Brightness enhancement film, optical film stack, backlight module, and display device

Abstract

The embodiment of the present application provides a brightness enhancement film, an optical film group, a backlight module and a display device, wherein the brightness enhancement film comprises: a base material; a plurality of prism strips arranged on one side of the base material and arranged along a first direction, each prism strip extends along a second direction perpendicular to the first direction, and the plurality of prism strips comprise first prism strips, and the included angles between the two surfaces of the first prism strips parallel to the second direction and the base material are not equal. The technical scheme of the embodiment of the present application can improve the brightness uniformity of the viewing angle of the display device, so that the brightness ratio of the display device at a specific viewing angle in the horizontal direction and the vertical direction can be less than or equal to 1.73, and the TCO requirement is met.

Description

Technical Field

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

[0002] TCO certification is a display certification standard promoted by the Swedish Federation of Professional Employees (TCO). TCO requires that a display's brightness ratio at a specific viewing angle, both horizontally and vertically, be less than or equal to 1.73. Some displays struggle to meet this requirement. Summary of the Invention

[0003] The embodiments of the present application provide a brightness enhancement film, an optical film assembly, a backlight module, and a display device to solve or alleviate one or more technical problems in the prior art.

[0004] As a first aspect of an embodiment of the present application, an embodiment of the present application provides a brightness enhancement film, comprising: a substrate; a plurality of prism strips, arranged on one side of the substrate and arranged along a first direction, each prism strip extending along a second direction perpendicular to the first direction, the plurality of prism strips including a first prism strip, and the angles between the two surfaces of the first prism strip parallel to the second direction and the substrate are not equal.

[0005] In one embodiment, there are multiple first prism strips divided into multiple first prism groups, and the first prism strips of two adjacent first prism groups are symmetrical about a first symmetry plane, which is perpendicular to the first direction and the second direction.

[0006] In one embodiment, the first prism strip disposed at the end of the substrate in the first direction is an end prism strip, and the angle between the surface of the end prism strip close to the corresponding edge of the substrate and the substrate is α, wherein 40°≤α<45°.

[0007] In one embodiment, the angle between two surfaces of the first prism strip parallel to the second direction is an obtuse angle.

[0008] In one embodiment, the plurality of prism strips further include a second prism strip, and the angles between two surfaces of the second prism strip parallel to the second direction and the substrate are equal.

[0009] In one embodiment, the plurality of prism strips are divided into a plurality of second prism groups, each second prism group includes a first prism strip and a second prism strip, and the prism strips of two adjacent second prism groups are symmetrical about a second symmetry plane, which is perpendicular to the first direction and the second direction.

[0010] In one embodiment, each second prism group includes a plurality of first prism bars, and the second prism bar is located between two first prism bars at both ends.

[0011] As a second aspect of an embodiment of the present application, an embodiment of the present application provides an optical film group, comprising: a diffuser; two brightness enhancing films as in any of the above-mentioned embodiments, arranged on the same side of the diffuser, the prism strips of each brightness enhancing film being arranged on the side of the substrate away from the diffuser, and the extension directions of the prism strips of the two brightness enhancing films being not parallel.

[0012] As a third aspect of the embodiments of the present application, the embodiments of the present application provide a backlight module, including: a light source; a light guide plate, arranged on the light output side of the light source; and an optical film group such as any of the above embodiments, arranged on the light output side of the light guide plate.

[0013] In one embodiment, there are multiple light sources; the extension direction of the prism strips of the brightness enhancement film located at the upper part of the optical film group is parallel to the arrangement direction of the multiple light sources, and the extension direction of the prism strips of the brightness enhancement film located at the lower part of the optical film group is perpendicular to the arrangement direction of the multiple light sources.

[0014] In one embodiment, the light guide plate includes two light guiding surfaces and multiple light guiding side surfaces connected between the two light guiding surfaces, one of the multiple light guiding side surfaces is the light incident surface, one of the two light guiding surfaces is the light exit surface, and the other of the two light guiding surfaces and the remaining light guiding side surfaces are all reflective surfaces.

[0015] As a fourth aspect of the embodiments of the present application, the embodiments of the present application provide a display device, comprising a backlight module according to any one of the above embodiments.

[0016] The embodiment of the present application adopts the above technical solution to improve the brightness uniformity of the display device at a certain viewing angle, so that the brightness ratio of the display device at a specific viewing angle in the horizontal direction and the vertical direction can be less than or equal to 1.73, meeting the TCO requirements.

[0017] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present application will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0019] Figure 1A schematic diagram showing a test position of a display in the related art;

[0020] Figure 2 A schematic diagram showing a horizontal direction test of a display in the related art is shown;

[0021] Figure 3 A schematic diagram of a vertical direction test of a display in the related art is shown;

[0022] Figure 4 A schematic diagram showing a horizontal viewing angle of a display in the related art is shown;

[0023] Figure 5 A schematic diagram showing a vertical viewing angle of a display in the related art;

[0024] Figure 6 A schematic diagram showing the structure of a brightness enhancement film for a display in the related art is shown;

[0025] Figure 7 A schematic diagram showing the three-dimensional structure of a brightness enhancement film according to an embodiment of the present application is shown;

[0026] Figure 8 A schematic structural diagram of a brightness enhancement film according to an embodiment of the present application is shown;

[0027] Figure 9 A schematic structural diagram of a brightness enhancement film according to another embodiment of the present application is shown;

[0028] Figure 10 A schematic structural diagram of a brightness enhancement film according to another embodiment of the present application is shown;

[0029] Figure 11 An exploded schematic diagram of an optical film assembly according to an embodiment of the present application is shown;

[0030] Figure 12 A comparison diagram showing a full-viewing angle simulation diagram of an optical film assembly according to an embodiment of the present application and a full-viewing angle simulation diagram of an optical film assembly in the related art;

[0031] Figure 13 A schematic diagram showing the three-dimensional structure of a backlight module according to an embodiment of the present application is shown;

[0032] Figure 14 Show Figure 13 The exploded view of the backlight unit is shown in .

[0033] Description of reference numerals:

[0034] Related technologies: 1: display; 11: brightness enhancement film; 111: substrate; 112: prism strip;

[0035] This application: 100: brightness enhancement film; 110: substrate; 120: first prism strip; 121: end prism strip;

[0036] 130: second prism strip;

[0037] L1: first direction; L2: second direction;

[0038] 200: Optical film group; 210: Diffuser;

[0039] 300: Backlight module; 310: Light source; 320: Light guide plate; 330: Reflector; 340: Substrate; 350: Plastic frame. DETAILED DESCRIPTION

[0040] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present application. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.

[0041] TCO Certification is a monitor certification standard promoted by the Swedish Federation of Professional Employees (TCO). To pass this certification, developed by the Swedish Federation of Professional Employees, monitors must meet standards in four areas: ecology, energy, emissions, and ergonomics. Therefore, TCO Certification addresses both human health and the ecological environment, directly impacting the health impact of monitors on users.

[0042] Figure 1 Schematic diagram of the test position of the display in the related art is shown. Figure 1 As shown, H is the length of the display screen of the display 1; V is the width of the display screen. C is the center point of the display 1; P L For too much P C The intersection of the horizontal line of the point and the vertical line H / 10 from one end of the length direction of the display screen; P R For too much P C The intersection of the horizontal line of the point and the vertical line H / 10 from the other end of the length direction of the display screen. T For too much P C The intersection of the vertical line of the point and the horizontal line V / 10 away from one side of the width direction of the display screen; B For too much P C The intersection of the vertical line of the point and the horizontal line V / 10 away from the other side of the width direction of the display screen. Among them, each horizontal line is parallel to the length direction of the display screen, and each vertical line is parallel to the width direction of the display screen.

[0043] Figure 2 The horizontal direction test diagram of the display in the related art is shown. Figure 2 , the brightness ratio A of the display 1 at a specific viewing angle in the horizontal direction is [(L max+30° / L min+30° )+(L max-30° / L min-30° )] / 2, TCO requirement A≤1.73. Combined Figure 2 , L max+30° It is the maximum viewing angle brightness of the display 1 when it is rotated +30° around the vertical axis passing through the center point of the display 1 glass. min+30° It is the minimum viewing angle brightness of display 1 when it is rotated +30° around the vertical axis passing through the center point of the display 1 glass, and “+” is clockwise. max-30° L is the maximum viewing angle brightness of display 1 when it is rotated -30° around the vertical axis passing through the center point of the display glass. min-30° The minimum viewing angle brightness of the display 1 when it is rotated -30° around the vertical axis passing through the center point of the glass of the display 1. “-” indicates the counterclockwise direction.

[0044] Figure 3 A schematic diagram of a vertical direction test of a display in the related art is shown. Figure 3 , the first viewing angle brightness ratio B1 of the display 1 at a specific viewing angle in the vertical direction is L max+15° / L min+15° , the second viewing angle brightness ratio B2 is L max-15° / L min-15° , TCO requires B1≤1.73 and B2≤1.73. Combined Figure 3 , L max+15° It is the maximum viewing angle brightness of the display 1 when it is rotated +15° around the horizontal axis passing through the center point of the display 1 glass. min+15° It is the minimum viewing angle brightness of the display 1 when it is rotated +15° around the horizontal axis passing through the center point of the display 1 glass. “+” is in the backward direction. max-15° L is the maximum viewing angle brightness of the display 1 when it is rotated -15° around the horizontal axis passing through the center point of the display 1 glass. min-15° It is the minimum viewing angle brightness when the display 1 is rotated -15° around the horizontal axis passing through the center point of the display 1 glass, and “-” indicates the forward direction.

[0045] In the related art, the brightness ratio of some displays at a specific viewing angle is greater than 1.73, which makes it difficult to meet the TCO requirement of a brightness ratio at a specific viewing angle of less than or equal to 1.73. Figure 4 A schematic diagram showing a horizontal viewing angle of a display in the related art is shown; Figure 5 Schematic diagram of vertical viewing angle of display in related art is shown. Take 27-inch display as an example. Figure 4As shown, the brightness ratio of display 1 at specific horizontal viewing angles is related to the brightness at horizontal viewing angles of 17.17° and 40.22°. To meet TCO requirements, the brightness at the 40.22° viewing angle needs to be increased and the brightness at the 17.17° viewing angle needs to be reduced. The brightness ratio of display 1 at specific vertical viewing angles is related to the brightness at vertical viewing angles of 7.55° and 21.96°. To meet TCO requirements, the brightness at the 21.96° viewing angle needs to be increased and the brightness at the 7.55° viewing angle needs to be reduced.

[0046] Figure 6 The schematic diagram of the structure of the brightness enhancement film of the display in the related art is shown. Figure 6 As shown, the brightness enhancement film 11 includes a substrate 111 and a plurality of prism strips 112 disposed on the substrate 111. Each prism strip 112 extends along the X-direction. The two surfaces of each prism strip 112 parallel to the X-direction have equal angles with the substrate 111, and the two surfaces of each prism strip 112 parallel to the X-direction are perpendicular to each other. The cross-sectional shape of each prism strip 112 is an isosceles right triangle. When the brightness enhancement film 11 is applied to a display 1, the brightness of the display 1 is higher when the user looks straight at the display 1 (i.e., the user's line of sight is perpendicular to the display 1). When the user looks at the display 1 at an angle (i.e., the user's line of sight is not perpendicular to the display 1), the brightness of the display 1 is lower at certain viewing angles (for example, a 27-inch display 1 with a horizontal viewing angle of 40.22° and a vertical viewing angle of 21.96°). This results in a brightness ratio greater than 1.73 at specific viewing angles for some portions of the display 1, resulting in poor brightness uniformity across viewing angles.

[0047] The following combination Figure 7-10 A brightness enhancement film 100 according to an embodiment of the first aspect of the present application is described. The brightness enhancement film 100 can be applied to a display device. In the following description of the present application, the application of the brightness enhancement film 100 to a display device is taken as an example.

[0048] Figure 7 FIG. 1 is a schematic diagram showing a three-dimensional structure of a brightness enhancement film 100 according to an embodiment of the present application; Figure 8 FIG. 1 shows a schematic structural diagram of a brightness enhancement film 100 according to an embodiment of the present application. Figure 7 and Figure 8 As shown, the brightness enhancement film 100 according to an embodiment of the present application includes a substrate 110 and a plurality of prism strips. In the description of the present application, "plurality" means two or more.

[0049] Specifically, a plurality of prism bars are disposed on one side of the substrate 110 and arranged along a first direction L1. Each prism bar extends along a second direction L2 perpendicular to the first direction L1. The plurality of prism bars include a first prism bar 120. The angles between the two surfaces of the first prism bar 120 parallel to the second direction L2 and the substrate 110 are not equal.

[0050] Exemplarily, each prism bar may include two surfaces and two side surfaces, the two side surfaces are respectively connected to the two ends of the two surfaces, and an angle may be formed between the two surfaces. The surfaces of the first prism bar 120 may be respectively parallel to the second direction L2, and the side surfaces of the first prism bar 120 may be respectively parallel to the first direction L1. At this time, the cross-sectional shape of the first prism bar 120 is a non-isosceles triangle, and the cross-section of the first prism bar 120 is parallel to the first direction L1. Compared with the brightness enhancement film in the related art, the two surfaces of the first prism bar 120 parallel to the second direction L2 can change the emission direction of light and change the viewing angle of the light-emitting surface of the display device. When the user looks at the display device at an angle, the brightness of the display device is greater, thereby improving the brightness uniformity of the display device at a specific viewing angle, so that the brightness ratio of the display device at a specific viewing angle can be less than or equal to 1.73.

[0051] Optionally, the substrate 110 may be polyethylene glycol terephthalate (PET), but is not limited thereto.

[0052] According to the brightness enhancement film 100 of the embodiment of the present application, by making the multiple prism strips include a first prism strip 120 and the angles between the two surfaces of the first prism strip 120 parallel to the second direction L2 and the substrate 110 are not equal, when the brightness enhancement film 100 is applied to a display device, the brightness uniformity of the display device at a viewing angle can be improved, so that the brightness ratio of the display device at a specific viewing angle in the horizontal direction and the vertical direction can be less than or equal to 1.73, meeting the TCO requirements.

[0053] Figure 9 FIG. 1 is a schematic structural diagram of a brightness enhancement film 100 according to another embodiment of the present application. Figure 7-Figure 9 As shown, there are multiple first prism bars 120 divided into multiple first prism groups. The first prism bars 120 of two adjacent first prism groups are symmetrical about a first symmetry plane, and the first symmetry plane is perpendicular to the first direction L1 and the second direction L2.

[0054] Here, it should be noted that the first symmetry plane is a virtual plane for describing the symmetry relationship between two adjacent first prism groups, and is not an actual plane in the brightness enhancement film 100 .

[0055] In one example, referring to Figure 8Each first prism group can include a first prism bar 120. In this case, the number of first prism groups equals the number of first prism bars 120, and two adjacent first prism bars 120 are symmetrical about the first symmetry plane. Thus, when the brightness enhancement film 100 is applied to a display device, the brightness of the display device can be consistent when a user views the display device from two angles, further improving the brightness uniformity of the display device across viewing angles.

[0056] In another example, referring to Figure 9 , each first prism group may include N first prism bars 120, where N>1. In this case, the number of first prism bars 120 may be N times the number of first prism groups. Figure 9 In the example shown, each first prism group includes two first prism bars 120. The two first prism bars 120 of each first prism group are symmetrical with the two first prism bars 120 of the adjacent first prism group about the first symmetry plane. With this arrangement, when the brightness enhancement film 100 is applied to a display device, the brightness of the display device can also be maintained consistent, thereby ensuring brightness uniformity across the viewing angle of the display device.

[0057] In this embodiment, by making the first prism strips 120 of two adjacent first prism groups symmetrical about the first symmetry plane, when the brightness enhancement film 100 is applied to a display device, the luminous viewing angle of the display device can be widened. When the user looks at the display device at an angle from the left or right sides or from the top or bottom, the brightness of the display device can remain symmetrical, thereby meeting the TCO requirements.

[0058] In one embodiment, the first prism strip 120 disposed at the end of the substrate 110 in the first direction L1 is an end prism strip 121. The angle α between the surface of the end prism strip 121 near the corresponding edge of the substrate 110 and the substrate 110 is 40°≤α<45°. For example, α may be 43°, but is not limited thereto.

[0059] For example, the substrate 110 can be formed into a rectangular shape. The substrate 110 can include two first edges parallel to the first direction L1 and two second edges parallel to the second direction L2. There are two end prism strips 121, each of which is disposed adjacent to the two second edges of the substrate 110. Here, α is the angle between the surface of each end prism strip 121 adjacent to the corresponding second edge and the substrate 110.

[0060] In this embodiment, by ensuring that 40°≤α<45°, the slope of the surface of the corresponding edge of the end prism strip 121 close to the substrate 110 is relatively small. When the brightness enhancement film 100 is applied to a display device, while effectively improving the brightness uniformity of the viewing angle of the display device, the overall brightness of the display device is ensured to be large, thereby improving the display effect of the display device.

[0061] In one embodiment, the angle between the two surfaces of the first prism strip 120 parallel to the second direction L2 is an obtuse angle. With this configuration, the angle between the two surfaces of the first prism strip 120 parallel to the second direction L2 and the substrate 110 is relatively small, thereby making the slope of the two surfaces of the first prism strip 120 parallel to the second direction L2 relatively small. When the brightness enhancement film 100 is applied to a display device, the overall brightness of the display device can also be improved, ensuring the display effect of the display device.

[0062] Figure 10 FIG. 1 shows a schematic structural diagram of a brightness enhancement film 100 according to another embodiment of the present application. Figure 7 and Figure 10 As shown, the plurality of prism strips further includes a second prism strip 130. The angles between the two surfaces of the second prism strip 130 parallel to the second direction L2 and the substrate 110 are equal. In this case, the cross-section of the second prism strip 130 is an isosceles triangle, and the cross-section of the second prism strip 130 is parallel to the first direction L1. For example, the angle between the two surfaces of the second prism strip 130 parallel to the second direction L2 can be a right angle, in which case the cross-section of the second prism strip 130 is an isosceles right triangle.

[0063] Therefore, by providing the second prism strips 130 , when the brightness enhancement film 100 is applied to a display device, the overall brightness of the display device can be further improved while ensuring the brightness uniformity of the display device at all viewing angles, thereby effectively improving the user experience.

[0064] In one embodiment, combined Figure 7 and Figure 10 The multiple prism strips are divided into multiple second prism groups, each second prism group includes a first prism strip 120 and a second prism strip 130, and the prism strips of two adjacent second prism groups are symmetrical about the second symmetry plane, and the second symmetry plane is perpendicular to the first direction L1 and the second direction L2.

[0065] It should be noted that, similar to the first symmetry plane, the second symmetry plane is a virtual plane for describing the symmetry relationship between two adjacent second prism groups, and is not an actual plane in the brightness enhancement film 100 .

[0066] For example, each second prism group may include a plurality of first prism bars 120. In each second prism group, the second prism bar 130 is located between two first prism bars 120 at both ends. Figure 10In the example, each second prism group includes two first prism bars 120 and two second prism bars 130, and the two second prism bars 130 are located between the two first prism bars 120. Of course, each second prism group can also include one or more second prism bars 130, and this application does not limit the number of second prism bars 130 in the second prism group.

[0067] In this embodiment, by having each second prism group include a first prism bar 120 and a second prism bar 130, when the brightness enhancement film 100 is applied to a display device, the first prism bar 120 can change the direction of light emission, improving the viewing angle of the module's light-emitting surface, while the second prism bar 130 can enhance the overall brightness of the display device, ensuring the display quality. By aligning the prism bars of two adjacent second prism groups with respect to the second symmetry plane, the viewing angle of the display device can be widened. When a user views the display device from the left or right side, or from above or below, the brightness of the display device remains symmetrical, thus meeting TCO requirements.

[0068] The following combination Figure 11 and Figure 12 The optical film assembly 200 according to the second embodiment of the present application is described.

[0069] Figure 11 FIG. 2 shows an exploded schematic diagram of the optical film assembly 200 according to an embodiment of the present application. Figure 8 and Figure 11 As shown, an optical film assembly 200 according to an embodiment of the present application includes a diffuser 210 and two brightness enhancement films 100 according to any of the embodiments of the first aspect described above. The two brightness enhancement films 100 are disposed on the same side of the diffuser 210, and the prism strips of each brightness enhancement film 100 are disposed on a side of the substrate 110 facing away from the diffuser 210. The prism strips of the two brightness enhancement films 100 extend in non-parallel directions.

[0070] For example, the two brightness-enhancing films 100 can be a first brightness-enhancing film and a second brightness-enhancing film, respectively. The first brightness-enhancing film is located on the side of the second brightness-enhancing film facing away from the diffuser 210. The prism strips of the first brightness-enhancing film can extend perpendicularly to the prism strips of the second brightness-enhancing film. A full-viewing angle simulation of the optical film assembly 200 was performed, with the surface of each end prism strip 121 near the corresponding edge of the substrate 110 at a 40° angle to the substrate 110. Furthermore, an optical film assembly from the related art was used as a control film assembly for comparison. The control film assembly included the diffuser and two brightness-enhancing films from the related art.

[0071] Table 1 shows simulated horizontal data for the optical film assembly 200 and the control film assembly. Referring to Table 1, the center brightness of the control film assembly is 3282 mcd / ㎡, and the brightness ratio of the control film assembly at a specific horizontal viewing angle is 2.055. The center brightness of the optical film assembly 200 is 2585 mcd / ㎡, and the brightness ratio of the optical film assembly 200 at a specific horizontal viewing angle is 1.32. Compared to the control film assembly, the center brightness of the optical film assembly 200 is 78.76% of the center brightness of the control film assembly. Although the center brightness of the optical film assembly 200 is reduced, the brightness ratio of the optical film assembly 200 at a specific horizontal viewing angle is reduced by 0.735, meeting the TCO requirement of 1.73 or less.

[0072] Table 1

[0073] Control membrane group Optical film set Center brightness 3282 2585 Brightness ratio at a specific viewing angle in the horizontal direction 2.055 1.32

[0074] Table 2 shows simulated vertical data for the optical film assembly 200 and the control film assembly. Referring to Table 2, the center brightness of the control film assembly is 3282 mcd / ㎡, and the brightness ratio of the control film assembly at a specific vertical viewing angle is 1.6. The center brightness of the optical film assembly 200 is 2585 mcd / ㎡, and the brightness ratio of the optical film assembly 200 at a specific vertical viewing angle is 0.99. Compared to the control film assembly, the center brightness of the optical film assembly 200 is 78.76% of the center brightness of the control film assembly. Although the center brightness of the optical film assembly 200 is reduced, the brightness ratio of the optical film assembly 200 at a specific vertical viewing angle is reduced by 0.61, meeting the TCO requirement of less than or equal to 1.73.

[0075] Table 2

[0076] Control membrane group Optical film set Center brightness 3282 2585 Brightness ratio at a specific viewing angle in the vertical direction 1.6 0.99

[0077] Figure 12 The full-viewing angle simulation diagram of the optical film assembly 200 according to the embodiment of the present application is compared with the full-viewing angle simulation diagram of the optical film assembly in the related art. (a) is the full-viewing angle simulation diagram of the optical film assembly in the related art; (b) is the full-viewing angle simulation diagram of the optical film assembly 200 according to the embodiment of the present application. Figure 12 As shown, when the user looks at the optical film assembly at an angle, the brightness of the optical film assembly 200 according to the embodiment of the present application is greater, which can effectively improve the brightness uniformity of the viewing angle of the optical film assembly 200, so that the brightness ratio of the optical film assembly 200 at specific viewing angles in the horizontal direction and the vertical direction can be less than or equal to 1.73.

[0078] According to the optical film assembly 200 of the embodiment of the present application, by adopting the above-mentioned brightness enhancement film 100, the brightness uniformity of the display device at a viewing angle can be improved, so that the brightness ratio of the display device at a specific viewing angle in the horizontal direction and the vertical direction can be less than or equal to 1.73, meeting the TCO requirements.

[0079] The following combination Figure 13 and Figure 14 The backlight module 300 according to the third embodiment of the present application is described.

[0080] Figure 13 FIG. 1 is a schematic diagram showing a three-dimensional structure of a backlight module 300 according to an embodiment of the present application; Figure 14 Show Figure 13 The exploded view of the backlight module 300 is shown in FIG. Figure 13 and Figure 14 As shown, the backlight module 300 according to the embodiment of the third aspect of the present application includes a light source 310, a light guide plate 320, and an optical film assembly 200 as any embodiment of the second aspect described above. The light guide plate 320 is disposed on the light-emitting side of the light source 310 to guide the scattering direction of light, improve the brightness of the display device, and ensure the brightness uniformity of the display device across the viewing angle. The optical film assembly 200 is disposed on the light-emitting side of the light guide plate 320. The light source 310 may be an LED, but is not limited thereto.

[0081] According to the backlight module 300 of the embodiment of the present application, by adopting the above-mentioned optical film group 200, the brightness uniformity of the display device at a viewing angle can be improved, so that the brightness ratio of the display device at a specific viewing angle in the horizontal direction and the vertical direction can be less than or equal to 1.73, meeting the TCO requirements.

[0082] In one embodiment, reference Figure 13 and Figure 14 There can be multiple light sources 310. The extension direction of the prism strips of the upper brightness enhancement film 100 in the optical film group 200 is parallel to the arrangement direction of the multiple light sources 310, and the extension direction of the prism strips of the lower brightness enhancement film 100 in the optical film group 200 is perpendicular to the arrangement direction of the multiple light sources 310.

[0083] It should be noted that “parallel” in this application should be understood in a broad sense, referring to being approximately parallel, for example, with an angle less than or equal to 10°, and is not limited to being completely parallel.

[0084] For example, the optical film assembly 200 may further include a substrate 340, such as an aluminum substrate. The light sources 310 are disposed on a side of the substrate 340 facing the light guide plate 320. Multiple light sources 310 may be arranged in an intermittent pattern. The diffuser 210 may be positioned above the light guide plate 320, with both the first and second brightness enhancement films positioned above the diffuser 210. The prism strips of the first brightness enhancement film extend parallel to the arrangement direction of the multiple light sources 310, while the prism strips of the second brightness enhancement film extend perpendicular to the arrangement direction of the multiple light sources 310.

[0085] In this embodiment, the extension direction of the brightness enhancement film 100 located at the top can be parallel to the arrangement direction of the multiple light sources 310, thereby effectively improving the brightness of the display device in the horizontal direction. When the user looks at the display device at an angle in the horizontal direction, the brightness of the display device is greater, thereby ensuring the brightness uniformity of the display device in the horizontal viewing angle.

[0086] In one embodiment, Figure 13 and Figure 14 As shown, the light guide plate 320 includes two light guide surfaces and multiple light guide side surfaces connected between the two light guide surfaces, one of the multiple light guide side surfaces is the light incident surface, one of the two light guide surfaces is the light exit surface, and the other of the two light guide surfaces and the remaining light guide side surfaces are all reflective surfaces.

[0087] Exemplarily, the light incident surface of the light guide plate 320 is opposite to the light source 310, so that light emitted by the light source 310 can enter the light guide plate 320. The light guide plate 320 may include four light-guiding side surfaces, and the other three light-guiding side surfaces except the light incident surface are all reflective surfaces. The upper surface of the light guide plate 320 may be a light-emitting surface, and the lower surface of the light guide plate 320 is a reflective surface. The backlight module 300 may also include a plastic frame 350 and four reflective sheets 330, and the four reflective sheets 330 are respectively arranged opposite to the four reflective sheets 330. The plastic frame 350 is arranged above the first brightness enhancement film 100 for light shielding.

[0088] The display device according to the embodiment of the fourth aspect of the present application includes the backlight module 300 of any implementation manner of the third aspect mentioned above.

[0089] According to the display device of the embodiment of the present application, by adopting the above-mentioned backlight module 300, the brightness uniformity of the viewing angle can be improved, so that the brightness ratio of the display device at a specific viewing angle in the horizontal direction and the vertical direction can be less than or equal to 1.73, meeting the TCO requirements.

[0090] The brightness enhancement film 100, optical film assembly 200, backlight module 300 and other components of the display device in the above embodiment can adopt various technical solutions known to ordinary technicians in this field now and in the future, and will not be described in detail here.

[0091] In the description of this specification, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0092] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly indicate the quantity of the technical features indicated. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0093] In this application, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0094] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0095] The disclosure above provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described above. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0096] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A brightness enhancement film, characterized in that: include: substrate; a plurality of prism bars disposed on one side of the substrate and arranged along a first direction, each of the prism bars extending along a second direction perpendicular to the first direction, the plurality of prism bars including a first prism bar, wherein two surfaces of the first prism bar parallel to the second direction have unequal angles with the substrate; The plurality of prism strips further include a second prism strip, wherein the angles between two surfaces of the second prism strip parallel to the second direction and the substrate are equal; The plurality of prism strips are divided into a plurality of second prism groups, each of the second prism groups includes a first prism strip and a second prism strip, the prism strips of two adjacent second prism groups are symmetrical about a second symmetry plane, and the second symmetry plane is perpendicular to the first direction and the second direction; Each of the second prism groups includes a plurality of first prism bars, and the second prism bar is located between two of the first prism bars at both ends.

2. The brightness enhancement film according to claim 1, characterized in that There are multiple first prism bars divided into multiple first prism groups. The first prism bars of two adjacent first prism groups are symmetrical about a first symmetry plane, and the first symmetry plane is perpendicular to the first direction and the second direction.

3. The brightness enhancement film according to claim 1, characterized in that: The first prism strip disposed at the end of the substrate in the first direction is an end prism strip, and the angle between the surface of the end prism strip close to the corresponding edge of the substrate and the substrate is α, wherein 40°≤α<45°.

4. The brightness enhancement film according to claim 1, characterized in that An angle between two surfaces of the first prism strip parallel to the second direction is an obtuse angle.

5. An optical film assembly, characterized in that: include: diffuser; Two brightness enhancement films according to any one of claims 1 to 4 are arranged on the same side of the diffuser, the prism strips of each brightness enhancement film are arranged on the side of the substrate away from the diffuser, and the extension directions of the prism strips of the two brightness enhancement films are not parallel.

6. A backlight module, characterized in that: include: light source; A light guide plate, arranged on the light-emitting side of the light source; The optical film assembly according to claim 5 is arranged on the light output side of the light guide plate.

7. The backlight module according to claim 6, wherein: There are multiple light sources; the extension direction of the prism strips of the brightness enhancing film located at the top of the optical film group is parallel to the arrangement direction of the multiple light sources, and the extension direction of the prism strips of the brightness enhancing film located at the bottom of the optical film group is perpendicular to the arrangement direction of the multiple light sources.

8. The backlight module according to claim 7, characterized in that: The light guide plate includes two light guide surfaces and multiple light guide side surfaces connected between the two light guide surfaces, one of the multiple light guide side surfaces is a light incident surface, one of the two light guide surfaces is a light exit surface, and the other of the two light guide surfaces and the remaining light guide side surfaces are all reflective surfaces.

9. A display device, characterized in that: The invention comprises a backlight module according to any one of claims 6 to 8.

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