Optical film and display device

Abstract

The invention provides an optical film. The optical film includes a grating layer. The grating layer is provided with a first surface, a second surface, a light shielding part and a light transmitting part. The first surface is opposite to the second surface. The light shielding parts and the light transmitting parts are located between the first surface and the second surface and are alternately arranged. The light shielding portion has the following characteristics. The third surface is coplanar with the first surface. The fourth surface and the fifth surface are connected with two opposite sides of the third surface. The included angle between the fourth surface and the third surface is A1, and the included angle between the fifth surface and the third surface is A2. The sixth surface connects the fourth surface and the second surface. The seventh surface connects the fifth surface and the second surface. The included angle between the sixth surface and the second surface is A3, and the included angle between the seventh surface and the second surface is A4. A1 and A2 are in a range of 85-90 degrees, A3 and A4 are in a range of 0-85 degrees, A2 is not equal to A4, and A1 is not equal to A3. The invention further provides a display device. The display device comprises the optical film.

Description

Technical Field

[0001] The present invention relates to an optical element, and in particular to an optical film and a display device having the optical film. Background Art

[0002] According to different types of light sources, existing display devices may include liquid crystal display devices, light emitting diode (LED) display devices, organic light emitting diode (OLED) display devices, etc. For example, the main components of a liquid crystal display device include a backlight module, a display panel, and a frame, etc., wherein the backlight module can be divided into an edge-lit backlight module and a direct-lit backlight module. Generally speaking, the cost of an edge-lit backlight module is lower, while the direct-lit backlight module is more conducive to achieving the function of local dimming. In addition, the above-mentioned types of display devices are usually also provided with an optical film to adjust the imaging effect according to different needs.

[0003] This "background technology" section is only used to help understand the content of the present invention, so the content disclosed in the "background technology" may contain some prior art that is not known to those skilled in the art. In addition, the content disclosed in the "background technology" does not represent the problem to be solved by the content or one or more embodiments of the present invention, nor does it mean that it has been known or recognized by those skilled in the art before the application of the present invention. Summary of the invention

[0004] The present invention provides an optical film, which can reduce the light output angle, thereby reducing stray light caused by excessive light output angle.

[0005] The invention provides a display device to improve image quality.

[0006] Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

[0007] To achieve one or part or all of the above purposes or other purposes, the optical film provided by the present invention includes a grating layer. The grating layer has a first surface, a second surface, a plurality of shading portions and a plurality of light-transmitting portions. The first surface is opposite to the second surface and parallel to each other. The shading portion and the light-transmitting portion are located between the first surface and the second surface, and the shading portion and the light-transmitting portion are alternately arranged along the first surface. Each shading portion has a third surface, a fourth surface, a fifth surface, a sixth surface and a seventh surface. The third surface is coplanar with the first surface. The fourth surface and the fifth surface are respectively connected to opposite sides of the third surface. The first angle between the fourth surface and the third surface is A1, and the second angle between the fifth surface and the third surface is A2. The sixth surface connects the fourth surface and the second surface. The seventh surface connects the fifth surface and the second surface. The third angle between the sixth surface and the second surface is A3, and the fourth angle between the seventh surface and the second surface is A4. Among them, 85°<A1≤90°, 85°<A2≤90°, 0°<A3<85°, 0°<A4<85°, A2≠A4, and A1≠A3.

[0008] In one embodiment of the present invention, each of the above-mentioned light shielding portions may also have a first corner and a second corner. Each fourth surface has an opposite first edge and a second edge. The first edge is adjacent to the third surface. The second edge is connected to the sixth surface, and the first corner is located between the fourth surface and the sixth surface. Each fifth surface has an opposite third edge and a fourth edge. The third edge is adjacent to the third surface. The fourth edge is connected to the seventh surface, and the second corner is located between the fifth surface and the seventh surface. In a first direction from the first surface to the second surface, each first corner and each second corner are away from the first surface and close to the second surface.

[0009] In an embodiment of the present invention, the light shielding portions are disposed on the first surface at equal distances from each other.

[0010] In one embodiment of the present invention, in the direction in which the shading portions and the light-transmitting portions are alternately arranged along the first surface, the distance between the third edge of the fifth surface of one shading portion connected to the third surface and the third edge of the fifth surface of another adjacent shading portion connected to the third surface may be between 30um and 200um.

[0011] In an embodiment of the present invention, in a first direction pointing from the first surface to the second surface, the distance between the first surface and the second surface may be between 30 um and 200 um.

[0012] In an embodiment of the present invention, a side of the sixth surface of each light shielding portion connected to the second surface and a side of the seventh surface connected to the second surface are, for example, adjacent to each other or not adjacent to each other.

[0013] In an embodiment of the present invention, a cross section of each of the light shielding portions extending from the first surface to the second surface may have an asymmetric shape.

[0014] In an embodiment of the present invention, any two of the above-mentioned light shielding portions may have different shapes.

[0015] In an embodiment of the present invention, the optical film further includes a first light-transmitting plate, which is disposed on a side of the second surface away from the light-shielding portion.

[0016] In one embodiment of the present invention, the first light-transmitting plate may have a first light-transmitting surface and a second light-transmitting surface. The first light-transmitting surface and the second light-transmitting surface are opposite to each other, and the first light-transmitting surface is disposed on a side of the second surface away from the light-shielding portion. The second light-transmitting surface has a plurality of first microstructures.

[0017] In one embodiment of the present invention, the optical film may further include a plurality of first light scattering particles, and the first light scattering particles are disposed in the first light-transmitting plate.

[0018] In an embodiment of the present invention, the optical film may further include a light-transmitting layer, and the light-transmitting layer is disposed between the second surface and the first light-transmitting plate.

[0019] In an embodiment of the present invention, the optical film further includes a second light-transmitting plate, and the second light-transmitting plate is disposed on the first surface.

[0020] In one embodiment of the present invention, the second light-transmitting plate may have a third light-transmitting surface and a fourth light-transmitting surface. The third light-transmitting surface and the fourth light-transmitting surface are opposite to each other, and the third light-transmitting surface is disposed on the first surface. The fourth light-transmitting surface has a plurality of second microstructures.

[0021] In one embodiment of the present invention, the optical film may further include a plurality of second light scattering particles, and the plurality of second light scattering particles are disposed in the second light-transmitting plate.

[0022] In one embodiment of the present invention, the second light-transmitting plate includes, for example, a brightness enhancement film.

[0023] In an embodiment of the present invention, the absolute value of the refractive index difference between the light shielding portion and the light transmitting portion is, for example, greater than 0.005.

[0024] Effect: Good total reflection effect, increasing light brightness

[0025] To achieve one or part or all of the above purposes or other purposes, the display device provided by the present invention includes a light guide plate, a light source, a display panel and an optical film. The light guide plate has a light incident surface and a light emitting surface, and the light emitting surface is connected to the light incident surface. The light source is arranged opposite to the light incident surface. The display panel is arranged opposite to the light emitting surface. The optical film is arranged between the light emitting surface and the display panel.

[0026] In an embodiment of the present invention, the first surface or the second surface may face the display panel.

[0027] The optical film of the present invention adopts a grid layer, wherein the grid layer has a plurality of shading parts and a plurality of light-transmitting parts. In detail, the opposite sides of the shading part respectively have two surfaces (i.e., the fourth surface, the fifth surface, the sixth surface and the seventh surface) that are connected to each other and inclined relative to each other, and the light-transmitting part is located between two adjacent shading parts. In this way, the light beam can be incident on the fourth surface or the fifth surface when passing through the light-transmitting part, and then be reflected by the fourth surface or the fifth surface and emerge from the grid layer. Based on the above, the angle of the light beam emerging from the grid layer can be smaller than the angle of the light beam incident on the grid layer. Therefore, the optical film of the present invention can reduce stray light formed by excessive light output angle. Since the display device of the present invention adopts the above-mentioned optical film, it can improve the stray light appearing at a large viewing angle, thereby improving the image quality.

[0028] In order to make the above and other objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 FIG. 4 is a schematic top view of an optical film according to an embodiment of the present invention.

[0030] Figure 2 yes Figure 1 A schematic partial cross-sectional view of an optical film along the AA section line.

[0031] Figure 3 FIG. 4 is a schematic top view of an optical film according to another embodiment of the present invention.

[0032] Figure 4 FIG. 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention.

[0033] Figure 5 FIG. 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention.

[0034] Figure 6 FIG. 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention.

[0035] Figure 7 FIG. 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention.

[0036] Figure 8 FIG. 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention.

[0037] Fig. 9 FIG. 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention.

[0038] Fig.10 FIG. 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention.

[0039] Fig.11 FIG. 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention.

[0040] Fig.12 FIG. 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention.

[0041] Fig.13 FIG. 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention.

[0042] Fig.14 FIG. 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention.

[0043] Fig.15 FIG. 1 is a side view schematic diagram of a display device according to an embodiment of the present invention.

[0044] Fig.16 yes Fig.15 A schematic cross-sectional view of an optical film and a display panel.

[0045] Fig.17 FIG. 4 is a cross-sectional schematic diagram of an optical film and a display panel of a display device according to another embodiment of the present invention.

[0046] Fig.18 It is a schematic diagram of the light output field pattern of a conventional display device and the light output field pattern of a display device according to an embodiment of the present invention.

[0047] Fig.19 Schematic diagram of the distribution of vertical viewing angle brightness of a display device according to an embodiment of the present invention and a light output field pattern of a conventional display device.

[0048] Reference numerals list

[0049] 10, 10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h, 10i, 10j, 10k, 10l: Optical film

[0050] 20, 20a: Display device

[0051] 21: Light guide plate

[0052] 22: Light Source

[0053] 23: Display Panel

[0054] 100, 100a, 100j, 100k, 100l: grid layer

[0055] 101, 101a: first side

[0056] 102, 102a: second side

[0057] 103a: Third side

[0058] 104a: Fourth side

[0059] 110: first surface

[0060] 120: Second surface

[0061] 130, 130a, 130j, 130k: light shielding part

[0062] 131: Third surface

[0063] 132: Fourth Surface

[0064] 133: Fifth Surface

[0065] 134: Sixth Surface

[0066] 135: Seventh Surface

[0067] 136: Eighth Surface

[0068] 140, 140a, 140j, 140k, 140l: light-transmitting portion

[0069] 200, 200c, 200d: first light-transmitting plate

[0070] 210: first light-transmitting surface

[0071] 211: Light-entering surface

[0072] 212: Bright side

[0073] 213: Surface

[0074] 220c, 220d: second light-transmitting surface

[0075] 221c, 221d: first microstructure

[0076] 300: first light scattering particle

[0077] 400: light-transmitting layer

[0078] 500: Second light-transmitting plate

[0079] 510: third light-transmitting surface

[0080] 520: Fourth light-transmitting surface

[0081] 521: Second microstructure

[0082] 600: Second light scattering particles

[0083] 1340, 1350: Side

[0084] A1, A2, A3, A4: Angle

[0085] B1, B2: beam

[0086] C1: First corner

[0087] C2: Second corner

[0088] CA, CA': cross section

[0089] D: Direction

[0090] D1: First direction

[0091] E1: First Edge

[0092] E2: Second Edge

[0093] E3: The Third Edge

[0094] E4: The Fourth Edge

[0095] EA, IA: Zhang Jiao

[0096] F1: Diffuser

[0097] F2: Brightening film

[0098] H, P: distance

[0099] IA1: First angle

[0100] IA2: Second angle

[0101] IA3: The third angle

[0102] IA4: Fourth Angle

[0103] L1, L2, L3, L4: Length

[0104] S: Imaginary surface

[0105] T: Prism structure

[0106] Z1, Z2: area. DETAILED DESCRIPTION

[0107] The above and other technical contents, features and effects of the present invention will be clearly presented in the detailed description of a preferred embodiment made with reference to the drawings below. The directional terms (e.g., up, down, left, right, front or back, etc.) mentioned in the following embodiments are only the directions of the reference drawings. Therefore, the directional terms used are used for explanation and are not used to limit the present invention.

[0108] Figure 1FIG. 4 is a schematic top view of an optical film according to an embodiment of the present invention. Figure 2 yes Figure 1 A partial cross-sectional view of the optical film along the AA section line. Please refer to Figure 1 and Figure 2 The optical film 10 includes a grid layer 100. The grid layer 100 has a first surface 110 and a second surface 120 (shown in FIG. Figure 2 ), a plurality of light shielding portions 130 and a plurality of light transmitting portions 140. The first surface 110 is opposite to the second surface 120 and is parallel to each other. The light shielding portions 130 and the light transmitting portions 140 are located between the first surface 110 and the second surface 120, and the light shielding portions 130 and the light transmitting portions 140 are alternately arranged along the first surface 110. Each light shielding portion 130 has a third surface 131, a fourth surface 132, a fifth surface 133, a sixth surface 134 and a seventh surface 135. The third surface 131 is coplanar with the first surface 110. The fourth surface 132 and the fifth surface 133 are connected to opposite sides of the third surface 131, respectively. The first angle IA1 between the fourth surface 132 and the third surface 131 is A1, and the second angle IA2 between the fifth surface 133 and the third surface 131 is A2. The sixth surface 134 connects the fourth surface 132 and the second surface 120. The seventh surface 135 connects the fifth surface 133 and the second surface 120. The third angle IA3 between the sixth surface 134 and the second surface 120 is A3, and the fourth angle IA4 between the seventh surface 135 and the second surface 120 is A4. Among them, 85°<A1≤90°, 85°<A2≤90°, 0°<A3<85°, 0°<A4<85°, A2≠A4, and A1≠A3. It should be further explained that, by Figure 1 As can be seen from the top view of , each light shielding portion 130 may extend from the first side 101 of the grid layer 100 to the second side 102 of the grid layer 100 opposite to the first side 101 , but the present invention is not limited thereto.

[0109] The light-transmitting portion 140 can provide light beams B1 and B2 (shown in FIG. Figure 2 ) through. In this embodiment, the material of the light-transmitting portion 140 may include ultraviolet curing glue. Incidentally, the light-transmitting portion 140 is attached to and covers the outer surface of the light-shielding portion 130. For example, in this embodiment, the light-transmitting portion 140 is attached to and covers the fourth surface 132, the fifth surface 133, the sixth surface 134 and the seventh surface 135 of the light-shielding portion 130.

[0110] Please continue to refer to Figure 2, the light shielding portion 130 can reflect the light beams B1 and B2 via the fourth surface 132 and the fifth surface 133. In detail, the fourth surface 132 and the fifth surface 133 can be inclined toward each other relative to the first surface 110, thereby forming a first angle IA1 and a second angle IA2. Therefore, after being reflected by the fourth surface 132 and the fifth surface 133, the light beams B1 and B2 can be emitted from the grid layer 100 at an angle smaller than the angle at which they are incident on the grid layer 100, thereby reducing the angle at which the light beams B1 and B2 are emitted from the grid layer 100. For example, the light beams B1 and B2 are incident on the grid layer 100 at an angle IA, and are emitted from the grid layer 100 at an angle EA, wherein the angle EA is smaller than the angle IA. Furthermore, the light shielding portion 130 and the light transmitting portion 140 are alternately arranged with each other, for example, along a direction D, so that the light shielding portion 130 can reduce the angle of the light beams B1 and B2 in the direction D (also shown in FIG. 1 ). Figure 1 ) from the grid layer 100. In one embodiment, the fourth surface 132 and the fifth surface 133 may be substantially perpendicular to the first surface 110; in other words, the angle of the first angle IA1 and the angle of the second angle IA2 may be approximately 90°, which can further reduce the angle EA of the light beams B1 and B2 emitted from the grid layer 100. Incidentally, the material of the shading portion 130 may include ultraviolet curing glue and carbon black. However, in one embodiment, the material of the shading portion 130 may include a light reflecting material, which can also increase the light utilization rate. However, the present invention does not impose many restrictions on the material of the shading portion 130.

[0111] In the present embodiment, each light shielding portion 130 may further have a first corner C1 and a second corner C2. Each fourth surface 132 has opposite first edges E1 and second edges E2. The first edge E1 is adjacent to the third surface 131. The second edge E2 is connected to the sixth surface 134, and the first corner C1 is located between the fourth surface 132 and the sixth surface 134. Each fifth surface 133 has opposite third edges E3 and fourth edges E4. The third edge E3 is adjacent to the third surface 131. The fourth edge E4 is connected to the seventh surface 135, and the second corner C2 is located between the fifth surface 133 and the seventh surface 135. In the first direction D1 directed from the first surface 110 to the second surface 120, each first corner C1 and each second corner C2 are away from the first surface 110 and close to the second surface 120, so as to further reduce the opening angle EA of the light beams B1 and B2 emitted from the grid layer 100. In other words, the length L1 of the third surface 131 may be greater than the length L2 of the sixth surface 134, and the length L3 of the fifth surface 133 may be greater than the length L4 of the seventh surface 135, so that the first corner C1 and the second corner C2 are away from the first surface 110 and close to the second surface 120. In this embodiment, the first corner C1 may be adjacent to the second edge E2 and the sixth surface 134, and the second corner C2 may be adjacent to the fourth edge E4 and the seventh surface 135. Incidentally, the number of the first corner C1 and the second corner C2 is respectively illustrated as one, and the shape of the light shielding portion 130 is illustrated as a pentagon, but the present invention is not limited thereto. For example, in one embodiment, the number of the first corner C1 and the second corner C2 may be greater than one, and the shape of the light shielding portion 130 may not be limited to a pentagon.

[0112] In the present embodiment, the side 1340 of the sixth surface 134 of each light shielding portion 130 connected to the second surface 120 and the side 1350 of the seventh surface 135 connected to the second surface 120 are, for example, adjacent to each other. For example, the side 1340 of the sixth surface 134 and the side 1350 of the seventh surface 135 are adjacent to each other to form a sharp angle. However, in one embodiment, the side 1340 of the sixth surface 134 and the side 1350 of the seventh surface 135 are adjacent to each other to form a rounded corner, and the present invention does not impose any restrictions on the shape of the connection between the sixth surface 134 and the seventh surface 135.

[0113] In the present embodiment, in the direction D in which the light shielding portions 130 and the light-transmitting portions 140 are alternately arranged along the first surface 110, the distance P between the third edge E3 of the fifth surface 133 of one light shielding portion 130 and the third edge E3 of the fifth surface 133 of another adjacent light shielding portion 130 may be between 30um and 200um. Specifically, the third edge E3 is, for example, connected to the third surface 131 and is coplanar with the first surface 110 and the third surface 131. In other words, the distance P may be the spacing between the third edges E3 of two adjacent light shielding portions 130 in the direction D. Incidentally, the light shielding portions 130 of the present embodiment may be arranged equidistantly from each other, that is, the distance P between any two adjacent light shielding portions 130 may be equal to each other, but the present invention is not limited thereto. On the other hand, in the present embodiment, in the first direction D1, the distance H between the first surface 110 and the second surface 120 may be between 30um and 200um. Similarly, the distance H of each light shielding portion 130 may be substantially equal to each other. However, in other embodiments, the distance H between each light shielding portion 130 may be slightly different, and the present invention is not limited thereto.

[0114] Compared with the prior art, the optical film 10 of the present embodiment adopts a grid layer 100, wherein the grid layer 100 has a plurality of light shielding portions 130 and a plurality of light-transmitting portions 140. In detail, the opposite sides of the light shielding portion 130 respectively have two surfaces (i.e., the fourth surface 132, the fifth surface 133, the sixth surface 134, and the seventh surface 135) connected to each other and inclined relative to each other, and the light-transmitting portion 140 is located between two adjacent light shielding portions 130. When passing through the light-transmitting portion 140, the light beams B1 and B2 can be incident on the fourth surface 132 or the fifth surface 133, and then reflected by the fourth surface 132 or the fifth surface 133 and emitted from the grid layer 100. Based on the above, the opening angle EA of the light beams B1 and B2 emitted from the grid layer 100 can be smaller than the opening angle IA incident on the grid layer 100. Therefore, the optical film 10 of the present embodiment can reduce the stray light formed by the excessively large light angle.

[0115] Incidentally, in one embodiment, the absolute value of the difference in refractive index between the light shielding portion 130 and the light transmitting portion 140 is, for example, greater than 0.005, so as to improve the light reflectivity of the grid layer 100. In other words, the refractive index of the light shielding portion 130 may be smaller than the refractive index of the light transmitting portion 140, so that the light beams B1 and B2 are more likely to be totally reflected in the light transmitting portion 140, thereby improving the brightness of the light beams B1 and B2 emitted from the grid layer 100. However, the refractive index of the light shielding portion 130 may also be greater than the refractive index of the light transmitting portion 140, and the present invention is not limited thereto.

[0116] Figure 3 FIG. 1 is a top view of an optical film according to another embodiment of the present invention. It is understood that in other embodiments, the extending direction of the light shielding portion 130 may not be limited to Figure 1 and Figure 2 For example, refer to Figure 3 The optical film 10a of the embodiment, wherein a portion of the light shielding portion 130a extends from the first side 101a of the grid layer 100a to the second side 102a of the grid layer 100a opposite to the first side 101a, wherein another portion of the light shielding portion 130a extends from the third side 103a of the grid layer 100a to the fourth side 104a of the grid layer 100a opposite to the third side 103a, and the first side 101a and the third side 103a are perpendicular to each other (for example, substantially perpendicular to each other). In other words, the light shielding portions 130a of the embodiment can be arranged in a checkerboard shape on the grid layer 100a. Due to the structure and advantages of the light shielding portion 130a and the light-transmitting portion 140a and Figure 1 The embodiments of the present invention are substantially the same, so the related description is omitted here.

[0117] Figure 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention. The structure and advantages of the optical film 10b of this embodiment are similar to those of Figure 1 The following is an example of the difference. Figure 4 , the optical film 10b, for example, further includes a first light-transmitting plate 200, which is disposed on a side of the second surface 120 away from the light-shielding portion 130. For example, in the present embodiment, the first light-transmitting plate 200 may be attached to the second surface 120 of the grid layer 100. In this way, the light-shielding portion 130 and the light-transmitting portion 140 can be fixed on the first light-transmitting plate 200 to prevent the light-shielding portion 130 and the light-transmitting portion 140 from being separated from each other, thereby improving the structural strength of the optical film 10b. In the present embodiment, the material of the first light-transmitting plate 200 may include polyethylene terephthalate (PET), but other embodiments are not limited thereto.

[0118] Figure 5 FIG. 4 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention. Figure 6 FIG. 1 is a partial cross-sectional view of an optical film according to another embodiment of the present invention. The structure and advantages of the optical films 10c and 10d are similar to those of FIG. Figure 4 The following is an example of the differences. Please refer to Figure 5, the first light-transmitting plate 200c may have a first light-transmitting surface 210 and a second light-transmitting surface 220c. The first light-transmitting surface 210 and the second light-transmitting surface 220c are opposite to each other, and the first light-transmitting surface 210 is disposed on a side of the second surface 120 that is away from the light-shielding portion 130 (for example, the second surface 120). The second light-transmitting surface 220c may have a plurality of first microstructures 221c to enhance the optical quality of the optical film 10c. For example, in the present embodiment, the first microstructure 221c may be formed by roughening the second light-transmitting surface 220c to enhance the uniformity of light emission of the optical film 10c. However, in one embodiment, please refer to Figure 6 , the first microstructure 221d may include a prism structure T. In this way, the angle of the light beam incident from the first light-transmitting plate 200d to the grid layer 100 can be further reduced, thereby further reducing the angle of the light beam emitted from the grid layer 100. It can be understood that the present invention does not impose any restrictions on the specific shapes of the first microstructures 221c and 221d.

[0119] Figure 7 is a partial cross-sectional schematic diagram of an optical film of another embodiment of the present invention. The structure and advantages of the optical film 10e of this embodiment are similar to those of Figure 4 The following is an example of the differences. Please refer to Figure 7 The optical film 10e may further include a plurality of first light scattering particles 300, which are disposed in the first light-transmitting plate 200. In this way, the optical quality of the optical film 10e can be further improved. In this embodiment, the material of the first light scattering particles 300 may include a light-reflecting material, and may be evenly distributed in the first light-transmitting plate 200.

[0120] Figure 8 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention. The structure and advantages of the optical film 10f of this embodiment are similar to those of Figure 4 The following is an example of the difference. Figure 8 The optical film 10f may further include a light-transmitting layer 400, and the light-transmitting layer 400 is disposed between the second surface 120 and the first light-transmitting plate 200. In other words, the light-transmitting layer 400 may be sandwiched between the second surface 120 and the first light-transmitting plate 200. In this embodiment, the material of the light-transmitting layer 400 may be the same as the material of the light-transmitting portion 140, but the present invention does not impose any further restrictions on this.

[0121] Fig. 9 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention. The structure and advantages of the optical film 10g of this embodiment are similar to those of Figure 4 The following is an example of the difference. Fig. 9, the optical film 10g, for example, also includes a second light-transmitting plate 500, and the second light-transmitting plate 500 is disposed on the first surface 110 of the grid layer 100. In this way, the first light-transmitting plate 200 and the second light-transmitting plate 500 can further fix the light-shielding portion 130 and the light-transmitting portion 140, thereby further improving the structural strength of the optical film 10g. In one embodiment, the second light-transmitting plate, for example, includes a dual brightness enhancement film (DBEF), which can also improve the light output brightness of the optical film 10g. By the way, in another embodiment, the second light-transmitting plate 500 may include a prism sheet. Other features of the second light-transmitting plate 500 are the same as those of the first light-transmitting plate 200, so the relevant description is omitted here.

[0122] Fig.10 is a partial cross-sectional schematic diagram of an optical film of another embodiment of the present invention. The structure and advantages of the optical film 10h of this embodiment are similar to those of Fig. 9 The following is an example of the difference. Fig.10 , the second light-transmitting plate 500 may have a third light-transmitting surface 510 and a fourth light-transmitting surface 520. The third light-transmitting surface 510 and the fourth light-transmitting surface 520 are opposite to each other, and the third light-transmitting surface 510 is disposed on the first surface 110. The fourth light-transmitting surface 520, for example, has a plurality of second microstructures 521 to improve the optical quality of the optical film 10h. The characteristics of the second microstructures 521 are similar to those of the optical film 10h. Figure 5 The first microstructure 221c or Figure 6 The features of the first microstructure 221d are the same, so the related description is omitted here.

[0123] Fig.11 is a partial cross-sectional schematic diagram of an optical film of another embodiment of the present invention. The structure and advantages of the optical film 10i of this embodiment are similar to those of Fig. 9 The following is an example of the difference. Fig.11 The optical film 10i may further include a plurality of second light scattering particles 600, which are disposed in the second light-transmitting plate 500. In this way, the optical quality of the optical film 10i can be further improved. Figure 7 The features of the first light scattering particles 300 are the same, so the related description is omitted here.

[0124] Fig.12 is a partial cross-sectional schematic diagram of an optical film of another embodiment of the present invention. The structure and advantages of the optical film 10j of this embodiment are similar to those of Figure 1 The following is an example of the difference. Fig.12In the grid layer 100j, a side 1340 of the sixth surface 134 of each light shielding portion 130j connected to the second surface 120 and a side 1350 of the seventh surface 135 connected to the second surface 120 are, for example, not adjacent to each other. In other words, the side 1340 of the sixth surface 134 and the side 1350 of the seventh surface 135 may be separated from each other. For example, the light shielding portion 130j may also have an eighth surface 136, and the eighth surface 136 may be connected between the side 1340 of the sixth surface 134 and the side 1350 of the seventh surface 135. In addition, the eighth surface 136 is, for example, opposite to the first surface 110 and the third surface 131, and may be coplanar with the second surface 120. However, the present invention does not impose many restrictions on the specific structure in which the sixth surface 134 and the seventh surface 135 are separated from each other. Incidentally, the shape of the light-transmitting portion 140j can be changed according to the shape of the light-shielding portion 130j, so that the light-transmitting portion 140j can fill the space between two adjacent light-shielding portions 130j and adhere to the outer surface of the light-shielding portion 130j. The present invention does not impose any restrictions on the shape of the light-transmitting portion 140j.

[0125] Fig.13 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention. The structure and advantages of the optical film 10k of this embodiment are similar to those of Figure 1 The following is an example of the difference. Fig.13 In the grid layer 100k, the cross section CA of each light shielding portion 130k extending from the first surface 110 to the second surface 120 may have an asymmetric shape. It should be noted that the opposite sides of the cross section CA are connected to the first surface 110 and the second surface 120 respectively. In detail, in the present embodiment, each light shielding portion 130K may also have an imaginary surface S, the imaginary surface S is perpendicular to the first surface 110 and the second surface 120, and the imaginary surface S extends from the center of the third surface 131 to the second surface 120, and the direction faced by the imaginary surface S is perpendicular to the extension direction of the light shielding portion 130K. The light shielding portion 130k may be asymmetric to the imaginary surface S. Furthermore, the fourth surface 132 and the fifth surface 133 may be asymmetric to the imaginary surface S, and the sixth surface 134 and the seventh surface 135 may be asymmetric to the imaginary surface S. However, the present invention does not impose many restrictions on the shape of the light shielding portion 130k. Likewise, in this embodiment, the shape of the light-transmitting portion 140 k can be changed according to the shape of the light-shielding portion 130 k , and the present invention does not impose any restrictions on the shape of the light-transmitting portion 140 k .

[0126] Fig.14 is a partial cross-sectional schematic diagram of an optical film according to another embodiment of the present invention. The structure and advantages of the optical film 101 of this embodiment are similar to those of Figure 1 In this embodiment, any two of the shading portions may have different shapes. For example, please refer to Fig.14, the grid layer 1001 may include light shielding portions 130 and 130k, and the light shielding portions 130 and 130k have different shapes. For example, the cross section CA' of the light shielding portion 130 extending from the first surface 110 to the second surface 120 may have a symmetrical shape, and the cross section CA of the light shielding portion 130k extending from the first surface 110 to the second surface 120 may have an asymmetrical shape. Since other features of the light shielding portions 130 and 130k have been described above, the relevant description is omitted here. It can be understood that in other embodiments, the grid layer 1001 may include the light shielding portion 130, the light shielding portion 130j, the light shielding portion 130k or a combination thereof, and the shape of the light shielding portion of this embodiment is not limited to the above examples. Similarly, the shape of the light-transmitting portion 140l of this embodiment may be changed according to the shape of the light shielding portion 130, the light shielding portion 130j or the light shielding portion 130k, and the present invention does not impose more restrictions on the shape of the light-transmitting portion 140l.

[0127] Fig.15 is a side view schematic diagram of a display device according to an embodiment of the present invention. Fig.15 The display device 20 includes a light guide plate 21, a light source 22, a display panel 23, and an optical film 10. The light guide plate 21 has a light incident surface 211 and a light emitting surface 212, and the light emitting surface 212 is connected to the light incident surface 211. The light source 22 is disposed opposite to the light incident surface 211. The display panel 23 is disposed opposite to the light emitting surface 212. The optical film 10 is disposed between the light emitting surface 212 and the display panel 23.

[0128] The light guide plate 21, for example, has a light incident surface 211 and a light emitting surface 212, wherein the light incident surface 211 is connected to the light emitting surface 212 and is opposite to the light source 22. The material of the light guide plate 21 may include plastic, glass or other materials suitable for light to penetrate. For example, in the present embodiment, the material of the light guide plate 21 may include polymethyl methacrylate (PMMA); however, in other embodiments, the material of the light guide plate 21 may include cycloolefin polymer (COP) or polycarbonate (PC). In addition, the light guide plate 21 of the present embodiment may be made by hot pressing or injection molding, but the present invention does not impose any restrictions on this. In one embodiment, the surface 213 of the light guide plate 21 opposite to the light emitting surface 212 may have a light astigmatism structure, and the light astigmatism structure may reflect more light beams to the light emitting surface 212, thereby improving the light utilization rate.

[0129] The light source 22 of this embodiment may include a light-emitting diode (LED), wherein the number of the light-emitting diodes may be multiple. Further, the light emission wavelength of the light-emitting diode may include blue light or white light, but the present invention does not limit this.

[0130] In this embodiment, the optical film 10 may be disposed on a side of the light guide plate 21 having the light incident surface 211. In addition, the optical film 10 may be the one closest to the display panel 23 among all the optical films of the display device 20. For example, the display device 20 may further include two diffusers F1 and a brightness enhancement film (BEF) F2, wherein the diffusers F1 and the brightness enhancement film F2 are disposed between the light guide plate 21 and the optical film 10, and the optical film 10 is closer to the display panel 23 than the diffusers F1 and the brightness enhancement film F2. It is understood that in one embodiment, the number of the diffusers F1 and the brightness enhancement film F2 is not limited to Fig.15 In another embodiment, the display device 20 can be provided with other types of optical films between the light guide plate 21 and the optical film 10 according to actual needs, and the present invention does not limit these details.

[0131] Fig.16 yes Fig.15 A schematic cross-sectional view of an optical film and a display panel. Fig.17 is a cross-sectional schematic diagram of an optical film and a display panel of a display device according to another embodiment of the present invention. Fig.15 and Fig.16 , the first surface 110 of the grid layer 100 faces the display panel 23; in other words, the light beam can enter the grid layer 100 from the second surface 120, and leave the grid layer 100 from the first surface 110 to enter the display panel 23. However, in one embodiment, for example Fig.17 In the display device 20a shown in FIG. 1 , the second surface 120 of the grid layer 100 may face the display panel 23 to provide a display panel different from the display panel 23. Fig.16 The display device 20 has the effect of reducing the light output angle. For example, the light beam is Fig.16 The opening angle of the light emitted from the first surface 110 of the grid layer 100 can be relatively large. Fig.17 The second surface 120 of the grid layer 100 emits light with a small opening angle. Fig.16 or Fig.17 The optical film 10 is arranged in the manner shown, but the present invention is not limited thereto.

[0132] Please refer to Fig.15 The display panel 23 of this embodiment can receive the light beam emitted from the optical film 10. The display panel 23 includes, for example, a liquid crystal display panel, but other embodiments are not limited thereto.

[0133] Compared with the prior art, the display device 20 of the present embodiment adopts the above-mentioned optical film 10, so it can improve the stray light appearing at a large viewing angle, thereby improving the image quality. In addition, in other embodiments, the optical film 10 can be replaced by optical films 10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h, 10i, 10j, 10k or 10l.

[0134] Fig.18 It is a schematic diagram of the light output field pattern of a conventional display device and the light output field pattern of a display device according to an embodiment of the present invention. Fig.19 1 is a schematic diagram of the distribution of the light output field of an existing display device and the vertical viewing angle brightness of a display device according to an embodiment of the present invention. It should be noted that: Fig.18 The density of dots is used to indicate the intensity of light. The higher the density of dots in the mesh pattern, the stronger the light intensity in that area. Conversely, the lower the density of dots in the mesh pattern, the weaker the light intensity in that area. Fig.18 , (a) is a schematic diagram of the light output field of an existing display device, and (b) is a schematic diagram of the light output field of a display device according to an embodiment of the present invention. The distribution density of the dots representing the light output brightness in the regions Z1 and Z2 of the display device of the present invention shown in (b) is significantly lower than that of the existing display device shown in (a). Therefore, the display device of the present invention can effectively reduce the stray light emitted at a large viewing angle. For further information, please refer to Fig.19 Compared with the existing display device, the display device of one embodiment of the present invention can reduce the light intensity at a larger vertical viewing angle, wherein the larger vertical viewing angle is, for example, between 50° and 90° and -50° and -90°. On the other hand, the display device of the present invention can further concentrate the light within a smaller vertical viewing angle, wherein the smaller vertical viewing angle is, for example, between -40° and 40°, but the present invention is not limited thereto. Please refer to Table 1 for the half-width at half-maximum of the display device of one embodiment of the present invention and the existing display device in the vertical viewing angle and the horizontal viewing angle.

[0135] Table 1

[0136] Existing display device Display device of the present invention Full width at half maximum at horizontal viewing angle 101.3 98.4 Full width at half maximum at vertical viewing angle 69.9 41.7

[0137] Incidentally, since the display device 20 of this embodiment has a small vertical viewing angle, in one embodiment, the display device 20 can be used as an anti-peeping display device. In addition, in another embodiment, the display device 20 can be a vehicle display device. However, the present invention does not impose many restrictions on the specific use of the display device 20.

[0138] In summary, the optical film of the present invention adopts a grid layer, wherein the grid layer has a plurality of shading parts and a plurality of light-transmitting parts. In detail, the opposite sides of the shading part respectively have two surfaces (i.e., the fourth surface, the fifth surface, the sixth surface and the seventh surface) that are connected to each other and inclined relative to each other, and the light-transmitting part is located between two adjacent shading parts. In this way, the light beam can be incident on the fourth surface or the fifth surface when passing through the light-transmitting part, and then be reflected by the fourth surface or the fifth surface and emerge from the grid layer. Based on the above, the angle of the light beam emerging from the grid layer can be smaller than the angle of the light beam incident on the grid layer. Therefore, the optical film of the present invention can reduce stray light formed by excessive light output angle. Since the display device of the present invention adopts the above-mentioned optical film, it can improve the stray light appearing at a large viewing angle, thereby improving the image quality.

[0139] However, the above is only a preferred embodiment of the present invention, and it cannot be used to limit the scope of the implementation of the present invention. That is, all simple equivalent changes and modifications made in accordance with the claims of the present invention and the specification of the present invention are still within the scope of the patent of the present invention. In addition, any embodiment or claim of the present invention is not required to achieve all the purposes, advantages or features disclosed in the present invention. In addition, the abstract of the specification and the name of the invention are only used to assist in the retrieval of patent documents, and are not used to limit the scope of rights of the present invention. In addition, the terms "first", "second", etc. mentioned in this specification or claims are only used to name the name of the element or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements.

Claims

1. An optical film, characterized in that: The optical film comprises a grid layer, wherein the grid layer has a first surface, a second surface, a plurality of light shielding portions and a plurality of light transmitting portions. The first surface is opposite to the second surface and parallel to each other, the plurality of light shielding portions and the plurality of light transmitting portions are located between the first surface and the second surface, and the plurality of light shielding portions and the plurality of light transmitting portions are alternately arranged along the first surface; Each of the plurality of light shielding portions comprises a third surface, a fourth surface, a fifth surface, a sixth surface and a seventh surface, the third surface is coplanar with the first surface, the fourth surface and the fifth surface are respectively connected to opposite sides of the third surface, a first angle between the fourth surface and the third surface is A1, and a second angle between the fifth surface and the third surface is A2; The sixth surface connects the fourth surface and the second surface, the seventh surface connects the fifth surface and the second surface, a third angle between the sixth surface and the second surface is A3, and a fourth angle between the seventh surface and the second surface is A4; Among them, 85°<A1≤90°, 85°<A2≤90°, 0°<A3<85°, 0°<A4<85°, A2≠A4, and A1≠A3.

2. The optical film according to claim 1, characterized in that: The plurality of light shielding portions also have a first corner and a second corner: The fourth surface has a first edge and a second edge opposite to each other, the first edge is adjacent to the third surface, the second edge is connected to the sixth surface, and the first corner is located between the fourth surface and the sixth surface; The plurality of fifth surfaces have opposite third edges and fourth edges, the third edge is adjacent to the third surface, the fourth edge is connected to the seventh surface, and the second corner is located between the fifth surface and the seventh surface; In a first direction directed from the first surface to the second surface, each of the plurality of first corners and each of the plurality of second corners are away from the first surface and close to the second surface.

3. The optical film according to claim 1, characterized in that: The plurality of light shielding portions are arranged on the first surface at equal distances from each other.

4. The optical film according to claim 3, characterized in that: In the direction in which the multiple light-shielding portions and the multiple light-transmitting portions are alternately arranged along the first surface, a distance between a third edge of the fifth surface of one of the multiple light-shielding portions connected to the third surface and a third edge of the fifth surface of another light-shielding portion adjacent to the one light-shielding portion connected to the third surface is between 30um and 200um.

5. The optical film according to claim 1, characterized in that: In a first direction pointing from the first surface to the second surface, a distance between the first surface and the second surface is between 30 um and 200 um.

6. The optical film according to claim 1, characterized in that: A side of the sixth surface connected to the second surface and a side of the seventh surface connected to the second surface of each of the plurality of light shielding portions are adjacent to or not adjacent to each other.

7. The optical film according to claim 1, characterized in that: A cross section of the plurality of light shielding portions extending from the first surface to the second surface has an asymmetric shape.

8. The optical film according to claim 1, characterized in that: Any two of the plurality of light shielding portions have different shapes.

9. The optical film according to claim 1, characterized in that: The optical film further includes a first light-transmitting plate, which is disposed on a side of the second surface away from the plurality of light-shielding portions.

10. The optical film according to claim 9, characterized in that: The first light-transmitting plate has a first light-transmitting surface and a second light-transmitting surface, the first light-transmitting surface and the second light-transmitting surface are opposite to each other, and the first light-transmitting surface is arranged on the side of the second surface away from the multiple light-shielding parts, and the second light-transmitting surface has multiple first microstructures.

11. The optical film according to claim 9, characterized in that: The optical film further includes a plurality of first light scattering particles, and the plurality of first light scattering particles are disposed in the first light-transmitting plate.

12. The optical film according to claim 9, characterized in that: The optical film further includes a light-transmitting layer, and the light-transmitting layer is disposed between the second surface and the first light-transmitting plate.

13. The optical film according to claim 9, characterized in that: The optical film further includes a second light-transmitting plate, and the second light-transmitting plate is disposed on the first surface.

14. The optical film according to claim 13, characterized in that: The second light-transmitting plate has a third light-transmitting surface and a fourth light-transmitting surface, the third light-transmitting surface and the fourth light-transmitting surface are opposite to each other, and the third light-transmitting surface is disposed on the first surface, and the fourth light-transmitting surface has a plurality of second microstructures.

15. The optical film according to claim 13, characterized in that: The optical film further includes a plurality of second light scattering particles, and the plurality of second light scattering particles are disposed in the second light-transmitting plate.

16. The optical film according to claim 13, characterized in that: The second light-transmitting plate includes a brightness enhancement film.

17. The optical film according to claim 1, characterized in that: An absolute value of a refractive index difference between the plurality of light-shielding portions and the plurality of light-transmitting portions is greater than 0.

005.

18. A display device, characterized in that: The display device comprises a light guide plate, a light source, a display panel and an optical film, wherein: The light guide plate has a light incident surface and a light emitting surface, and the light emitting surface is connected to the light incident surface; The light source is arranged opposite to the light incident surface; The display panel is arranged opposite to the light emitting surface; The optical film is disposed between the light emitting surface and the display panel, wherein the optical film comprises a grid layer, the grid layer having a first surface, a second surface, a plurality of light shielding portions and a plurality of light transmitting portions, The first surface is opposite to the second surface and parallel to each other, the plurality of light shielding portions and the plurality of light transmitting portions are located between the first surface and the second surface, and the plurality of light shielding portions and the plurality of light transmitting portions are alternately arranged along the first surface; Each of the plurality of light shielding portions comprises a third surface, a fourth surface, a fifth surface, a sixth surface and a seventh surface, the third surface is coplanar with the first surface, the fourth surface and the fifth surface are respectively connected to opposite sides of the third surface, a first angle between the fourth surface and the third surface is A1, and a second angle between the fifth surface and the third surface is A2; The sixth surface connects the fourth surface and the second surface, the seventh surface connects the fifth surface and the second surface, a third angle between the sixth surface and the second surface is A3, and a fourth angle between the seventh surface and the second surface is A4; Among them, 85°<A1≤90°, 85°<A2≤90°, 0°<A3<85°, 0°<A4<85°, A2≠A4, and A1≠A3.

19. The display device according to claim 18, characterized in that The first surface or the second surface faces the display panel.

Images