Composite Optical Film

Abstract

The present disclosure relates to a composite optical film having diffusion and light homogenization functions. The composite optical film includes a multifaceted recess structure and a reverse-prism structure. The composite optical film may be laminated with a lower prism film to form a single integrated 2-in-1 composite optical film structure, or laminated with lower and upper prism films to form a single integrated 3-in-1 composite optical film structure.

Description

Technology Field

[0001] Cross-reference regarding related applications

[0002] This application claims the benefit of U.S. provisional application No. 63 / 754,504 filed on February 5, 2025, said provisional application is incorporated herein by reference.

[0003] Field of invention

[0004] The present disclosure relates to an optical film for a liquid crystal display (LCD) panel, more specifically to a composite optical film having multifunctional low-diffusion properties and a laminating structure thereof. Background Technology

[0005] With the continuous advancement of electronic technology, there is an increasing demand for electronic display products that are lightweight, ultra-thin, miniaturized, and energy-efficient, meeting environmental requirements such as energy saving and carbon reduction. Accordingly, Liquid Crystal Display (LCD) panels have been developed in the direction of reducing thickness, lowering power consumption, and improving optical efficiency. In addition to reducing the thickness of the panel glass substrate, the overall brightness of the panel has been enhanced by improving the luminance performance of the optical films used in the backlight module.

[0006] In conventional backlight modules, optical films play a key role in controlling light propagation and improving luminance efficiency. Prism optical films are essential components of backlight modules. Based on the principles of refraction and reflection, the prism film structure is configured to increase on-axis luminance by redirecting light toward the forward viewing direction. By recirculating and reusing light that would otherwise be wasted by being emitted outside a predetermined viewing angle, the overall brightness of the backlight module can be significantly improved. On the other hand, diffusion films are generally used to conceal point defects in the light guide plate and improve luminance uniformity across the module. The problem to be solved

[0007] Accordingly, conventional backlight modules typically include a plurality of optical films, including a light guide plate, a low-diffusion film, a lower prism film, an upper prism film, and an upper diffusion film, and these five optical films form a laminated structure. However, this configuration increases the overall thickness of the backlight module and can negatively affect power consumption and thermal performance. means of solving the problem

[0008] summation

[0009] To solve the above problems, embodiments of the present disclosure provide a composite optical film that provides diffusion and light homogenization functions. The composite optical film includes a multifaceted recess structure and a reverse-prism structure. The composite optical film may be laminated with a lower prism film to form a single integrated 2-in-1 composite optical film structure, or laminated with lower and upper prism films to form a single integrated 3-in-1 composite optical film structure.

[0010] By integrating multiple optical functions into a single laminated optical film, the number of optical films required for a backlight module can be reduced. Specifically, by combining two or three optical films from a conventional configuration into a single composite optical film, the overall thickness of the optical laminate can be reduced.

[0011] Accordingly, a 2-in-1 or 3-in-1 laminating composite optical film according to an embodiment of the present disclosure can reduce the overall thickness of the optical film while simultaneously improving the overall brightness of the backlight module by about 10% to 20%. As a result, the backlight module can achieve (1) a reduction in module thickness, (2) a reduction in the number of brightness diodes (LEDs), (3) a reduction in heat generated by the LEDs, and (4) a reduction in overall power consumption. Accordingly, the disclosed backlight module structure can simultaneously enable the thinning of the module and improvement of energy efficiency, thereby satisfying the requirements for energy saving and carbon reduction.

[0012] In one embodiment of the present disclosure, the present disclosure discloses a composite optical film comprising: a first substrate having a lower surface and an upper surface; a plurality of inverse prisms disposed on the lower surface of the first substrate; and a plurality of polyhedral recesses arranged on the upper surface of the first substrate.

[0013] In one embodiment, the composite optical film further comprises a plurality of first prisms disposed over a plurality of polyhedral concave portions, wherein the plurality of first prisms are disposed on the upper surface of a second substrate, and the second substrate is adhered to the plurality of polyhedral concave portions through a first adhesive layer.

[0014] In one embodiment, the first adhesive layer comprises a thermosetting resin or a UV-curing resin.

[0015] In one embodiment, the first adhesive layer further includes beads to improve diffusion.

[0016] In one embodiment, the added beads are selected from the organic group consisting of PMMA, PS, and melamine.

[0017] In one embodiment, the added beads are selected from the inorganic group consisting of silicon, SiO2, TiO2, CaCO3, Al2O3, and ZrO2.

[0018] In one embodiment, the first adhesive layer includes a matte structure formed by embossing.

[0019] In one embodiment, the composite optical film further comprises a plurality of second prisms disposed on a plurality of first prisms, wherein the plurality of second prisms are disposed on a third substrate, and the third substrate is adhered to the plurality of first prisms through a second adhesive layer.

[0020] In one embodiment, the second adhesive layer comprises a thermosetting resin or a UV-curing resin.

[0021] In one embodiment, the second adhesive layer further includes beads to improve diffusion.

[0022] In one embodiment, the added beads are selected from the organic group consisting of PMMA, PS, and melamine. In one embodiment, the added beads are selected from the inorganic group consisting of silicon, SiO2, TiO2, CaCO3, Al2O3, and ZrO2.

[0023] In one embodiment, the second adhesive layer includes a matte structure formed by embossing.

[0024] In one embodiment, a plurality of polyhedral indentations are inverted-pyramid microstructures.

[0025] In one embodiment, the inverted pyramidal microstructure includes a circular cone or a polygonal cone. In another embodiment, the inverted prism is triangular or semicircular.

[0026] Detailed technical descriptions for implementing the present invention and preferred embodiments are described in conjunction with the attached drawings in the following paragraphs so that those skilled in the art may fully understand the features of the claimed invention. Brief explanation of the drawing

[0027] The above aspects of the present disclosure and the many advantages associated therewith will be more easily understood when the invention is better understood by referring to the detailed description below together with the accompanying drawings. FIG. 1 shows a composite multifunctional low-diffusion optical film having a diffusion effect by combining an inverse prism structure and a polyhedral concave structure; FIG. 2A shows a three-dimensional view (3D view) of a 2-in-1 composite optical film structure formed by laminating a composite multifunctional low-diffusion optical film and a lower prism film together with a single optical sheet; FIG. 2B shows a cross-sectional view of the 2-in-1 composite optical film structure of FIG. 2A; Figure 3A shows a three-dimensional view of a 3-in-1 composite optical film structure formed by laminating a composite multifunctional low-diffusion optical film, a lower prism film, and an upper prism film into a single optical sheet. Figure 3B shows a cross-sectional view of the 3-in-1 composite optical film structure of Figure 3A. Figure 4A shows a three-dimensional view of a 2-in-1 composite optical film structure in which the laminating adhesive layer contains organic or inorganic beads. Figure 4B shows a cross-sectional view of the 2-in-1 composite optical film structure of Figure 4A. Figure 5A shows a three-dimensional view of a 3-in-1 composite optical film structure in which the upper UV-curable adhesive layer contains organic or inorganic beads. Figure 5B shows a cross-sectional view of the 3-in-1 composite optical film structure of Figure 5A. Figure 6A shows a three-dimensional view of a 3-in-1 composite optical film structure in which both the upper and lower UV-curable adhesive layers contain organic or inorganic beads. Figure 6B shows a cross-sectional view of the 3-in-1 composite optical film structure of Figure 6A. Specific details for implementing the invention

[0028] Detailed description of preferred embodiments

[0029] The following preferred embodiments of the present invention use a prism structure having different prism angles on the incident surface of an inverse prism film to determine the optimal prism angle. The exit surface of the inverse prism film is provided with an inverse pyramid-shaped microstructure that provides a diffusion function, thereby forming a multifunctional low-diffusion composite optical film having defect concealment and brightness enhancement functions as shown in FIG. 1.

[0030] The exit surface of the multifunctional low-diffusion composite optical film, i.e., the surface having an inverted pyramid microstructure, is laminated to the incident surface (i.e., PET surface) of the lower prism film by a lamination process using a UV-curable adhesive layer, so that the two optical films are bonded together to form a single integrated 2-in-1 composite optical film, thereby creating a composite optical film structure as shown in FIGS. 2A and 2B.

[0031] Alternatively, the exit surface (i.e., the prism-structured surface) of the 2-in-1 composite optical film can be further laminated to the incident surface (i.e., the PET surface) of the upper prism film by a lamination process using a UV-curable adhesive layer, thereby bonding the three optical films together to form a single integrated 3-in-1 composite optical film, which can produce a composite optical film structure as shown in FIGS. 3A and 3B.

[0032] The aforementioned 2-in-1 and 3-in-1 composite optical films can each improve brightness by about 10 to 20%. These can effectively reduce the thickness and material costs of the backlight module (Back Light Unit, BLU) by about one-third to one-half, reduce the number of LEDs required, lower the heat generation temperature of the LEDs within the backlight module, reduce overall power consumption, reduce transportation volume and costs, and simplify BLU assembly, thereby achieving numerous benefits including module thinning, energy saving, and carbon reduction.

[0033] As illustrated in FIG. 1, a composite multifunctional low-diffusion optical film (1) having a diffusion effect, comprising an inverse prism structure (10) and a polyhedral concave structure (12), is schematically illustrated. The inverse prism structure (10) and the polyhedral concave structure (12) are formed on a substrate (16) which may be made of PET, PEN, PAr, PC, or TAC. The inverse prism structure (10) includes triangular and semicircular pyramids, and the prism tip exhibits various heights. The prism angle is in the range of 50 to 140 degrees, preferably 65 to 125 degrees. Preferably, the polyhedral structure includes an inverse pyramid having a circular or polygonal cone. Based on the isotropic light-gathering principle of the inverse prism structure (10), by using an inverse prism film having a specific prism angle, light emitted from a light guide plate can be redirected substantially vertically upward, thereby utilizing the utilization rate of light emitted from the light guide plate by about 10% to 30%. In addition, by providing an inverse pyramid-shaped microstructure (12) that provides a diffusion function on the emission surface, brightness uniformity and defect concealment effects are achieved. Thus, the overall brightness gain of the composite optical film can be effectively improved while maintaining the diffusion function.

[0034] The polyhedral concave structure (12) includes a plurality of polyhedral concave portions.

[0035] In one embodiment, the polyhedral concave portion includes at least four sides.

[0036] In one embodiment, a plurality of polyhedral concave portions are arranged side by side along the length direction of the substrate, and a plurality of polyhedral concave portions are arranged side by side along the width direction of the substrate. That is, there is no gap between two adjacent polyhedral concave portions, and there is no gap between two adjacent polyhedral concave portions.

[0037] The inverse prism structure (10) includes a plurality of inverse prisms.

[0038] The composite optical film structure disclosed in FIG. 1 includes a diffusion function provided by an inverted pyramid microstructure and, when combined with an inverted prism, exhibits the following characteristics: (1) the composite optical film is configured to replace a conventional low-diffusion film and does not increase the overall thickness of the backlight module; (2) the composite optical film does not negatively affect the overall optical chromaticity of the backlight module; (3) the overall brightness of the backlight module can be improved by about 10% to 20%.

[0039] As illustrated in FIGS. 2A and 2B, a 2-in-1 composite optical film structure formed by laminating a composite multifunctional low-diffusion optical film (1) and a lower prism film (2) into a single optical sheet is schematically illustrated. The lower prism film (2) comprises a substrate (26) and a plurality of first prisms (27) disposed on the upper surface of the substrate (26), and the substrate (26) is adhered to a plurality of polyhedral concave portions through a first adhesive layer (20) which may be made of PET, PEN, PAr, PC, or TAC. In order to reduce the thickness of the composite optical film and simplify assembly, in the embodiments of FIGS. 2A and 2B, a single integrated 2-in-1 composite optical film as shown in FIGS. 2A and 2B is formed by bonding the two optical films together using a process in which the exit surface (i.e., inverted pyramidal microstructure surface) (12) of the multifunctional low-diffusion composite optical film is laminated to the incident surface (i.e., PET surface) of the lower prism film (2) using a thermosetting or UV-curable adhesive layer (20).

[0040] As such, the composite optical film structure disclosed in FIGS. 2A and 2B combines the diffusion function provided by an inverted prism and an inverted pyramid microstructure, and by laminating this structure with a lower prism film to form a single integrated 2-in-1 composite optical film, it exhibits the following characteristics: (1) The composite optical film is configured to replace a conventional lower diffusion film and a conventional lower prism film, thereby effectively reducing the overall thickness of the backlight module; (2) The composite optical film does not negatively affect the overall chromaticity of the backlight module; (3) The overall brightness of the backlight module can be substantially maintained; (4) The thickness and material cost of the backlight module (backlight unit, BLU) can be reduced by about 1 / 3 to 1 / 2; (5) The transport volume and associated transport costs can be reduced; (6) The assembly complexity and assembly cost of the BLU can be reduced.

[0041] As illustrated in FIGS. 3A and 3B, a 3-in-1 composite optical film structure formed by laminating a composite multifunctional low-diffusion optical film, a lower prism film, and an upper prism film into a single optical sheet is schematically illustrated. The lower prism film (2) comprises a substrate (26) which may be made of PET, PEN, PAr, PC, or TAC, and a plurality of first prisms (27) disposed on the upper surface of the substrate (26). Likewise, the upper prism film (3) comprises a substrate (36) which may be made of PET, PEN, PAr, PC, or TAC, and a plurality of first prisms (37) disposed on the upper surface of the substrate (36). In FIGS. 3A and 3B, the exit surface (12) (i.e., the inverted pyramid microstructure surface) of a multifunctional low-diffusion composite optical film is first laminated to the incident surface (i.e., the PET surface) of a lower prism film using a thermosetting or UV-curable adhesive layer (20) to form a 2-in-1 composite optical film. Then, the 2-in-1 composite optical film is laminated to the incident surface (i.e., the PET surface) of an upper prism film using another thermosetting or UV-curable adhesive layer (30) to bond the three optical films together, thereby forming a single integrated 3-in-1 composite optical film structure.

[0042] Accordingly, the composite optical film structure disclosed in FIGS. 3A and 3B, which is created by combining the diffusion function provided by an inverted pyramid microstructure with an inverted prism and further laminating this structure with a lower prism film and an upper prism film to form a single integrated 3-in-1 composite optical film, exhibits the following characteristics: (1) The composite optical film is configured to replace a conventional lower diffusion film, a conventional lower prism film, and a conventional upper prism film, thereby effectively reducing the overall thickness of the backlight module; (2) The composite optical film does not negatively affect the overall chromaticity of the backlight module; (3) The overall brightness of the backlight module can be substantially maintained; (4) The thickness and material cost of the backlight module (backlight unit, BLU) can be reduced by about 1 / 3 to 1 / 2; (5) The transport volume and associated transport costs can be reduced; (6) The assembly complexity and assembly cost of the BLU can be reduced.

[0043] In a single-sheet 3-in-1 laminating prism composite optical film, the prism structure of the upper and lower prism films or the lower prism film in a single-sheet 2-in-1 laminating prism composite optical film may use a prism tip with varying height, such as an H-shaped or G-shaped structure, or a configuration including one high prism tip and one low prism tip, or one high prism tip and two low prism tips. Such a configuration can effectively reduce adhesion and sticking problems between adjacent optical films.

[0044] Additionally, the UV-curable adhesive layer used to laminate the multifunctional low-diffusion composite optical film and the lower prism film in a single sheet 2-in-1 composite optical film may be a transparent UV adhesive. Alternatively, a matte adhesive layer (40) having a diffusion effect may be used. The matte treatment may include adding organic or inorganic beads to the thermocurable or UV adhesive or forming a matte surface through embossing, thereby providing defect concealment and anti-mura effects as shown in FIGS. 4A and 4B. For example, the added beads include diffusion beads selected from organic beads and inorganic beads, wherein the organic beads include PMMA, PS, or melamine, and the inorganic beads include silicon, SiO2, TiO2, CaCO3, Al2O3, or ZrO2, and the haze range is 2% to 60%, preferably 10% to 30%. When the matte adhesive layer (40) is formed as a matte coating by embossing, the haze value is in the range of 2% to 60%. Thus, the lower diffusion film can be omitted, thereby simultaneously achieving a reduction in thickness and high brightness.

[0045] Additionally, the UV-curable adhesive layer used to laminate the multifunctional low-diffusion composite optical film, the lower prism film, and the upper prism film in a single-sheet 3-in-1 composite optical film may be a transparent UV adhesive as shown in FIGS. 3A and 3B, or a matte adhesive layer (50A and / or 50B) having a diffusion effect. The matte treatment may include providing defect concealment and anti-rain effect as shown in FIGS. 5A, 5B, 6A, and 6B by adding organic or inorganic beads (beads) to the UV adhesive or forming a matte surface by embossing. For example, the added beads include diffusion beads selected from organic beads and inorganic beads, wherein the organic beads include PMMA, PS, or melamine, and the inorganic beads include silicon, SiO2, TiO2, CaCO3, Al2O3, or ZrO2, and the haze range is 2% to 60%, preferably 10% to 30%. When the matte adhesive layer (40) is formed as a matte coating by embossing, the haze value is in the range of 2% to 60%. Therefore, since the upper and lower diffusion films can be omitted, a reduction in thickness and high brightness can be achieved simultaneously.

[0046] Therefore, by omitting the upper diffusion film, the thickness can be reduced and high brightness can be achieved.

[0047] Accordingly, a single sheet 2-in-1 or 3-in-1 composite optical film formed by laminating a multifunctional low-diffusion composite optical film with a lower prism film and / or an upper prism film can have a lamination adhesive strength of more than 50 g / 25 mm. When using an adhesive containing organic or inorganic beads, the haze of the adhesive layer can be controlled to about 1% to 60%.

[0048] Based on the isotropic light-gathering principle of an inverse prism film, by using an inverse prism film having a specific prism angle as shown in FIG. 1, light emitted from a light guide plate can be redirected substantially vertically upward. As a result, the utilization rate of light emitted from the light guide plate can be increased from about 10% to 30%. In addition, light homogenization and defect concealment are achieved by providing an inverse pyramid-shaped microstructure with a diffusion function on the emission surface. Therefore, the overall brightness gain of the composite optical film can be effectively improved while maintaining the diffusion function.

[0049] To reduce the thickness of the composite optical film and simplify assembly, the present invention utilizes a lamination technique in which the exit surface (i.e., the inverted pyramid microstructure surface) of a multifunctional low-diffusion composite optical film is laminated to the incident surface (i.e., the PET surface) of a lower prism film using a UV-curable adhesive layer. This allows the two optical films to be bonded together to form a single integrated 2-in-1 composite optical film, thereby creating a composite optical film structure as shown in FIGS. 2A and 2B.

[0050] Alternatively, the exit surface (i.e., the inverted pyramid microstructure surface) of a multifunctional low-diffusion composite optical film is first laminated to the incident surface (i.e., the PET surface) of a lower prism film using a UV-curable adhesive layer to form a 2-in-1 composite optical film. Then, the 2-in-1 composite optical film is laminated to the incident surface (i.e., the PET surface) of an upper prism film using a UV-curable adhesive layer to bond the three optical films together, thereby forming a single integrated 3-in-1 composite optical film structure as shown in FIGS. 3A and 3B.

[0051] In summary, the composite optical film structure, which integrates the isotropic light-gathering characteristics of an inverted prism film and the diffusion and light homogenization functions provided by an inverted pyramid microstructure, and is laminated with a lower prism film and optionally an upper prism film to form a single-sheet 2-in-1 or 3-in-1 composite optical film, provides the following advantages:

[0052] 1. Under the same backlight module configuration, the overall module brightness can be improved by about 10 to 20% by using a multifunctional composite diffusion optical film that combines an inverse prism film having isotropic light-gathering characteristics and an inverse pyramid microstructure having diffusion and light uniformization functions.

[0053] 2. When a multifunctional composite diffusion optical film is laminated with a lower prism film and optionally an upper prism film using an adhesive that does not add organic or inorganic beads (beads) to form a single sheet 2-in-1 or 3-in-1 prism composite optical film, the thickness of the backlight module (backlight unit, BLU) can be effectively reduced while meeting high brightness requirements.

[0054] 3. The number of required LEDs can be reduced and the overall power consumption of the backlight module can be improved, thereby realizing the benefits of reduced thickness, energy savings, and carbon reduction.

[0055] 4. When a multifunctional composite diffusion optical film is laminated with a lower prism film and optionally an upper prism film using an adhesive containing organic or inorganic beads to form a single sheet 2-in-1 or 3-in-1 prism composite optical film, the upper diffusion film can be replaced, thereby simultaneously achieving reduced thickness and high brightness. In this configuration, the overall thickness of the backlight module (BLU) can be reduced by about 1 / 3 to 1 / 2.

[0056] 5. A single sheet 2-in-1 or 3-in-1 prism composite optical film can further improve the thermal stability and anti-wrinkle performance of the composite optical film.

[0057] 6. The composite optical film structure does not negatively affect the overall optical color of the backlight module.

[0058] 7. It can reduce transportation volume and related transportation costs, and reduce the assembly complexity and assembly costs of BLU.

[0059] The foregoing disclosure relates to the detailed technical content and original features thereof. Those skilled in the art may make various modifications and substitutions based on the foregoing disclosure and proposal of the present invention without departing from the characteristics of the invention. Even if such modifications and substitutions are not disclosed in detail in the foregoing description, they are substantially included in the following claims.

Claims

Claim 1 A composite optical film comprising: a first substrate having a lower surface and an upper surface; a plurality of reverse prisms disposed on the lower surface of the first substrate; and a plurality of multi-faceted recesses disposed on the upper surface of the first substrate. Claim 2 A composite optical film according to claim 1, wherein a plurality of first prisms are disposed on a plurality of polyhedral concave portions, wherein a plurality of first prisms are disposed on the upper surface of a second substrate, and the second substrate is adhered to the plurality of polyhedral concave portions through a first adhesive layer. Claim 3 In paragraph 2, the first adhesive layer is a composite optical film comprising a thermosetting resin or a photocuring resin. Claim 4 In paragraph 2, the first adhesive layer is a composite optical film further comprising beads added to provide a diffusion effect. Claim 5 In paragraph 2, the first adhesive layer is a composite optical film comprising a matte structure formed by embossing. Claim 6 A composite optical film according to paragraph 2, wherein a plurality of second prisms are disposed on a plurality of first prisms, wherein the plurality of second prisms are disposed on a third substrate, and the third substrate is adhered to the plurality of first prisms through a second adhesive layer. Claim 7 In claim 6, the second adhesive layer is a composite optical film comprising a thermosetting resin or a photocuring resin. Claim 8 In claim 6, the second adhesive layer is a composite optical film further comprising beads added to provide a diffusion effect. Claim 9 In claim 6, the second adhesive layer is a composite optical film comprising a matte structure formed by embossing. Claim 10 A composite optical film according to claim 1, wherein a plurality of polyhedral concave portions are inverted-pyramid microstructures.

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