TWI804286B - Optical film, backlight module and display device - Google Patents

Abstract

An optical film, a backlight module and a display device are provided. The optical film includes a main body, plural first prism structures and plural second prism structures. The main body has a first optical surface and a second optical surface. The first prism structures are disposed on the first optical surface. Each of the first prism structures extends along a first direction. The second prism structures are disposed on the second optical surface. Each of the second prism structures extends along a second direction. The first direction is different from the second direction.

Description

Optical film, optical film group, backlight module and display device

This disclosure relates to an optical film and its application, and in particular to an optical film capable of producing a larger light-emitting viewing angle, an optical film group, and a backlight module using the optical film and optical film group and display device.

The automotive display defined by the European Union has a viewing angle specification (Deutsches Flachdisplay Forum) in consideration of the viewing angle of the driver and co-pilot. Therefore, the current vehicle product specifications are designed with reference to this specification.

At present, the chip used in the backlight module is mainly used to concentrate the light in the direction of the normal viewing angle. However, since the car display is installed below the line of sight, and the center console (Center Informative Display, CID) needs to be designed so that both the driver and the co-pilot can watch it. Therefore, the specification of the viewing angle is on the upper side (upper viewing angle is within 20 degrees, and the lower viewing angle is within 15 degrees), and the distribution of left and right viewing angles is relatively wide (left and right viewing angles are within 50 degrees), which is different from ordinary tablet computers or notebooks. Computer viewing angle requirements are quite different.

Generally speaking, although the viewing angle can be narrowed by using the privacy protection film, the energy loss of the privacy protection film is quite large. If only by increasing the overall luminance, the luminance at large viewing angles can reach the desired value, but there is also the problem of power consumption. Therefore, how to develop an optical film that meets a specific viewing angle and luminance when applied to a display device, and can also achieve the purpose of saving power is the motivation of the present invention.

Therefore, one purpose of the present disclosure is to provide an optical film and an optical film set, which can be used in a backlight module and a display device to meet a specific viewing angle.

According to the above purpose of the present disclosure, an optical film is proposed. The optical film includes a body, a plurality of first pleated structures and a plurality of second pleated structures. The main body has a first optical surface and a second optical surface opposite to each other. The first plaster structures are disposed on the first optical surface, and each of the first plaster structures has a first extending direction. The second braided structures are disposed on the second optical surface, and each second braided structure has a second extending direction. Wherein, the first extending direction is different from the second extending direction.

According to an embodiment of the present disclosure, the above-mentioned first 稜鏡 structures have an arrangement density Y, and each first 稜鏡 structure has a first side and a second side connected to each other, and there is an included angle between the first side and the second side X, where the arrangement density Y and the included angle X satisfy a relational expression, the relational expression is Y≥0.441+0.01249X-3.2875*10 ^-4 X ² +1.95833*10 ^-6 X ³ .

According to an embodiment of the present disclosure, there is a blank portion between the above-mentioned first fan structures, and the arrangement density Y is calculated according to a function, wherein the function is Y=(P ₁ −W ₁ )/P ₁ . Wherein, P ₁ is the distance between any two adjacent first plaster structures, and W ₁ is the width of each blank portion.

According to an embodiment of the present disclosure, each of the above-mentioned first embossed structures is a strip structure that is concave or protruding from the first optical surface.

According to an embodiment of the present disclosure, the included angle between the above-mentioned first extending direction and the second extending direction is 90 degrees.

According to an embodiment of the present disclosure, when a light enters the body from one of the first optical surface and the second optical surface, and the other one of the first optical surface and the second optical surface exits, a part of the light The light is emitted along the direction of the front view, and part of the light is emitted along the direction of the side view. Wherein, the ratio of the light output from the side view direction to the light output from the front view direction is greater than 0.4, including the endpoint value.

According to an embodiment of the present disclosure, the above-mentioned front view direction is parallel to the light emitting normal of the optical film, and the angle between the side view direction and the light emitting normal is greater than 40 degrees, inclusive.

According to the above purpose of the present disclosure, another backlight module is provided. The backlight module includes a light guide plate, a light source, the above-mentioned optical film and a film group. The light guide plate has a light incident surface and a light output surface. The light source is adjacent to the light incident surface. The optical film is arranged in front of the light emitting surface. The diaphragm group is located between the optical diaphragm and the light guide plate.

According to the above purpose of the present disclosure, a backlight module is proposed. The backlight module includes a light source and the above-mentioned optical film. The light source includes a substrate and a plurality of light emitting units arranged on the substrate. The optical film is arranged in front of the light source.

According to the above purpose of the present disclosure, a display device is proposed. The display device includes the above-mentioned backlight module and a display panel. The display panel is arranged in front of the backlight module.

According to the above purpose of the present disclosure, an optical film set is proposed. The optical film set includes a first film and a second film. The first film has a first optical surface and a plurality of first pleated structures, wherein the first pleated structures are arranged on the first optical surface, and each first pleated structure has a first extending direction. The second diaphragm has a second optical surface and a plurality of second 稜鏡 structures, wherein the first optical surface and the second optical surface respectively face opposite directions, the second 稜鏡 structures are arranged on the second optical surface, and each The second fringe structure has a second extending direction. Wherein the first extending direction is different from the second extending direction.

According to an embodiment of the present disclosure, the above-mentioned first 稜鏡 structures have an arrangement density Y, and each first 稜鏡 structure has a first side and a second side connected to each other, and there is an included angle between the first side and the second side X, wherein the arrangement density Y and the included angle X satisfy a relational expression, and the relational expression is Y≥0.441+0.01249X-3.2875*10 ^-4 X ² +1.95833*10 ^-6 X ³ .

According to an embodiment of the present disclosure, there is a blank portion between any two of the above-mentioned adjacent first fringe structures, and the arrangement density Y is calculated according to a function, wherein the function is Y=(P ₁ -W ₁ ) /P ₁ , where P ₁ is the distance between any two adjacent first interlocking structures, and W ₁ is the width of each blank portion.

According to an embodiment of the present disclosure, each of the above-mentioned first embossed structures is a strip structure that is concave or protruding from the first optical surface.

According to an embodiment of the present disclosure, the included angle between the above-mentioned first extending direction and the second extending direction is 90 degrees.

According to an embodiment of the present disclosure, when the light enters from one of the first optical surface and the second optical surface and exits from the other of the first optical surface and the second optical surface, a part of the light is Light is emitted along the front view direction, and part of the light is emitted along the side view direction, wherein the ratio of the light output from the side view direction to the light output from the front view direction is greater than 0.4, including the endpoint value.

According to an embodiment of the present disclosure, the front viewing direction is parallel to the light emitting normal of the optical film set, and the angle between the side viewing direction and the light emitting normal is greater than 40 degrees, inclusive.

According to the above purpose of the present disclosure, another backlight module is proposed. The backlight module includes a light guide plate, a light source, the above-mentioned optical film set and the film set. The light guide plate has a light incident surface and a light output surface. The light source is adjacent to the light incident surface. The optical film group is arranged in front of the light-emitting surface. The diaphragm group is located between the optical diaphragm and the light guide plate.

According to the above purpose of the present disclosure, a backlight module is proposed. The backlight module includes a light source and the above-mentioned optical film group. The light source includes a substrate and a plurality of light emitting units arranged on the substrate. The optical film is arranged in front of the light source.

According to the above purpose of the present disclosure, a display device is proposed. The display device includes the above-mentioned backlight module and a display panel. The display panel is arranged in front of the backlight module.

According to an embodiment of the present disclosure, there is a blank portion between any two of the above-mentioned adjacent first fringe structures, and the arrangement density Y is calculated according to a function, wherein the function is Y=(P ₁ -W ₁ ) /P ₁ , where P ₁ is the distance between any two adjacent first interlocking structures, and W ₁ is the width of each blank portion.

From the above, it can be known that the present disclosure is mainly through the design of the first and second fringe structures on the optical film or the optical film group, which can convert part of the straight light to other viewing angle directions, so as to improve the overall field of view. There is no need to increase the current to increase the overall brightness to meet a specific viewing angle.

Please refer to FIG. 1 , which is a schematic diagram of an optical film applied to a direct-lit backlight module according to an embodiment of the present disclosure. The optical film 100 of this embodiment can be mainly applied to the direct type backlight modules 200 and 500 as shown in FIG. 1 and FIG. 8 , or to the side type backlight module 300 as shown in FIG. 9 . To increase the light output viewing angle of the backlight module 200 or the backlight module 300 . In the backlight module 200 shown in FIG. 1 , the optical film 100 is disposed in front of the light source 210 . Wherein, the light source 210 includes a substrate 211 and a plurality of light emitting units 212 arrayed on the substrate 211 . In this way, the light provided by the light source 210 can directly pass through the optical film 100 , and then exit the optical film 100 .

As shown in FIG. 1 , the optical film 100 of this embodiment includes a body 110 , a plurality of first pleated structures 120 and a plurality of second pleated structures 130 . Wherein, the body 110 has a first optical surface 111 and a second optical surface 112 , the first plaster structure 120 is disposed on the first optical face 111 , and the second plaster structure 130 is disposed on the second optical face 112 . As shown in FIG. 1 , the first elongated structure 120 has a first extending direction D1, and the second eel structure 130 has a second extending direction D2, wherein the first extending direction D1 is different from the second extending direction D2. In this way, when light enters the optical film 100 from the first optical surface 111, the first ray structure 120 can turn part of the straight light into light in other directions, and then make the light after turning pass through the second optical surface 112. The second light-emitting structure 130 emits light. Specifically, as shown in FIG. 1 , after the light is acted on by the optical film 100, a part of the light (for example, light L1) can pass through the blank portion S1 between the first interstitial structures 120 and emit light along the direction of the front view, and a part of the light The light (for example, light L2 ) can be emitted along the side view direction through the action of the first incandescent structure 120 . Wherein, the front view direction referred to here refers to the normal direction of light parallel to the optical film 100 , and the side view direction has an included angle θ with the front view direction, wherein. More specifically, the front viewing direction is parallel to a light emitting normal of the optical film 100 , and the angle θ between the side viewing direction and the light emitting normal is greater than 40 degrees, inclusive. In this way, the optical film 100 of this embodiment can further convert part of the straight light to other viewing directions, adjust the size of the viewing angle in the horizontal direction to expand the viewing angle, and increase the overall brightness without increasing the current. Conform to a specific viewing angle and brightness, while achieving the purpose of power saving.

In this embodiment, each of the first cornel structures 120 is a strip structure protruding from the first optical surface 111 . In other embodiments, the first embossed structure 120 can also be a strip structure that is concave into the first optical surface 111 . In some embodiments, the included angle between the first extending direction D1 and the second extending direction D2 is 90 degrees. Please also refer to FIG. 2 . FIG. 2 is a partial schematic view of an optical film according to an embodiment of the present disclosure. In one embodiment, each of the first plaster structures 120 has a first side 121 and a second side 122 connected to each other, and an angle X is formed between the first side 121 and the second side 122 . The first plaster structures 120 have an arrangement density, and there is a pitch P ₁ between any two adjacent first plaster structures 120 , and the blank portion S1 has a width W ₁ . Wherein, the arrangement density is calculated according to the function, wherein the function is expressed as follows: Y=(P ₁ -W ₁ )/P ₁ .

In this embodiment, when the light passes through the optical film 100, the ratio of the light output of the light L2 emitted from the side view direction to the light output of the light L1 emitted from the front view direction is greater than or equal to 0.4, that is, the optical film is required When the ratio of the side view light output to the front view light output of 100 is more than 40%, the design of the first fan structure 120 must satisfy a relational expression: this relational expression is Y≥0.441+0.01249X-3.2875*10 ^-4 X ² +1.95833*10 ^-6 X ³ .

Please refer to FIG. 3 and Table 1. FIG. 3 is a schematic diagram showing the viewing angle specification of a conventional EU-defined vehicle display. In an EU-defined viewing angle specification for vehicle displays (Deutsches Flachdisplay Forum), in order to simultaneously consider the viewing angles of the front and passenger seats, such as the area A+, area A, and area B shown in Figure 3, the vehicle display is specified from the side The ratio of the amount of light emitted from the viewing direction (that is, the luminance of area B) to the amount of light emitted from the frontal viewing direction (that is, the luminance of area A+) should be at least greater than 37.5%. However, this embodiment adopts a higher standard than the standard for the viewing angle of vehicle displays defined by the European Union, and requires that the ratio of the amount of light emitted from the side-view direction to the amount of light emitted from the front-view direction be greater than or equal to 40% (that is, greater than 37.5 %), so using the relational expression of this embodiment to design the optical film 100 can expand the light-emitting viewing angle and comply with the luminance regulations of automotive displays defined by the European Union. Table 1. Field of View Angle Range and EU Viewing Angle Specifications of Each Area in Figure 3

Please also refer to FIG. 4 and FIG. 5 together, wherein FIG. 4 is a graph showing the relationship between the included angle (X) and the arrangement density (Y) of a first 稜鏡 structure according to an embodiment of the present disclosure, and FIG. 5 is A schematic diagram of the ratio of the side-view light output to the front-view light output generated by the optical films with different angles and different arrangement densities of the first fringe structure according to an embodiment of the present disclosure. As can be seen from Figures 4 and 5, when the ratio of the side-view light output to the front-view light output of the optical film 100 is required to be 40%, the included angle X of the first fringe structure 120 can be set to 40 degrees and the arrangement density is 54%. , or set the angle X of the first 稜鏡 structure 120 to 60 degrees and the arrangement density to 43%, or set the angle X of the first 稜鏡 structure 120 to 90 degrees and the arrangement density to 33%, or set the first 樜鏡 structure 120 to 33% The included angle X of 120 is 120 degrees and the arrangement density is 59%, so as to generate a specific light-emitting viewing angle requirement.

Please refer to FIG. 6A and FIG. 6B at the same time. FIG. 6A is a schematic diagram of the simulation of light output brightness at various viewing angles of a conventional optical film, and FIG. 6B is a light output at various viewing angles of an optical film with a first enamel structure according to an embodiment of the present disclosure. Schematic diagram of brightness simulation. Compared with the brightness simulation schematic diagram of the conventional optical film in Figure 6A, it can be clearly seen that the dark area of the embodiment in Figure 6B will be separated into two areas, reducing the brightness of the light output at the front viewing angle to reduce the energy consumption of the light output at the front viewing angle, and improve As for the brightness of the side viewing angles of the front and passenger seats, as for the comparison example of the general film or the film that does not meet the relational formula, the dark area cannot be separated into two areas, and the purpose of the present invention cannot be achieved.

It should be noted that the present disclosure is not limited to the above-mentioned angle and arrangement density, and the corresponding included angle X and arrangement density of the first fennel structure 120 can be calculated according to the proportional requirement of the light output by using the relational formula of the present disclosure. For example, the curve in FIG. 4 represents the relation curve between the angle X of the first fennel structure 120 and the arrangement density when the ratio of the side view light output to the front view light output of the optical film 100 is equal to 40%. The range above this curve represents the relationship between the included angle X of the first fennel structure 120 and the arrangement density corresponding to a higher ratio of side-view light output to front-view light output. Taking the point where the included angle X is 90 degrees as an example, when the included angle X of the first fan structure 120 is 90 degrees, the arrangement density is 33%, and the ratio of side-viewed light output to front-viewed light output is 40%. When a higher ratio of side-view light output to front-view light output is required, under the same condition that the included angle X of the first jelly structure 120 is 90 degrees, by increasing the arrangement density of the first jelly structure 120, for example Setting the arrangement density to be greater than 33% can achieve the purpose of increasing the ratio of side-view light output to front-view light output.

Please also refer to FIG. 7 . FIG. 7 is a graph showing the relationship between viewing angle and brightness simulated by using the optical film 100 of an embodiment of the present disclosure and the optical film of a comparative example respectively. Among them, the optical film of the comparative example is a general single-sided film. It can be seen from FIG. 7 that when the light exits through a general single-sided film, the light exit angle ranges from -40° to +40° and has a relatively high light output; and the light exits through the optical film 100 of the embodiment of the present disclosure. Finally, although the brightness from the optical film 100 at the normal viewing angle range of -30 degrees to +30 degrees is lower than that of the optical film of the comparative example, it is more than -40 degrees to +40 degrees. The amount of light output at viewing angle positions outside the range is significantly increased, for example, the relative brightness of the viewing angle range of -50 degrees and +50 degrees increases from 0.3 to 0.5. This means that the optical film 100 of this embodiment can reduce the light output brightness at the front viewing angle to reduce the energy consumption of the light output at the front viewing angle, and increase the brightness at the side viewing angle of the front and passenger seats, so as to meet the usage requirements of the vehicle display.

Please also refer to FIG. 8 . FIG. 8 is a schematic diagram of an optical film applied to a direct-lit backlight module according to an embodiment of the present disclosure. The backlight module 500 of this embodiment includes a light source 210 , a diffusion film 510 , a diffusion plate 520 and an optical film 100 . In the backlight module 500 shown in FIG. 8 , the optical film 100 is disposed in front of the light source 210 . The diffusion film 510 and the diffusion plate 520 are disposed between the light source 210 and the optical film 100 . In this way, the light provided by the light source 210 can pass through the diffusion film 510 and the diffusion plate 520 , and then enter the optical film 100 , and then pass through the optical film 100 to form light with a wide viewing angle.

Please also refer to FIG. 9 . FIG. 9 is a schematic diagram of an optical film applied to an edge-lit backlight module according to an embodiment of the present disclosure. The optical film 100 of this embodiment can also be applied in the side-lit backlight module 300 . Wherein, the backlight module 300 includes a light source 310 , a light guide plate 320 , a film set 330 and an optical film 100 . Wherein, the light source 310 is disposed adjacent to the light incident surface 321 of the light guide plate 320 , and the optical film 100 is disposed in front of the light exit surface 322 of the light guide plate 320 . The film group 330 is disposed between the light guide plate 320 and the optical film 100 . In this way, the light provided by the light source 310 can enter the light guide plate 320 to form a surface light source, and then pass through the film set 330 and then enter the optical film 100 to form a wide viewing angle light output through the optical film 100 .

Please also refer to FIG. 10 , which is a schematic diagram of a display device according to an embodiment of the present disclosure. The display device 400 of this embodiment includes a backlight module 200 and a display panel 410 as shown in FIG. 1 . The display panel 410 is disposed in front of the backlight module 200 . Thus, the design of the optical film 100 in the backlight module 200 of the display device 400 also achieves the purpose of reducing the light output at the front viewing angle and increasing the light output at the side viewing angle, so details will not be repeated here. Wherein, in this embodiment, the application of the backlight module 200 shown in FIG. 1 in the display device 400 is only used for demonstration purposes and is not intended to limit the present disclosure. The backlight modules of other embodiments (for example, the backlight module 300 shown in FIG. 9 ) can be applied to display devices to produce the same effect of expanding the viewing angle.

Please refer to FIG. 11 , which is a schematic diagram of an optical film set applied to a direct-lit backlight module according to an embodiment of the present disclosure. The optical film set 600 of this embodiment can be mainly applied to the direct-type backlight module 700 as shown in FIG. 11 , or to the side-type backlight module 800 as shown in FIG. The light emitting angle of the group 700 or the backlight module 800 . In the backlight module 700 shown in FIG. 11 , the optical film set 600 is disposed in front of the light source 710 . Wherein, the light source 710 includes a substrate 711 and a plurality of light emitting units 712 arrayed on the substrate 711 . In this way, the light provided by the light source 710 can directly pass through the optical film set 600 , and then exit the optical film set 600 .

As shown in FIG. 11 , the optical film set 600 of this embodiment includes a first film 610 and a second film 620 . Wherein, the first diaphragm 610 has a first optical surface 612 and a plurality of first pleated structures 611, the second diaphragm 620 has a second optical surface 622 and a plurality of second pleated structures 621, and the first pleated structures 611 It is disposed on the first optical surface 612 , and the second embossed structure 621 is disposed on the second optical surface 622 . As shown in FIG. 11 , the first elongated structure 611 has a first extending direction D1, and the second eel structure 621 has a second extending direction D2, wherein the first extending direction D1 is different from the second extending direction D2. In this way, when light enters the optical film set 600 from the first optical surface 612, the first fringe structure 611 can turn part of the straight light into light in other directions, and then make the light after turning pass through the second optical surface 622 The light is emitted from the second 稜鏡 structure 621 on the top. Specifically, as shown in FIG. 11 , after the light passes through the optical film 600, a part of the light (for example, light L1) can pass through the blank portion S2 between the first interstitial structures 611 and emit light along the direction of the front view, while a part of the light The light (for example, light L2 ) can be emitted along the side view direction through the action of the first incandescent structure 611 . Wherein, the front view direction referred to here refers to the direction of light parallel to the normal line of the optical film group 600 , and the side view direction has an included angle θ with the front view direction, wherein. More specifically, the front view direction is parallel to one of the light emitting normals of the optical film set 600 , and the included angle θ between the side viewing direction and the light emitting normal is greater than 40 degrees, inclusive. In this way, the optical film set 600 of this embodiment can further convert part of the straight light to other viewing directions, adjust the size of the viewing angle in the horizontal direction to expand the viewing angle, and increase the overall brightness without increasing the current. It can meet the specific viewing angle and brightness, and achieve the purpose of saving power at the same time.

In this embodiment, each of the first cornel structures 611 is a strip structure protruding from the first optical surface 612 . In other embodiments, the first embossed structure 611 can also be a strip structure concave into the first optical surface 612 . In some embodiments, the included angle between the first extending direction D1 and the second extending direction D2 is 90 degrees. Please also refer to FIG. 12 . FIG. 12 is a partial schematic diagram of an optical film set according to an embodiment of the present disclosure. In one embodiment, each of the first plaster structures 611 has a first side 611 a and a second side 611 b connected to each other, and an angle X is formed between the first side 611 a and the second side 611 b. The first plaster structures 611 have an arrangement density Y, and there is a pitch P1 between any two adjacent first plaster structures 611 , and the blank portion S2 has a width W1. Wherein, the arrangement density is calculated according to the function, wherein the function is expressed as follows: Y=(P ₁ -W ₁ )/P ₁ .

In this embodiment, when the light passes through the optical film group 600, the ratio of the light output of the light L2 emitted from the side view direction to the light output of the light L1 emitted from the front view direction is greater than or equal to 0.4, that is, the optical film is required. When the ratio of the side view light output to the front view light output of the sheet group 600 is more than 40%, the design of the first screen structure 611 must satisfy a relational expression: this relational expression is Y≥0.441+0.01249X-3.2875*10 ^{- 4} X ² +1.95833*10 ^-6 X ³ .

Please also refer to FIG. 13 . FIG. 13 is a schematic diagram of an optical film set applied to an edge-lit backlight module according to an embodiment of the present disclosure. The optical film set 600 of this embodiment can also be applied to the side-lit backlight module 800 . Wherein, the backlight module 800 includes a light source 810 , a light guide plate 820 , a film set 830 and an optical film set 600 . Wherein, the light source 810 is disposed adjacent to the light incident surface 821 of the light guide plate 820 , and the optical film 600 is disposed in front of the light exit surface 822 of the light guide plate 820 . The film group 830 is disposed between the light guide plate 820 and the optical film 600 . In this way, the light provided by the light source 810 can enter the light guide plate 820 to form a surface light source, and then pass through the film set 830 and then enter the optical film set 600 to form a wide viewing angle light exit through the optical film set 600 .

Please also refer to FIG. 14 , which is a schematic diagram of a display device according to another embodiment of the present disclosure. The display device 900 of this embodiment includes a backlight module 700 and a display panel 910 as shown in FIG. 11 . The display panel 910 is disposed in front of the backlight module 700 . Thus, the design of the optical film set 600 in the backlight module 700 of the display device 900 also achieves the purpose of reducing the light output at the front viewing angle and increasing the light output at the side viewing angle, so details will not be repeated here. Wherein, in this embodiment, the application of the backlight module 700 shown in FIG. 11 in the display device 900 is only used for demonstration purposes and is not intended to limit the present disclosure. The backlight modules of other embodiments (for example, the backlight module 800 shown in FIG. 13 ) can be applied to display devices to produce the same effect of expanding the viewing angle.

It can be seen from the above embodiments of the present disclosure that the present disclosure is mainly through the design of the first and second pleated structures on the optical film or the optical film group, which can convert part of the straight light to other viewing directions, so as to improve The overall field of view does not need to increase the current to improve the overall brightness, and it can meet a specific viewing angle. On the other hand, the relational formula disclosed in the present disclosure can also be used to design the angle change and arrangement density of the first and second fan structures, so as to meet the viewing angle requirements of different vehicle-mounted display devices.

100: optical film 110: main body 111: first optical surface 112: second optical surface 120: first enamel structure 121: first side 122: second side 130: second enamel structure 200: backlight module 210 : light source 211: substrate 212: light emitting unit 300: backlight module 310: light source 320: light guide plate 321: light incident surface 322: light exit surface 330: membrane group 400: display device 410: display panel 500: backlight module 510: Diffusion film 520: Diffusion plate 600: Optical film group 610: First film 611: First scalloped structure 611a: First side 611b: Second side 612: First optical surface 620: Second film 621: Second Secondary structure 622: Second optical surface 700: Backlight module 710: Light source 711: Substrate 712: Light emitting unit 800: Backlight module 810: Light source 820: Light guide plate 821: Light incident surface 822: Light exit surface 830: Diaphragm Group 900: display device 910: display panel A: area B: area A+: area D1: first extending direction D2: second extending direction L1: light beam L2: light beam P ₁ : spacing S1: blank portion S2: blank portion W ₁ :Width θ:Included angle X:Included angle

For a more complete understanding of the embodiments and advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a schematic diagram of an optical film applied to a direct-lit backlight module according to an embodiment of the present disclosure; FIG. 2 is a partial schematic diagram of an optical film according to an embodiment of the present disclosure; FIG. 3 is a schematic diagram illustrating the conventionally known EU-defined vehicle display viewing angle specification; FIG. 4 is a graph showing the relationship between the included angle (X) and the arrangement density (Y) of a first fennel structure according to an embodiment of the present disclosure; FIG. 5 is a schematic diagram of the ratio of the side-view light output to the front-view light output produced by optical films with different angles and different arrangement densities using an embodiment of the present disclosure; FIG. 6A is a schematic diagram of a simulation of light output brightness at various viewing angles of a conventional optical film; FIG. 6B is a schematic diagram of a simulation of light output brightness at various viewing angles of the optical film of the first 稜鏡 structure according to an embodiment of the present disclosure; 7 is a graph showing the relationship between viewing angle and brightness simulated by using an optical film according to an embodiment of the present disclosure and an optical film according to a comparative example; FIG. 8 is a schematic diagram of an optical film applied to a direct-lit backlight module according to an embodiment of the present disclosure; FIG. 9 is a schematic diagram of an optical film applied to a side-lit backlight module according to an embodiment of the present disclosure; FIG. 10 is a device schematic diagram of a display device according to an embodiment of the present disclosure; FIG. 11 is a schematic diagram showing an optical film set applied to a direct-lit backlight module according to an embodiment of the present disclosure; FIG. 12 is a partial schematic diagram of an optical film set according to an embodiment of the present disclosure; FIG. 13 is a schematic diagram showing an optical film set applied to an edge-lit backlight module according to an embodiment of the present disclosure; and FIG. 14 is a device schematic diagram of a display device according to another embodiment of the present disclosure.

Domestic deposit information (please note in order of depositor, date, and number) none Overseas storage information (please note in order of storage country, institution, date, and number) none

100: Optical film

110: Ontology

111: the first optical surface

112: second optical surface

120: The first 稜鏡 structure

130: The second structure

200: Backlight module

210: light source

211: Substrate

212: Lighting unit

D1: first extension direction

D2: Second extension direction

L1: light

L2: light

S1: Blank part

θ: included angle

Claims (18)

An optical film, comprising: a body having an opposite first optical surface and a second optical surface; a plurality of first rib structures arranged on the first optical surface, wherein each of the first ribs The mirror structure has a first extending direction; and a plurality of second 稜鏡 structures are arranged on the second optical surface, wherein each of the second 稜鏡 structures has a second extending direction; wherein the first extending direction Different from the second extension direction; wherein when a light enters the body from one of the first optical surface and the second optical surface, and from the other of the first optical surface and the second optical surface After the light is emitted, part of the light is emitted along a front-view direction, and part of the light is emitted along a side-view direction, wherein the ratio of the light output from the side-view direction to the light output from the front-view direction Greater than 0.4, inclusive of endpoint values. The optical film according to claim 1, wherein the first pleated structures have an arrangement density Y, and each of the first pleated structures has a first side and a second side connected to each other, the There is an included angle X between the first side and the second side, wherein the arrangement density Y and the included angle X satisfy a relational expression, the relational expression is: Y

0.441+0.01249X-3.2875*10 ^-4 X ² +1.95833*10 ^-6 X ³ . The optical film as described in claim 2, wherein there is a blank portion between any two of the first adjacent structures, and the arrangement density Y is calculated according to a function, wherein the function is Y= (P ₁ -W ₁ )/P ₁ , wherein P ₁ is the distance between any two adjacent first scalloped structures, and W ₁ is the width of each of the blank portions. The optical film according to claim 1, wherein each of the first ribbed structures is a strip-shaped structure concave or convex on the first optical surface. The optical film according to claim 1, wherein the included angle between the first extending direction and the second extending direction is 90 degrees. The optical film according to claim 1, wherein the front viewing direction is parallel to a light emitting normal of the optical film, and the angle between the side viewing direction and the light emitting normal is greater than 40 degrees, inclusive. A backlight module, comprising: a light guide plate having a light incident surface and a light exit surface; a light source adjacent to the light incident surface; the optical film as described in any one of claim 1 to claim 6 , arranged in front of the light exit surface; a film group, located between the optical film and the light guide plate. A backlight module, comprising: A light source includes a substrate and a plurality of light-emitting units arranged on the substrate; and the optical film as described in any one of claim 1 to claim 6 is arranged in front of the light source. A display device, comprising: a backlight module according to claim 7 or claim 8; and a display panel arranged in front of the backlight module. An optical film set, comprising a first film and a second film, wherein: the first film has a first optical surface and a plurality of first pleated structures, wherein the first pleated structures It is arranged on the first optical surface, and each of the first braided structures has a first extension direction; the second diaphragm has a second optical surface and a plurality of second braided structures, wherein the first The optical surface and the second optical surface respectively face in opposite directions, the second 稜鏡 structures are arranged on the second optical surface, and each of the second 稜鏡 structures has a second extending direction; and wherein the The first extending direction is different from the second extending direction; wherein when a light enters from one of the first optical surface and the second optical surface, and enters from the other of the first optical surface and the second optical surface After one emits light, a part of the light is emitted along a front-view direction, and a part of the light is emitted along a side-view direction, wherein the difference between the amount of light emitted from the side-view direction and the amount of light emitted from the front-view direction is The ratio is greater than 0.4, Contains the endpoint value. The optical film set as claimed in claim 10, wherein the first pleated structures have an arrangement density Y, and each of the first pleated structures has a first side and a second side connected to each other, There is an included angle X between the first side and the second side, wherein the arrangement density Y and the included angle X satisfy a relational expression, the relational expression is: Y

0.441+0.01249X-3.2875*10 ^-4 X ² +1.95833*10 ^-6 X ³ . The optical film set as claimed in claim 11, wherein there is a blank portion between any two adjacent first scalloped structures, and the arrangement density Y is calculated according to a function, wherein the function is Y =(P ₁ -W ₁ )/P ₁ , where P ₁ is the distance between any two adjacent first scalloped structures, and W ₁ is the width of each of the blank portions. The optical film set as claimed in claim 10, wherein each of the first embossed structures is a strip structure that is concave or protruding from the first optical surface. The optical film set according to claim 10, wherein the angle between the first extending direction and the second extending direction is 90 degrees. The optical film set as described in claim 10, wherein the positive The viewing direction is parallel to a light-emitting normal of the optical film group, and the angle between the side-viewing direction and the light-emitting normal is greater than 40 degrees, inclusive. A backlight module, comprising: a light guide plate having a light incident surface and a light exit surface; a light source adjacent to the light incident surface; the optical film as described in any one of claim 10 to claim 15 A group is arranged in front of the light exit surface; a film group is located between the optical film group and the light guide plate. A backlight module, comprising: a light source, including a substrate and a plurality of light-emitting units arranged on the substrate; and an optical film group as described in any one of Claim 10 to Claim 15, arranged in front of the light source . A display device, comprising: a backlight module according to claim 16 or claim 17; and a display panel arranged in front of the backlight module.

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