A privacy film, a preparation method thereof, and a display device

Abstract

The application provides a kind of privacy film and its preparation method, display device, the privacy film includes: substrate layer and privacy structure layer, substrate layer can let light pass through;Privacy structure layer is set on substrate layer, the refractive index of privacy structure layer is greater than or equal to 1.5;Privacy structure layer includes protrusion, protrusion includes light inlet surface, first light outlet surface and second light outlet surface, light inlet surface is parallelly arranged on the side surface of substrate, light inlet surface, first light outlet surface and second light outlet surface are connected two by two, and the three intersection lines formed are parallel two by two;First light outlet surface is outer convex curved surface, the orthographic projection of third intersection line on light inlet surface is located between first intersection line and second intersection line, so that the light emitted through first light outlet surface converges and deflects in the direction close to third intersection line.The privacy film achieves the purpose of considering narrow viewing angle display and high transmittance, and has good display effect.

Description

Technical Field

[0001] This application relates to the field of privacy display technology, and in particular to a privacy film, its preparation method, and a display device. Background Technology

[0002] With the continuous development of electronic display technology, flexible screens, curved screens, and foldable screens are gradually being favored by manufacturers of electronic display devices such as mobile phones and tablets. At the same time, in order to increase the privacy and security of the display screen, a privacy screen is usually set on the display screen to make the display device have a privacy effect. Specifically, it meets the viewing needs when viewed directly, but the information on the display screen cannot be seen when viewed from a certain angle.

[0003] Among the privacy films in related technologies, some use a louver structure, filling two adjacent light-transmitting areas with light-blocking material; others use a black and white grating structure. Although both of these methods can achieve narrow viewing angles and thus provide privacy for the display device, the light transmittance of the privacy films in these technologies is low, resulting in poor display quality. Summary of the Invention

[0004] This application provides a privacy film, its preparation method, and a display device to solve the problem that privacy films in related technologies cannot simultaneously achieve narrow viewing angles and high transmittance.

[0005] In a first aspect, embodiments of this application provide a privacy film, comprising: a substrate layer and a privacy structure layer, wherein the substrate layer allows light to pass through; the privacy structure layer is disposed on the substrate layer, and the refractive index of the privacy structure layer is greater than or equal to 1.5; the privacy structure layer includes a protrusion, the protrusion including a light-incoming surface, a first light-emitting surface and a second light-emitting surface, the light-incoming surface being disposed parallel to one side surface of the substrate, the light-incoming surface, the first light-emitting surface and the second light-emitting surface being connected in pairs, the intersection line formed by the intersection of the light-incoming surface and the second light-emitting surface being a first intersection line, the intersection line formed by the intersection of the first light-emitting surface and the light-incoming surface being a second intersection line, and the intersection line formed by the intersection of the first light-emitting surface and the second light-emitting surface being a third intersection line, the second intersection line, the third intersection line and the first intersection line being parallel to each other; the first light-emitting surface is an outwardly convex curved surface, and the orthographic projection of the third intersection line on the light-incoming surface is located between the first intersection line and the second intersection line, such that the light emitted through the first light-emitting surface converges and deflects towards the direction closer to the third intersection line.

[0006] In some embodiments, the orthographic projection profile of the first light-emitting surface on the first plane conforms to a first curve, such that the distance between a point on the first curve and the first intersection line gradually decreases from the second intersection line to the third intersection line; wherein the first plane is perpendicular to the first intersection line.

[0007] In some embodiments, the second light-emitting surface is a plane, the second light-emitting surface is inclined relative to the light-incoming surface, and the included angle between the second light-emitting surface and the light-incoming surface is 40°-50°.

[0008] In some embodiments, the number of protrusions is multiple, and the multiple protrusions are arranged in an array, with adjacent protrusions connected.

[0009] In some embodiments, the protrusion is columnar, the length direction of the protrusion is parallel to the first intersection line, and the length direction of the protrusion is perpendicular to the thickness direction of the substrate layer.

[0010] In some embodiments, the length direction of the protrusion is parallel to the first direction, and a plurality of the protrusions are arranged along a second direction, wherein the second direction, the first direction, and the thickness direction of the substrate layer are parallel to each other.

[0011] In some embodiments, the privacy shield layer includes a first protrusion group and a second protrusion group, wherein the first protrusion group includes a plurality of protrusions, the second protrusion group includes a plurality of protrusions, and the plurality of protrusions in the same protrusion group are arranged in the same direction.

[0012] In some embodiments, at least a portion of the protrusions are arranged symmetrically.

[0013] In some embodiments, the protrusion is annular, with the first light-emitting surface located on the outer side of the protrusion and the second light-emitting surface located on the inner side of the protrusion; preferably, a plurality of the protrusions are arranged in a radial array along the protrusion.

[0014] Secondly, embodiments of this application also provide a method for preparing a privacy film, used to prepare the privacy film as described in the first aspect above, the preparation method comprising:

[0015] A first film layer is formed on the substrate layer;

[0016] An anti-spy structure layer is formed on the first film layer by etching;

[0017] Dry the privacy shield layer to form a privacy film;

[0018] Wherein, the refractive index of the first film layer is greater than or equal to 1.5.

[0019] In some embodiments, the first film layer is formed on one side surface of the substrate layer by spin coating.

[0020] Thirdly, embodiments of this application also provide a display device, including the privacy film as described in the first aspect above.

[0021] According to the privacy film provided in the embodiments of this application, a privacy structure layer is provided on the substrate layer. The privacy structure layer includes a protrusion, and the protrusion includes a light-incoming surface, a first light-emitting surface, and a second light-emitting surface. The light-incoming surface, the first light-emitting surface, and the second light-emitting surface are connected in pairs. The first light-emitting surface of the protrusion is an outwardly convex curved surface, and the orthographic projection of the third intersection line formed by the connection of the first light-emitting surface and the second light-emitting surface on the light-incoming surface is located between the first intersection line and the second intersection line on the light-incoming surface. In this way, when light enters from the light-incoming surface, the light emitted after passing through the first light-emitting surface converges and deflects towards the direction closer to the third intersection line. In other words, when the optical axis of the light entering the light-receiving surface is parallel to the thickness direction of the substrate layer, the light emitted from the first light-emitting surface converges towards the optical axis, thereby reducing the field of view of the light emitted through the privacy structure layer, thus achieving a narrow viewing angle display. At the same time, the refractive index of the privacy structure layer is greater than or equal to 1.5, which means that the material used in the privacy structure layer has a relatively high refractive index, so that the light can achieve a high refractive index after passing through the privacy structure layer, which is conducive to improving the transmittance of the privacy film, thus enabling the privacy film to achieve the purpose of reducing the field of view and high transmittance. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a cross-sectional schematic diagram of the privacy film provided in the embodiments of this application on the first plane;

[0024] Figure 2 for Figure 1 An enlarged view of the orthographic projection of the protrusion onto the first plane;

[0025] Figure 3 This is a schematic diagram of a three-dimensional structure of a columnar protrusion in some embodiments of this application;

[0026] Figure 4 A schematic diagram showing an arrangement of multiple columnar protrusions;

[0027] Figure 5 A cross-sectional schematic diagram of a privacy film comprising multiple first protrusion groups and second protrusion groups arranged at intervals on a first plane.

[0028] Figure 6 A schematic cross-section of a privacy film with two adjacent protrusions arranged symmetrically in sequence on the first plane;

[0029] Figure 7This is a schematic diagram of a three-dimensional structure of a ring-shaped protrusion in some embodiments of this application;

[0030] Figure 8 A schematic diagram showing multiple circular protrusions arranged in a matrix;

[0031] Figure 9 A schematic diagram showing multiple hexagonal ring-shaped protrusions arranged in a regular hexagonal pattern;

[0032] Figure 10 A schematic diagram showing the radial arrangement of multiple annular protrusions;

[0033] Figure 11 This is a flowchart illustrating the preparation process of the privacy film in some embodiments of this application.

[0034] Figure label:

[0035] 1. First intersection line; 2. Second intersection line; 3. Third intersection line;

[0036] 10. Substrate layer;

[0037] 20. Privacy protection layer; 201. Protrusion; 21. Light-inlet surface; 22. First light-outlet surface; 23. Second light-outlet surface. Detailed Implementation

[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0039] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0040] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly, for example, as fixed connection, detachable connection, or integral connection; those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0041] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0042] With the continuous development of electronic display technology, flexible screens, curved screens, and foldable screens are gradually being favored by manufacturers of electronic display devices such as mobile phones and tablets. At the same time, in order to increase the privacy and security of the display screen, a privacy screen is usually set on the display screen to make the display device have a privacy effect. Specifically, it meets the viewing needs when viewed directly, but the information on the display screen cannot be seen when viewed from a certain angle.

[0043] Some privacy films in related technologies use a louver structure, with grooves set in two adjacent light-transmitting areas and light-blocking material filled in the grooves; others use a black and white grating structure. Although both of these methods can achieve narrow viewing angles and make the display device have a privacy effect, the light transmittance of the privacy films in these technologies is low, resulting in poor display effects. In other words, privacy films in these technologies cannot simultaneously achieve narrow viewing angles and high transmittance.

[0044] To address the issue that privacy films in related technologies cannot simultaneously achieve narrow viewing angles and high transmittance, this application provides a privacy film, its preparation method, and a display device.

[0045] Figure 1 The diagram shows structural schematics of some embodiments of this application. For ease of explanation, only the parts relevant to this embodiment are shown, and are described in detail below:

[0046] like Figures 1 to 4The privacy film provided in this application embodiment includes: a substrate layer 10 and a privacy structure layer 20. The substrate layer 10 allows light to pass through. The privacy structure layer 20 is disposed on the substrate layer 10, and the refractive index of the privacy structure layer 20 is greater than or equal to 1.5. The privacy structure layer 20 includes a protrusion 201, which includes a light-incoming surface 21, a first light-emitting surface 22, and a second light-emitting surface 23. The light-incoming surface 21 is disposed parallel to one side surface of the substrate. The light-incoming surface 21, the first light-emitting surface 22, and the second light-emitting surface 23 are connected in pairs. The light-incoming surface 21 and the first light-emitting surface 22 are connected in pairs. The intersection line formed by the two light-emitting surfaces 23 is the first intersection line 1. The intersection line formed by the first light-emitting surface 22 and the light-receiving surface 21 is the second intersection line 2. The intersection line formed by the first light-emitting surface 22 and the second light-emitting surface 23 is the third intersection line 3. The second intersection line 2, the third intersection line 3 and the first intersection line 1 are parallel to each other. The first light-emitting surface 22 is a convex curved surface. The orthographic projection of the third intersection line 3 on the light-receiving surface 21 is located between the first intersection line 1 and the second intersection line 2, so that the light rays emitted through the first light-emitting surface 22 converge and deflect towards the direction closer to the third intersection line 3.

[0047] The aforementioned substrate layer 10 serves to support the privacy structure layer 20. At the same time, it needs to have high transparency, good optical performance and certain mechanical strength, and be easy to process later (such as setting a privacy microstructure layer).

[0048] The aforementioned privacy screen layer 20 is the core layer for achieving narrow viewing angle display. It should be noted that the field of view in narrow viewing angle display refers to a reduced field of view compared to when the privacy screen layer 20 is not present. However, the specific size of the field of view for a display module with the privacy screen layer 20 needs to be determined by considering the light emission angle of the light source and the specific structure of the privacy screen layer 20, and is not specifically limited here. The privacy screen layer 20 includes protrusions 201, which mainly refer to protruding microstructures disposed on one side surface of the substrate layer 10. For example, by combining the structure of each protrusion 201 and the arrangement of multiple protrusions 201 in various ways, display modules with different field of view ranges can be designed to meet different light emission requirements.

[0049] It should be noted that this privacy screen protector is applied to a display screen, and the size of the protrusion 201 is much smaller than the display screen, that is, the size of the substrate layer 10. In other words, the microstructure here refers to the relatively small size of the protrusion 201 relative to the size of the display screen. The microstructure here is a relative concept and does not refer to the microscopic organizational structure of the material. It typically refers to the structural details observable under an optical or electron microscope, generally ranging from nanometers to micrometers.

[0050] In this embodiment, the first light-emitting surface 22 of the protrusion 201 is an outwardly convex curved surface, that is, the first light-emitting surface 22 is similar to a convex lens, which plays the role of converging light. When light enters the interior of the protrusion 201 through the light-inlet surface 21, it then exits from the first light-emitting surface 22, causing the light to converge, thereby realizing a narrow viewing angle display.

[0051] The connection between the aforementioned light-inlet surface 21, the first light-outlet surface 22, and the second light-outlet surface 23 means that the light-inlet surface 21, the first light-outlet surface 22, and the second light-outlet surface 23 are connected to form a closed shape in a first plane perpendicular to the extension direction of the protrusion 201. The extension direction of the protrusion 201 refers to the extension direction of the first intersection line 1. The first plane is perpendicular to the first intersection line 1. Since the first intersection line 1, the second intersection line 2, and the third intersection line 3 are parallel to each other, that is to say, the first plane is perpendicular to all three intersection lines.

[0052] On the first plane, the light-entering surface 21, the first light-exiting surface 22, and the second light-exiting surface 23 are connected in pairs to form a triangle-like shape. The first intersection line 1, the second intersection line 2, and the third intersection line 3 correspond to... Figure 2 Points A, B, and C in the diagram correspond to line segment AB on the light-entry surface 21, line segment BC on the first light-exit surface 22, and line segment AC on the second light-exit surface 23.

[0053] The aforementioned light-gathering surface 21 is disposed parallel to one side surface of the substrate (the surface in the thickness direction of the substrate layer 10, such as...). Figure 1 On the upper surface of the structure layer 20, it means that during the setting of the privacy structure layer 20, the light-receiving surface 21 of the protrusion 201 is perpendicular to the thickness direction of the substrate layer 10.

[0054] In this embodiment, in addition to the structural requirements for the protrusions 201 of the privacy screen layer 20, some parameters of the privacy screen layer 20 are also required. Specifically, in this embodiment, the refractive index of the privacy screen layer 20 is greater than or equal to 1.5, that is, the refractive index of the material used in the preparation of the privacy screen layer 20 is greater than or equal to 1.5. Using a material with a refractive index greater than or equal to 1.5 in the preparation of the privacy screen layer 20 effectively increases the light transmittance through it. Therefore, when the privacy screen is placed on the display screen, it provides privacy protection while minimizing the impact on the clarity or brightness of the information displayed on the screen. This helps improve the overall brightness and clarity of the display device, enhancing its display effect and enabling the display device to achieve a balance between narrow viewing angle, high brightness, and high definition.

[0055] In this embodiment, the privacy screen layer 20 can be made of cyanurate (C3H3N3O3C3H3N3O3). Cyanurate is a compound produced by the esterification reaction of cyanuric acid with alcohols or other hydroxyl compounds. The privacy screen layer 20 can also be made of thioester (R-CO-S-R'). Thiolester is an organic compound containing a C(=O)-SR functional group, where the carbonyl carbon (C=O) is directly bonded to a sulfur atom (S), and the other end of the sulfur atom is bonded to an alkyl or aryl group (R). Besides the two materials mentioned above, other materials can also be used for the privacy screen layer 20, as long as the refractive index meets the requirements.

[0056] The outline of the substrate layer 10 can be square, circular, or other shapes.

[0057] According to the privacy film provided in the embodiments of this application, a privacy structure layer 20 is provided on the substrate layer 10. The privacy structure layer 20 includes a protrusion 201, which includes a light-inlet surface 21, a first light-outlet surface 22, and a second light-outlet surface 23. The light-inlet surface 21, the first light-outlet surface 22, and the second light-outlet surface 23 are connected in pairs. The first light-outlet surface 22 in the protrusion 201 is an outwardly convex curved surface, and the orthographic projection of the third intersection line 3 formed by the connection of the first light-outlet surface 22 and the second light-outlet surface 23 on the light-inlet surface 21 is located between the first intersection line 1 and the second intersection line 2 on the light-inlet surface 21. In this way, when light enters from the light-inlet surface 21, the light emitted after passing through the first light-outlet surface 22 is directed towards... The light rays converge and deflect towards the direction close to the third intersection line 3. That is, when the optical axis of the light entering the light-incoming surface 21 is parallel to the thickness direction of the substrate layer 10, the light rays emitted through the first light-emitting surface 22 converge towards the optical axis, thereby reducing the field of view of the light rays emitted through the privacy screen layer 20. This achieves a narrow viewing angle display. Simultaneously, the refractive index of the privacy screen layer 20 is greater than or equal to 1.5, meaning the material used in the privacy screen layer 20 has a relatively high refractive index. This allows light to achieve a high refractive index after passing through the privacy screen layer 20, which helps improve the transmittance of the privacy film. Thus, the privacy film achieves the goal of both reducing the field of view and increasing transmittance. Therefore, when this privacy film is placed on the display screen, it provides a privacy protection effect while having minimal impact on the clarity or brightness of the information displayed on the screen. This helps improve the overall brightness and clarity of the display device, enhancing the display effect and enabling the display device to achieve the goals of narrow viewing angle display, high brightness, and high clarity.

[0058] like Figures 1 to 2 As shown, in this embodiment, the orthographic projection contour of the first light-emitting surface 22 on the first plane conforms to the first curve, so that the light-emitting surface 22 originates from the second intersection line 2 ( Figure 2From point B in the middle to the third intersection line 3 ( Figure 2 The direction of point C in (e.g.) Figure 1 As shown in the first plane, from the end of the first curve near the light-inlet surface 21 to the end near the second light-outlet surface 23, the distance between the points on the first curve and the first intersection line 1 gradually decreases; wherein, the first plane is perpendicular to the first intersection line 1.

[0059] The orthographic projection contour of the first light-emitting surface 22 on the first plane can be a first curve or a curve formed by fitting multiple lines that conforms to the first curve.

[0060] With the above settings, the first light-emitting surface 22 can be adjusted according to the size of the field of view, so that the privacy film can achieve different display effects at different field of view and has a wide range of applications.

[0061] Based on this, when the second light-emitting surface 23 is a plane and is inclined relative to the light-incoming surface 21, the closed shape formed by connecting the light-incoming surface 21, the first light-emitting surface 22, and the second light-emitting surface 23 on the first plane is similar to a fan. At this time, the included angle formed between the second light-emitting surface 23 and the light-incoming surface 21 is also called the central angle of the fan-shaped circle. Figure 2 The included angle ∠A at point A in the middle.

[0062] With the above settings, the deflection angle of the light rays emitted from the first light-emitting surface 22 on the first plane, from the second intersection line 2 to the third intersection line 3, gradually becomes smaller, so that the main light rays are mainly concentrated near the optical axis, thus achieving narrow viewing angle display.

[0063] The first curve was obtained through optical simulation software. Specifically, a light source is arranged on the side of the substrate layer 10 away from the optical privacy structure layer 20. The orthographic projection of the light source onto the light-incoming surface 21 is located at the center of the light-incoming surface 21. The optical axis of the light source is parallel to the thickness direction of the substrate layer 10. First, the light source is discretized into multiple point light sources evenly distributed between the substrate layer 10 and the light-incoming surface 21. Based on the Lambertian light source, combined with parameters such as the field of view of the light source, the refractive index of air, the refractive index of the substrate layer 10, and the refractive index of the privacy structure layer 20, the field of view of the discretized point light sources is determined. Then, the light rays of the point light sources are divided into n parts, and the energy of each ray is calculated using the law of refraction. Based on the energy of each ray... Figure 2 Starting from point B, determine the coordinates of point B1, and so on, determining the coordinates of B2, B3, ..., Bn. Connect B1, B2, B3, ..., Bn sequentially. Simultaneously, in... Figure 2 In the plane shown, line segments AB and ∠A are defined as shown. In this embodiment, ∠A = 45°. The equation of the first curve is obtained through fitting. Theoretically, the more points the light source is divided into, the closer the equation of the first curve will be. Figure 2 As shown, the smoother the transition between line segments B1, B2, B3, ..., Bn, the better.

[0064] It should be noted that the aforementioned included angle Figure 2 In addition to 45°, ∠A can also be 40°, 41°, 42°, 42°, 43°, 44°, ..., 47°, 48°, 49°, 50°, etc., without any specific limitation here.

[0065] In addition to being a plane, the second light-emitting surface 23 can also be a convex curve. The orthographic projection contour of the second surface on the first plane conforms to the second curve. The method of determining the second curve is the same as that of determining the first curve. The equations of the second curve and the first curve can be the same or different, which will not be elaborated here.

[0066] like Figure 1 and Figure 4 As shown, in this embodiment, there are multiple protrusions 201, which are arranged in an array, and adjacent protrusions 201 are connected.

[0067] The privacy protection structure layer 20 includes a plurality of interconnected arrays of protrusions 201. This reduces the size of each protrusion 201 and can play a role in uniform light distribution, thereby making the light more uniform.

[0068] It should be noted that the arrangement of the multiple protrusions 201 needs to be determined according to the specific structure of the protrusions 201, and no specific limitation is made here.

[0069] In addition, the number of protrusions 201 needs to be determined in combination with the structure of protrusions 201 and the size of the substrate layer 10, and no specific limit is made here.

[0070] like Figure 1 , Figure 3 and Figure 4 As shown, in some embodiments, the protrusion 201 is columnar, the length direction of the protrusion 201 is parallel to the first intersection line 1, and the length direction of the protrusion 201 is perpendicular to the thickness direction of the substrate layer 10. In this case, the first plane is a cross-section perpendicular to the length direction of the protrusion 201.

[0071] Specifically, the length direction of the protrusion 201 is parallel to the first direction, and multiple protrusions 201 are arranged along the second direction. The second direction, the first direction, and the thickness direction of the substrate layer 10 are parallel to each other.

[0072] When the substrate layer 10 is square, the first direction and the second direction can correspond to the length direction and the width direction of the substrate layer 10. That is, when the length direction of the protrusion 201 is parallel to the length direction of the substrate layer 10, multiple protrusions 201 are arranged along the width direction of the substrate layer 10, thus the field of view of the substrate layer 10 in the width direction can be adjusted; when the length direction of the protrusion 201 is parallel to the width direction of the substrate layer 10, multiple protrusions 201 are arranged along the length direction of the substrate layer 10, thus the field of view of the substrate layer 10 in the length direction can be adjusted.

[0073] It should be noted that, in one embodiment, when all the protrusions 201 are parallel along their length, the first light-emitting surfaces 22 of the protrusions 201 can all face the same side, for example, as shown in the example. Figure 1 As shown, the first light-emitting surface 22 of all the protrusions 201 faces to the left, thus making the privacy film... Figure 1 In this configuration, the field of view of the portion of light rays located to the left of the optical axis in the horizontal direction decreases, while the field of view of the other portion of light rays located to the right of the optical axis remains unchanged, resulting in a narrow viewing angle display at half the field of view. In another embodiment, such as... Figure 1 As shown, one part of the protrusions 201 is symmetrically arranged with another part of the protrusions 201, so that a narrow viewing angle display with a full field of view can be achieved.

[0074] When displaying a narrow viewing angle across the entire field of view, in the second direction, half of the protrusions 201 can be symmetrical to the other half, such as... Figure 1 As shown. We refer to a group of multiple adjacent protrusions 201 with the same arrangement as a protrusion group, and the first light-emitting surface 22 of the multiple protrusions 201 in the protrusion group has the same orientation.

[0075] like Figure 1 As shown, the privacy screen layer 20 includes a first protrusion group ( Figure 1 The first group of protrusions includes multiple protrusions 201 within a dashed box, and the second group of protrusions includes multiple protrusions 201. The number of protrusions 201 in the first group of protrusions is the same as the number of protrusions 201 in the second group of protrusions.

[0076] Specifically, such as Figure 1 As shown, in some embodiments, when multiple protrusions 201 are symmetrically arranged in the second direction, they may include half of the first protrusion group as a whole and the other half of the second protrusion group as a whole, which are symmetrical from left to right. In this way, a narrow viewing angle display with a full field of view is achieved.

[0077] Furthermore, to improve the uniformity of the emitted light, the number of protrusions 201 in the first and second protrusion groups can be reduced, while the number of protrusion groups can be increased. The first and second protrusion groups are arranged alternately, that is, along the second direction, one first protrusion group and one second protrusion group are arranged sequentially. Specifically, as shown... Figure 5 and Figure 6 As shown, the number of the first protrusion group and the second protrusion 201 can be distributed according to the position of the light source of the display screen. A first protrusion group and a second protrusion group are set at the position corresponding to a light source. In this way, the light source can be controlled with a narrow viewing angle across the entire field of view. At the same time, the emitted light after passing through the privacy film is relatively uniform, and the display consistency is good.

[0078] The structure of the protrusion 201 can be columnar or annular.

[0079] like Figure 7 As shown, in some other embodiments, the protrusion 201 is annular, with the first light-emitting surface 22 located on the outside of the protrusion 201 and the second light-emitting surface 23 located on the inside of the protrusion 201.

[0080] In this way, the light passing through each protrusion 201 can achieve a 360° narrow viewing angle display.

[0081] The above-mentioned rings include circular rings and square rings. The following explanation will use the circular ring as an example.

[0082] like Figures 7 to 9 As shown, in one embodiment, when the protrusion 201 is annular, the first intersection line 1 can be a point or a circle. In this embodiment, the first intersection line 1 is a point. The array arrangement of the multiple protrusions 201 includes a regular polygonal arrangement or a radial arrangement. A polygonal arrangement means that the multiple protrusions 201 surround each other, and the centers of the multiple protrusions 201 are connected in pairs to form a regular polygon.

[0083] Figure 8 and Figure 9 The diagram only illustrates the array arrangement of multiple protrusions 201. The cross-sectional view of the protrusions 201 in the privacy structure layer 20 on the first plane is the same as the cross-sectional shape of the column shown in Figure 6.

[0084] The regular polygon mentioned above can be a square, such as... Figure 8 As shown; the above regular polygon can be a regular hexagon, such as... Figure 9 As shown. In addition to squares and regular hexagons, the regular polygons mentioned above can also be pentagons, regular heptagons, regular octagons, etc., without specific limitations here.

[0085] When the size of the regular polygon is larger than the outer contour size of the protrusion 201, the protrusion 201 can be set in the middle of the regular polygon to cover the substrate layer 10 as much as possible. Figure 9 As shown.

[0086] like Figure 10 As shown, in another embodiment, the first intersection line 1, the second intersection line 2 and the third intersection line 3 of the protrusions 201 are all circles. Multiple protrusions 201 are arranged in a radial array along the protrusions 201, that is, one protrusion 201 nests another protrusion 201, that is, two adjacent protrusions 201 are nested together. In this way, a 360° narrow viewing angle display can also be achieved.

[0087] It should be noted that, Figure 10 The diagram illustrates the arrangement of multiple protrusions 201, and the protrusions 201 in the privacy structure layer 20 have the same cross-sectional shape on the first plane as the aforementioned annular protrusions 201.

[0088] Of course, if multiple protrusions 201 are arranged radially, the extension direction of each protrusion 201 can also be in the shape of a square ring to adapt to the square substrate layer 10. In this way, the substrate layer 10 can be fully covered as much as possible, thus improving the display effect.

[0089] To address the aforementioned problems, this application also provides a method for preparing a privacy film, such as... Figure 11 As shown, the preparation method includes:

[0090] Step S100: A first film layer is formed on the substrate layer 10, wherein the refractive index of the first film layer is greater than or equal to 1.5.

[0091] In the process of preparing the privacy film, the first film layer is the basis of the privacy structure layer 20. That is to say, the first film layer uses the same material as the privacy structure layer 20. At the same time, the thickness of the first film layer must be greater than or equal to the height of the protrusion 201 in the privacy structure layer 20. The height of the protrusion 201 refers to the distance between the third intersection line 3 in the protrusion 201 and the light-gathering surface 21. That is to say, the distance from point C (the orthographic projection point of the third intersection line 3 on the first plane) of the protrusion 201 to the perpendicular line of line segment AB (the orthographic projection of the light-gathering surface 21 on the first plane).

[0092] Before step S100, there is also step S10, which provides a substrate layer 10.

[0093] The substrate layer 10 can be a pre-prepared semi-finished product or a finished product. Alternatively, the preparation step of the substrate layer 10 can be added directly before the preparation of the first film layer. The specific preparation method used depends on the optical requirements and cost of the privacy film, and the selection of materials and parameters for the substrate layer 10 is not specifically limited here. It can be prepared directly...

[0094] The aforementioned substrate layer 10 can be any one of acrylic (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), cellulose triacetate (TAC), cyclic olefin polymer (COP), or transparent glass. Since PMMA has good light transmittance, the following explanation uses PMMA as an example for the substrate layer 10.

[0095] In this embodiment, the material used for the first film layer can be cyanurate (C3H3N3O3C3H3N3O3). Cyanurate is a type of compound generated by the esterification reaction of cyanuric acid with alcohols or other hydroxyl compounds. The material used for the privacy shield layer 20 can be thioester (R-CO-S-R'). Thiolester (or Thioester) is a type of organic compound containing a C(=O)-SR functional group, wherein the carbonyl carbon (C=O) is directly connected to a sulfur atom (S), and the other end of the sulfur atom is connected to an alkyl or aryl group (R). In addition to the above two materials, other materials can also be used for the first film layer, as long as the refractive index meets the requirements.

[0096] The first film layer can be prepared using various processing methods depending on the materials and process requirements. For example, in some embodiments, the first film layer is formed on one side surface of the substrate layer 10 by spin coating.

[0097] The aforementioned spin coating thin film preparation technology is widely used in semiconductors, optical devices, photovoltaic cells and other fields.

[0098] Spin coating involves dropping a solution onto a substrate and using centrifugal force generated by high-speed rotation to spread the solution evenly. After the solvent evaporates, a thin film is formed.

[0099] The first film layer is formed on one side surface of the substrate layer 10 by spin coating, which allows the thickness of the first film layer to be controlled and makes the first film layer more uniform, thus helping to meet the optical requirements of the privacy structure layer 20.

[0100] In addition to being formed on the substrate layer 10 by spin coating, in some embodiments, the first film layer can also be coated onto one side surface of the substrate layer 10 by various techniques (such as blade coating, spray coating, dip coating, roll coating, etc.), forming a film layer on the substrate surface through physical or chemical means. Coating methods include blade coating, spray coating, dip coating, etc.

[0101] Blade coating uses a blade to control the thickness, making it suitable for large-area fabrication (such as flexible electronics).

[0102] Spray coating is applied by spraying an atomized solution and is suitable for substrates with complex shapes.

[0103] Dip coating involves immersing the substrate in a solution and then lifting it out; the thickness is controlled by the lifting speed.

[0104] Alternatively, the first film layer can also be applied to one side of the substrate layer 10 by various methods such as spraying or sputtering, without any specific limitation.

[0105] After step S100, step S200 is also included, forming a privacy protection structure layer 20 on the first film layer by etching.

[0106] In other words, the excess portion on the first film layer, that is, the space between two adjacent protrusions 201, is etched to form an array of protrusions 201, which is the privacy protection structure layer 20.

[0107] Etching is a key process in semiconductor manufacturing, microelectronics processing, and materials science, used to selectively remove material from specific areas of a material surface to form desired patterns or structures. Depending on the application and principle, and the material used for the first film layer, wet or dry etching is selected.

[0108] Following step S200, step 300 is also included: drying the privacy shield layer 20 to form a privacy shield film.

[0109] Through the above steps S100 to S300, a privacy film is formed.

[0110] It should be noted that the above drying process is to facilitate the final quality inspection of the anti-spy structure layer 20 before it leaves the factory, such as manual inspection or inspection using AOI equipment, and no specific limitations are made here.

[0111] The privacy film prepared by the above method has the same structure as the privacy film in any of the above embodiments, and will not be described again here.

[0112] To address the aforementioned issues, this application also provides a display device, including a privacy film and a display screen.

[0113] The privacy film and the display screen can be two semi-finished products that are assembled together by bonding, or the privacy film can be manufactured together during the manufacturing process of the display screen to form an integrated structure.

[0114] The aforementioned display device can be applied to electronic devices with a display screen, including terminal devices such as mobile phones, tablets, watches or bracelets, laptops, smart glasses, health monitoring devices, or industrial or medical devices.

[0115] According to the privacy film provided in the embodiments of this application, a privacy structure layer 20 is provided on the substrate layer 10. The privacy structure layer 20 includes a protrusion 201, which includes a light-inlet surface 21, a first light-outlet surface 22, and a second light-outlet surface 23. The light-inlet surface 21, the first light-outlet surface 22, and the second light-outlet surface 23 are connected in pairs. The first light-outlet surface 22 in the protrusion 201 is an outwardly convex curved surface, and the orthographic projection of the third intersection line 3 formed by the connection of the first light-outlet surface 22 and the second light-outlet surface 23 on the light-inlet surface 21 is located between the first intersection line 1 and the second intersection line 2 on the light-inlet surface 21. In this way, when light enters from the light-inlet surface 21, the light emitted after passing through the first light-outlet surface 22 is directed towards... The light rays converge and deflect towards the direction of the third intersection line 3. That is, when the optical axis of the light rays entering the light-incoming surface 21 is parallel to the thickness direction of the substrate layer 10, the light rays emitted through the first light-emitting surface 22 converge toward the optical axis, thereby reducing the field of view of the light rays emitted through the privacy structure layer 20, thus achieving a narrow viewing angle display. At the same time, the refractive index of the privacy structure layer 20 is greater than or equal to 1.5, that is, the material used in the privacy structure layer 20 has a relatively high refractive index, so that the light rays can achieve a high refractive index after passing through the privacy structure layer 20, which is beneficial to improving the transmittance of the privacy film, thereby enabling the privacy film to achieve the purpose of reducing the field of view and high transmittance.

[0116] When the privacy film is applied to the display screen, it provides privacy protection while minimizing the impact on the clarity or brightness of the information displayed. This helps improve the overall brightness and clarity of the display device, enhancing its display performance and enabling the device to achieve a balance between narrow viewing angles, high brightness, and high definition.

[0117] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A privacy film, characterized in that, include: A substrate layer (10) and a privacy structure layer (20) are provided on the substrate layer (10), wherein the substrate layer (10) allows light to pass through; the privacy structure layer (20) is disposed on the substrate layer (10), and the refractive index of the privacy structure layer (20) is greater than or equal to 1.5; The privacy protection structure layer (20) includes a protrusion (201), the protrusion (201) includes a light-inlet surface (21), a first light-outlet surface (22) and a second light-outlet surface (23), the light-inlet surface (21) is parallel to one side surface of the substrate, the light-inlet surface (21), the first light-outlet surface (22) and the second light-outlet surface (23) are connected in pairs, the intersection line formed by the intersection of the light-inlet surface (21) and the second light-outlet surface (23) is the first intersection line (1), the intersection line formed by the intersection of the first light-outlet surface (22) and the light-inlet surface (21) is connected to form the second intersection line (2), the intersection line formed by the intersection of the first light-outlet surface (22) and the second light-outlet surface (23) is the third intersection line (3), the second intersection line (2), the third intersection line (3) and the first intersection line (1) are parallel to each other; The first light-emitting surface (22) is a convex curved surface. The orthographic projection of the third intersection line (3) on the light-entry surface (21) is located between the first intersection line (1) and the second intersection line (2), so that the light emitted through the first light-emitting surface (22) converges and deflects towards the direction closer to the third intersection line (3).

2. The privacy film according to claim 1, characterized in that, The orthographic projection profile of the first light-emitting surface (22) on the first plane conforms to the first curve, such that the distance between a point on the first curve and the first intersection line (1) gradually decreases from the second intersection line (2) to the third intersection line (3); wherein the first plane is perpendicular to the first intersection line (1); And / or, the second light-emitting surface (23) is a plane, the second light-emitting surface (23) is inclined relative to the light-incoming surface (21), and the included angle between the second light-emitting surface (23) and the light-incoming surface (21) is 40°-50°.

3. The privacy film according to claim 1 or 2, characterized in that, The number of protrusions (201) is multiple, and the multiple protrusions (201) are arranged in an array, with two adjacent protrusions (201) connected.

4. The privacy film according to claim 3, characterized in that, The protrusion (201) is columnar, and the length direction of the protrusion (201) is parallel to the first intersection line (1), while the length direction of the protrusion (201) is perpendicular to the thickness direction of the substrate layer (10).

5. The privacy film according to claim 4, characterized in that, The length direction of the protrusion (201) is parallel to the first direction, and the plurality of protrusions (201) are arranged along the second direction. The second direction, the first direction and the thickness direction of the substrate layer (10) are parallel to each other.

6. The privacy film according to claim 4 or 5, characterized in that, The privacy protection structure layer (20) includes a first protrusion group and a second protrusion group. The first protrusion group includes a plurality of protrusions (201), and the second protrusion group includes a plurality of protrusions (201). The plurality of protrusions (201) in the same protrusion group are arranged in the same direction. And / or, at least a portion of the protrusions (201) are symmetrically arranged.

7. The privacy film according to claim 3, characterized in that, The protrusion (201) is annular, the first light-emitting surface (22) is located on the outside of the protrusion (201), and the second light-emitting surface (23) is located on the inside of the protrusion (201); Preferably, the plurality of the protrusions (201) are arranged in a radial array along the protrusions (201).

8. A method for preparing a privacy film, used in the privacy film as described in any one of claims 1-7, characterized in that, The preparation method includes: A first film layer is formed on the substrate layer; An anti-spy structure layer is formed on the first film layer by etching; Dry the privacy shield layer to form a privacy film; Wherein, the refractive index of the first film layer is greater than or equal to 1.

5.

9. The preparation method according to claim 8, characterized in that, The first film layer is formed on one side surface of the substrate layer by spin coating.

10. A display device, characterized in that, Including the privacy film as described in any one of claims 1-7.

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