Optical film and optical device

Abstract

An optical film includes a substrate layer and a microstructure layer, wherein the microstructure layer includes a plurality of raised microstructure units, the bottom surface of the microstructure unit contacts the substrate layer, and the single microstructure unit has a platform surface and an inclined surface on the side away from the substrate layer, wherein the platform surfaces and the inclined surfaces are alternately arranged, the number of platform surfaces in the single microstructure unit is N, the number of inclined surfaces is at least N+1, and the number of platform surfaces N in the single microstructure unit is greater than or equal to 2. An optical device, wherein the optical film is applied in the optical device. The optical film of the present application has a special optical structure of alternating inclined surfaces and planes, wherein the viewing angle of light is expanded by the platform surface, and the light is converged as much as possible within the light viewing angle of the target by the inclined surface portion, thereby improving the optical viewing angle range while maintaining high brightness.

Description

Technical Field

[0001] The present invention relates to the technical field of optical materials, and in particular to an optical film and an optical device. Background Art

[0002] With the iterative development of modern lighting technology, some products, such as teaching displays, require the expansion of the optical viewing angle while ensuring a certain brightness, so that the audience can see the screen image more clearly at different angles. In order to expand the wide viewing angle, the industry generally adopts a trapezoidal microstructure to change the slope of the structure to radiate part of the light outward, thereby achieving the effect of expanding the optical viewing angle. However, due to the limitation of the single-layer structure, this processing method can only achieve a final optical viewing angle of about 65°-70°, and there is still room for further improvement in the optical viewing angle of the display device.

[0003] There is an urgent need for an optical film that can further expand the optical viewing angle of optical devices while maintaining a high brightness. Summary of the invention

[0004] In order to solve the above-mentioned deficiencies of the prior art, the present invention provides an optical film and an optical device. The application of the optical film described in the present application can further improve the optical viewing angle of the optical device while maintaining a high brightness.

[0005] The technical problem to be solved by this application is achieved through the following technical solutions:

[0006] The present application provides an optical film, comprising a substrate layer and a microstructure layer, wherein the microstructure layer comprises a plurality of raised microstructure units, wherein the bottom surfaces of the microstructure units are in contact with the substrate layer, wherein a single microstructure unit has a platform surface and an inclined surface on a side away from the substrate layer, wherein the platform surfaces and the inclined surfaces are alternately arranged, wherein the number of platform surfaces in the single microstructure unit is N, the number of inclined surfaces is at least N+1, and the number N of platform surfaces in the single microstructure unit is greater than or equal to 2.

[0007] Furthermore, in the single microstructure unit, the number N of platform surfaces is greater than or equal to 5.

[0008] Furthermore, in the single microstructure unit, the number N of platform surfaces is less than or equal to 7.

[0009] Furthermore, the microstructure units in the microstructure layer are arranged along a first direction, the microstructure units extend or are arranged along a second direction, and the platform surface of the microstructure layer is parallel to one side surface of the substrate layer.

[0010] Furthermore, the cross-section of the microstructure unit parallel to the first direction and perpendicular to the bottom surface is a geometric figure enclosed by an oblique line and a straight line parallel to the bottom surface, and the angle ɑ between the oblique surface and the horizontal plane where the bottom surface is located is 70°-80°; the width W1 of the projection of the single oblique surface perpendicular to the plane where the bottom surface is located in the first direction is 1.25-7μm; the width W2 of the single platform surface in the first direction is 2-10μm.

[0011] Furthermore, the widths W1 of different inclined surfaces in the single microstructure unit are the same or different; and / or the angles ɑ of different inclined surfaces in the single microstructure unit are the same or different; the widths W2 of different platform surfaces in the single microstructure unit are the same or different.

[0012] Furthermore, a width W3 of the bottom surface of the microstructure unit in the first direction is 17.5-82 μm.

[0013] Furthermore, a spacing S1 between different microstructure units in the first direction is less than or equal to 10 μm.

[0014] Further, the spacing S1 between the different microstructure units in the first direction is 0 μm.

[0015] An optical device, in which any one of the above-mentioned optical films is applied.

[0016] The present application provides an optical film having a special optical structure of alternating inclined surfaces and flat surfaces. The viewing angle of light is expanded by the platform surface, and the light is gathered as much as possible within the target light viewing angle through the inclined surface. In this way, the optical viewing angle range can be improved while maintaining high brightness. By controlling the slope of the inclined surface and the width of the inclined surface and the platform surface, the effect of expanding the optical viewing angle under high brightness can be further achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of an optical film in one embodiment;

[0018] Figure 2 is a schematic cross-sectional view of a microstructure unit in a first direction X;

[0019] Figure 3 Schematic diagram of the cross section of different microstructure units;

[0020] Figure 4 Schematic diagram of arrangement of microstructure units in different implementation modes;

[0021] Figure 5 is a schematic diagram of the arrangement of microstructure units in one embodiment;

[0022] Figure 6It is a schematic diagram of a microstructure layer in the prior art.

[0023] Figure numerals: 1, microstructure layer; 11, microstructure unit; 111, inclined plane; 1111, first inclined plane; 1112, second inclined plane; 1113, third inclined plane; 1114, fourth inclined plane; 1115, fifth inclined plane; 1116, sixth inclined plane; 112, platform surface; 1121, first platform surface; 1122, second platform surface; 1123, third platform surface; 1124, fourth platform surface; 1125, fifth platform surface; 2, substrate layer; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] The present application is described in detail below with reference to the accompanying drawings and embodiments.

[0028] An optical film comprises a substrate layer 2 and a microstructure layer 1, wherein the microstructure layer 1 comprises a plurality of raised microstructure units 11, wherein the bottom surfaces of the microstructure units 11 are in contact with the substrate layer 2, wherein a platform surface 112 and an inclined surface 111 are present on a side of the single microstructure unit 11 away from the substrate layer 2, wherein the platform surfaces 112 and the inclined surfaces 111 are alternately arranged, wherein the number of the platform surfaces 112 in the single microstructure unit 11 is N, and the number of the inclined surfaces 111 is at least N+1, wherein N is greater than or equal to 2.

[0029] Specifically, Figure 1As shown, the optical film described in the present application includes a substrate layer 2, the substrate layer 2 provides support for the microstructure layer 1, the microstructure layer 1 includes a plurality of raised microstructure units 11, the microstructure units 11 extend substantially along the second direction Y, are arranged along the first direction X, and the microstructure units 11 are raised in the third direction Z. The first direction X, the second direction Y and the third direction Z are perpendicular to each other. The bottom surface of the single microstructure unit 11 is in direct contact with the surface of one side of the substrate layer 2, and the single microstructure unit 11 has a platform surface 112 and an inclined surface 111 on the side away from the substrate layer 2. The side of the microstructure unit 11 away from the substrate layer 2 is alternately arranged by inclined surfaces 111 and platform surfaces 112, all inclined surfaces 111 and platform surfaces 112 of the microstructure unit 11 are in contact with each other and enclose the outer contour of the microstructure unit 11 with the bottom surface, and the microstructure unit 11 is a solid structure. The number of platform surfaces 112 in the single microstructure unit 11 is N, and the number of inclined surfaces 111 is at least N+1, and N is greater than or equal to 2. At this time, the light enters from the bottom surface of the microstructure unit 11, and is refracted and / or reflected inside the microstructure unit 11, and finally emitted from different surfaces of the microstructure unit 11 away from the substrate layer 2. An optical structure with alternating inclined surfaces 111 and platform surfaces 112 is adopted. The viewing angle of the light is expanded through the platform surface 112, and the light is converged as much as possible within the target light viewing angle through the inclined surface 111, thereby improving the optical viewing angle range while maintaining high brightness.

[0030] For ease of understanding, Figure 3 As shown in A-1, when the number N of the platform surfaces 112 is 2, the number of the inclined surfaces 111 is 3. Since the platform surfaces 112 and the inclined surfaces 111 are alternately arranged, two adjacent platform surfaces 112 are at different horizontal heights. Through the cooperation between different platform surfaces 112 and different inclined surfaces 111, the optical viewing angle can be further expanded compared to the trapezoidal structure in the prior art, while also ensuring a higher brightness gain.

[0031] Furthermore, in the single microstructure unit 11 , the number N of the platform surfaces 112 is greater than or equal to 3; more preferably, the number N of the platform surfaces 112 is greater than or equal to 5.

[0032] Specifically, in order to further improve the optical viewing angle, in the single microstructure unit 11, since the platform surfaces 112 and the inclined surfaces 111 are alternately arranged, as the number of the platform surfaces 112 increases, the number of the inclined surfaces 111 also increases adaptively, and when the number N of the platform surfaces 112 is greater than or equal to 3, the optical viewing angle range is further improved. Further preferably, the number N of the platform surfaces 112 is less than or equal to 7. When the number N of the platform surfaces 112 exceeds 7, the optical viewing angle tends to decrease, and the light transmittance also has the risk of decreasing.

[0033] Some specific implementations are provided below to further explain the invention. As a specific implementation, Figure 3 As shown in A-2, when the number N of the platform surfaces 112 is 3, the corresponding number of the inclined surfaces 111 is 4; the number of the inclined surfaces 111 is not necessarily N+1, but may also be N+2, N+3, etc. As another specific implementation, Figure 3 As shown in A-3, when the number N of the platform surfaces 112 is 4, the corresponding number of the inclined surfaces 111 is 6. At this time, the structure of the microstructure unit 11 can be regarded as a large trapezoidal structure, on which two independent small trapezoidal structures are arranged in close contact with each other. By controlling the number of small trapezoidal structures, the number of inclined surfaces 111 of the microstructure unit 11 can be increased; as another specific implementation method, as Figure 3 As shown in A-4, when the number N of the platform surfaces 112 is 5, the corresponding number of the inclined surfaces 111 is 6. At this time, the structure of the microstructure unit 11 can be regarded as a large trapezoidal structure, on which two independent small trapezoidal structures are arranged. At this time, the independent small trapezoidal structures are arranged at intervals, and there is a certain distance between the independent small trapezoidal structures. At this time, the distance between the independent small trapezoidal structures also constitutes a platform surface 112, which can also provide a certain effect of expanding the optical viewing angle; as another specific implementation method, as Figure 3 As shown in A-5, the number N of the platform surfaces 112 is 7, and the corresponding number of the inclined surfaces 111 is 8.

[0034] Further preferably, the number N of the platform surfaces 112 described in the present application is preferably 5, and the number of the inclined surfaces 111 is 6. Figure 2 As shown, at this time, the microstructure layer 1 has an excellent breadth of optical viewing angle and can also ensure its excellent brightness.

[0035] Furthermore, the cross section of the microstructure unit 11 perpendicular to the bottom surface along the first direction X is a geometric figure enclosed by a straight line and an oblique line parallel to the bottom surface, the straight line is the projection of the platform surface 112 on the cross section, and the oblique line is the projection of the oblique surface 111 on the cross section. Figure 2 .

[0036] Furthermore, if Figure 3As shown, the angle ɑ between the inclined surface 111 and the horizontal plane where the bottom surface is located is 70°-80°. When the angle ɑ is less than 70°, the optical viewing angle of the optical film is narrow. When the angle ɑ is greater than 80°, the brightness of the optical film is insufficient. The width W1 of the projection of the single inclined surface 111 perpendicular to the plane where the bottom surface is located in the first direction X is 1.25-7μm. When the width W1 is less than 1.25μm, the brightness of the optical film tends to decrease and it is difficult to meet the actual use. When the width is greater than 7μm, the viewing angle of the optical film decreases. The width W2 of the single platform surface 112 in the first direction X is 2-10μm. When the width W2 is less than 2μm, the optical viewing angle of the optical film decreases and the viewing angle becomes narrower. When the width W2 is greater than 7μm, the brightness of the optical film decreases.

[0037] Furthermore, the widths W1 of the different inclined surfaces 111 are the same or different; the angles ɑ of the different inclined surfaces 111 are the same or different; and the widths W1 of the different platform surfaces 112 are the same or different.

[0038] Specifically, the microstructure unit 11 has different platform surfaces 112 and different inclined surfaces 111, and the projection width W1 of the different inclined surfaces 111, the angle ɑ of the inclined surfaces 111, and the width W1 of the different platform surfaces 112 can be independently the same or different. As a specific embodiment, the width W1 of the different inclined surfaces 111 is the same, the angle ɑ of the different inclined surfaces 111 is the same, and the width W1 of the different platform surfaces 112 is the same. As another specific embodiment, the width W1 of the different inclined surfaces 111 is different, the angle ɑ of the different inclined surfaces 111 is different, and the width W1 of the different platform surfaces 112 is different. As a specific embodiment, the width W1 of the different inclined surfaces 111 is the same, the angle ɑ of the different inclined surfaces 111 is different, and the width W1 of the different platform surfaces 112 is different. When the widths W1 of the slopes 111 of the microstructure unit 11 are the same and the angles ɑ of the different slopes 111 are the same, the optical brightness of the optical film is higher. When the widths W1 of the slopes 111 of the microstructure unit 11 are different and the angles ɑ of the different slopes 111 are different, the optical brightness of the optical film is slightly worse but the optical interference can be reduced to a certain extent. The widths W1 of different slopes 111 and the angles ɑ of different slopes 111 can be set according to actual conditions.

[0039] Further, such as Figure 3 As shown, the width W3 of the bottom surface of the microstructure unit 11 in the first direction X is 17.5-82 μm. When the width W3 is less than 17.5 μm, the brightness of the optical film decreases. When the width W3 is greater than 82 μm, the appearance of the optical film will have more obvious textures.

[0040] Specifically, as a specific implementation, at this time, the number N of platform surfaces 112 in the microstructure unit 11 is 5, and the number of inclined surfaces 111 is 6. Specifically, from left to right, the first inclined surface 1111, the first platform surface 1121, the second inclined surface 1112, the second platform surface 1122, the third inclined surface 1113, the third platform surface 1123, the fourth inclined surface 1114, the fourth platform surface 1124, the fifth inclined surface 1115, the fifth platform surface 1125 and the sixth inclined surface 1116 are included in sequence. At this time, the angle ɑ between the first inclined surface 1111 and the bottom surface is 70°-80°, the projection width W1 of the first inclined surface 1111 on the bottom surface is 1.25-7μm, and the projection width W2 of the first platform surface 1121 on the bottom surface is 2-10μm. At this time, the light enters from the bottom of the structural unit. According to the law of refraction, incident light at different angles will have different refraction conditions. The light emitted from the platform surface 112 will be refracted outward, so the light viewing angle of the structure is larger. In addition, since the platform surface 112 is parallel to the substrate layer 2, no light incident from the bottom will be totally reflected on this platform surface 112. When the light is incident on the inclined surface 111 area and does not undergo total reflection, the outgoing light in this area will converge toward the center, thereby ensuring the brightness within the light viewing angle; when the light is incident on the inclined surface 111 area and undergoes total reflection, this part of the light will be emitted from the other side of the structure after total reflection, and most of the light will be refracted by the inclined surface 111 on the other side and converge toward the center, reducing the number of light that is totally reflected back to the bottom by the platform surface 112, thereby ensuring the brightness within the light viewing angle.

[0041] Furthermore, the spacing S1 between the different microstructure units 11 in the first direction X is less than or equal to 10 μm.

[0042] Specifically, the different microstructure units 11 are arranged along the first direction X, the adjacent microstructure units 11 can be arranged in close contact, or the adjacent microstructure units 11 can be arranged at intervals, and the spacing S1 between the different microstructure units 11 in the first direction X is less than or equal to 10 μm. When the adjacent microstructure units 11 can be arranged in close contact, as shown in the attached Figure 4 As shown in the arrangement of B-1 in FIG. 1 , the spacing S1 between the different microstructure units 11 in the first direction X is 0 μm. Figure 4 As shown in the arrangement of B-2, at this time, there is a spacing S1 between different microstructure units 11 in the first direction X. Furthermore, the spacing S1 between different microstructure units 11 in the first direction X is 0 μm.

[0043] Furthermore, the arrangement of the microstructure units 11 in the microstructure layer 1 can be as follows: Figure 1As shown, the single microstructure unit 11 is basically a columnar structure, and the single microstructure unit 11 extends along the second direction Y and penetrates the substrate layer 2, and is arranged in parallel along the first direction X; it can also be as shown in Figure 6 As shown, a single microstructure unit 11 is basically in the shape of a pagoda, with a larger quadrangular pyramid at the bottom and a quadrangular pyramid structure of decreasing sizes at the upper layer. The top surface of the quadrangular pyramid is the platform surface 112, and the four side surfaces of the quadrangular pyramid are the inclined surfaces 111. The microstructure units 11 are arranged in sequence along the first direction X and the second direction Y.

[0044] An optical device, in which the above optical film is applied. Specifically, when the optical film is applied to an optical device such as a display screen for teaching, the viewing angle of the optical device can be improved.

[0045] The optical film described in the present application adopts an optical structure with alternating bevels 111 and planes, and the viewing angle of light is expanded through the plane part, and the light is gathered as much as possible within the target light viewing angle through the bevel 111 part, thereby improving the optical viewing angle range while maintaining high brightness. By controlling the slope and width of different parts, the optical viewing angle can be expanded under high brightness.

[0046] The solution of this application is described below by means of specific embodiments:

[0047] Embodiment 1:

[0048] refer to Figure 2 , the number N of platform surfaces 112 of the microstructure unit 11 is 5, the number of inclined surfaces 111 is 6, which are the first inclined surface 1111, the first platform surface 1121, the second inclined surface 1112, the second platform surface 1122, the third inclined surface 1113, the third platform surface 1123, the fourth inclined surface 1114, the fourth platform surface 1124, the fifth inclined surface 1115, the fifth platform surface 1125 and the sixth inclined surface 1116 which are arranged in sequence, and the projection width W2 of different platform surfaces 112 at the bottom is The same, W2 is 8μm, the projection width W1 of the inclined surface 111 of the microstructure unit 11 at the bottom is the same, W1 is 5μm, the width W3 of the bottom surface of the microstructure unit 11 in the first direction X is 70μm, the angle ɑ between the inclined surface 111 of the microstructure unit 11 and the bottom is the same, the angle ɑ is 70°, the microstructure unit 11 basically extends along the second direction Y, and is arranged along the first direction X, and the spacing S1 between adjacent microstructure units 11 is 0.

[0049] Embodiment 2:

[0050] The difference from Example 1 is:

[0051] At this time, the projection widths W2 of different platform surfaces 112 at the bottom are all the same, which is 2 μm. The projection widths W1 of the inclined surfaces 111 of the microstructure units 11 at the bottom are all the same, which is 1.25 μm. The width W3 of the bottom surface of the microstructure unit 11 in the first direction X is 17.5 μm.

[0052] Embodiment 3:

[0053] At this time, the projection widths W2 of different platform surfaces 112 at the bottom are all the same, which is 10 μm. The projection widths W1 of the inclined surfaces 111 of the microstructure units 11 at the bottom are all the same, which is 5 μm. The width W3 of the bottom surface of the microstructure unit 11 in the first direction X is 80 μm.

[0054] Embodiment 4:

[0055] At this time, the projection widths W2 of different platform surfaces 112 at the bottom are all the same, which is 8 μm. The projection widths W1 of the inclined surfaces 111 of the microstructure units 11 at the bottom are all the same, which is 3 μm. The width W3 of the bottom surface of the microstructure unit 11 in the first direction X is 58 μm.

[0056] Embodiment 5:

[0057] The included angle ɑ between the inclined surface 111 of the microstructure unit 11 and the bottom is the same, and the included angle ɑ is 80°.

[0058] Embodiment 6:

[0059] At this time, the projection widths W2 of different platform surfaces 112 at the bottom are all the same, which is 4 μm. The projection widths W1 of the inclined surfaces 111 of the microstructure units 11 at the bottom are all the same, which is 2.5 μm. The width W3 of the bottom surface of the microstructure unit 11 in the first direction X is 35 μm.

[0060] Embodiment 7:

[0061] At this time, the projection widths W2 of different platform surfaces 112 at the bottom are all the same, which is 6 μm. The projection widths W1 of the inclined surfaces 111 of the microstructure units 11 at the bottom are all the same, which is 5 μm. The width W3 of the bottom surface of the microstructure unit 11 in the first direction X is 60 μm.

[0062] Embodiment 8:

[0063] At this time, the projection widths W2 of different platform surfaces 112 at the bottom are all the same, which is 8 μm. The projection widths W1 of the inclined surfaces 111 of the microstructure units 11 at the bottom are all the same, which is 7 μm. The width W3 of the bottom surface of the microstructure unit 11 in the first direction X is 82 μm.

[0064] Embodiment 9:

[0065] The difference from Example 1 is that

[0066] The reference Figure 2 , the number N of the platform surfaces 112 of the microstructure unit 11 is 5, the number of the inclined surfaces 111 is 6, which are the first inclined surface 1111, the first platform surface 1121, the second inclined surface 1112, the second platform surface 1122, the third inclined surface 1113, the third platform surface 1123, the fourth inclined surface 1114, the fourth platform surface 1124, the fifth inclined surface 1115, the fifth platform surface 1125 and the sixth inclined surface 1116 arranged in sequence, at this time, the projection widths W1 of different inclined surfaces 111 at the bottom are not completely the same, the projection widths W2 of different platform surfaces 112 at the bottom are the same, and the width W1-1 of the first inclined surface 1111 is 9μm, the width W2-1 of the first platform surface 1121 is 8μm, the width W1-2 of the second inclined surface 1112 is 9μm, the width W2-2 of the second platform surface 1122 is 8μm, the width W1-3 of the third inclined surface 1113 is 9μm, the width W2-3 of the third platform surface 1123 is 9μm, the width W1-4 of the fourth inclined surface 1114 is 5μm, the width W2-4 of the fourth platform surface 1124 is 8μm, the width W1-5 of the fifth inclined surface 1115 is 5μm, the width W2-5 of the fifth platform surface 1125 is 8μm and the width W1-6 of the sixth inclined surface 1116 is 5μm.

[0067] Embodiment 10:

[0068] The difference from Example 1 is that

[0069] The reference Figure 2, the number N of the platform surfaces 112 of the microstructure unit 11 is 5, the number of the inclined surfaces 111 is 6, which are the first inclined surface 1111, the first platform surface 1121, the second inclined surface 1112, the second platform surface 1122, the third inclined surface 1113, the third platform surface 1123, the fourth inclined surface 1114, the fourth platform surface 1124, the fifth inclined surface 1115, the fifth platform surface 1125 and the sixth inclined surface 1116 arranged in sequence, at this time, the projection widths W1 of different inclined surfaces 111 at the bottom are not completely the same, the projection widths W2 of different platform surfaces 112 at the bottom are the same, and the width W1-1 of the first inclined surface 1111 is 5 μm, the width W2-1 of the first platform surface 1121 is 4 μm, the width W1-2 of the second inclined surface 1112 is 5 μm, the width W2-2 of the second platform surface 1122 is 8 μm, the width W1-3 of the third inclined surface 1113 is 5 μm, the width W2-3 of the third platform surface 1123 is 8 μm, the width W1-4 of the fourth inclined surface 1114 is 5 μm, the width W2-4 of the fourth platform surface 1124 is 8 μm, the width W1-5 of the fifth inclined surface 1115 is 5 μm, the width W2-5 of the fifth platform surface 1125 is 12 μm and the width W1-6 of the sixth inclined surface 1116 is 5 μm.

[0070] Embodiment 11:

[0071] The difference from Example 1 is that

[0072] The reference Figure 2 , the number N of the platform surfaces 112 of the microstructure unit 11 is 5, the number of the inclined surfaces 111 is 6, which are the first inclined surface 1111, the first platform surface 1121, the second inclined surface 1112, the second platform surface 1122, the third inclined surface 1113, the third platform surface 1123, the fourth inclined surface 1114, the fourth platform surface 1124, the fifth inclined surface 1115, the fifth platform surface 1125 and the sixth inclined surface 1116 which are arranged in sequence. At this time, the projection widths W1 of different inclined surfaces 111 at the bottom are not completely the same, the projection widths W2 of different platform surfaces 112 at the bottom are not completely the same, and the width W1-1 of the first inclined surface 1111 is The width W2-1 of the first platform surface 1121 is 9μm, the width W2-1 of the second inclined surface 1112 is 4μm, the width W1-2 of the second inclined surface 1112 is 9μm, the width W2-2 of the second platform surface 1122 is 4μm, the width W1-3 of the third inclined surface 1113 is 9μm, the width W2-3 of the third platform surface 1123 is 4μm, the width W1-4 of the fourth inclined surface 1114 is 5μm, the width W2-4 of the fourth platform surface 1124 is 8μm, the width W1-5 of the fifth inclined surface 1115 is 5μm, the width W2-5 of the fifth platform surface 1125 is 8μm and the width W1-6 of the sixth inclined surface 1116 is 5μm.

[0073] Embodiment 12:

[0074] The difference from Example 1 is:

[0075] refer to Figure 3 As shown in A-1 in the figure, the number N of the platform surfaces 112 of the microstructure unit 11 is 2, and the number of the inclined surfaces 111 is 3, which are the first inclined surface 1111, the first platform surface 1121, the second inclined surface 1112, the second platform surface 1122 and the third inclined surface 1113 arranged in sequence. At this time, the projection widths W2 of different platform surfaces 112 at the bottom are different. The projection width W2-1 of the first platform surface 1121 is 16 μm, the projection width W2-2 of the second platform surface 1122 is 8 μm, and the projection width W1 of the inclined surface 111 of the microstructure unit 11 at the bottom is are not completely the same, the projection width W1-1 of the first inclined surface 1111 is 5μm, the projection width W1-2 of the second inclined surface 1112 is 5μm, the projection width W1-3 of the third inclined surface 1113 is 10μm, the width W3 of the bottom surface of the microstructure unit 11 in the first direction X is 44μm, the angle ɑ between the inclined surface 111 and the bottom of the microstructure unit 11 is the same, and the angle ɑ is 70°, the microstructure unit 11 basically extends along the second direction Y, and is arranged along the first direction X, and the spacing S1 between adjacent microstructure units 11 is 0.

[0076] Embodiment 13:

[0077] The difference from Example 1 is:

[0078] The microstructure units 11 extend substantially along the second direction Y and are arranged along the first direction X. The spacing S1 between adjacent microstructure units 11 is 8 μm.

[0079] Comparative Example 1:

[0080] Single-layer trapezoidal structure, the cross section of the microstructure unit 11 is a trapezoid, the trapezoid is an isosceles trapezoid with a bottom width of 18.5 μm and a top width of 10 μm, and the distance between every two trapezoids is 7 μm. Figure 6 shown.

[0081] Comparative Example 2:

[0082] The double-layer trapezoidal structure includes a first substrate layer and a first microstructure layer, a second substrate layer and a second microstructure layer, and the microstructure unit 11 of the microstructure layer is consistent with that of Comparative Example 1.

[0083] The present invention demonstrates the technical effect of the present invention by comparing the 1 / 2 brightness viewing angle and the through light brightness between different embodiments and comparative examples, and the brightness percentage is based on the brightness of embodiment 1. All embodiments must meet the setting conditions of the microstructure of the present invention.

[0084] Test method:

[0085] Vertical 1 / 2 viewing angle: The vertical brightness drops to 1 / 2 of the center brightness, which is the vertical 1 / 2 viewing angle.

[0086] 1 / 2 viewing angle in parallel direction: The point where the brightness in the parallel direction drops to 1 / 2 of the central brightness is the 1 / 2 viewing angle in the parallel direction.

[0087] Brightness: Use BM-7 to measure the brightness at the center of the backlight.

[0088] The test results of Examples 1-13 and Comparative Examples 1-2 are shown in Table 1:

[0089] Table 1

[0090]

[0091] The results of the above embodiments show that the optical films of Examples 1-13 can maintain a relatively high brightness performance under a larger viewing angle compared to the single-layer trapezoidal microstructure of Comparative Example 1. Compared to Comparative Example 1, the optical films of Examples 1-13 can more effectively utilize the light that is totally reflected in the bevel 111 area, improve the visual viewing angle in the vertical direction and / or parallel direction, and ensure excellent optical brightness. Compared to Comparative Example 2, Examples 1-13 have multiple microstructure layers in Comparative Example 2, and the optical brightness is improved to a certain extent, but the optical viewing angle of Comparative Example 2 is narrow. In summary, the optical film described in the present application has a specific microstructure unit 11, and adopts an optical structure in which the bevel 111 and the plane alternate, so that the viewing angle of the light is expanded through the plane part, and then the light is converged as much as possible within the light viewing angle of the target through the bevel 111 part, thereby improving the optical viewing angle range while maintaining high brightness.

[0092] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example.

[0093] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An optical film, characterized in that: The invention comprises a substrate layer (2) and a microstructure layer (1), wherein the microstructure layer (1) comprises a plurality of protruding microstructure units (11), the bottom surface of the microstructure unit (11) is in contact with the substrate layer (2), a platform surface (112) and an inclined surface (111) are present on the side of the single microstructure unit (11) away from the substrate layer (2), the platform surfaces (112) and the inclined surfaces (111) are arranged alternately, the number of the platform surfaces (112) in the single microstructure unit (11) is N, the number of the inclined surfaces (111) is at least N+1, and the number N of the platform surfaces (112) in the single microstructure unit (11) is greater than 2 and less than or equal to 7; the microstructure units (11) in the microstructure layer (1) are arranged along a first direction, the microstructure units (11) extend or are arranged along a second direction, and the platform surfaces of the microstructure layer (1) are arranged along a first direction and a second direction. (112) is parallel to the surface of one side of the substrate layer (2); the cross section of the microstructure unit (11) parallel to the first direction and perpendicular to the bottom surface is a geometric figure enclosed by an oblique line and a straight line parallel to the bottom surface, and the angle ɑ between the oblique surface (111) and the horizontal plane where the bottom surface is located is 70°-80°; the width W1 of the projection of the single oblique surface (111) perpendicular to the plane where the bottom surface is located in the first direction is 1.25-7μm; the width W2 of the single platform surface (112) in the first direction is 2-10μm; the width W3 of the bottom surface in the microstructure unit (11) in the first direction is 17.5-82μm; light enters from the bottom surface of the microstructure unit (11), is refracted and / or reflected in the microstructure unit (11), and finally is emitted from different surfaces of the microstructure unit (11) away from the substrate layer (2).

2. The optical film according to claim 1, characterized in that: In the single microstructure unit (11), the number N of the platform surfaces (112) is greater than or equal to 5.

3. The optical film according to claim 1, characterized in that: The widths W1 of different inclined surfaces (111) in the single microstructure unit (11) are the same or different; the included angles ɑ of different inclined surfaces (111) in the single microstructure unit (11) are the same or different; and the widths W2 of different platform surfaces (112) in the single microstructure unit (11) are the same or different.

4. The optical film according to claim 1, characterized in that: There is a spacing S1 between the different microstructure units (11) in the first direction, and the spacing S1 is less than or equal to 10 μm.

5. The optical film according to claim 3, characterized in that: The spacing S1 between the different microstructure units (11) in the first direction is 0 μm.

6. An optical device, characterized in that: The optical film according to claim 1 is applied to the optical device.

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