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, with the viewing angle-adjusting layer 12 disposed on the light-emitting side of the base layer 11. The optical film structure 100 has a narrow viewing angle mode and a wide viewing angle mode, and 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 beam to a first exit 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 exit angle of the light beam to a second exit angle, the second exit angle being larger than the first exit angle. Switching between the narrow viewing angle mode and the wide viewing angle mode is achieved by adjusting the shape of the viewing angle-adjusting layer 12.

Description

Technical Field

[0001] The present disclosure relates to the field of display technologies, and specifically to an optical film structure, a backlight module, and a display device.

Background Art

[0002] Conventional liquid crystal display devices include a display panel and a backlight module. The backlight module usually includes optical film components for improving light emission efficiency, such as a brightness enhancement film and a diffusion film.

[0003] In the process of researching and practicing the prior art, the inventor of the present disclosure discovered that after the optical film components are provided, the viewing angle of the display device cannot be adjusted by adjusting the optical film components.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Embodiments of the present disclosure provide an optical film structure, a backlight module, and a display device, which can realize the switching between a narrow viewing angle and a wide viewing angle.

Means for Solving the Problems

[0005] Embodiments of the present disclosure provide an optical film structure. The optical film structure includes a base layer and a viewing angle adjustment layer disposed on the light-emitting side of the base layer. The optical film structure includes a narrow viewing angle mode and a wide viewing angle mode. When the optical film structure is in the narrow viewing angle mode, the viewing angle adjustment layer is configured to narrow the emission angle of light rays to a first emission angle. When the optical film structure is in the wide viewing angle mode, the viewing angle adjustment layer is configured to adjust the emission angle of the light rays to a second emission angle, and the second emission angle is larger than the first emission angle.

[0006] Selectively, in some embodiments of the present disclosure, when the optical film structure is in a narrow viewing angle mode, the viewing angle adjustment layer includes a plurality of first prisms, each first prism including a first sidewall portion extending along a first direction and a second sidewall portion extending along a second direction, the first and second directions intersect, the first and second sidewall portions are connected, a first cavity is formed between the first prism and the base layer, and the first cavity is filled with a transparent medium.

[0007] Selectively, in some embodiments of the present disclosure, when the optical film structure is in a wide-viewing-angle mode, the viewing-angle adjustment layer includes a plurality of second prisms, each second prism including a first sidewall portion extending along a third direction and a second sidewall portion extending along a fourth direction, where the third and fourth directions intersect, the first and second sidewall portions are connected, a second cavity is formed between the second prism and the base layer, the second cavity is filled with the transparent medium, and each first prism includes a first vertex angle formed by the first and second sidewall portions, and each second prism includes a second vertex angle formed by the first and second sidewall portions, the second vertex angle being greater than the first vertex angle.

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

[0009] Selectively, in some embodiments of the present disclosure, the first vertex angle is acute or right, and the second vertex angle is obtuse.

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

[0011] When the optical film structure is in wide-viewing-angle mode, the first sidewall and the second sidewall of the viewing-angle adjustment layer are installed partially overlapping in the thickness direction of the optical film structure.

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

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

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

[0015] Selectively, in some embodiments of the present disclosure, the viewing angle adjustment layer comprises a flexible layer and scattering particles, wherein the scattering particles are located within the flexible layer.

[0016] The embodiments of this disclosure further provide a backlight module including the optical film structure described in any one of the embodiments.

[0017] Embodiments of the present disclosure further provide a display device, the display device comprising a display panel and a backlight module as described in any one of the embodiments, wherein 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 adjustment layer installed on the light-emitting side of the base layer, and the embodiment of the present disclosure achieves switching between the narrow viewing angle mode and the wide viewing angle mode by adjusting the shape of the viewing angle adjustment layer. [Brief explanation of the drawing]

[0019] [Figure 1] One structural diagram of the optical film structure provided by the embodiments of the present disclosure in the narrow viewing angle mode. [Figure 2] One structural diagram of the optical film structure provided by the embodiments of the present disclosure in the wide viewing angle mode. [Figure 3] A ray path diagram of the optical film structure provided by the embodiments of the present disclosure passing through the first prism and the second prism. [Figure 4] Another structural diagram of the optical film structure provided by the embodiments of the present disclosure in the narrow viewing angle mode. [Figure 5] Another structural diagram of the optical film structure provided by the embodiments of the present disclosure in the wide viewing angle mode. [Figure 6] Yet another structural diagram of the optical film structure provided by the embodiments of the present disclosure in the wide viewing angle mode. [Figure 7] One structural diagram of the backlight module provided by the embodiments of the present disclosure in the narrow viewing angle mode. [Figure 8] One structural diagram of the backlight module provided by the embodiments of the present disclosure in the wide viewing angle mode. [Figure 9] One structural diagram of the display device provided by the embodiments of the present disclosure in the narrow viewing angle mode. [Figure 10] One structural diagram of the display device provided by the embodiments of the present disclosure in the wide viewing angle mode.

Embodiments for Carrying Out the Invention

[0020] The following will clearly and completely describe 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 only some embodiments of the present disclosure, not all embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present disclosure. It should also be understood that the specific implementation manners described herein are only for 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 repeated explanations will not be given one by one. Also, unless otherwise stated, the orientation terms used, such as "upper" and "lower", usually refer to the upper and lower of the actual use or operating state of the device, specifically the up and down directions in the drawings. "Inner" and "outer" are described with respect to the outline of the device. The terms "first", "second", "third", etc. are only used as marks, and no numerical requirements or order establishment are forced.

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

[0022] Referring to FIGS. 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 adjustment layer 12. The viewing angle adjustment 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 adjustment layer 12 is configured to narrow the emission angle of the light rays to a first emission angle. When the optical film structure 100 is in the wide viewing angle mode, the viewing angle adjustment layer 12 is configured to adjust the emission angle of the light rays to a second emission angle, and the second emission angle is larger than the first emission angle.

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

[0025] What should be understood is that in narrow viewing angle mode, the viewing angle adjustment layer 12 is used to achieve a narrow viewing angle by narrowing the emission angle of the light rays. In wide viewing angle mode, the viewing angle adjustment layer 12 is used to achieve a wide viewing angle by adjusting the emission angle of the light rays to be greater than the emission angle in narrow viewing angle mode.

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

[0027] Selectively, in some embodiments, the base layer 11 is a transparent film layer, which may be in a flat, full-surface form.

[0028] The material of the base layer 11 may be one of the following: 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] Selectively, in some embodiments, the thickness of the base layer 11 is between 50 microns and 250 microns, and may be, 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] As the thickness of the base layer 11 increases, the pressure it can resist also increases, and so does the optical loss. Therefore, in order to satisfy the requirements for good support and pressure resistance of the base layer 11 at a narrow viewing angle, the thickness of the base layer 11 is selected to be between 50 micrometers and 250 micrometers.

[0031] Selectively, in some embodiments of the present disclosure, the viewing angle adjustment layer 12 includes a flexible layer rx and scattering particles ss placed within the flexible layer rx.

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

[0033] Selectively, the material of the flexible layer rx may be a transparent organic material, for example, one of the following: polyethylene, polypropylene, polystyrene, polylactic acid, polyethylene glycol dicarboxylic acid, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyethersulfone, aromatic fluorotoluene including polyarylate, polycycloolefin, polyimide, or polyurethane.

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

[0035] The particle size of the scattered 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 size of the scattered particles ss, the thicker the flexible layer rx becomes, and the lower the density of scattered particles ss that can be placed within the viewing angle adjustment layer 12, the worse the scattering effect. Therefore, by setting the particle size of the scattered particles ss from 1 micron to 30 microns, a good scattering effect can be achieved without significantly increasing the thickness of the viewing angle adjustment layer 12.

[0037] Referring to Figures 1 and 2, in some embodiments of this disclosure, the viewing angle adjustment layer 12 and the base layer 11 may be installed separately or integrally.

[0038] When the optical film structure 100 is in narrow viewing angle mode, the viewing angle adjustment layer 12 includes a plurality of first prisms 12a, each first prism 12a including a first sidewall portion 121 extending along a first direction m and a second sidewall portion 122 extending along a second direction n, where the first direction m and the second direction n intersect. The first sidewall portion 121 and the second sidewall portion 122 are connected, and a first cavity kq1 is formed between the first prism 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 adjustment layer 12. As the amount of transparent medium 13 increases, the transparent medium 13 supports the viewing angle adjustment layer 12 so that it forms a prism. Here, as the amount of transparent medium 13 increases, the prism is gradually stretched, the apex angle of the prism gradually decreases, and the effect of narrowing the light rays is improved. In the narrow viewing angle mode, the effect of narrowing the light rays of the viewing angle adjustment layer 12 can be adjusted by controlling the amount of input of the transparent medium 13 as needed.

[0040] In selectively narrow viewing angle mode, it is defined that the first cavity kq1 is filled with a transparent medium 13 such that the prism formed by the viewing angle adjustment layer 12 becomes the first prism 12a. The apex angle of the first prism 12a is the first apex angle α, which is the angle in the extension direction of the first sidewall portion 121 and the second sidewall 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 adjustment layer 12 is installed completely separate from the base layer 11, and a transparent medium 13 is sandwiched between the viewing angle adjustment layer 12 and the base layer 11.

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

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

[0044] In some embodiments of this disclosure, the transparent medium 13 comprises either a gas or a liquid. An example in which the transparent medium 13 is a gas is described below.

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

[0046] The first prism 12a includes a first vertex angle α formed by the first sidewall portion 121 and the second sidewall portion 122. The second prism 12b includes a second vertex angle β formed by the first sidewall portion 121 and the second sidewall portion 122. The second vertex angle β is greater than the first vertex angle α.

[0047] Referring to Figure 3, compared to the narrow viewing angle mode, the amount of transparent medium 13 in the optical film structure 100 is reduced in the wide viewing angle mode. This reduces the degree to which the first prism 12a is stretched, causing the first sidewall portion 121 and the second sidewall portion 122 to tilt and spread apart, forming the second prism 12b. As the first sidewall portion 121 and the second sidewall portion 122 tilt and spread apart, the first cavity kq1 is reduced in size, the angle of the first vertex angle α changes to the second vertex angle β, and the reduction of the first cavity kq1 to the second cavity kq2 has the effect of expanding the light ray emission angle more effectively than the first vertex angle α, thereby achieving an even wider viewing angle.

[0048] For example, as shown in Figure 3, light rays of the same angle are radiated by the first prism 12a and the second prism 12b. Since the first vertex angle α of the first prism 12a is relatively small, the first prism 12a can narrow the light rays at a larger angle, and the second prism 12b can narrow the light rays at a smaller angle. Therefore, relatively speaking, the first prism 12a can achieve a narrow field of view, and the second prism 12b can achieve a wide field of view.

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

[0050] Here, the first vertex angle α is acute or right, which can better narrow the angle of emission of light rays. The second vertex angle β is obtuse, which can better reduce the degree to which the angle of emission of light rays narrows, thereby better reflecting the difference between the narrow and wide field of view angles. For example, the first vertex angle α is 45 degrees and the second vertex angle β is 135 degrees, or the first vertex angle α is 90 degrees and the second vertex angle β is 150 degrees.

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

[0052] It can be understood that the contact point 12c with the base layer 11 minimizes the second cavity kq2, reducing the thickness of the optical film structure 100, and also returns the viewing angle adjustment layer 12 to a non-elastic state, thereby improving the lifespan of the viewing angle adjustment layer 12.

[0053] Selectively, the connection point 12c can come into contact with the base layer 11 by electrostatic attraction.

[0054] Note that the number of prisms corresponding to the two modes in Figures 1 and 2 are approximate and do not mean that the number of prisms in the two modes is not the same. The number of prisms in the corresponding diagrams below are also approximate configurations.

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

[0056] In Figures 4 and 5, to avoid repetition, we will describe the parts that differ from those of the above embodiment.

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

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

[0059] The fixed connection area is the connection area between the connection point 12c and the base layer 11. The joint 12c may be connected to the base layer 11 by adhesive, but is not limited to this; for example, it may be connected by hot melt adhesive.

[0060] The viewing angle adjustment layer 12 and the base layer 11 are fixedly connected with a gap between them, thereby fixing the position of the prism and avoiding the risk of the prism shifting position. Furthermore, because the viewing angle adjustment 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 vertex angle α, the input amount to the transparent medium 13 is reduced, the height of the first prism 12a is lowered, and the optical film structure 100 can be made thinner.

[0061] Referring to Figure 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 Figure 6, to avoid repetition, we will explain the parts that differ from those in the above embodiment.

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

[0064] In addition, compared to 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 drawn out from the first cavity kq1, causing the first prism 12a to drop in, and the first sidewall portion 121 and the second sidewall portion 122 of the viewing angle adjustment layer 12 are attached to the base layer 11, so that the viewing angle adjustment layer 12 does not have a prism shape, and in this case the viewing angle adjustment layer 12 has a wider viewing angle, that is, the light rays have a larger emission angle.

[0065] Selectively, the first sidewall portion 121 and the second sidewall portion 122 may be attached to the base layer 11 by electrostatic adsorption or by vacuum adsorption.

[0066] In some embodiments of the present disclosure, when the optical film structure 100 is in wide-viewing-angle mode, the first sidewall portion 121 and the second sidewall portion 122 of the viewing-angle adjustment layer 12 are installed in a partially overlapping manner 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 with a partial overlap so that the overlapping region has a better scattering effect and improves the uniformity of brightness.

[0068] In some embodiments of the present disclosure, a fold zh extending along the stretching direction of the first prism 12a is provided in either the first sidewall portion 121 or the second sidewall portion 122.

[0069] Here, taking the case where the fold zh is located on the first sidewall portion 121 as an example, when the optical film structure 100 switches from a narrow viewing angle mode to a wide viewing angle mode, the transparent medium 13 is pulled apart to a certain extent, causing the first sidewall portion 121 to be folded along the fold zh to form a first folded portion 121a and a second folded portion 121b, with the first folded portion 121a being attached to the base layer 11 and the second folded portion 121b being laminated on the first folded portion 121a. The first folded portion 121a and the second folded portion 121b are installed overlapping at least partially, and the second sidewall portion 122 is installed lying down and overlapping the second folded portion 121b.

[0070] By creating the fold zh, the first side wall portion 121 and the second side wall portion 122 can be folded regularly, thereby improving the uniformity of brightness.

[0071] Selectively, in some embodiments, the number of scattered particles ss located within the second folded portion 121b is less than the number of scattered particles ss located within the first folded portion 121b. On the other 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 wrinkles in the first folded portion 121a is reduced. On the other hand, because there are fewer scattered particles ss in the second folded portion 121b, the second folded portion 121b has better flexibility and is easier to fold. Next, since the first folded portion 121a and the second folded portion 121b are installed stacked, the area where they are stacked has two layers of scattered particles ss. Therefore, there are fewer scattered particles ss in the second folded portion 121b, and the overall uniformity of light emission can be improved.

[0072] Referring to Figures 7 and 8, embodiments of the present disclosure further provide a backlight module BL including the optical film structure 100 described in any one of the embodiments.

[0073] The optical film structure of the backlight module BL in the embodiments of this disclosure is similar to or the same as the optical film structure 100 of any of the embodiments described above, and will not be described repeatedly here. Furthermore, the backlight module BL of the display device in the embodiments of this disclosure is shown based on the optical film structure 100 corresponding to Figures 1 and 2, but is not limited thereto. For example, it may be shown based on the optical film structure 100 corresponding to Figures 4 and 5, or it may be shown based on the optical film structure 100 corresponding to Figures 1 and 6. Moreover, it may be shown based on the optical film structure 100 corresponding to Figures 4 and 6.

[0074] Here, the embodiments of this disclosure are described as examples in which the backlight module BL is of the direct type, but are not limited to this, and for example, the backlight module BL may be of the 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 placed on the back frame b1 and connected to the periphery of the back frame b1 to form a housing 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 housing cavity Rn. The quantum dot film b5 is placed on the light-emitting element substrate b4. The optical film structure 100 is placed 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 into the optical film structure 100.

[0078] In some embodiments, the light-emitting element substrate b4 can emit white light, thereby saving the quantum dot film b5.

[0079] Referring to Figures 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 as described in any one of the embodiments, wherein the display panel PN is on the light-emitting side of the backlight module BL.

[0080] The backlight module of the display device 1000 in the embodiment of this disclosure is similar to or the same as the structure of the backlight module BL in any of the embodiments described above, and will not be described repeatedly here. Furthermore, although the backlight module BL of the display device 1000 in the embodiment of this disclosure is shown based on the optical film structure 100 corresponding to Figures 1 and 2, it is not limited thereto, and may be, for example, the optical film structure 100 corresponding to Figures 4 and 5, or the optical film structure 100 corresponding to Figures 1 and 6. Alternatively, it may be the optical film structure 100 corresponding to Figures 4 and 6.

[0081] The optical film structure 100 of the display device 1000 in 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 adjustment layer 12 installed on the light-emitting 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 adjustment layer 12.

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

[0083] Selectively, the display device 1000 can be applied to and used in a variety of products, the variety of products including, for example, 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] Furthermore, the display device 1000 in several embodiments can be applied to and used within wearable devices, the wearable devices including smartwatches, watch phones, glasses-type displays, and head-mounted displays (HMDs). In addition, in several embodiments, the display device 1000 can be applied to the instrument panel of an automobile, a display in a central information display (CID) located on the central instrument panel or instrument panel of an automobile, an interior mirror display in place of a side mirror of an automobile, and a display for 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 this disclosure have been described in detail above. The principles and embodiments of this disclosure have been illustrated using specific embodiments. The description of these embodiments is solely for the purpose of helping to understand the methods and core ideas of this disclosure. At the same time, those skilled in the art may modify the specific embodiments and scope of applications based on the ideas of this disclosure. In short, the contents of this document should not be construed as limitations of this disclosure.

Claims

1. An optical film structure, It includes a base layer and a viewing angle adjustment layer installed on the light-emitting 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 adjustment layer is configured to narrow the emission angle of the light rays to a first emission angle, and when the optical film structure is in the wide viewing angle mode, the viewing angle adjustment layer is configured to adjust the emission angle of the light rays to a second emission angle, and the second emission angle is greater than the first emission angle. When the optical film structure is in a narrow viewing angle mode, the viewing angle adjustment layer includes a plurality of first prisms, each first prism including a first sidewall portion extending along a first direction and a second sidewall portion extending along a second direction, the first and second directions intersect, the first and second sidewall portions are connected, a first cavity is formed between the first prism and the base layer, and the first cavity is filled with a transparent medium. When the optical film structure is in wide-viewing-angle mode, the viewing-angle adjustment layer includes a plurality of second prisms, each second prism including a first sidewall portion extending along a third direction and a second sidewall portion extending along a fourth direction, the third and fourth directions intersect, the first and second sidewall portions are connected, a second cavity is formed between the second prism and the base layer, and the transparent medium is filled into the second cavity. The first prism includes a first vertex angle formed by the first side wall portion and the second side wall portion, and the second prism includes a second vertex angle formed by the first side wall portion and the second side wall portion, wherein the second vertex angle is greater than the first vertex angle. An optical film structure characterized by the following features.

2. When the optical film structure is in wide-angle mode, the connection point between two adjacent second prisms contacts the base layer. The optical film structure according to feature 1.

3. The first vertex angle is acute or right, and the second vertex angle is obtuse. The optical film structure according to feature 1.

4. When the optical film structure is in wide-viewing-angle mode, the first sidewall portion and the second sidewall portion of the viewing-angle adjustment layer are in close contact with the base layer. The optical film structure according to feature 1.

5. When the optical film structure is in wide-viewing-angle mode, the first sidewall and the second sidewall of the viewing-angle adjustment layer are installed partially overlapping in the thickness direction of the optical film structure. The optical film structure according to feature 4.

6. When the optical film structure is in a narrow viewing angle mode, the viewing angle adjustment layer is installed separately from the base layer, and the transparent medium is sandwiched between the viewing angle adjustment layer and the base layer. The optical film structure according to any one of claims 1 to 5.

7. When the optical film structure is in a narrow field of view mode, the connection point between two adjacent first prisms is fixedly connected to the base layer. The optical film structure according to any one of claims 1, 3, 4, or 5.

8. The transparent medium includes one of a gas and a liquid. The optical film structure according to any one of claims 1 to 5.

9. The viewing angle adjustment layer includes a flexible layer and scattering particles, wherein the scattering particles are placed within the flexible layer. The optical film structure according to any one of claims 1 to 5.

10. It is a backlight module, The optical film structure includes the one described in any one of claims 1 to 5. A backlight module characterized by the following features.

11. A display device, The display panel and the backlight module described in claim 10 are included, wherein the display panel is located on the light-emitting side of the backlight module. A display device characterized by the following features.

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