly provided in the embodiment of the present application, at least one of the substrate and the first bonding layer includes multiple scattering particles, which can improve the haze of the optical film assembly, so that the light is broken up and evenly dispersed after reaching the film layer where the scattering particles are located, and the evenly dispersed light is deflected after reaching the first prism or the second prism, which is more conducive to improving the uniformity of the brightness of the output light.

[0066] Next, a simulation is performed using an example where both the substrate and the first bonding layer include multiple scattering particles to illustrate the relationship between the haze and brightness of an optical film assembly. The simulation results are as follows: if the haze of the substrate increases by 0.02 and the haze of the first bonding layer increases by 0.01, the brightness at the horizontal viewing angle increases by 10%; if the haze of the substrate increases by 0.04 and the haze of the first bonding layer increases by 0.01, the brightness at the vertical viewing angle increases by 10%. The first optical film assembly in which neither the substrate nor the first bonding layer includes scattering particles and the second optical film assembly in which both the substrate and the first bonding layer include 10% scattering particles are simulated. The full viewing angle brightness graph of the first optical film assembly is still the same as above. Figure 4 As shown, the full viewing angle brightness diagram of the second optical film assembly is as follows Fig.12 As shown, according to Figure 4 , Fig.12 It can be seen that after adding scattering particles, the brightness difference at 17.17° and 40.22° is significantly reduced, that is, the TCO viewing angle is improved. Comparison of the horizontal viewing angle brightness curves of the first optical film assembly and the second optical film assembly Fig.13 shown.

[0067] In some embodiments, the volume of the scattering particles in the film layer is greater than or equal to 5% and less than or equal to 45%.

[0068] It should be noted that the volume of the scattering particles in the film layer in which they are located affects the haze of the film layer in which they are located. Haze refers to the percentage of the transmitted light intensity that deviates from the incident light by more than 2.5° to the total transmitted light intensity. The greater the haze, the lower the gloss and transparency of the film layer. The larger the volume of the scattering particles in the film layer in which they are located, the higher the haze of the film layer in which they are located.

[0069] In some embodiments, the haze of the first bonding layer and the haze of the substrate are greater than or equal to 10% and less than or equal to 45%.

[0070] In some embodiments, the haze of the first bonding layer is greater than or equal to 15% and less than or equal to 30%.

[0071] It should be noted that if the haze of the first bonding layer is less than 15%, the content of scattering particles is relatively small, and the shielding property of the scattering particles to light is relatively poor, which affects the uniformity of light dispersion. If the haze of the first bonding layer is greater than 30%, the content of scattering particles is high, and the loss of light brightness is obvious. That is, in the optical module assembly provided in the embodiment of the present application, the haze of the first bonding layer is greater than or equal to 15% and less than or equal to 30%, thereby improving the uniformity of light brightness while avoiding excessive brightness loss, so that the optical module assembly meets the requirements of TCO.

[0072] In some embodiments, the substrate has a haze greater than or equal to 25% and less than or equal to 45%.

[0073] It should be noted that if the haze of the substrate is less than 25%, the viewing angle brightness cannot meet the TCO requirements. If the haze of the substrate is greater than 45%, the scattering particle content is high and the brightness loss of the light output is obvious. That is, the optical module assembly provided in the embodiment of the present application has a haze of the substrate greater than or equal to 25% and less than or equal to 45%, so that the optical module assembly can meet the TCO requirements without excessive brightness loss.

[0074] In some embodiments, the scattering particles are spherical in shape, and the diameter of the scattering particles is greater than or equal to 2 micrometers and less than or equal to 3 micrometers.

[0075] In some embodiments, Figure 14 to Figure 17As shown, the cross-section shape of the first prism 201 along the first direction is a first triangle, and the first triangle includes a first vertex 2012 away from the side of the substrate 1; the cross-section shape of the second prism 301 along the third direction is a second triangle, and the second triangle includes a second vertex 3012 away from the side of the substrate 1;

[0076] like Fig.14 As shown, the first vertex angle 2012 is 90°, or, as Fig.16 As shown, the first vertex 2012 is a rounded corner, and the central angle corresponding to the rounded corner is 90°;

[0077] like Fig.15 As shown, the second vertex angle 3012 is 90°, or, as Fig.17 As shown, the second vertex 3012 is a rounded corner, and the center angle corresponding to the rounded corner is 90°.

[0078] It should be noted that Fig.14 , Fig.16 The fifth direction is perpendicular to the second direction. Fig.15 , Fig.17 It is a cross-sectional view along the third direction Y. Fig.15 , Fig.17 Only a partial region of the first adhesive layer 4 is shown.

[0079] That is, the first triangle and the second triangle can be triangles or rounded triangles. When the first triangle is a triangle, the first vertex angle is a right angle, and when the second triangle is a triangle, the second vertex angle is a right angle; when the first triangle is a rounded triangle, the first vertex angle is rounded, and when the second triangle is a triangle, the second vertex angle is rounded.

[0080] It should be noted that, compared with other angles, when the first vertex angle is 90°, the second vertex angle is 90°, or the central angle corresponding to the rounded angle is 90°, the light output brightness of the optical module assembly is the highest.

[0081] In some embodiments, the refractive index of the substrate, the refractive index of the first prism layer, the refractive index of the second prism layer, and the refractive index of the first bonding layer are greater than or equal to 1.45 and less than or equal to 1.7.

[0082] For example, to improve the performance of the optical module assembly, further, the refractive index of the substrate, the refractive index of the first prism layer, the refractive index of the second prism layer and the refractive index of the first bonding layer are greater than or equal to 1.5 and less than or equal to 1.6.

[0083] It should be noted that the higher the refractive index of each film layer of the optical module assembly, the better the TCO, but when the refractive index is greater than 1.6, the scratch resistance of the film layer decreases, causing the optical film assembly to be easily damaged. That is, the refractive index of the substrate, the refractive index of the first prism layer, the refractive index of the second prism layer, and the refractive index of the first bonding layer are greater than or equal to 1.5 and less than or equal to 1.6, which can ensure the scratch resistance of the optical module assembly while meeting the TCO requirements.

[0084] In some embodiments, the period of the first prism is equal to the period of the second prism. The period of the first prism is the maximum width of the first prism in the fifth direction when multiple first prisms are closely arranged, and the period of the second prism is the maximum width of the first prism in the third direction when multiple second prisms are closely arranged. Considering the difficulty of making the first prism and the second prism, in a specific implementation, the period of the first prism is equal to the period of the second prism, for example, greater than or equal to 25 microns and less than or equal to 50 microns; further, the period of the first prism is equal to the period of the second prism, which is greater than or equal to 30 microns and less than or equal to 45 microns.

[0085] Next, the simulation results of the refractive index, the first vertex angle, the second vertex angle, and the period of the prism on TCO are illustrated. If the refractive index of the first prism layer and the second prism layer are both increased by 0.01, the refractive index of the first prism layer increases by 0.01, resulting in a 0.05 decrease in the horizontal and vertical TCO, and the refractive index of the second prism layer increases by 0.01, resulting in a 0.1 decrease in the horizontal and vertical TCO. When the first triangle and the second triangle are triangles, when the first vertex angle and the second vertex angle are reduced by 10°, the horizontal TCO decreases by 0.05~0.2, and the vertical TCO decreases by 0.2. When the first triangle and the second triangle are rounded triangles, when the radian of the rounded corners decreases by 1 radian, the horizontal TCO decreases by 0.01, and the vertical TCO decreases by 0.03. It can be seen that changing the refractive index and the vertex angle can significantly improve the uniformity of the TCO viewing angle, but increasing the radian of the rounded corners and the period of the prism structure have little effect on the uniformity of the TCO viewing angle. However, if the vertex angle is reduced, it will lead to brightness loss. The refractive index of each film layer can be increased to improve the direction of light while reducing the vertex angle to compensate for the brightness loss caused by the reduction of the vertex angle.

[0086] The present application provides a backlight module, such as Fig.18 As shown, it includes: a light source 8, and an optical film assembly 6 provided in an embodiment of the present application located on one side of the light source 8.

[0087] In a specific implementation, for example, the light source is disposed opposite to a side surface of the substrate.

[0088] In some embodiments, Fig.18As shown, the backlight module further includes: a brightness enhancement film 7 located on the light emitting side of the optical film assembly 6 .

[0089] A display device provided in an embodiment of the present application is Fig.19 As shown, the display device includes: a backlight module 9 provided in an embodiment of the present application, and a display panel 10 located on the light emitting side of the backlight module 9 .

[0090] In specific implementation, Fig.19 As shown, the display panel 10 is, for example, a liquid crystal display panel, which includes: an array substrate 1001 and an opposite substrate 1002 that are oppositely arranged, and a liquid crystal layer 1003 located between the array substrate 1001 and the opposite substrate 1002 .

[0091] The display device provided in the embodiment of the present application is any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a laptop computer, a digital photo frame, a navigator, etc. Other essential components of the display device should be understood by ordinary technicians in the field, and will not be described in detail here, nor should they be used as limitations on the present application. The implementation of the display device can refer to the above-mentioned embodiment of the display panel, and the repeated parts will not be described in detail.

[0092] In summary, in the optical film assembly, backlight module and display device provided by the embodiments of the present application, the two prism layers are bonded by the first bonding layer, that is, the two prism layers are integrated into one structure, and there is no need to set up an additional substrate to support the second prism layer located on the upper layer. The thickness of the first bonding layer is much smaller than the thickness of the substrate, that is, compared with the situation in which the two prism layers are independently set in the prior art, the total thickness of the optical film assembly can be reduced. The optical film assembly is applied to the backlight module of the display product, which can reduce the thickness of the backlight module, and then reduce the thickness of the display product.

[0093] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0094] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. An optical film assembly, characterized in that: The optical film assembly comprises: a substrate, a first prism layer located on one side of the substrate, a second prism layer located on a side of the first prism layer away from the substrate, and a first bonding layer located between the first prism layer and the second prism layer; The first prism layer includes a plurality of first prisms arranged along a first direction and extending along a second direction; the second prism layer includes a plurality of second prisms arranged along a third direction and extending along a fourth direction; the first direction intersects with the third direction; and the second direction intersects with the fourth direction.

2. The optical film assembly according to claim 1, characterized in that: The angle between the fourth direction and the first direction is greater than or equal to 20° and less than or equal to 40°; the angle between the second direction and the first direction is greater than or equal to 50°.

3. The optical film assembly according to claim 2, characterized in that: The non-obtuse angle between the fourth direction and the first direction is greater than or equal to 25° and less than or equal to 33°.

4. The optical film assembly according to claim 3, characterized in that: A non-obtuse angle between the second direction and the first direction is greater than or equal to 65° and less than or equal to 80°.

5. The optical film assembly according to any one of claims 1 to 4, characterized in that: At least one of the substrate and the first bonding layer includes a plurality of scattering particles.

6. The optical film assembly according to claim 5, characterized in that: The volume of the scattering particles in the film layer is greater than or equal to 5% and less than or equal to 45%.

7. The optical film assembly according to claim 6, characterized in that: The haze of the first adhesive layer is greater than or equal to 15% and less than or equal to 30%.

8. The optical film assembly according to claim 7, characterized in that: The substrate has a haze of greater than or equal to 25% and less than or equal to 45%.

9. The optical film assembly according to claim 5, characterized in that: The diameter of the scattering particles is greater than or equal to 2 micrometers and less than or equal to 3 micrometers.

10. The optical film assembly according to any one of claims 1 to 4 and 7 to 9, characterized in that: The cross-section shape of the first prism along the first direction is a first triangle, and the first triangle includes a first vertex angle away from the substrate; the cross-section shape of the second prism along the third direction is a second triangle, and the second triangle includes a second vertex angle away from the substrate; The first vertex angle is 90°, or the first vertex angle is a rounded angle, and the central angle corresponding to the rounded angle is 90°; The second vertex angle is 90°, or the second vertex angle is a rounded angle, and the center angle corresponding to the rounded angle is 90°.

11. The optical film assembly according to any one of claims 1 to 4 and 7 to 9, characterized in that: A refractive index of the substrate, a refractive index of the first prism layer, a refractive index of the second prism layer, and a refractive index of the first bonding layer are greater than or equal to 1.5 and less than or equal to 1.

6.

12. A backlight module, characterized in that: include: A light source, and an optical film assembly according to any one of claims 1 to 11, located on one side of the light source.

13. The backlight module according to claim 12, characterized in that: The backlight module further comprises: a brightness enhancement film located on the light emitting side of the optical film assembly.

14. A display device, characterized in that: The display device comprises: the backlight module according to claim 12 or 13, and a display panel located on the light emitting side of the backlight module.

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