Optical structure, backlight module, display apparatus, and preparation method for optical structure

Abstract

Disclosed in the present application are an optical structure, a backlight module, a display apparatus, and a preparation method for the optical structure. The optical structure comprises a substrate layer, a brightness enhancement layer, and a diffusion layer, the substrate layer, the brightness enhancement layer, and the diffusion layer being of the same base material and being integrally injection molded.

Description

Optical structure, backlight module, display device, and method for preparing optical structure

[0001] This application claims priority to Chinese patent application No. 202311833701.9 filed on December 27, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of backlight modules, and in particular to an optical structure, a backlight module, a display device, and a method for preparing the optical structure. Background Art

[0003] In traditional direct-lit backlight modules, the diffuser plate, along with other films such as the brightness enhancement film and the diffusion film, are stacked separately. Due to the large clearance between the diffuser plate and the films, these separate layers can scratch the polarizer beneath the LCD panel, impacting the backlight module's yield rate.

[0004] To address this issue, existing backlight modules utilize optical adhesive to bond the diaphragm and diffuser plates of the optical functional panel together, effectively mitigating scratching. However, due to the different base materials of the diaphragm and diffuser plates, their thermal expansion coefficients differ by several times. This makes existing backlight modules susceptible to warping, deformation, and delamination in high-temperature or extremely cold environments. Technical issues

[0005] The main purpose of this application is to provide an optical structure, which aims to solve the problem that when the diaphragm and the diffuser are bonded together by optical glue, warping, deformation and delamination may easily occur due to the different basic materials of the diaphragm and the diffuser. Technical Solutions

[0006] To achieve the above-mentioned purpose, the optical structure proposed in this application is applied to a backlight module, and the optical structure includes a substrate layer, a light-enhancing layer and a diffusion layer. There is an air layer between the substrate layer and the light-enhancing layer, and between the light-enhancing layer and the diffusion layer. The basic material of the substrate layer, the light-enhancing layer and the diffusion layer is the same and is injection molded as one piece.

[0007] In one embodiment, the base material is PS material, PC material, MS material or PMMA material.

[0008] In one embodiment, the substrate layer has a multi-layer discontinuous bubble structure inside, and the refractive index of the substrate layer is 1.5 to 1.6.

[0009] In one embodiment, the light enhancement layer is a transparent layer, the light incident surface of the light enhancement layer is smooth, and the light emitting surface of the light enhancement layer is configured as a triangular prism structure.

[0010] In one embodiment, the diffusion layer is a semi-transparent plate, and a light diffusing agent is doped into a base material of the diffusion layer.

[0011] In one embodiment, the substrate layer and the light-enhancing layer both include a fixing portion and a protruding portion, the protruding portion is arranged to protrude relative to the fixing portion, and two adjacent protruding portions are adhered to each other.

[0012] In one embodiment, the protrusions are provided on both sides or around the fixing portion, and the air layer is located between two adjacent fixing layers.

[0013] The present application also provides a backlight module, which includes an optical structure.

[0014] The present application also provides a display device, which includes an optical structure.

[0015] The present application provides a method for preparing an optical structure, which is applicable to preparing an optical structure. The method for preparing the optical structure comprises the following steps:

[0016] Heat and melt the raw materials containing the base material;

[0017] The molten raw material is injected into the mold, and the raw material flows out from the multiple injection ports of the mold from bottom to top, and the substrate layer, the light-enhancing layer, and the diffusion layer are injection-molded layer by layer in the cavity of the mold. The substrate layer, the light-enhancing layer, and the diffusion layer in the mold are adhered to each other in a molten state and formed into one piece to form an optical functional panel;

[0018] Wherein, under the condition of injection molding the substrate layer, adding a foaming agent to foam the substrate layer, and cooling the foamed substrate layer;

[0019] Under the condition that the substrate layer is in a molten state, the light-enhancing layer is injection-molded, a triangular prism structure is transferred to the injected light-enhancing layer, and the light-enhancing layer after the triangular prism structure transfer is cooled;

[0020] Under the condition that the light-enhancing layer is in a molten state, a diffusing agent is doped on the molten raw material, and the diffusion layer is injection-molded;

[0021] The optical functional plate is cut and trimmed to form the optical structure. Beneficial effects

[0022] The technical solution of the present application adopts the same basic material for the substrate layer, the light-enhancing layer, and the diffusion layer, and is integrally injection molded. Since the substrate layer, the light-enhancing layer, and the diffusion layer are all integrally injection molded, and the substrate layer, the light-enhancing layer, and the diffusion layer are made of the same basic material, during the injection molding process, the peripheral edge regions of the substrate layer, the light-enhancing layer, and the diffusion layer adhere to each other in the molten state due to similar dissolution, and the mutually adhered optical structure is not easily displaced and moved, and the optical structure has a small range of movement in the backlight module, thereby reducing the substrate layer, the light-enhancing layer, and the diffusion layer in the optical structure from moving and scratching the polarizer under the liquid crystal panel; and since the basic material is the same, the thermal expansion coefficients of the substrate layer, the light-enhancing layer, and the diffusion layer are slightly different, and in high temperature or extremely cold environments, the substrate layer and the light-enhancing layer, and the light-enhancing layer and the diffusion layer of the optical structure are not easily warped, deformed, or delaminated. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0024] FIG1 is a schematic structural diagram of a conventional direct-lit backlight module;

[0025] FIG2 is a schematic structural diagram of an optical functional board of a conventional backlight module;

[0026] FIG3 is a schematic structural diagram of an embodiment of an optical structure of the present application;

[0027] FIG4 is a schematic diagram of a three-dimensional structure of an optical structure according to an embodiment of the present application;

[0028] FIG5 is a schematic structural diagram of an embodiment of a backlight module of the present application;

[0029] FIG6 is a cross-sectional view of an embodiment of a cavity in a mold of the present application.

[0030] Description of Figure Numbers:

[0031] Reference number name Reference number name 10 optical structure 30 backplane 11 substrate layer 40 liquid crystal panel 12 light-enhancing layer 500 mold 120 triangular prism structure 50 cavity 13 diffusion layer 51 injection port 14 air layer 511 first injection port 15 fixing portion 512 second injection port 16 raised portion 513 third injection port 17 adhesive 521 first molding groove 18 optical adhesive 522 second molding groove 100 backlight module 523 third molding groove 20 backlight source 53 mold core

[0032] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. Modes for Carrying Out the Invention

[0033] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0034] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In this application, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text is to include three parallel solutions. Taking "A and / or B as an example", it includes solution A, or solution B, or a solution in which both A and B are satisfied. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0037] In an embodiment of the present application, as shown in Figures 3 to 5, the optical structure 10 is applied to a backlight module 100. The optical structure 10 includes a substrate layer, a light-enhancing layer 12, and a diffusion layer 13. An air layer 14 is provided between the substrate layer 11 and the light-enhancing layer 12, and between the light-enhancing layer 12 and the diffusion layer 13. The substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 are made of the same basic material and are integrally injection molded.

[0038] As shown in Figure 1, a schematic diagram of the structure of a traditional direct-lit backlight module 100 is shown. The traditional direct-lit backlight module includes a backlight source 20, a backplane 30, a liquid crystal panel 40, and an optical structure 10. The liquid crystal panel 40 and the optical structure 10 are both mounted on the backplane 30 and located above the backlight source 20. The optical structure 10 is located below the liquid crystal panel 40. The optical structure 10 in the traditional direct-lit backlight module 100 utilizes a diffuser plate, a light-enhancing film, a diffuser film, and other films stacked separately. The space between the diffuser plate and the films is relatively large, and the separately stacked diffuser plate and films can scratch the polarizer under the liquid crystal panel, thereby affecting the backlight module's yield rate.

[0039] Figure 2 shows the optical structure of a conventional backlight module. To address the issue of traditional direct-lit backlight modules prone to scratching the polarizer beneath the LCD panel, the existing backlight module's optical structure consists of two layers of film and a diffuser bonded together using optical adhesive. However, because the base material of the two layers of film differs from that of the diffuser, and their coefficients of thermal expansion differ by several times, the existing backlight module is prone to warping, deformation, and delamination in high-temperature or extremely cold environments.

[0040] To this end, as shown in FIG3 , the technical solution of the present application adopts the same basic material for the substrate layer 11 , the light enhancement layer 12 and the diffusion layer 13 and is integrally injection molded. Since the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 are all integrally injection molded, and the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 are made of the same basic material, during the injection molding process, the peripheral edge regions of the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 are adhered to each other in the molten state due to their similar dissolution. The adhered optical structure 10 is not easily displaced and moved, and the optical structure 10 has a small range of movement in the backlight module 100, thereby reducing the possibility of the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 in the optical structure 10 moving and scratching the polarizer under the liquid crystal panel. Furthermore, since the basic material is the same, the thermal expansion coefficients of the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 are slightly different. Therefore, in a high temperature or extremely cold environment, the optical structure 10 is not prone to warping, deformation, or delamination between the substrate layer 11 and the light-enhancing layer 12, or between the light-enhancing layer 12 and the diffusion layer 13.

[0041] In one embodiment, the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 of the optical structure 10 are made of the same base material and are integrally injection-molded. Because the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 adhere to each other in a molten state due to their similar dissolvability, adhesive bonding is unnecessary, thereby reducing adhesive usage and conserving materials.

[0042] The basic material refers to the material foundation needed to make the substrate layer 11, the light enhancement layer 12 or the diffusion layer 13. The basic material can also be referred to as the base material.

[0043] Furthermore, because the diaphragm and the diffuser plate on the existing backlight module 100 are bonded together by optical adhesive 18, the light emitted by the backlight source of the backlight module 100 is incident on the diaphragm and needs to pass through the optical adhesive 18 when crossing the layer to the diffuser plate, resulting in light energy loss. In order to avoid light energy loss, the substrate layer 11, the light-enhancing layer 12, and the diffuser layer 13 of the optical structure 10 of the present application are integrally injection molded, and the substrate layer 11, the light-enhancing layer 12, and the diffuser layer 13 are adhered to each other, without the need for optical adhesive 18. In addition, there is an air layer 14 between the substrate layer 11 and the light-enhancing layer 12, and between the light-enhancing layer 12 and the diffuser layer 13. When the light from the backlight source on the backlight module 100 is incident on the optical structure 10, the incident light has less light energy loss when crossing the layer from the substrate layer to the light-enhancing layer and from the light-enhancing layer to the diffuser layer, thereby significantly improving the luminous efficiency of the backlight module 100.

[0044] In one embodiment, the base material is PS material, PC material, MS material or PMMA material.

[0045] To ensure the same expansion system for the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13, the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 all use the same base material. These layers can be made of any of PS (polystyrene), PC (polycarbonate), MS (polyacrylate organic-inorganic nanocomposite material), or PMMA (polymethyl methacrylate).

[0046] In one embodiment, the base material used for the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 can be PS to ensure consistency in the expansion and contraction coefficients of the substrate, light-enhancing, and diffusion layers. Consequently, in high-temperature or extremely cold environments, warping, deformation, and delamination are less likely to occur between the substrate layer 11 and the light-enhancing layer 12, and between the light-enhancing layer 12 and the diffusion layer 13, of the optical structure 10. Specifically, because the diffuser plate of the existing optical structure 10 is made of PS and the other film layers are made of PET, the expansion coefficient of the PS diffuser is approximately 8×10-6 / °C, and the expansion coefficient of the PET used in the other film layers is approximately 80×10-6 / °C, a ten-fold difference. This mechanical bonding method can cause the film layers to warp and bulge significantly in extreme environments such as high temperature, high humidity, or low temperature. The substrate layer, light-enhancing layer, and diffusion layer of the optical structure 10 of the present application include a substrate layer 11, a light-enhancing layer 12, and a diffusion layer 13. The base materials of the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 of the present application are all made of PS material. The expansion coefficient and contraction coefficient of the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 are consistent. In a high temperature or extremely cold environment, the substrate layer, the light-enhancing layer, and the diffusion layer are not prone to warping, deformation, or delamination. Among them, the base materials of the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 of the optical structure 10 of the present application can also all be made of PC material. The base materials of the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 of the optical structure 10 of the present application can also all be made of MS material. Or the base materials of the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 of the optical structure 10 of the present application can also all be made of PMMA material. It should be noted that the basic materials of the substrate layer 11 , the light enhancement layer 12 and the diffusion layer 13 cannot be mixed and need to be the same material to ensure that the expansion systems of the substrate layer 11 , the light enhancement layer 12 and the diffusion layer 13 are the same.

[0047] As shown in FIG3 and FIG4 , the optical structure 10 comprises a substrate layer 11 , a light enhancement layer 12 , and a diffusion layer 13 from the light incident surface to the light exit surface, and an air layer 14 of about 0.2 mm is provided between the substrate layer 11 and the light enhancement layer 12 , and between the light enhancement layer 12 and the diffusion layer 13 .

[0048] As shown in FIG3 , the substrate layer 11 has a multi-layer discontinuous bubble structure inside, and the refractive index of the substrate layer 11 is 1.5 to 1.6.

[0049] In one embodiment, the substrate layer 11 is transparent and has a multi-layered, non-continuous bubble structure inside. The refractive index of the substrate layer 11 is 1.5 to 1.6, while the refractive index of air is 1. This significant difference in refractive index allows incident light energy to be fully refracted and reflected within the substrate layer, forming uniformly scattered light energy. The thickness H1 of the substrate layer 11 ranges from 0.5 mm to 1.0 mm. If the thickness H1 of the substrate layer 11 is too small, the substrate layer 11 will be too thin and prone to deformation and breakage. If the thickness H1 of the substrate layer 11 is too large, the substrate layer 11 will be too thick, increasing the cost of the optical structure 10. Therefore, the thickness H1 of the substrate layer 11 is set to range from 0.5 mm to 1.0 mm.

[0050] As shown in FIG. 3 , the light enhancement layer 12 is a transparent layer. The light incident surface of the light enhancement layer 12 is smooth, and the light emitting surface of the light enhancement layer 12 is configured as a triangular prism structure 120 .

[0051] In one embodiment, the light-enhancing layer is transparent. The side of the fixing portion 15 of the light-enhancing layer 12 facing away from the substrate layer is the light-emitting surface, and the light-emitting surface of the light-enhancing layer 12 is configured as a triangular prism structure 120. The triangular prism structure 120 is transfer-molded on the light-emitting surface of the light-enhancing layer using a mold 500. The triangular prism structure 120 comprises a plurality of triangular prisms, each of which has a cross-section that is an isosceles right triangle, the vertex angle of the triangular prism cross-section being 90°±2°, and the arrangement spacing of the plurality of triangular prisms being 50μm to 90μm. The triangular prism structure 120 can concentrate the light energy incident on the light-enhancing layer within a spatial range of a solid angle of about 70°, having a focusing effect, and a gain coefficient of 110% to 115%. The thickness H2 of the light-enhancing layer 12 is set in the range of 0.2mm to 0.5mm.

[0052] In one embodiment, the diffusion layer is a semi-transparent plate, and a light diffusing agent is doped into the base material of the diffusion layer.

[0053] In one embodiment, the diffusion layer 1313 is formed by injection molding a base material uniformly doped with a diffusing agent. Typically, the diffusing agent is SiO2 or TiO2 particles, with TiO2 being preferred. The mass ratio of the diffusing agent is 1% to 5%. By utilizing the difference in refractive index between the base material and the diffusing agent, light incident on the diffusion layer 13 is effectively refracted and reflected, minimizing issues such as viewing angle and glare. The thickness H3 of the diffusion layer 13 is set between 0.2 mm and 0.5 mm.

[0054] As shown in Figures 3 to 5, in order to bond the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 to each other, the substrate layer 11 and the light-enhancing layer 12 each include a fixing portion 15 and a raised portion 16. The raised portion 16 is provided to protrude relative to the fixing portion 15, and two adjacent raised portions 16 are bonded to each other.

[0055] In one embodiment, the raised portion 16 of the substrate layer 11 is used to adhere to the bottom of the raised portion 16 of the light enhancement layer 12 . The raised portion 16 of the light enhancement layer 12 is used to adhere to the bottom of the diffusion layer 13 .

[0056] In one embodiment, the raised portions 16 provided on the substrate layer 11 and the light-enhancing layer 12 are arranged to protrude relative to the fixing portion 15. During the injection molding process of the optical structure 10, the substrate layer 11 and the light-enhancing layer 12 in a molten state have strong adhesion. Because the substrate layer 11, the light-enhancing layer 12, and the diffusion layer are all made of the same base material, adjacent substrate layers 11 and light-enhancing layers 12 will adhere to each other due to similar dissolution. Similarly, adjacent light-enhancing layers 12 and diffusion layers 13 will also adhere to each other due to similar dissolution. Specifically, the substrate layer 11 adheres to the bottom of the light-enhancing layer 12 via the raised portion 16, and the other side of the light-enhancing layer 12 adheres to the bottom of the diffusion layer via the raised portion 16.

[0057] In another embodiment, adhesive may be added to the raised portion 16 of the substrate layer 11 to stabilize the bonding between the adjacent substrate layer 11 and the light-enhancing layer 12. Glue may also be added to the raised portion 16 of the light-enhancing layer 12 to stabilize the bonding between the adjacent light-enhancing layer 12 and the diffusion layer 13.

[0058] In order to prevent the sticky protrusions 16 from affecting the cross-layer transmission of incident light, the protrusions 16 are provided on both sides or around the fixing portion 15 , and the air layer 14 is located between two adjacent fixing layers.

[0059] In one embodiment, the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 are all configured as layered structures. The raised portion 16 of each layered structure is a non-active display area. Adjacent layers of the layered structures are bonded together via the raised portion 16. The fixed portion 15 of each layered structure is an active display area. Incident light strikes the fixed portion 15 of each layered structure. An air layer 14 is provided between the fixed portions 15 of adjacent layers to minimize cross-layer light energy loss.

[0060] In one embodiment, the raised portion 16 on the substrate layer 11 and the raised portion 16 on the light enhancement layer 12 are both non-effective display areas, and the fixed portion 15 on the substrate layer 11 and the fixed portion 18 on the light enhancement layer 12 are both effective display areas.

[0061] This application also proposes a backlight module 100. As shown in FIG5 , the backlight module 100 includes a backplate 30 and an optical structure 10. The specific structure of the optical structure 10 is similar to the above-described embodiments. Since the present backlight module 100 utilizes all the technical solutions of all the above-described embodiments, it at least has all the beneficial effects brought about by the technical solutions of the above-described embodiments, which will not be described in detail here. The optical structure 10 is adhered to the backplate 30 on two sides or four sides, and an adhesive 17 is provided between the optical structure 10 and the backplate 30.

[0062] Because the diffuser and film of a conventional direct-lit backlight module 100 can shift and move on the backplate 30, potentially scratching the polarizer beneath the liquid crystal panel 40, the optical structure 10 of the present application is adhered to the backplate 30 on both sides or all four sides by adhesive 17. This ensures that the substrate layer, light-enhancing layer, and diffuser layer of the optical structure 10 are fixed to the backplate 30 and prevent them from shifting and moving, thereby preventing the optical structure 10 from scratching the polarizer beneath the liquid crystal panel 40.

[0063] As shown in FIG5 , the backlight module 100 further includes a backlight source, which is disposed on the back panel 30 . The back panel 30 has a light outlet, through which light emitted by the backlight source is emitted. The optical structure 10 is located at the light outlet and adhered to the back panel 30 .

[0064] In one embodiment, double-sided tape or spray glue is attached to the non-effective display area around the optical structure 10. Specifically, double-sided tape or spray glue is attached to the side of the base layer away from the raised portion 16. The base layer is adhered to the back panel 30 through the double-sided tape or glue, so that the optical structure 10 is fixed at the light outlet of the back panel 30, thereby limiting the movable gap of the optical structure 10 inside the backlight module 100, thereby achieving the effect of protecting the liquid crystal panel 40.

[0065] The present application also provides a display device, which includes an optical structure 10. The display device can be a display screen.

[0066] The present application also proposes a process for preparing the optical structure 10, which is suitable for preparing the optical structure 10 and includes the following steps:

[0067] Heat and melt the raw materials containing the base material;

[0068] The molten raw material is injected into the mold 500. The raw material flows out from the multiple injection ports of the mold 500 from the bottom to the top, and the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 are injection-molded layer by layer in the cavity of the mold 500. The substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 in the mold 500 are adhered to each other in the molten state and are integrally formed to form an optical functional panel.

[0069] The optical functional plate is cut and trimmed to form an optical structure 10 .

[0070] In one embodiment, raw materials containing a base material can be placed into an injection molding machine, which heats and pressurizes the raw materials. The injection molding machine then pours the melted raw materials into the mold 500. Subsequently, the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 are injection-molded layer by layer in the mold 500. In the mold 500, the molten substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 adhere to each other and are integrally molded due to their similarity and dissolution, thereby forming an optical functional plate. The injection molding temperature is 2000 to 250°C. The mold 500 is then maintained under pressure at a pressure of 150 to 250 MPa for a time of 6 to 8 seconds. The substrate layer, the light-enhancing layer, and the diffusion layer in the cavity 50 of the mold 500 are then cooled, and finally, the mold is opened to produce an optical functional plate. The optical functional plate can be cut using a cutting mechanism, and then trimmed using a trimming mechanism to form the optical structure 10.

[0071] In one embodiment, as shown in FIG6 , three injection ports 51 are arranged on the side of the mold 500 from bottom to top, and the three injection ports 51 are connected to the mold cavity 50. Two mold cores 53 in the mold cavity 50 of the mold 500 divide the mold cavity 50 into three molding grooves, and the three injection ports 51 are arranged corresponding to the three molding grooves. Specifically, the injection ports 51 include a first injection port 511, a second injection port 512, and a third injection port 513, and the molding grooves include a first molding groove 521, a second molding groove 522, and a third molding groove 523. The raw materials are injected from the first injection port 511, the second injection port 512, and the third injection port 513 in sequence to inject the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 into the mold cavity 50 one by one. The substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 adhere to each other in a molten state and are molded after cooling to form an optical functional plate.

[0072] The steps of injecting molten raw materials into the mold 500, allowing the raw materials to flow out from multiple injection ports of the mold 500 from bottom to top, and injection molding the substrate layer 11, the light-enhancing layer 12, and the diffusion layer 13 layer by layer in the cavity of the mold 500 include:

[0073] Under the condition that the substrate layer 11 is injection molded, a foaming agent is added to foam the substrate layer 11, and the foamed substrate layer 11 is cooled;

[0074] Under the condition that the substrate layer 11 is in a molten state, the light-enhancing layer 12 is injection-molded, a triangular prism structure is transferred to the injected light-enhancing layer 12, and the light-enhancing layer 12 after the triangular prism structure transfer is cooled;

[0075] Under the condition that the light enhancement layer 12 is in a molten state, a diffusing agent is doped into the molten raw material, and the diffusion layer 13 is injection-molded.

[0076] In one embodiment, the raw material is injected from the first injection port 511, and the substrate layer 11 is injection molded in the first molding groove 521 located at the bottom; then, the raw material is injected from the second injection port 512, and the light enhancement layer 12 is injection molded in the second molding groove 522 located in the middle; thereafter, the raw material containing the base material is doped with a diffusing agent, and the raw material doped with the diffusing agent is injected from the third injection port 513, and the diffusion layer 13 is injection molded in the third molding groove 523.

[0077] In one embodiment, after the raw material is injected from the first injection port 511 , the foaming agent is injected from the first injection port 511 to foam the raw material in the first molding groove 521 to form the substrate layer 11 .

[0078] After the raw material is injected from the second injection port 512 , a mold core 53 having a triangular prism structure 120 in the mold 500 can be pressed downward to transfer the triangular prism structure 120 to the light-enhancing layer 12 in the second molding groove 522 , thereby making the side of the light-enhancing layer 12 facing away from the substrate layer 11 have a triangular prism structure 120 .

[0079] The present application also proposes a mold 500 for preparing an optical structure 10 , which is used to prepare the optical structure 10 . The mold 500 is provided with a cavity 50 and a plurality of injection ports 51 . The plurality of injection ports 51 are arranged in sequence from bottom to top in the mold 500 and are connected to the cavity 50 .

[0080] As shown in FIG6 , the side of the mold 500 is provided with at least three injection ports 51 , which are arranged from bottom to top. The two mold cores 53 within the cavity 50 divide the cavity 50 into three molding grooves, and the three injection ports 51 are provided corresponding to the three molding grooves. Specifically, the injection ports 51 include a first injection port 511 , a second injection port 512 , and a third injection port 513 . The molding grooves include a first molding groove 521 , a second molding groove 522 , and a third molding groove 523 . The first injection port 511 is connected to the first molding groove 521 , the second injection port 512 is connected to the second molding groove 522 , and the third injection port 513 is connected to the third molding groove 523 .

[0081] As shown in FIG6 , the interior of the cavity 50 of the mold 500 is concave, and the outer edge of the cavity 50 is convex.

[0082] In one embodiment, the first and second molding grooves 521 and 522 are both rectangular, concave in the center and elevated around the edges. This allows the substrate layer and light-enhancing layer formed in the first and second molding grooves 521 and 522 to form a rectangular shape. The protruding structure of the substrate layer 11 is a raised portion 16, which adheres to the bottom of the light-enhancing layer 12. Similarly, the protruding structure of the light-enhancing layer 12 is a raised portion 16, which adheres to the bottom of the diffusion layer 13.

[0083] During the injection molding process, the raw material is injected from the first injection port 511, and the substrate layer 11 is injection molded in the first molding groove 521 located at the bottom; then, the raw material is injected from the second injection port 512, and the light enhancement layer 12 is injection molded in the second molding groove 522 located in the middle; thereafter, the raw material containing the base material is doped with a diffusing agent, and the raw material doped with the diffusing agent is injected from the third injection port 513, and the diffusion layer 13 is injection molded in the third molding groove 523.

[0084] The above descriptions are merely some embodiments of the present application and are not intended to limit the patent scope of the present application. All equivalent structural transformations made using the contents of the present application specification and drawings under the inventive concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. An optical structure, wherein, The optical structure is applied to a backlight module. The optical structure includes a substrate layer, a light enhancement layer, and a diffusion layer. There are air layers between the substrate layer and the light enhancement layer, and between the light enhancement layer and the diffusion layer. The base materials of the substrate layer, the light enhancement layer, and the diffusion layer are the same and are integrally injection molded.

2. The optical structure according to claim 1, wherein, The base material is PS material, PC material, MS material, or PMMA material.

3. The optical structure according to claim 1, wherein, From the light incident surface to the light exit surface of the optical structure, there are successively the substrate layer, the light enhancement layer, and the diffusion layer. And there is an air layer with a thickness of 0.2 mm between the substrate layer and the light enhancement layer, and between the light enhancement layer and the diffusion layer.

4. The optical structure according to claim 1, wherein, The interior of the substrate layer has multiple discontinuous bubble structures, and the refractive index of the substrate layer is between 1.5 and 1.

6.

5. The optical structure according to claim 4, wherein, The substrate layer is a transparent structure, and the thickness of the substrate layer is between 0.5 mm and 1.0 mm.

6. The optical structure according to claim 1, wherein, The light enhancement layer is a transparent layer. The light incident surface of the light enhancement layer is smooth, and the light exit surface of the light enhancement layer is provided with a triangular prism structure.

7. The optical structure according to claim 6, wherein, The thickness of the light enhancement layer is between 0.2 mm and 0.5 mm.

8. The optical structure according to claim 1, wherein, The diffusion layer is a semi-transparent plate, and a light diffusing agent is doped in the base material of the diffusion layer.

9. The optical structure according to claim 8, wherein, The diffusing agent includes SiO2 and TiO2, and the mass ratio of the diffusing agent is between 1% and 5%.

10. The optical structure according to claim 8, wherein, The thickness of the diffusion layer is between 0.2 mm and 0.5 mm.

11. The optical structure according to any one of claims 1 to 10, wherein, Both the substrate layer and the light enhancement layer include a fixing part and a protruding part. The protruding part protrudes relative to the fixing part, and adjacent protruding parts are adhered to each other.

12. The optical structure according to claim 11, wherein, The protruding part is provided on both sides or around the fixing part, and the air layer is located between two adjacent fixing layers.

13. A backlight module, wherein, The backlight module includes the optical structure described in any one of claims 1 to 12.

14. A display device, wherein, The display device includes the optical structure described in any one of claims 1 to 12.

15. A method for preparing an optical structure, wherein, The preparation method is applicable to preparing the optical structure described in any one of claims 1 to 12, and includes the following steps: Heat and melt the raw material containing the base material; Inject the molten raw material into a mold. The raw material flows out from multiple injection ports of the mold from bottom to top, and the substrate layer, the light enhancement layer, and the diffusion layer are successively injection molded layer by layer in the cavity of the mold. The substrate layer, the light enhancement layer, and the diffusion layer in the mold are adhered to each other and integrally formed in the molten state to form an optical functional plate; Wherein, under the condition of injection molding the substrate layer, a foaming agent is added for foaming, and the foamed substrate layer is cooled; Under the condition that the substrate layer is in a molten state, the light enhancement layer is injection molded. The triangular prism structure is transferred to the injection molded light enhancement layer, and the light enhancement layer after the triangular prism structure transfer is cooled; Under the condition that the light enhancement layer is in a molten state, a diffusing agent is doped in the molten raw material, and the diffusion layer is injection molded; Cut and trim the optical functional plate to form the optical structure.

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