Backlight module with V-shaped emergent light distribution

Abstract

The invention relates to the technical field of backlight display, in particular to a backlight module with V-shaped emergent light distribution, which comprises a backlight source LED and a light guide plate, the light guide plate comprises a light incident surface, a light emergent surface and a lattice point surface, the light incident surface is opposite to the light emitting surface of the light source LED, and the light emergent surface and the lattice point surface are vertically connected with the light incident surface; the wedge-shaped lattice point structure is characterized in that the lattice point surface is provided with wedge-shaped lattice point structures which are arranged in a mathematical mode, the wedge-shaped lattice point structures are formed by being concaved inwards from the surface of the lattice point surface to D3, and the tip ends of the wedge-shaped lattice point structures point to the light incident surface. By optimizing the shape, the size and the section angle of the microstructure and cooperating with the efficient light uniformizing film, the brightness can be improved by 20%-30% (the effect is slightly different according to different specific parameters), a more excellent light uniformizing effect is achieved, the method can be applied to an OD = 0 framework, and the thickness of a backlight module can be reduced by 2-5 mm.

Description

Technical Field

[0001] This invention relates to the field of backlight display technology, and more specifically to a backlight module with a V-shaped light emission distribution. Background Technology

[0002] Liquid crystal displays (LCDs) have significant advantages such as small size, low power consumption, and no radiation, making them the mainstream display devices on the market today. As a passively emitting LCD, the backlight module is one of its crucial components. The backlight module contains multiple light-emitting devices (LED chips) that provide the light source for the LCD screen.

[0003] To achieve privacy protection, common side-lit backlights typically add a privacy film to the backlight assembly. The privacy protection principle is designed to limit the viewing angle of light after it passes through the film using a microstructured louver grating. However, this significantly reduces the brightness of the display device, increasing the power consumption and cost of the backlight module. Furthermore, the privacy film can only achieve privacy protection in one direction, with a minimum privacy protection angle of only ±30° (5% brightness viewing angle), still resulting in a relatively large viewing angle and failing to achieve perfect privacy protection. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention discloses a backlight module with a V-shaped light output distribution to solve the aforementioned problems.

[0005] This invention is achieved through the following technical solution:

[0006] This invention provides a backlight module with a V-shaped light emission distribution, including a backlight LED and a light guide plate. The light guide plate includes a light incident surface, a light emitting surface, and a dotted surface. The light incident surface is opposite to the light emitting surface of the LED, and the light emitting surface and the dotted surface are perpendicularly connected to the light incident surface. The dotted surface is provided with a wedge-shaped dot structure arranged in a mathematical manner. The wedge-shaped dot structure is formed concavely from the surface of the dotted surface towards D3, and the tip of the wedge-shaped dot structure points towards the light incident surface.

[0007] Furthermore, the mathematical arrangement can be any of the following: Bessel equation, offset rectangle, radial polynomial, grid, random number, or list.

[0008] Furthermore, a mirror-reflective film is provided below the light guide plate.

[0009] Furthermore, a prism light-enhancing film is disposed above the light guide plate. The prism light-enhancing film is parallel to the D1 direction and is used to deflect the large-angle emitted light in the D2 direction to achieve collimation and maintain large-angle split light in the D1 direction.

[0010] Furthermore, a diffusion film is provided above the prism light-enhancing film to atomize the light and make the emitted light evenly distributed within a set viewing angle range.

[0011] Furthermore, the light guide plate is provided with a wedge-shaped pyramidal light-diffusing film. The length of the base of the wedge-shaped pyramidal light-diffusing film ranges from 10 to 100 mm, the height of the wedge-shaped pyramid ranges from 10 to 60 mm, and the length a of the wedge-shaped pyramid is x times the length of the base b, where x ≥ 1.

[0012] Furthermore, the convex structure of the wedge-shaped pyramidal light-diffusing film near the light source is a wedge-shaped pyramidal ultrastructure, and the concave structure of the wedge-shaped pyramidal light-diffusing film away from the light source is a wedge-shaped multi-pyramidal ultrastructure.

[0013] Furthermore, the side length of the pyramidal microstructure of the wedge-shaped pyramidal light-diffusing film ranges from 10 to 100 micrometers, and the depth ranges from 10 to 60 micrometers.

[0014] Furthermore, the propagating light rays of the backlight LED along the D2 direction are deflected on the light-facing surface by the wedge-shaped dot structure, and the refracted light rays are emitted obliquely upwards. The angle between the planar components formed by D2 and D3 is γn=γ1-n*2γ≤arcsin(1 / n1). When a beam of propagating light rays with an angle of γ1, where γ1>LGP critical angle, is reflected by n γ angle dots, it can be incident on the light-emitting surface at an angle of γn, where γn≤LGP critical angle, and finally emitted into the air at an angle of γm, where γn and γm satisfy the law of refraction: n1 sin(γn)=n2 sin(γm), where n1 is the refractive index of the light guide plate, n2 is the refractive index of air, and n is an integer greater than 0.

[0015] Furthermore, the light-facing surface of the wedge-shaped dot structure forms an angle β with the incident surface. The deflection angle on the plane formed by the D1 and D2 directions satisfies the law of refraction with β. The refraction angle is 2*β with D2. Finally, it exits into the air at an angle βm, where β and βm satisfy the law of refraction: n1 sin(2*β)=n2 sin(βm), where n1 is the refractive index of the light guide plate and n2 is the refractive index of air.

[0016] The beneficial effects of this invention are as follows:

[0017] This invention optimizes the shape, size, and cross-sectional angle of the microstructure, and, in conjunction with a high-efficiency light-diffusing film, can increase brightness by 20%-30% (the effect may vary slightly depending on the specific parameters), and has a superior light-diffusing effect. It can be applied to OD=0 architecture and can reduce the thickness of the backlight module by 2-5mm. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the light guide plate structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the light propagation trajectory in the light guide plate of the present invention;

[0021] Figure 3 This is a schematic diagram of the wedge-shaped dot structure in the light guide plate of the present invention;

[0022] Figure 4 This is a schematic diagram of the light propagation trajectory of the light emitting surface of the light guide plate of the present invention;

[0023] Figure 5 This is a schematic diagram of the light propagation trajectory of the light emitting surface of the light guide plate of the present invention.

[0024] Figure 6 This is a schematic diagram of the wedge-shaped dot structure of the present invention;

[0025] Figure 7 This is a schematic diagram of the single-sided light-incident backlight module architecture according to an embodiment of the present invention;

[0026] Figure 8 This is a simulation diagram of the light emission angle distribution of the backlight module in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figure 1-8 ,in Figure 1 This is a schematic diagram of the light guide plate structure of the present invention; Figure 2 This is a schematic diagram of the light propagation trajectory in the light guide plate of the present invention; Figure 3 This is a schematic diagram of the wedge-shaped dot structure in the light guide plate of the present invention; Figure 4 This is a schematic diagram of the light propagation trajectory of the light emitting surface of the light guide plate of the present invention; Figure 5 This is a schematic diagram of the light propagation trajectory of the light emitting surface of the light guide plate of the present invention. Figure 6This is a schematic diagram of the wedge-shaped dot structure of the present invention; Figure 7 This is a schematic diagram of the single-sided light-incident backlight module architecture according to an embodiment of the present invention; Figure 8 This is a simulation diagram of the light emission angle distribution of the backlight module according to an embodiment of the present invention.

[0029] This embodiment provides a backlight module with a V-shaped light output distribution, including a backlight LED 200 and a light guide plate 100, as shown in the reference. Figure 1 As shown, the light guide plate 100 includes a light incident surface 101, a light emitting surface 102, and a dot surface 103. The light incident surface 101 is opposite to the light emitting surface of the light source LED 200, and the light emitting surface 102 and the dot surface 103 are perpendicularly connected to the light incident surface 101. The dot surface 103 is characterized by having a wedge-shaped dot structure 104 arranged mathematically. The wedge-shaped dot structure 104 is formed concavely from the surface of the dot surface towards D3, and the tip of the wedge-shaped dot structure 104 points towards the light incident surface 101.

[0030] This embodiment uses the unique triangular prism dot structure of the light guide plate to control the direction of light propagation in the light guide plate. The continuous prism curved surface light control microstructure on the light-emitting surface shrinks stray light, so that the light passing through this new light guide plate is concentrated in a very small viewing angle range. By adjusting the angle of the bevel of the triangular prism dot, the collimation of the emitted light is controlled.

[0031] In one embodiment, reference is made to Figure 2 As shown, in the D2 direction, the angle between the ridge of the wedge-shaped dot structure and the dot surface is γ, and the angle α between the non-light-facing surface and the dot surface is 45°≤α<90° due to processing limitations. The light propagating in the light guide plate is reflected by the dot structure and continues to propagate to the far end in the D2 direction. Moreover, the light propagating in the light guide plate undergoes more or less dot reflections, which can meet the angle of total internal reflection requirements. Therefore, the emitted light with a relatively concentrated viewing angle distribution can be obtained.

[0032] In one embodiment, such as Figure 3 As shown, the propagating ray along the D2 direction is deflected by the dots on the light-facing surface, and the refracted ray is emitted obliquely upwards, with its spatial distribution as follows. Figure 4 As shown; the angle between the planar components formed by D2 and D3 is γn=γ1-n*2γ≤arcsin(1 / n1). When a beam of light with an angle of γ1 (γ1>LGP critical angle) is reflected by n (an integer greater than 0) γ angle dots, it can be incident on the light-emitting surface at an angle of γn (γn≤LGP critical angle) and finally exit into the air at an angle of γm. γn and γm satisfy the law of refraction: n1sin(γn)=n2sin(γm), where n1 is the refractive index of the light guide plate and n2 is the refractive index of air.

[0033] In one embodiment, such as Figure 5As shown, the light-facing surface of the wedge-shaped dot pattern forms a certain angle β with the incident surface. The deflection angle on the plane formed by the D1 and D2 directions satisfies the law of refraction with β. The refraction angle is 2*β with D2. Finally, it exits into the air at an angle βm, where β and βm satisfy the law of refraction: n1 sin(2*β)=n2 sin(βm), where n1 is the refractive index of the light guide plate and n2 is the refractive index of air.

[0034] In one embodiment, such as Figure 6 The diagram shows wedge-shaped dots with a dot height H ranging from 1µm to 20µm; edge length L ≤ 100µm; tanβ = W / 2L; 45° ≥ β ≥ 0°; 90° ≥ α ≥ 75° (considering the manufacturing process).

[0035] In one embodiment, the positional pattern of the triangular prism dots 130 on the dot surface of the light guide plate can be set according to the Bessel equation:

[0036]

[0037] Therefore, light incident from the incident surface can be uniformly reflected to the emitting surface, improving the uniformity of brightness across the emitting surface and further achieving a more uniform display. The arrangement of the triangular prism dots can also be optimized using different dot arrangement methods, such as offset rectangles, polygons, radial polynomials, grids, random numbers, lists, etc.; the light guide structure 120 is distributed in the remaining area of ​​the dot surface excluding the dot positions.

[0038] In one embodiment, reference is made to Figure 7 As shown, a schematic diagram of a backlight module is disclosed. The backlight module includes multiple backlight LEDs 200, a specular reflective film 500 placed below a light guide plate, and a prism-enhancing film above the light guide plate. The prism of the film is parallel to the D1 direction and is used to deflect large-angle emitted light in the D2 direction to achieve collimation, maintaining large-angle split light in the D1 direction. Above the prism film is a diffuser film, which increases the haze of the backlight module, thereby atomizing the light and distributing the emitted light evenly within a certain viewing angle range. Simultaneously, it shields the prism structure, optimizing the display effect of the backlight module. Figure 8 This simulation of the light emission angle distribution of the backlight module can meet the needs of products with special display angles.

[0039] In one embodiment, using the ultra-microstructure light-diffusing film and backlight module provided by this patent can not only increase the brightness by 20%-30% (the effect varies slightly depending on the specific parameters), but also has a better light-diffusing effect, which can reduce the OD value to 0 and reduce the thickness of the backlight module by 2-5mm.

[0040] In one embodiment, an ultrastructured light-diffusing film with a wedge-shaped pyramidal convex surface structure A is provided. Preferably, the base length of the wedge-shaped pyramid ranges from 10 to 100 mm, the height ranges from 10 to 60 mm, and the length a of the wedge-shaped pyramid is x (x≥1) times the base length b. The height and width of the wedge-shaped pyramid exhibit the same trend (both increasing or decreasing) along the pyramidal orientation, and adjacent wedge-shaped pyramidal units have opposite orientations.

[0041] In one embodiment, an ultrastructured light-diffusing film with a wedge-shaped pyramidal convex surface structure B is provided. Preferably, the base length of the wedge-shaped pyramid ranges from 10 to 100 mm, the height ranges from 10 to 60 mm, and the length a of the wedge-shaped pyramid is x (x≥1) times the base length b. The wedge-shaped pyramid B is structurally complementary to the wedge-shaped pyramid A and can be obtained by recessing the wedge-shaped pyramid A.

[0042] The wedge-shaped pyramidal convex microstructure provided in this embodiment can be used as a single-sided microstructure uniform light film without a concave structure, while the other side is not made of microstructure shape, or diffuse particles are added to enhance the uniformity of light.

[0043] In one embodiment, an ultrastructured light-diffusing film with a wedge-shaped multi-faceted pyramidal concave surface is provided. The wedge-shaped structure is disposed on the surface of a base pyramid, with the triangular base of the wedge-shaped structure perpendicular to the base of the base pyramid. The side length of the wedge-shaped structure is y (y≤1) times the side length of the base pyramid, and the height of the wedge-shaped pyramid gradually decreases along the surface of the base pyramid towards the corresponding base edge. Preferably, the side length of the base pyramidal microstructure ranges from 10 to 100 micrometers, and the depth ranges from 10 to 60 micrometers.

[0044] The wedge-shaped multi-faceted concave microstructure provided in this embodiment can also be used as a single-sided microstructure uniform light film without a convex structure, with the other side not having a microstructure shape, or with the addition of diffusing particles to enhance uniform light performance.

[0045] In one embodiment, a double-sided ultra-microstructure light-diffusing film with a wedge-shaped structure is provided. The convex structure of the light-diffusing film near the light source is a wedge-shaped pyramidal ultra-microstructure, and the concave structure of the light-diffusing film away from the light source is a wedge-shaped multi-pyramidal ultra-microstructure. Preferably, the thickness of the substrate such as PC is in the range of 0.05 to 2 mm.

[0046] In one embodiment, an ultra-thin backlight module employing the above-mentioned microstructure uniform light film can reduce the OD value to 0 and reduce the thickness of the backlight module by 2-5 mm.

[0047] This invention discloses a unique optimized combination of microstructure shape, size, and cross-sectional angle, creating a highly efficient light-diffusing film. This light-diffusing film significantly improves brightness, achieving a 20%–30% increase, with slight variations depending on the parameters. This light-diffusing film not only enhances brightness but also delivers superior light-diffusing performance, resulting in more uniform light distribution and reduced light spots and dark areas.

[0048] To achieve this highly efficient light-uniforming film, this invention involved in-depth research and meticulous experimentation. Through repeated adjustments and optimizations to the shape, size, and cross-sectional angles of the microstructures, we successfully improved brightness and enhanced the light-uniforming effect. This optimization is reflected not only in the characteristics of individual microstructures but also in the macroscopic effect of the entire film layer.

[0049] It's worth noting that this light-diffusing film can be applied to OD=0 architectures, meaning it can be seamlessly integrated into existing backlight modules without increasing module thickness. On the contrary, due to its efficient light-diffusing effect and light utilization, the thickness of the backlight module can be reduced by 2-5mm. This is a significant advantage for modern electronic products, as thinner backlight modules not only reduce product size and weight but also improve portability and aesthetics.

[0050] Furthermore, this light-diffusing film has broad application prospects. It can be applied to various electronic products that require backlight modules, such as LCD monitors, televisions, laptops, and tablets. This highly efficient light-diffusing film can bring brighter and more uniform display effects to these products, improving the user's visual experience.

[0051] In summary, the high-efficiency light-uniforming film disclosed in this invention achieves a significant increase in brightness and improved light uniformity through optimization of its microstructure shape, size, and cross-sectional angle. It can be applied to OD=0 architectures, reducing the thickness of backlight modules by 2-5mm, bringing new possibilities and advantages to modern electronic products.

[0052] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A backlight module with a V-shaped light emission distribution, comprising a backlight LED 200 and a light guide plate 100, wherein the light guide plate 100 includes a light incident surface 101, a light emitting surface 102, and a dotted surface 103, the light incident surface 101 being opposite to the light emitting surface of the LED 200, and the light emitting surface 102 and the dotted surface 103 being perpendicularly connected to the light incident surface 101; characterized in that, The dot surface 103 is provided with a wedge-shaped dot structure 104 arranged in a mathematical manner. The wedge-shaped dot structure 104 is formed concavely from the surface of the dot surface towards D3, and the tip of the wedge-shaped dot structure 104 points towards the light-incident surface 101.

2. A backlight module with a V-shaped light emission distribution according to claim 1, characterized in that, The mathematical arrangement can be any of the following: Bessel equation, offset rectangle, radial polynomial, grid, random number, or list.

3. A backlight module with a V-shaped light emission distribution according to claim 1, characterized in that, A mirror-reflective film 500 is provided below the light guide plate 100.

4. A backlight module with a V-shaped light emission distribution according to claim 1, characterized in that, A prism light-enhancing film is disposed above the light guide plate. The prism light-enhancing film is parallel to the D1 direction and is used to deflect the large-angle emitted light in the D2 direction to achieve collimation and maintain the large-angle split light in the D1 direction.

5. A backlight module with a V-shaped light emission distribution according to claim 4, characterized in that, A diffusion film is provided above the prism light-enhancing film to atomize the light and make the emitted light evenly distributed within a set viewing angle range.

6. A backlight module with a V-shaped light emission distribution according to claim 1, characterized in that, The light guide plate is provided with a wedge-shaped pyramidal light-diffusing film. The length of the base of the wedge-shaped pyramidal light-diffusing film ranges from 10 to 100 mm, the height of the wedge-shaped pyramidal film ranges from 10 to 60 mm, and the length a of the wedge-shaped pyramidal film is x times the length of the base b, where x ≥ 1.

7. A backlight module with a V-shaped light emission distribution according to claim 6, characterized in that, The convex structure of the wedge-shaped pyramidal light-diffusing film near the light source is a wedge-shaped pyramidal ultrastructure, and the concave structure of the wedge-shaped pyramidal light-diffusing film away from the light source is a wedge-shaped multi-pyramidal ultrastructure.

8. A backlight module with a V-shaped light emission distribution according to claim 6, characterized in that, The wedge-shaped pyramidal light-diffusing film has a pyramidal microstructure with a side length ranging from 10 to 100 micrometers and a depth ranging from 10 to 60 micrometers.

9. A backlight module with a V-shaped light emission distribution according to claim 1, characterized in that, The backlight LED propagating along the D2 direction is deflected on the light-facing surface by the wedge-shaped dot structure 104, and the refracted light is emitted obliquely upward. The angle between the planar components formed by D2 and D3 is γn = γ1 - n*2γ ≤ arcsin(1 / n1). When a beam of propagating light with an angle of γ1, where γ1 > LGP critical angle, is reflected by n γ angle dots, it can be incident on the light-emitting surface at an angle of γn, where γn ≤ LGP critical angle, and finally emitted into the air at an angle of γm, where γn and γm satisfy the law of refraction: n1sin(γn) = n2sin(γm), where n1 is the refractive index of the light guide plate, n2 is the refractive index of air, and n is an integer greater than 0.

10. A backlight module with a V-shaped light emission distribution according to claim 1, characterized in that, The wedge-shaped dot structure 104 forms an angle β between its light-facing surface and its incident surface. The angle of deflection on the plane formed by the D1 and D2 directions satisfies the law of refraction with β. The angle of refraction is 2*β with D2. Finally, it exits into the air at an angle βm, where β and βm satisfy the law of refraction: n1 sin(2*β)=n2 sin(βm), where n1 is the refractive index of the light guide plate and n2 is the refractive index of air.

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