Optical structure and optical film for shaping brightness distribution of Lambert light source

Abstract

The utility model discloses an optical film for shaping the brightness distribution of a Lambert light source, and belongs to the field of light-transmitting structures. Comprising a base film, a plurality of optical structures are arranged on the light-emitting surface of the base film, and each optical structure comprises a first body and a second body which are of an integrated structure. The lens structure is of a two-section type combined structure, the brightness angle distribution of the LED light source is adjusted by adjusting parameters such as the angle, the size and the shape of the lens, and the needed brightness distribution effect is achieved. By adopting the lens structure, smoother brightness distribution can be realized by refracting and diffusing light rays, the hot spot effect is reduced, and the lens structure is suitable for scenes with high requirements on uniformity. The wide visual angle design of the lens structure is more flexible, and the beam angle can be flexibly controlled by adjusting the curvature and the arrangement mode of the lens. Moreover, compared with a microprism structure and a lens structure, the optical film technology compatibility is better, the microlens can be prepared in batches through technologies such as photoetching, hot pressing or UV curing, the cost is relatively low, and the optical film can be easily integrated with other optical films.

Description

Technical Field

[0001] This utility model relates to the field of light-transmitting structures, and in particular to an optical structure and optical film for shaping the brightness distribution of a Lambertian light source. Background Technology

[0002] LEDs are widely used in lighting, displays, and other fields due to their advantages such as high efficiency and energy saving, compact structure, rapid response, and ultra-long lifespan. Common LED chips typically emit light with a Lambertian distribution, meaning the brightness is consistent from all viewing angles. However, in some applications, the brightness distribution of the LED light source needs to be oriented at specific angles. Therefore, methods such as adding specific optical films to the surface of the light source are required to achieve this goal.

[0003] Most existing optical films adjust the angular distribution of light source brightness using microprism structures. Through the refraction and total internal reflection effects of prisms, light can be more precisely controlled to exit at specific angles (such as narrow beams or asymmetric light distribution), making them suitable for scenarios requiring strong directionality (such as backlight modules and traffic lights). Prism structures can reduce stray light loss, concentrate more light at the target angle, and improve optical efficiency (up to 80%–90%).

[0004] However, prism structures suffer from poor optical film uniformity, and the prism structure can lead to bright and dark stripes (Mura effect) in the brightness distribution. Furthermore, their manufacturing process is complex; the processing of high-precision prism arrays (such as nanoimprinting or precision injection molding) requires strict control over molds and materials, resulting in high costs. Additionally, the excessive light convergence of prism structures can narrow the viewing angle, limiting their applicability to applications requiring a wide viewing angle (such as general lighting). Utility Model Content

[0005] This invention provides an optical structure and optical film for shaping the brightness distribution of a Lambertian light source, which can solve the problems of poor uniformity and high processing difficulty of prism structure optical films in the prior art.

[0006] The objective of this utility model can be achieved through the following technical solutions:

[0007] An optical structure for shaping the brightness distribution of a Lambertian light source includes a first main body and a second main body of integral structure. The first main body has a light-incident surface S1, and the junction of the first main body and the second main body is a surface S2. The radius of surface S1 is R1, and the radius of surface S2 is S2.

[0008] In the side projection view of the optical structure:

[0009] The optical structure is arranged symmetrically with L0 as the axis of symmetry.

[0010] The first body includes a side profile L1, which is rotated around the axis of symmetry L0 to obtain the side surface S10 of the first body. The angle between L1 and surface S1 is θ1, and the height of the first body is H1.

[0011] The second body includes a side profile L2, which is a curve or a multi-segment broken line. The side profile L2 is rotated around the axis of symmetry L0 to obtain the surface S20 of the second body. The height dimension of the second body is H2.

[0012] Where 20°≤θ1≤80°, H1:R2=1:5~5:1, R2≤200μm.

[0013] In one embodiment of this utility model: the side profile L1 of the first main body is a partial ellipse or arc.

[0014] In one embodiment of this utility model: the side profile L1 of the first body is a concave multi-segment broken line.

[0015] In one embodiment of this utility model: the side profile L2 of the second main body is an arc, a partial ellipse, a hyperbola, or a parabola.

[0016] In one embodiment of this utility model: when the side profile L2 of the second body is an arc, its corresponding central angle is θ2, 20°≤θ2≤90°.

[0017] In one embodiment of this utility model: R2 = 25 μm, θ1 = 50°, R1 = 45.98 μm, H1 = 25 μm, θ2 varies within the range of 22° to 90°, and the corresponding height H2 of the second body varies between 5 μm and 25 μm.

[0018] In one embodiment of this utility model, the light transmittance of the material of the optical structure is between 1.45 and 1.55.

[0019] In one embodiment of this utility model: the optical structure is made of UV resin material.

[0020] An optical film for shaping the brightness distribution of a Lambertian light source includes a base film, wherein a plurality of optical structures as described above are disposed on the light-emitting surface of the base film.

[0021] In one embodiment of this utility model: the optical structure is arrayed on the base film.

[0022] The optical structure and optical film for shaping the brightness distribution of a Lambertian light source according to this utility model have at least one of the following technical effects:

[0023] This application provides an optical structure and optical film for shaping the brightness distribution of a Lambertian light source. A lens structure disposed on the base film of the optical film is used to shape the brightness distribution of the Lambertian light source. The lens structure adopts a two-segment combination structure. By adjusting parameters such as lens angle, size, and shape, the angular distribution of the LED light source brightness is adjusted to achieve the desired brightness distribution effect. Using a lens structure, by refracting and diffusing light, a smoother brightness distribution can be achieved, reducing hotspot effects, making it suitable for scenarios with high uniformity requirements (such as panel lights and medical lighting). Furthermore, the wide viewing angle design of the lens structure is more flexible; by adjusting the lens curvature and arrangement (such as hexagonal close-packed or random distribution), the beam angle can be flexibly controlled (from narrow beam to ultra-wide viewing angle). Moreover, compared to microprism structures, the lens structure optical film has better process compatibility. Microlenses can be mass-produced through processes such as photolithography, hot pressing, or UV curing, with relatively low cost, and are easily integrated with other optical films (such as diffusion films). This solves the problem in the prior art that "prism structure optical films used for adjusting the brightness distribution of LED light sources have certain shortcomings and cannot adapt to certain specific needs." Attached Figure Description

[0024] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood in conjunction with the following description of the embodiments with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this utility model, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Wherein:

[0025] Figure 1 This is a three-dimensional structural diagram of the entire utility model;

[0026] Figure 2 This is a three-dimensional structural diagram of the lens structure of this utility model;

[0027] Figure 3 This is a schematic diagram of the cross-section of the lens structure of this utility model;

[0028] Figure 4 This is a schematic diagram of the propagation path of light through the lens structure in this utility model;

[0029] Figure 5 This is a schematic diagram of the structure where H2 = 5 in Embodiment 1 of this utility model;

[0030] Figure 6 This is a schematic diagram of the structure in Embodiment 1 of this utility model where H2 = 25;

[0031] Figure 7 This is a graph showing the angular brightness curves for H2 values ​​of 5μm, 15μm, and 25μm in Embodiment 1 of this invention; the curve for H2 = 5 corresponds to... Figure 5 The curve corresponding to the lens structure in the image when H2 = 25 is... Figure 6 The lens structure in it;

[0032] Figure 8 This is a schematic diagram of the structure when θ1 = 25° in Embodiment 1 of this utility model;

[0033] Figure 9 This is a schematic diagram of the structure in Embodiment 1 of this utility model, where θ1 = 65°.

[0034] Figure 10 This is a graph showing the angular brightness curves for θ1 at 25°, 45°, and 65° in Embodiment 1 of this utility model; the curve for θ1 = 25° corresponds to... Figure 8 The lens structure in the image corresponds to the curve where θ1 = 65°. Figure 9 The lens structure in it;

[0035] Figure 11 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0036] Figure 12 This is a schematic diagram of the structure of Embodiment 3 of this utility model;

[0037] Figure 13 This is a schematic diagram of the structure of Embodiment 4 of this utility model;

[0038] Figure 14 This is a schematic diagram of the structure of Embodiment 5 of the present invention;

[0039] Figure 15 This is a structural schematic diagram of Embodiment 6 of the present invention.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1. First main body; 2. Second main body; 3. Base membrane. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0043] Most existing optical films adjust the angular distribution of light source brightness using microprism structures. While this has certain advantages, it also has a number of drawbacks. For example, prism-structured optical films have poor uniformity; due to the Mura effect, the prism structure can cause bright and dark stripes in the brightness distribution. Furthermore, the manufacturing process for prism-structured optical films is complex; the processing of high-precision prism arrays (such as nanoimprinting or precision injection molding) requires strict control over molds and materials, resulting in high costs. Additionally, the excessive light convergence of the prism structure can lead to a narrowed viewing angle, limiting its suitability for applications requiring a wide viewing angle (such as general lighting).

[0044] In summary, prism-structured optical films have certain shortcomings and cannot meet specific needs when used for adjusting the brightness distribution of LED light sources. Therefore, this application provides an optical structure and optical film for shaping the brightness distribution of a Lambertian light source. This application uses a lens structure disposed on the optical film base film 3 to shape the brightness distribution of the Lambertian light source. The lens structure adopts a two-segment combination structure. By adjusting parameters such as lens angle, size, and shape, the angular distribution of the LED light source brightness is adjusted to achieve the desired brightness distribution effect. Using a lens structure, by refracting and diffusing light, a smoother brightness distribution can be achieved, reducing hotspot effects, making it suitable for scenarios with high uniformity requirements (such as panel lights and medical lighting). Furthermore, the wide-viewing-angle design of the lens structure is more flexible; by adjusting the lens curvature and arrangement (such as hexagonal close-packed or random distribution), the beam angle can be flexibly controlled (from narrow beam to ultra-wide viewing angle). Furthermore, compared to microprism structures, lens structures offer better compatibility in optical film manufacturing processes. Microlenses can be mass-produced through processes such as photolithography, hot pressing, or UV curing, resulting in relatively low costs and easy integration with other optical films (such as diffusion films).

[0045] like Figure 1-15 As shown in the figure, this utility model provides an optical film for shaping the brightness distribution of a Lambertian light source, comprising a base film 3. A plurality of light-transmitting optical structures are disposed on the light-emitting surface of the base film 3. These optical structures can be arranged in an array on the base film 3, such as a rectangular array, a hexagonal array, or a circular axis array. A uniformly dense arrangement is also possible. The optical structures are lens structures, and the refractive index of the lens structure material is between 1.45 and 1.55 (the extreme values ​​can be taken). The lens structure can be made of UV resin material or other similar materials, and the structure is formed on the substrate using a specific molding die or other similar tools and a UV curing coating process. The lens structure includes a first body 1 and a second body 2, which are integrally formed. One end of the first body 1 is connected to the base film 3, and the other end is connected to the second body 2.

[0046] Example 1

[0047] In this embodiment, as Figure 3 As shown, this is a side projection view of the optical structure, which can also be considered a cross-sectional view. In this view, it is a symmetrical structure with an axis of symmetry L0, composed of a first main body 1 and a second main body 2. The first main body 1 includes surfaces S1 and S2, and a side L1. The angle between L1 and surface S1 is θ1, and the height of the first main body 1 is H1. The second main body 2 includes surface S2 and a side L2. L2 is an arc with a corresponding central angle θ2, and the height of the second main body 2 is H2. Surfaces S1 and S2 are circular, with radius R1 for surface S1 and radius S2 for surface S2. Surface S1 is the light-incident surface of the lens structure, and surface S2 is the intersection surface of the first main body 1 and the second main body 2. Surface S2 is provided for ease of describing the first main body 1 and the second main body 2 separately; in the actual structure, the lens structure is a single unit. Figure 2 As shown, surface S10 is obtained by rotating the side L1 of the first main body 1 around the axis of symmetry L0, and surface S20 is obtained by rotating the side L2 of the second main body 2 around the axis of symmetry L0. Surface S1 of the lens structure is in contact with the base film 3. After passing through the base film 3, light enters from surface S1 of the lens structure and then exits from surfaces S10 and S20.

[0048] like Figure 3 As shown, in this embodiment, the angle θ1 in the lens structure varies between 20° and 80°, the angle θ2 varies between 20° and 90°, H1:R2 = 1:5 to 5:1, R2 ≤ 200μm, and the value of R1 is determined according to the values ​​of R2, H1, and θ1.

[0049] like Figure 4 The diagram illustrates the propagation path of light rays through a lens structure. For ease of description, some light rays are labeled as ray 101, ray 202, ray 303, ray 404, and ray 505. The angle of ray 101, incident perpendicularly to surface S1, is defined as 0°, and the angle of light rays parallel to surface S1 is defined as 90°. Smaller angles indicate convergence, while larger angles indicate divergence. Ray 101, incident perpendicularly, exits perpendicularly after passing through the lens structure. Rays 102, 103, and those with similar angles are deflected at a certain angle in the vertical direction after passing through surface S20. Ray 104 is incident perpendicularly to surface S10 and exits at the same angle. Light rays with angles less than 104 are slightly deflected towards a smaller angle after passing through surface S10, while light rays with angles greater than 104 are slightly deflected towards a larger angle after passing through surface S10. After passing through surface S10, light 105 is slightly deflected in a large angle direction and is reflected and refracted at surface S10 of the adjacent lens structure.

[0050] As an example, Figure 5 , Figure 6 These are side views of typical optical film structures with H2 = 5 and 25, respectively. In these cases, the lens structure has R2 = 25 μm, θ1 = 50°, R1 = 45.98 μm, H1 = 25 μm, and the central angle θ2 of side L2 varies from 22° to 90°. Correspondingly, the height H2 of the second main body 2 varies from approximately 5 μm to 25 μm. As the height H2 of the second main body 2 increases, the corresponding central angle of the arc on side L2 gradually increases.

[0051] exist Figure 5 , Figure 6 Based on the lens structure shown. Figure 7 The diagram shows the angular brightness curves for H2 values ​​of 5μm, 15μm, and 25μm. When H2 = 5μm, the light passing through the optical film begins to decrease in brightness faster than the light source at approximately ±30°, until it intersects with the light source brightness at approximately ±80°, decreasing in brightness within a viewing angle range of 30° to 80°. As H2 increases, a peak appears between 30° and 80°. When H2 = 25μm, this peak is near 80°, and the light pattern at this point resembles a bat's wing. The above trends can be used as a reference when designing specific lens structure parameters.

[0052] like Figure 8 , Figure 9 The figures show side views of another typical optical film structure with angles of θ1 = 25° and 65°, respectively. In this case, the lens structure has R2 = 25 μm, H1 = 25 μm, the central angle θ2 of side L2 remains unchanged, and the corresponding height H2 of the second body 2 remains unchanged. As θ1 of the first body 1 changes, the radius R1 of the corresponding surface S1 changes accordingly.

[0053] exist Figure 8 , Figure 9 Based on the lens structure shown. Figure 10 The figures show the angular brightness curves for lens structures with θ1 values ​​of 25°, 45°, and 65°. When θ1 = 25°, the light passing through the optical film begins to decrease in brightness faster than the light source at approximately ±40°, until it intersects with the light source brightness at approximately ±80°, showing a decrease in brightness within the 40° to 80° viewing angle range. As θ1 increases, the brightness curve begins to decrease at smaller angles, intersecting with the light source curve at 80°, and a peak appears near 80°. When designing specific lens structure parameters, these trends can be used as a reference for selection.

[0054] Example 2

[0055] Please see Figure 11In this embodiment, based on embodiment 1, the side profile L2 of the second body 2 is changed from a circular arc to a partial ellipse. In this embodiment, the shape of the ellipse can be changed by adjusting R2:H2 to achieve the shaping of the light source brightness distribution.

[0056] Example 3

[0057] In this embodiment, as Figure 12 As shown, based on Embodiment 1, the side profile L2 of the second body 2 is changed from an arc to a hyperbola. In this embodiment, the shape of the curve can be changed by adjusting H2 to achieve the shaping of the light source brightness distribution.

[0058] Example 4

[0059] like Figure 13 As shown, in this embodiment, based on embodiment 1, the side profile L2 of the second body 2 is changed from an arc to a parabola. In this embodiment, the shape of the curve can be changed by adjusting H2 to achieve the shaping of the light source brightness distribution.

[0060] Example 5

[0061] like Figure 14 As shown, in this embodiment, based on embodiment 2, the side L2 of the second body 2 remains partially elliptical, while the side L1 of the first body 1 is an arc. In this embodiment, the brightness distribution of the light source can be shaped by changing the radius of curvature of the arc L1 and the concave or convex condition. The figure shows a schematic diagram of the concave condition.

[0062] Example 6

[0063] like Figure 15 As shown, in this embodiment, based on embodiment 2, the outline of the side L2 of the second main body 2 remains partially elliptical, and the side L1 of the first main body 1 can be partially elliptical. In this embodiment, the elliptical curve and the concave and convex conditions can be changed by changing the value of R1:H1 to shape the brightness distribution of the light source.

[0064] Example 7

[0065] Based on the above embodiments, when L1 and L2 are curves, the curves can be simplified into multi-segment broken lines, and similar effects as curve structures can be obtained.

[0066] The foregoing has provided a detailed description of one embodiment of the present invention, but the description is merely a preferred embodiment and should not be construed as limiting the scope of the present invention. All equivalent variations and improvements made within the scope of the claims of the present invention should still fall within the scope of the claims of the present invention.

[0067] In the description of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are used only for the convenience of describing this utility model and for 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 utility model. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0068] In the description of this utility model, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0069] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

Claims

1. An optical structure for shaping the brightness distribution of a Lambertian light source, characterized in that, The first body and the second body are integrally structured. The first body has a light-incident surface S1, and the junction of the first body and the second body is a surface S2. The radius of surface S1 is R1, and the radius of surface S2 is S2. In the side projection view of the optical structure: The optical structure is arranged symmetrically with L0 as the axis of symmetry. The first body includes a side profile L1, which is rotated around the axis of symmetry L0 to obtain the side surface S10 of the first body. The angle between L1 and surface S1 is θ1, and the height of the first body is H1. The second body includes a side profile L2, which is a curve or a multi-segment broken line. The side profile L2 is rotated around the axis of symmetry L0 to obtain the surface S20 of the second body. The height dimension of the second body is H2. Where 20°≤θ1≤80°, H1:R2=1:5~5:1, R2≤200μm.

2. The optical structure for shaping the brightness distribution of a Lambertian light source according to claim 1, characterized in that, The side profile L1 of the first main body is a partial ellipse or arc.

3. The optical structure for shaping the brightness distribution of a Lambertian light source according to claim 1, characterized in that, The side profile L1 of the first main body is a concave multi-segment broken line.

4. The optical structure for shaping the brightness distribution of a Lambertian light source according to claim 1, characterized in that, The side profile L2 of the second main body is an arc, a partial ellipse, a hyperbola, or a parabola.

5. The optical structure for shaping the brightness distribution of a Lambertian light source according to claim 1, characterized in that, When the side profile L2 of the second main body is an arc, its corresponding central angle is θ2, 20°≤θ2≤90°.

6. The optical structure for shaping the brightness distribution of a Lambertian light source according to claim 5, characterized in that, R2 = 25 μm, θ1 = 50°, R1 = 45.98 μm, H1 = 25 μm, θ2 varies from 22° to 90°, and the corresponding height H2 of the second body varies from 5 μm to 25 μm.

7. The optical structure for shaping the brightness distribution of a Lambertian light source according to claim 1, characterized in that, The light transmittance of the material of the optical structure is between 1.45 and 1.

55.

8. The optical structure for shaping the brightness distribution of a Lambertian light source according to claim 7, characterized in that, The optical structure is made of UV resin material.

9. An optical film for shaping the brightness distribution of a Lambertian light source, comprising a base film, characterized in that, The base film is provided with a plurality of optical structures according to any one of claims 1 to 8, wherein the surface S1 of the first main body of the optical structure is in contact with the base film.

10. An optical film for shaping the brightness distribution of a Lambertian light source according to claim 9, characterized in that, The optical structures are arrayed on the base film.

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