Novel backlight module with deflection prism

Abstract

The invention relates to the technical field of photoelectric display, in particular to a novel backlight module with a deflection prism, which comprises a light guide plate, a plurality of LED light sources are arranged on the light incident side of the light guide plate, and the angular deflection prism is arranged on the light emergent surface of the light guide plate; the bottom surface of the light guide plate is provided with a special-shaped lattice point structure, and the special-shaped lattice point structure comprises a convex or concave special-shaped microstructure; the top surface of the light guide plate is a prism surface, the prism surface comprises asymmetric prism structures, the heights of the prism structures are discontinuously and regularly arranged, and the prism structures comprise a high-low combination; a diffusion sheet and a convex hull reflection sheet are sequentially arranged on the light guide plate, a convex hull structure is arranged on the surface of the convex hull reflection sheet, and the radian of the convex hull structure is configured to shrink a light reflection angle; the prism units of the angular deflection prism are of a central symmetry structure, gradually deflect by a set angle from the center to the two sides and are used for focusing light rays in different areas in the front view direction, and the dark band phenomenon is improved.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic display technology, and particularly to a novel backlight module with a deflection prism. Background Art

[0002] A prism film, a thin film or lens structure designed based on optical principles, is widely used to improve the light-emitting efficiency of the backlight system in a backlight module. It is mainly applied to terminal consumer electronic products such as televisions, computers, mobile phones, as well as in-vehicle displays and other liquid crystal imaging fields. By refracting and reflecting the incident light through the prism structure, the prism film only allows light within a specific angular range to pass through, while reflecting other light back to the light source for recycling. Eventually, the light is concentrated in the frontal viewing direction, thereby improving the axial brightness.

[0003] The microstructure of a traditional prism sheet usually presents an isosceles symmetric structure, evenly distributed, without local or specific steering angle design. Therefore, its light output mode has no obvious difference as a whole. When observing from the center of the backlight to the surroundings, what is seen is not the highest value of the backlight brightness, resulting in a darker large-angle viewing angle and prone to the phenomenon of regional dark bands. To solve this problem, the present invention proposes to change the symmetric prism design to an inclined prism, and by adjusting the local optical light output angle, the strongest light in different regions is focused on the central viewing point area, thereby improving the dark band phenomenon. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention discloses a novel backlight module with a deflection prism to solve the above problems.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention provides a novel backlight module with a deflection prism, including a light guide plate, wherein a plurality of LED light sources are arranged on the light incident side of the light guide plate, and an angular deflection prism is arranged on the light output surface of the light guide plate;

[0007] An irregular dot structure is arranged on the bottom surface of the light guide plate, and the irregular dot structure includes raised or recessed irregular microstructures;

[0008] The top surface of the light guide plate is a prism surface, and the prism surface includes an asymmetric prism structure, and the height of the prism structure is arranged in a discontinuous regular pattern, including a combination of one high and multiple lows;

[0009] A diffusion sheet and a convex bump reflector are sequentially arranged below the light guide plate, and the convex bump reflector surface is provided with a convex bump structure, and the radian of the convex bump structure is configured to contract the light reflection angle;

[0010] The prism unit with an angular deflection prism has a centrosymmetric structure and gradually deflects a set angle from the center to both sides, which is used to focus the light in different regions in the front view direction and improve the dark band phenomenon.

[0011] Furthermore, the special-shaped dot structure is a raised special-shaped dot or a sunken special-shaped dot, and a groove structure is provided between adjacent dots, and the depth and width of the groove structure are adjusted according to the light concentration requirement.

[0012] Furthermore, the prism structure of the prism surface is a prismatic angle shape, an arc shape or a combined structure of a prismatic angle and an arc, its apex angle is 30°-80°, and the range of the prism height difference is 0.1μm-50μm.

[0013] Furthermore, the convex structure of the convex dot reflector is a hemispherical shape, a conical shape or a stepped shape, the convex dot height is 5μm-200μm, and the distance between adjacent convex dots is 50μm-500μm.

[0014] Furthermore, the diffusion sheet includes a substrate layer, a diffusion layer and a functional layer, the diffusion layer contains diffusion particles with mixed sizes, and the functional layer contains scratch-resistant particles or antistatic particles.

[0015] Furthermore, the deflection angle range of the angular deflection prism is 5°-45°, and the deflection direction is unidirectional or bidirectional gradual change to achieve 1%-50% anti-peeping viewing angle control.

[0016] Furthermore, the material of the light guide plate is PMMA, PC or glass, and the material of the angular deflection prism is PET or COP.

[0017] Furthermore, the LED light source has a side-in layout, the light source spacing is 1mm-10mm, and the light source power is 0.1W-5W.

[0018] Furthermore, the backlight module further includes a back plate, the convex dot reflector is fixed on the surface of the back plate, and the material of the back plate is metal or a high reflectivity composite material.

[0019] The beneficial effects of the present invention are:

[0020] The present invention effectively contracts the viewing angle by using a convex dot reflector, thereby achieving a specific visual effect. This design can not only concentrate the propagation direction of light, but also cover the defects on the screen by using a diffusion sheet, thereby reducing the defective rate of the product. In addition, the present invention also combines the design of the special-shaped dots of the light guide plate and the curved surface light output structure. The ingenious combination of these structures enables the light to be concentrated and emitted at the preset angle of the designer, greatly improving the light utilization rate and the display effect.

[0021] The present invention also introduces the light deflection function of the angled deflection diaphragm prism, which effectively improves the dark band phenomenon, making the screen brightness more uniform. At the same time, it can also achieve a certain anti-peeping effect to protect the privacy and security of users. In summary, through the comprehensive application of various technical means, the present invention not only improves the performance of the display device but also enhances the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 is a structural diagram of a new type of backlight module with a deflection prism;

[0024] Figure 2 is a structural diagram of a conventional prism;

[0025] Figure 3 is a perspective view of a human eye viewing a conventional collimated backlight;

[0026] Figure 4 is a structural diagram of a deflection prism;

[0027] Figure 5 is a perspective view of a human eye viewing an inclined collimated backlight;

[0028] The reference numerals in the drawings respectively represent:

[0029] 1. Angled deflection prism; 2. Light guide plate; 3. Diffusion sheet; 4. Convex hull reflector; 5. Back panel. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0031] In one embodiment, referring to Figure 1 as shown, this embodiment provides a new type of backlight module with a deflection prism, including a light guide plate. A plurality of LED light sources are provided on the light incident side of the light guide plate, and an angled deflection prism is provided on the light exit surface of the light guide plate;

[0032] The bottom surface of the light guide plate is provided with a special-shaped dot structure, and the special-shaped dot structure includes raised or sunken special-shaped microstructures;

[0033] The top surface of the light guide plate is a prismatic surface, and the prismatic surface includes an asymmetric prism structure. The height of the prism structure is arranged regularly at intervals and includes a combination of one high and multiple lows;

[0034] A diffusion sheet and a convex-hull reflector are sequentially arranged below the light guide plate. The surface of the convex-hull reflector is provided with a convex-hull structure, and the radian of the convex-hull structure is configured to contract the light reflection angle;

[0035] The prism unit with an angle-deflecting prism is a centrosymmetric structure and gradually deflects a set angle from the center to both sides, so as to focus the light in different regions in the front-view direction and improve the dark band phenomenon.

[0036] In this embodiment, the special-shaped dot structure is a raised special-shaped dot or a sunken special-shaped dot, and a groove structure is provided between adjacent dots. The depth and width of the groove structure are adjusted according to the light condensation requirement. The prism structure of the prismatic surface is a prismatic, arc-shaped or a combined structure of a prism and an arc, and its apex angle is 30°-80°, and the difference range of the prism height is 0.1μm-50μm.

[0037] In this embodiment, the convex-hull structure of the convex-hull reflector is hemispherical, conical or stepped, the convex-hull height is 5μm-200μm, and the distance between adjacent convex-hulls is 50μm-500μm.

[0038] In this embodiment, the diffusion sheet includes a substrate layer, a diffusion layer and a functional layer. The diffusion layer contains diffusion particles with mixed sizes, and the functional layer contains scratch-resistant particles or antistatic particles.

[0039] In this embodiment, the deflection angle range of the prism with an angle-deflecting prism is 5°-45°, and the deflection direction is unidirectional or gradually changes bidirectionally to achieve 1%-50% anti-peeping viewing angle control. The material of the light guide plate is PMMA, PC or glass, and the material of the prism with an angle-deflecting prism is PET or COP.

[0040] In this embodiment, the LED light source is in a side-in layout, the light source spacing is 1mm-10mm, and the light source power is 0.1W-5W.

[0041] In this embodiment, the backlight module further includes a back plate. The convex-hull reflector is fixed on the surface of the back plate, and the material of the back plate is metal or a high-reflectivity composite material.

[0042] The prisms of traditional light guide plates are generally regular raised or sunken arc-shaped prism structures, and their prism sizes are relatively large. The light collection effect is not good during use, and interference patterns are likely to appear when paired with backlight films.

[0043] In this embodiment, there are significant differences between the prism structure of the light guide plate and the traditional structure. The form of the prism structure is diverse and can be manifested as angular, arc-shaped, or a combination of angular and arc-shaped. The height of the prism is not uniform either, but shows a diverse combination of heights, such as one high and two low, one high and three low, one high and four low, etc., and these height variations are arranged in a certain regular pattern.

[0044] Taking the one-high-and-three-low prism structure as an example, the height difference, width, and apex angle between the prisms are all variable, and the selection of specific parameters needs to be customized according to specific optical requirements.

[0045] Compared with the common circular dot structure in traditional light guide plates, the dot structure of the present invention is innovative. It constructs a specific micro-structure on the dot surface, and through the special design of these micro-structures, the directional guiding of light is realized. The dot structure designed in the present invention includes raised irregular dots or sunken irregular dots. The size, height, and inclined surface angle of the irregular dots can all be adjusted according to optical requirements. The design principle of the sunken structure is similar to that of the raised structure. In addition, groove structures can be set between the dots, and these grooves also have a certain light-gathering effect.

[0046] The surface of the traditional silver reflective layer is usually smooth and without a specific structure, and its main function is to reflect the light that escapes from below the light guide plate back to achieve the reuse of light. As Figure 2 shown, it shows the propagation of light on the reflective layer after passing through the light guide plate. The reflective layer is a smooth plane, and when the light hits this layer, it will be reflected upward, thereby improving the utilization rate of light. The silver reflective layer involved in the present invention not only has the above functions, but also designs a specific structure on its surface. The shape of this structure is not fixed, but is correspondingly matched according to actual application requirements.

[0047] This embodiment shows a silver reflective layer with a convex structure (other possible shapes are not shown here), which can effectively solve the adsorption problem between the diaphragms, thereby improving the yield rate of diaphragm assembly. In addition, it also has the function of narrowing the viewing angle. The figure shows the propagation of light on the convex reflective layer after passing through the light guide plate. When the light hits the convex, since its surface is not a smooth plane and has a certain curvature, the reflection angle of the light will contract, and at the same time, it can also enhance the light output brightness of the backlight.

[0048] The diffusion film in this embodiment is composed of a multilayer film, which is a diffusion layer, a transparent substrate and a functional layer in sequence. The selection of the substrate should preferably be a high transmittance material, such as polyethylene terephthalate (PET), polycarbonate (PC), and polymethyl methacrylate (PMMA). The diffusion layer and the functional layer are formed by coating particles on both sides of the substrate. The particles contained in the resin in the functional layer can be anti-scratch particles, antistatic particles or other functional particles. In the top diffusion layer, the diffusion particles are evenly distributed in the resin, and particles of different sizes are mixed and used to become the key medium for light diffusion. The surface of the diffusion layer has a microstructure, and its shape is not limited. The figure is only an example. The microstructure pattern can be achieved by a variety of process technologies such as hot embossing, coating molding, printing technology, laser scanning, and the process technology itself has no specific restrictions.

[0049] The outer surface of a traditional prism has a microscopic array structure, which usually presents an isosceles symmetrical shape. Figure 2 As shown in Figure 1, these structures are evenly distributed. When the observer looks directly at the center of the backlight, the light is emitted in a collimated manner, and the observer sees the light of the brightest area. However, when the observer moves his eyes to the upper and lower areas, due to the collimated characteristics of the light, the position seen may not be the highest brightness area, but the waist or other areas, such as Figure 3 As shown. This results in the phenomenon of dark bands being easily observed at the upper and lower ends of the backlight, thus affecting the viewing experience. The prism involved in the present invention not only has the above functions, but also has a local adjustment of the prism structure and a design of a specific steering angle. Figure 4 As shown in the figure, the center of the prism maintains a symmetrical structure, but it is deflected from the center to both sides at a certain angle. When the observer looks directly at the backlight center, the light is also emitted in a collimated manner, and the observer sees the light in the brightest area. When the line of sight moves to the upper and lower areas, due to the deflection design of the prism angle, the position seen by the observer is the highest brightness area, as shown in the figure below. Figure 5 Therefore, the present invention effectively improves the dark band phenomenon at the upper and lower ends of the backlight viewing angle and improves the backlight effect.

[0050] The bottom of the module in this embodiment is the back panel, and above the back panel is a convex reflective film. The reflective film can be an optical film with mirror reflection properties or diffuse reflection properties. Above the reflective film is a diffuser, which is a high-transmittance and low-fog film. Above the diffuser is a light guide plate, and the light guide plate dots are special-shaped dots. Multiple LEDs are distributed on the side of the light guide plate, and a prism film with angled deflection is matched above the light guide plate. Through the deflection of the prism angle, the highest brightness around the backlight can also be seen from the center of the backlight, and at the same time, a 1%-50% anti-peeping effect is achieved.

[0051] In summary, the present invention effectively shrinks the viewing angle by using a convex hull reflector, thereby achieving a specific visual effect. This design can not only concentrate the propagation direction of light, but also cover the defects on the screen by using a diffusion sheet, thereby reducing the defective rate of the product. In addition, the present invention also combines the design of the light guide plate with special-shaped light points and the curved light-emitting structure. The ingenious combination of these structures enables light to be concentrated and emitted at the angles preset by the designer, greatly improving the utilization rate of light and the display effect.

[0052] The present invention also introduces the light deflection function of the angle-deflecting diaphragm prism. This function effectively improves the dark band phenomenon, making the screen brightness more uniform. At the same time, it can also achieve a certain anti-peeping effect to protect the privacy and security of users. In summary, through the comprehensive application of various technical means, the present invention not only improves the performance of the display device, but also enhances the user experience.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A novel backlight module with a deflection prism, characterized in that, It includes a light guide plate, on the light incident side of which there are multiple LED light sources, and on the light emitting surface of which there is an angular deflection prism; On the bottom surface of the light guide plate, there is a special-shaped dot structure, which includes raised or sunken special-shaped microstructures; The top surface of the light guide plate is a prism surface, which includes an asymmetric prism structure, and the height of the prism structure is arranged regularly at intervals, including a combination of one high and multiple lows; A diffusion sheet and a convex-hull reflector are sequentially arranged on the light guide plate. The convex-hull reflector surface is provided with convex-hull structures, and the curvature of the convex-hull structures is configured to contract the light reflection angle; The prism unit of the angular deflection prism is a centrosymmetric structure, and gradually deflects a set angle from the center to both sides, for focusing the light in different regions in the front view direction and improving the dark band phenomenon.

2. The novel backlight module with a deflection prism according to claim 1, characterized in that, The special-shaped dot structure is a raised or sunken special-shaped dot, and there is a groove structure between adjacent dots, and the depth and width of the groove structure are adjusted according to the light collection requirements.

3. The novel backlight module with a deflection prism according to claim 1, wherein, The prism structure of the prism surface is a prismatic, arc-shaped or a combined structure of prism and arc, its apex angle is 30°-80°, and the difference range of prism height is 0.1μm-50μm.

4. The novel backlight module with a deflection prism according to claim 1, characterized in that, The convex-hull structure of the convex-hull reflector is hemispherical, conical or stepped, the convex-hull height is 5μm-200μm, and the distance between adjacent convex-hulls is 50μm-500μm.

5. The novel backlight module with a deflection prism according to claim 1, characterized in that, The diffusion sheet includes a substrate layer, a diffusion layer and a functional layer. The diffusion layer contains diffusion particles with mixed sizes, and the functional layer contains scratch-resistant particles or antistatic particles.

6. The novel backlight module with a deflection prism according to claim 1, characterized in that, The deflection angle range of the angular deflection prism is 5°-45°, and the deflection direction is unidirectional or bidirectional gradual change, so as to achieve 1%-50% anti-peeping viewing angle control.

7. The novel backlight module with a deflection prism according to claim 1, characterized in that, The material of the light guide plate is PMMA, PC or glass, and the material of the angular deflection prism is PET or COP.

8. The novel backlight module with a deflection prism according to any one of claims 1-7, characterized in that, The LED light sources are arranged in a side-entry layout, the light source spacing is 1mm-10mm, and the light source power is 0.1W-5W.

9. The novel backlight module with a deflection prism according to claim 1, characterized in that, The backlight module further includes a back plate, the convex-hull reflector is fixed on the surface of the back plate, and the material of the back plate is metal or a high-reflectivity composite material.

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