Optical film structure, backlight module and display device

Abstract

An optical film structure, a backlight module and a display device are disclosed.SOLUTION: The optical film structure 100 includes a base layer 11 and a viewing angle adjusting layer 12, and the viewing angle adjusting layer 12 is disposed on a light emitting side of the base layer 11. The optical film structure 100 includes a narrow viewing angle mode and a wide viewing angle mode, when the optical film structure 100 is in the narrow viewing angle mode, the viewing angle adjusting layer 12 is configured to narrow an emitting angle of the light to a first emitting angle, and when the optical film structure 100 is in the wide viewing angle mode, the viewing angle adjusting layer 12 is configured to adjust the emitting angle of the light to a second emitting angle, where the second emitting angle is greater than the first emitting angle. The switching between the narrow viewing angle mode and the wide viewing angle mode is realized by adjusting the shape of the viewing angle adjusting layer 12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] A conventional liquid crystal display device includes a display panel and a backlight module, and the backlight module usually includes optical film components, such as a brightening film and a diffusing film, to improve light output efficiency.

[0003] In the course of researching and practicing the prior art, the inventors of the present disclosure found that after the optical film components are installed, the viewing angle of the display device cannot be adjusted by adjusting the optical film components. Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments of the present disclosure provide an optical film structure, a backlight module and a display device that can switch between narrow and wide viewing angles. [Means for solving the problem]

[0005] An embodiment of the present disclosure provides an optical film structure, including a base layer and a viewing angle-adjusting layer disposed on a light-emitting side of the base layer, the optical film structure having a narrow viewing angle mode and a wide viewing angle mode, wherein when the optical film structure is in the narrow viewing angle mode, the viewing angle-adjusting layer is configured to narrow an exit angle of a light ray to a first exit angle, and when the optical film structure is in the wide viewing angle mode, the viewing angle-adjusting layer is configured to adjust the exit angle of a light ray to a second exit angle, the second exit angle being greater than the first exit angle.

[0006] Optionally, in some embodiments of the present disclosure, when the optical film structure is in a narrow viewing angle mode, the viewing angle adjusting layer includes a plurality of first prisms, the first prisms include a first side wall portion extending along a first direction and a second side wall portion extending along a second direction, the first direction and the second direction intersect, the first side wall portion and the second side wall portion are connected, a first cavity is formed between the first prisms and the base layer, and a transparent medium is filled in the first cavity.

[0007] Optionally, in some embodiments of the present disclosure, when the optical film structure is in a wide viewing angle mode, the viewing angle adjusting layer includes a plurality of second prisms, the second prisms include the first side wall portion extending along a third direction and the second side wall portion extending along a fourth direction, the third direction and the fourth direction intersect, the first side wall portion and the second side wall portion are connected, a second cavity is formed between the second prisms and the base layer, the second cavity is filled with the transparent medium, the first prisms include a first apex angle formed by the first side wall portion and the second side wall portion, and the second apex angle formed by the first side wall portion and the second side wall portion, the second apex angle being larger than the first apex angle.

[0008] Optionally, in some embodiments of the present disclosure, when the optical film structure is in a wide viewing angle mode, a connection point between two adjacent second prisms contacts the base layer.

[0009] Optionally, in some embodiments of the present disclosure, the first apex angle is an acute angle or a right angle, and the second apex angle is an obtuse angle.

[0010] Optionally, in some embodiments of the present disclosure, when the optical film structure is in a wide viewing angle mode, the first sidewall portion and the second sidewall portion of the viewing angle adjusting layer are in close contact with the base layer.

[0011] When the optical film structure is in a wide viewing angle mode, the first sidewall and the second sidewall of the viewing angle adjusting layer are disposed to overlap each other in a thickness direction of the optical film structure.

[0012] Optionally, in some embodiments of the present disclosure, when the optical film structure is in a narrow viewing angle mode, the viewing angle adjusting layer is disposed separately from the base layer, and the transparent medium is sandwiched between the viewing angle adjusting layer and the base layer.

[0013] Optionally, in some embodiments of the present disclosure, when the optical film structure is in a narrow viewing angle mode, a connection point between two adjacent first prisms is fixedly connected to the base layer.

[0014] Optionally, in some embodiments of the present disclosure, the transparent medium comprises one of a gas and a liquid.

[0015] Optionally, in some embodiments of the present disclosure, the viewing angle adjusting layer includes a flexible layer and scattering particles, and the scattering particles are disposed within the flexible layer.

[0016] An embodiment of the present disclosure further provides a backlight module, including the optical film structure according to any one of the preceding embodiments.

[0017] An embodiment of the present disclosure further provides a display device, which includes a display panel and a backlight module according to any one of the embodiments, and the display panel is located on the light-emitting side of the backlight module. [Effects of the Invention]

[0018] The optical film structure of the embodiment of the present disclosure includes a narrow viewing angle mode and a wide viewing angle mode, and the optical film structure includes a base layer and a viewing angle adjusting layer disposed on the light-emitting side of the base layer, and the embodiment of the present disclosure realizes switching between the narrow viewing angle mode and the wide viewing angle mode by adjusting the shape of the viewing angle adjusting layer. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 2 is a structural diagram of an optical film structure provided by an embodiment of the present disclosure in a narrow viewing angle mode. [Figure 2] FIG. 2 is a structural diagram of an optical film structure provided by an embodiment of the present disclosure in a wide viewing angle mode. [Figure 3] FIG. 2 is a diagram illustrating the ray paths passing through a first prism and a second prism in an optical film structure provided by an embodiment of the present disclosure. [Figure 4] FIG. 10 is another structural diagram of the optical film structure provided by an embodiment of the present disclosure in a narrow viewing angle mode. [Figure 5] FIG. 10 is another structural diagram of the optical film structure provided by an embodiment of the present disclosure in a wide viewing angle mode. [Figure 6] FIG. 10 is yet another structural diagram of the optical film structure provided by the embodiments of the present disclosure in a wide viewing angle mode. [Figure 7] FIG. 2 is a structural diagram of a backlight module provided by an embodiment of the present disclosure in a narrow viewing angle mode. [Figure 8] FIG. 1 is a structural diagram of a backlight module provided by an embodiment of the present disclosure in a wide viewing angle mode. [Figure 9] FIG. 2 is a structural diagram of a display device provided by an embodiment of the present disclosure in a narrow viewing angle mode. [Figure 10] FIG. 2 is a structural diagram of a display device provided by an embodiment of the present disclosure in a wide viewing angle mode. DETAILED DESCRIPTION OF THE INVENTION

[0020] The following provides a clear and complete description of the technical solutions in the embodiments of the present disclosure, in conjunction with the drawings in the embodiments of the present disclosure. Of course, the described embodiments are merely some of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments that can be obtained by those skilled in the art without creative effort fall within the scope of protection of the present disclosure. It should be understood that the specific embodiments described herein are intended solely for the purpose of explaining and interpreting the present disclosure, and do not limit the present disclosure. In the present disclosure, each embodiment can be combined with each other, but will not be described repeatedly. Unless otherwise specified, directional terms, such as "upper" and "lower," generally refer to the upper and lower sides of the actual use or operating state of the device, specifically the up and down directions in the drawings. "Inner" and "outer" are described relative to the contour of the device. The terms "first," "second," "third," etc., are merely used as indicators and do not necessarily require numbers or establish a sequence.

[0021] The embodiments of the present disclosure provide an optical film structure, a backlight module, and a display device, which are described in detail below. Note that the order of description of the following embodiments does not limit the order of priority of the embodiments.

[0022] 1 and 2, an embodiment of the present disclosure provides an optical film structure 100. The optical film structure 100 includes a base layer 11 and a viewing angle adjusting layer 12. The viewing angle adjusting layer 12 is disposed on the light-emitting side of the base layer 11.

[0023] The optical film structure 100 includes a narrow viewing angle mode and a wide viewing angle mode. When the optical film structure 100 is in the narrow viewing angle mode, the viewing angle-adjusting layer 12 is configured to narrow the exit angle of the light ray to a first exit angle. When the optical film structure 100 is in the wide viewing angle mode, the viewing angle-adjusting layer 12 is configured to adjust the exit angle of the light ray to a second exit angle, which is greater than the first exit angle.

[0024] The optical film structure 100 of the embodiment of the present disclosure realizes switching between a narrow viewing angle mode and a wide viewing angle mode by adjusting the shape of the viewing angle adjusting layer 12 .

[0025] It should be understood that in the narrow viewing angle mode, the viewing angle-adjusting layer 12 is used to narrow the exit angle of the light beam to achieve a narrow viewing angle, and in the wide viewing angle mode, the viewing angle-adjusting layer 12 is used to adjust the exit angle of the light beam to be larger than the exit angle in the narrow viewing angle mode to achieve a wide viewing angle.

[0026] Here, the viewing angle-adjusting layer 12 has elasticity and can have different shapes in different modes to switch between a narrow viewing angle and a wide viewing angle. For example, in the narrow viewing angle mode, the viewing angle-adjusting layer 12 is pushed up by the transparent medium and stretched by the pressure of the transparent medium, forming a first prism film and narrowing the viewing angle. At this time, the viewing angle-adjusting layer 12 is in a stretched state and has a first elastic force. In the wide viewing angle mode, the viewing angle-adjusting layer 12 does not have elastic force, or the second elastic force it has is smaller than the first elastic force. That is, to achieve a wide viewing angle, the viewing angle-adjusting layer 12 is stretched without being pushed up by the transparent medium, or the degree of stretching due to being pushed up by the transparent medium is smaller than the degree of stretching in the narrow viewing angle mode.

[0027] Optionally, in some embodiments, base layer 11 is a transparent film layer that may be in the form of a flat, full surface.

[0028] The material of the base layer 11 may be one of silica, polyethylene, polypropylene, polystyrene, polylactic acid, polyethylene glycol dicarboxylic acid, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyethersulfone, aromatic fluorotoluene containing polyarylate, polycycloolefin, polyimide or polyurethane.

[0029] Optionally, in some embodiments, the thickness of base layer 11 is between 50 microns and 250 microns, for example, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns, 110 microns, 120 microns, 130 microns, 140 microns, 150 microns, 160 microns, 170 microns, 180 microns, 190 microns, 200 microns, 210 microns, 220 microns, 230 microns, 240 microns, or 250 microns.

[0030] The thicker the base layer 11, the greater the pressure it can resist and the greater the light loss. Therefore, in a narrow viewing angle, it can be understood that the thickness of the base layer 11 is selected between 50 micrometers and 250 micrometers to ensure that the base layer 11 has good support and pressure resistance.

[0031] Optionally, in some embodiments of the present disclosure, the view-angle adjusting layer 12 includes a flexible layer rx and scattering particles ss disposed within the flexible layer rx.

[0032] It can be seen that in order to enhance the scattering effect on light rays and improve the brightness uniformity, the haze of the viewing angle adjusting layer 12 can be increased by placing scattering particles ss in the viewing angle adjusting layer 12. In addition, in some embodiments, the scattering particles ss in the viewing angle adjusting layer 12 can also be transferred into the base layer 11, thereby achieving the effect of improving the brightness uniformity or saving the scattering particles ss, that is, the flexible layer rx is the viewing angle adjusting layer 12.

[0033] Alternatively, the material of the flexible layer rx may be a transparent organic material, such as one of polyethylene, polypropylene, polystyrene, polylactic acid, polyethylene glycol dicarboxylic acid, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyethersulfone, aromatic fluorotoluenes including polyarylates, polycycloolefins, polyimides, and polyurethanes.

[0034] The thicker the flexible layer rx, the higher the resistance to pressure and the greater the number of scattering particles ss that can be doped. The thickness of the flexible layer rx may be between 50 microns and 200 microns, for example, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns, 110 microns, 120 microns, 130 microns, 140 microns, 150 microns, 160 microns, 170 microns, 180 microns, 190 microns, or 200 microns, depending on the requirements for pressure resistance performance and large haze.

[0035] The particle size of the scattering particles ss is between 1 micron and 30 microns, and may be, for example, 1 micron, 2 microns, 3 microns, 4 microns, 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 11 microns, 12 microns, 13 microns, 14 microns, 15 microns, 16 microns, 17 microns, 18 microns, 19 microns, 20 microns, 21 microns, 22 microns, 23 microns, 24 microns, 25 microns, 26 microns, 27 microns, 28 microns, 29 microns or 30 microns.

[0036] It can be understood that the larger the particle diameter of the scattering particles ss, the thicker the flexible layer rx, and the lower the density of the scattering particles ss that can be placed in the viewing angle adjusting layer 12, the poorer the scattering effect. Therefore, by setting the particle diameter of the scattering particles ss to 1 micron to 30 microns, the thickness of the viewing angle adjusting layer 12 does not need to be too thick and yet the scattering effect is good.

[0037] 1 and 2, in some embodiments of the present disclosure, the view angle adjusting layer 12 and the base layer 11 may be disposed separately or integrally.

[0038] When the optical film structure 100 is in the narrow viewing angle mode, the viewing angle-adjusting layer 12 includes a plurality of first prisms 12a, each of which includes a first sidewall 121 extending along a first direction m and a second sidewall 122 extending along a second direction n, where the first direction m and the second direction n intersect. The first sidewall 121 and the second sidewall 122 are connected to form a first cavity kq1 between the first prisms 12a and the base layer 11, and the first cavity kq1 is filled with a transparent medium 13.

[0039] In the narrow viewing angle mode, the transparent medium 13 is inserted between the base layer 11 and the viewing angle-adjusting layer 12. As the transparent medium 13 increases, the viewing angle-adjusting layer 12 forms a prism, which supports the viewing angle-adjusting layer 12. As the transparent medium 13 increases, the prism is gradually elongated, and the apex angle of the prism gradually decreases, resulting in a better light narrowing effect. In the narrow viewing angle mode, the amount of input transparent medium 13 can be adjusted according to actual needs to adjust the light narrowing effect of the viewing angle-adjusting layer 12.

[0040] Optionally, in the narrow viewing angle mode, it is defined that the first cavity kq1 is filled with the transparent medium 13 so that the prism formed by the viewing angle-adjusting layer 12 is the first prism 12a. The apex angle of the first prism 12a is a first apex angle α, which is the angle between the extension directions of the first side wall portion 121 and the second side wall portion 122.

[0041] In some embodiments of the present disclosure, when the optical film structure 100 is in a narrow viewing angle mode, the viewing angle adjusting layer 12 is positioned completely separated from the base layer 11, and a transparent medium 13 is sandwiched between the viewing angle adjusting layer 12 and the base layer 11.

[0042] Since the viewing angle adjusting layer 12 is installed so that it can be completely separated from the base layer 11, it is only necessary to fill the first cavity kq1 with a transparent medium 13 using a single channel, and at the same time, it can be understood that the difficulty of connecting the viewing angle adjusting layer 12 and the base layer 11 is also reduced.

[0043] Alternatively, the peripheral portion of the viewing angle adjustment layer 12 may be connected to the peripheral portion of the base layer 11 via a connecting member, or the peripheral portion of the viewing angle adjustment layer 12 may be partially connected to the peripheral portion of the base layer 11 to form a sealed first cavity kq1.

[0044] Optionally, in some embodiments of the present disclosure, the transparent medium 13 includes one of a gas and a liquid. In the following, an example in which the transparent medium 13 is a gas will be described.

[0045] In some embodiments of the present disclosure, when the optical film structure 100 is in the wide viewing angle mode, the viewing angle-adjusting layer 12 includes a plurality of second prisms 12b, each of which includes a first side wall 121 extending along a third direction x and a second side wall 122 extending along a fourth direction y, where the third direction x and the fourth direction y intersect. The first side wall 121 and the second side wall 122 are connected to form a second cavity kq2 between the second prisms 12b and the base layer 11, and the second cavity kq2 is filled with a transparent medium 13.

[0046] First prism 12a includes a first apex angle α formed by first sidewall portion 121 and second sidewall portion 122. Second prism 12b includes a second apex angle β formed by first sidewall portion 121 and second sidewall portion 122. Second apex angle β is larger than first apex angle α.

[0047] Referring to FIG. 3, the amount of transparent medium 13 in optical film structure 100 in the wide viewing angle mode is smaller than that in the narrow viewing angle mode, so the degree of stretching of first prism 12a is reduced, and first side wall portion 121 and second side wall portion 122 are tilted and spread out to form second prism 12b. As first side wall portion 121 and second side wall portion 122 are tilted and spread out, first cavity kq1 shrinks, and the angle of first apex angle α changes to second apex angle β. As first cavity kq1 shrinks to second cavity kq2, the second apex angle β has the effect of better expanding the light exit angle compared to the first apex angle α, thereby achieving an even wider viewing angle.

[0048] 3, when a light beam having the same angle is emitted to the first prism 12a and the second prism 12b, the first prism 12a can narrow the light beam by a larger angle because the first apex angle α of the first prism 12a is relatively small, while the second prism 12b can narrow the light beam by a smaller angle. Therefore, the first prism 12a can realize a narrow viewing angle, while the second prism 12b can realize a wide viewing angle.

[0049] Optionally, in some embodiments of the present disclosure, the first apex angle α is an acute or right angle, and the second apex angle β is an obtuse angle.

[0050] Here, the first apex angle α is an acute angle or a right angle, which can better narrow the exit angle of the light ray. The second apex angle β is an obtuse angle, which can better reduce the degree of narrowing of the exit angle of the light ray, thereby better reflecting the difference between the narrow and wide viewing angles. For example, the first apex angle α is 45 degrees and the second apex angle β is 135 degrees, or the first apex angle α is 90 degrees and the second apex angle β is 150 degrees.

[0051] Optionally, in some embodiments of the present disclosure, when the optical film structure 100 is in the wide viewing angle mode, the connection points 12c between two adjacent second prisms 12b contact the base layer 11.

[0052] It can be seen that the contact of the connection point 12c with the base layer 11 not only minimizes the size of the second cavity kq2 and reduces the thickness of the optical film structure 100, but also returns the viewing angle adjusting layer 12 to a non-elastic state, thereby improving the service life of the viewing angle adjusting layer 12.

[0053] Alternatively, the connection points 12c can contact the base layer 11 by electrostatic attraction.

[0054] The numbers of prisms corresponding to the two modes in Figures 1 and 2 are merely approximate, and do not mean that the numbers of prisms in the two modes are inconsistent. The numbers of prisms in the following corresponding drawings are also merely approximate.

[0055] 4 and 5, Fig. 4 is a schematic diagram showing an optical film structure 100 according to another disclosed embodiment in a narrow viewing angle mode, and Fig. 5 is a schematic diagram showing an optical film structure 100 according to another disclosed embodiment in a wide viewing angle mode corresponding to Fig. 4.

[0056] 4 and 5, in order to avoid repetitive explanation, only the parts different from the above embodiment will be explained.

[0057] Referring to Figures 4 and 5, the viewing angle adjusting layer 12 and the base layer 11 in the optical film structure 100 are fixedly connected at intervals, that is, the viewing angle adjusting layer 12 and the base layer 11 are fixedly connected regularly, for example, at least one prism structure is sandwiched between any two fixed connection areas, for example, in the narrow viewing angle mode, at least one first prism 12a is sandwiched between any two fixed connection areas, and in the wide viewing angle mode, at least one second prism 12b is sandwiched between any two fixed connection areas.

[0058] Optionally, in some embodiments, when the optical film structure 100 is in the narrow viewing angle mode, the connection point 12c between two adjacent first prisms 12a is fixedly connected to the base layer 11. When the optical film structure 100 is in the wide viewing angle mode, the connection point 12c between two adjacent second prisms 12b is fixedly connected to the base layer 11.

[0059] The fixed connection region is a connection region between the connection portion 12c and the base layer 11. The joint portion 12c may be connected to the base layer 11 by adhesion, but is not limited to this, and may be connected by, for example, hot melt.

[0060] The viewing angle-adjusting layer 12 and the base layer 11 are fixedly connected with a gap between them, which fixes the position of the prism and prevents the prism from being easily displaced. Secondly, because the viewing angle-adjusting layer 12 and the base layer 11 are fixed with a gap between them, in the narrow viewing angle mode, when forming the same first apex angle α, the input amount of the transparent medium 13 can be reduced, the height of the first prism 12a can be reduced, and the optical film structure 100 can be made thinner.

[0061] Please refer to FIG. 6, which shows another schematic diagram of the optical film structure 100 in a wide viewing angle mode according to another disclosed embodiment.

[0062] In FIG. 6, in order to avoid repetitive explanation, only the parts that differ from the above embodiment will be explained.

[0063] Referring to FIG. 6, in some embodiments of the present disclosure, when the optical film structure 100 is in a wide viewing angle mode, the first side wall portion 121 and the second side wall portion 122 of the viewing angle adjusting layer 12 are attached to the base layer 11.

[0064] In addition, compared with the optical film structure 100 corresponding to Figures 2 and 5 in the wide viewing angle mode, the optical film structure 100 corresponding to Figure 6 has the following characteristics: in the wide viewing angle mode, the transparent medium 13 is pulled out from the first cavity kq1, thereby causing the first prism 12a to sink, and the first side wall portion 121 and the second side wall portion 122 of the viewing angle adjusting layer 12 are attached to the base layer 11, so that the viewing angle adjusting layer 12 does not have a prism shape, and at this time the viewing angle adjusting layer 12 has a wider viewing angle, that is, the light ray has a larger exit angle.

[0065] Alternatively, the first side wall portion 121 and the second side wall portion 122 may be attached to the base layer 11 by electrostatic adhesion or by vacuum adhesion.

[0066] In some embodiments of the present disclosure, when the optical film structure 100 is in a wide viewing angle mode, the first side wall portion 121 and the second side wall portion 122 of the viewing angle adjusting layer 12 are arranged to partially overlap in the thickness direction of the optical film structure 100.

[0067] Here, the first side wall portion 121 and the second side wall portion 122 are installed to be partially overlapped with each other so that the overlapping area has a better scattering effect and improves the uniformity of the brightness.

[0068] Optionally, in some embodiments of the present disclosure, one of the first side wall portion 121 and the second side wall portion 122 is provided with a fold zh extending along the extension direction of the first prism 12a.

[0069] Here, taking the fold line zh at the first side wall 121 as an example, when the optical film structure 100 switches from the narrow viewing angle mode to the wide viewing angle mode, the transparent medium 13 is pulled apart to a certain extent, and the first side wall 121 is folded along the fold line zh to form a first folding portion 121a and a second folding portion 121b, with the first folding portion 121a attached to the base layer 11 and the second folding portion 121b stacked on the first folding portion 121a. The first folding portion 121a and the second folding portion 121b are at least partially overlapping, and the second side wall 122 is folded over and overlapping the second folding portion 121b.

[0070] By providing the fold lines zh, the first side wall portion 121 and the second side wall portion 122 can be folded regularly, which improves the uniformity of the brightness.

[0071] Optionally, in some embodiments, the number of scattering particles ss located in the second folded portion 121b is less than the number of scattering particles ss located in the first folded portion 121b. On the one hand, by making the weight of the first folded portion 121a greater than the weight of the second folded portion 121b, the first folded portion 121a has good elasticity and the risk of wrinkling of the first folded portion 121a is reduced. On the other hand, because the second folded portion 121b has fewer scattering particles ss, the second folded portion 121b has better flexibility and is easier to fold. Secondly, because the first folded portion 121a and the second folded portion 121b are stacked, the area where the two are stacked has two layers of scattering particles ss. Therefore, the second folded portion 121b has fewer scattering particles ss, which improves the overall light output uniformity.

[0072] Referring to FIG. 7 and FIG. 8, an embodiment of the present disclosure further provides a backlight module BL, which includes the optical film structure 100 according to any one of the preceding embodiments.

[0073] It should be noted that the optical film structure of the backlight module BL in the embodiments of the present disclosure may be similar or identical to the structure of the optical film structure 100 in any of the above embodiments, and will not be described again here. Furthermore, the backlight module BL of the display device in the embodiments of the present disclosure is illustrated based on the optical film structure 100 corresponding to FIGS. 1 and 2, but is not limited thereto, and may be, for example, based on the optical film structure 100 corresponding to FIGS. 4 and 5, or based on the optical film structure 100 corresponding to FIGS. 1 and 6. Furthermore, it may be based on the optical film structure 100 corresponding to FIGS. 4 and 6.

[0074] Here, the embodiment of the present disclosure will be described as an example in which the backlight module BL is a direct type, but is not limited to this. For example, the backlight module BL may be an edge type.

[0075] In some embodiments, the backlight module BL may further include a back frame b1, a support frame b2, a first adhesive layer b3, a light-emitting element substrate b4, and a quantum dot film b5.

[0076] The support frame b2 is disposed on the back frame b1 and connected to the periphery of the back frame b1 to form a receiving cavity Rn. The light-emitting element substrate b4 is connected to the back frame b1 via a first adhesive layer b3 and is located within the receiving cavity Rn. The quantum dot film b5 is disposed on the light-emitting element substrate b4. The optical film structure 100 is disposed on the quantum dot film b5.

[0077] Here, the light emitting element on the light emitting element substrate b4 is a blue light emitting element, and the quantum dot film b5 is used to convert the blue light into white light and emit it to the optical film structure 100.

[0078] It is understood that in some embodiments, the light-emitting element substrate b4 can emit white light, thereby saving the quantum dot film b5.

[0079] 9 and 10, an embodiment of the present disclosure provides a display device 1000. The display device 1000 includes a display panel PN and a backlight module BL according to any one of the above embodiments, where the display panel PN is located on the light-emitting side of the backlight module BL.

[0080] It should be noted that the backlight module of the display device 1000 according to the embodiment of the present disclosure may have a structure similar to or the same as that of the backlight module BL of any of the above-described embodiments, and therefore will not be described again here. Furthermore, the backlight module BL of the display device 1000 according to the embodiment of the present disclosure is illustrated based on the optical film structure 100 corresponding to FIGS. 1 and 2, but is not limited thereto, and may be, for example, the optical film structure 100 corresponding to FIGS. 4 and 5, or the optical film structure 100 corresponding to FIGS. 1 and 6, or the optical film structure 100 corresponding to FIGS. 4 and 6.

[0081] The optical film structure 100 of the display device 1000 of the embodiment of the present disclosure includes a narrow viewing angle mode and a wide viewing angle mode, and the optical film structure 100 includes a base layer 11 and a viewing angle adjusting layer 12 disposed on the light output side of the base layer 11, and the embodiment of the present disclosure realizes switching between the narrow viewing angle mode and the wide viewing angle mode of the display device 1000 by adjusting the shape of the viewing angle adjusting layer 12.

[0082] Alternatively, the display panel PN may be a liquid crystal display panel, and its driving method may be a driving method based on edge field switching (FFS) technology, a driving method based on in-plane switching (IPS) technology, or a driving method based on vertical alignment (VA) technology.

[0083] Optionally, the display device 1000 can be applied to and used in various products, including portable electronic devices such as televisions, laptops, monitors, signs, Internet of Things (IoT) devices, mobile phones, smartphones, tablet personal computers, mobile communication terminals, electronic organizers, e-books, portable multimedia players (PMPs), navigation systems, and ultra-mobile personal computers (UMPCs).

[0084] In addition, the display device 1000 according to some embodiments can be applied to and used in wearable devices, including smart watches, watch phones, eyeglass-type displays, and head-mounted displays (HMDs). In addition, in some embodiments, the display device 1000 can be applied to an automobile dashboard, a display in a central information display (CID) located on the central instrument panel or dashboard of an automobile, an interior mirror display in place of an automobile's side mirror, and a display in an entertainment system located on the back of the front seats for rear-seat passengers in an automobile.

[0085] The optical film structure, backlight module, and display device provided by the embodiments of the present disclosure have been described in detail above. Specific examples are used in this document to illustrate the principles and embodiments of the present disclosure. The description of the above examples is only intended to help understand the method and core idea of ​​the present disclosure. At the same time, those skilled in the art may make changes to the specific embodiments and application scope based on the idea of ​​the present disclosure. In short, the contents of this description should not be interpreted as limitations of the present disclosure.

Claims

1. 1. An optical film structure, comprising: a base layer; and a viewing angle adjusting layer disposed on the light output side of the base layer, The optical film structure includes a narrow viewing angle mode and a wide viewing angle mode, and when the optical film structure is in the narrow viewing angle mode, the viewing angle adjusting layer is configured to narrow an exit angle of a light ray to a first exit angle, and when the optical film structure is in the wide viewing angle mode, the viewing angle adjusting layer is configured to adjust the exit angle of a light ray to a second exit angle, and the second exit angle is larger than the first exit angle; An optical film structure comprising:

2. When the optical film structure is in a narrow viewing angle mode, the viewing angle adjusting layer includes a plurality of first prisms, each of the first prisms includes a first sidewall portion extending along a first direction and a second sidewall portion extending along a second direction, the first direction and the second direction intersect, the first sidewall portion and the second sidewall portion are connected, a first cavity is formed between the first prisms and the base layer, and a transparent medium is filled in the first cavity.

2. The optical film structure of claim 1.

3. When the optical film structure is in a wide viewing angle mode, the viewing angle adjusting layer includes a plurality of second prisms, the second prisms include the first side wall portion extending along a third direction and the second side wall portion extending along a fourth direction, the third direction and the fourth direction intersect, the first side wall portion and the second side wall portion are connected, a second cavity is formed between the second prisms and the base layer, and the second cavity is filled with the transparent medium; the first prism includes a first apex angle formed by the first sidewall portion and the second sidewall portion, the second prism includes a second apex angle formed by the first sidewall portion and the second sidewall portion, the second apex angle being larger than the first apex angle; 3. The optical film structure of claim 2.

4. When the optical film structure is in a wide viewing angle mode, a connection point between two adjacent second prisms contacts the base layer.

4. The optical film structure of claim 3.

5. The first apex angle is an acute angle or a right angle, and the second apex angle is an obtuse angle.

4. The optical film structure of claim 3.

6. When the optical film structure is in a wide viewing angle mode, the first sidewall portion and the second sidewall portion of the viewing angle adjusting layer are in close contact with the base layer.

3. The optical film structure of claim 2.

7. When the optical film structure is in a wide viewing angle mode, the first sidewall portion and the second sidewall portion of the viewing angle adjusting layer are partially overlapped in a thickness direction of the optical film structure.

7. The optical film structure of claim 6.

8. When the optical film structure is in a narrow viewing angle mode, the viewing angle adjusting layer is disposed separately from the base layer, and the transparent medium is sandwiched between the viewing angle adjusting layer and the base layer.

8. An optical film structure according to any one of claims 2 to 7.

9. When the optical film structure is in a narrow viewing angle mode, a connection point between two adjacent first prisms is fixedly connected to the base layer.

8. The optical film structure according to claim 2, 3, 5, 6 or 7.

10. the transparent medium comprises one of a gas and a liquid; 8. An optical film structure according to any one of claims 2 to 7.

11. The viewing angle adjusting layer includes a flexible layer and scattering particles, and the scattering particles are disposed in the flexible layer.

8. An optical film structure according to any one of claims 1 to 7.

12. A backlight module, 8. An optical film structure comprising the optical film structure of claim 1 . A backlight module characterized by:

13. A display device, a display panel and the backlight module of claim 12, wherein the display panel is located on the light-emitting side of the backlight module; A display device characterized by:

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