Composite optical film

Abstract

A composite optical film includes a first substrate, a multi-faceted recessed structure, and an inverse prism structure. The composite optical film can be laminated with a lower prism film to form a two-in-one integrated composite optical film structure, or laminated with a lower prism film and an upper prism film to form a three-in-one integrated composite optical film structure.

Description

Technical Field

[0001] This invention relates to an optical film, and more particularly to a composite optical film. Background Technology

[0002] With the continuous advancement of electronic technology, the market demand for thin, compact, energy-efficient electronic display products that meet energy conservation, emission reduction, and environmental protection requirements is growing. Therefore, the research and development direction for liquid crystal display (LCD) panels is to reduce thickness, lower power consumption, and improve optical efficiency. In addition to reducing the thickness of the panel's glass substrate, improving the brightness performance of the optical films within the backlight module also enhances the overall brightness of the panel.

[0003] In traditional backlight modules, optical films play a crucial role in controlling light propagation and improving brightness efficiency. Prism optical films are a key component of backlight modules. Based on the principles of refraction and reflection, the prism film structure can guide light forward, thereby improving axial brightness. Light emitted outside the predetermined viewing angle, which would otherwise be wasted, can be recovered and reused through the prism film, significantly improving the overall brightness of the backlight module. On the other hand, diffuser films are typically used to cover point defects on the light guide plate and improve the brightness uniformity of the entire module.

[0004] Therefore, traditional backlight modules typically contain multiple optical films, such as a light guide plate, a lower diffuser film, a lower prism film, an upper prism film, and an upper diffuser film, a total of five optical films arranged in a stacked manner. However, this structure increases the overall thickness of the backlight module and may adversely affect power consumption and heat dissipation performance.

[0005] Therefore, the present invention proposes a new solution to overcome the above-mentioned shortcomings. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a composite optical film with diffusion and light homogenization functions. This composite optical film comprises a multi-faceted groove structure and a reverse prism structure. This composite optical film can be laminated with a lower prism film to form a single two-in-one integrated composite optical film structure, or laminated with both a lower prism film and an upper prism film to form a single three-in-one integrated composite optical film structure.

[0007] By integrating multiple optical functions into a single laminated optical film, the number of optical films required in a backlight module can be reduced. Specifically, two or three optical films in a conventional configuration can be combined into a single composite optical film, thereby reducing the overall thickness of the optical stack.

[0008] Therefore, according to embodiments of the present invention, a two-in-one or three-in-one laminated composite optical film can increase the overall brightness of the backlight module by approximately 10% to 20% while reducing the total thickness of the optical film. Thus, the backlight module can achieve: (1) reduced module thickness; (2) reduced number of light-emitting diodes (LEDs); (3) reduced heat generation of the LEDs; and (4) reduced overall power consumption. Accordingly, the provided backlight module structure can balance ultra-thinness and higher energy efficiency, thereby meeting the requirements of energy conservation and emission reduction.

[0009] In one embodiment, the present invention provides 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 multifaceted grooves disposed on the upper surface of the first substrate.

[0010] In one embodiment, the composite optical film further includes a plurality of first prisms disposed above the plurality of faceted grooves, wherein the plurality of first prisms are disposed on the upper surface of the second substrate, and the second substrate is adhered to the plurality of faceted grooves by a first adhesive layer.

[0011] In one embodiment, the first adhesive layer comprises a thermosetting resin or a photocurable resin.

[0012] In one embodiment, the first adhesive layer further includes added beads for providing a diffusion effect.

[0013] In one embodiment, the added beads are selected from organic compounds composed of PMMA, PS, and melamine.

[0014] In one embodiment, the added beads are selected from inorganic materials composed of silicon, SiO2, TiO2, CaCO3, Al2O3, and ZrO2.

[0015] In one embodiment, the first adhesive layer comprises a matte structure formed by embossing.

[0016] In one embodiment, the composite optical film further includes a plurality of second prisms disposed above the plurality of first prisms, wherein the plurality of second prisms are disposed on the third substrate, and the third substrate is adhered to the plurality of first prisms by a second adhesive layer.

[0017] In one embodiment, the second adhesive layer comprises a thermosetting resin or a photocurable resin.

[0018] In one embodiment, the second adhesive layer also includes added beads for providing a diffusion effect.

[0019] In one embodiment, the added beads are selected from the group of organic compounds consisting of PMMA, PS, and melamine. In another embodiment, the added beads are selected from the group of inorganic compounds consisting of silicon, SiO2, TiO2, CaCO3, Al2O3, and ZrO2.

[0020] In one embodiment, the second adhesive layer comprises a matte structure formed by embossing.

[0021] In one embodiment, the multifaceted groove has an inverted pyramid shape.

[0022] In one embodiment, the multifaceted groove has a circular cone or a polygonal cone.

[0023] In one embodiment, the reverse prism is triangular or semi-circular in shape.

[0024] After referring to the following paragraphs and the accompanying drawings, which describe the embodiments and detailed techniques of the present invention, those skilled in the art will understand the technical features and implementation of the present invention. Attached Figure Description

[0025] Figure 1 A composite optical film is shown, which combines an inverted prism structure and a multifaceted groove structure.

[0026] Figure 2A A three-dimensional view of a two-in-one composite optical film structure is shown, which is formed by laminating a composite multifunctional low-diffusion optical film and a lower prism film to form a single optical film.

[0027] Figure 2B It shows Figure 2A Cross-sectional view of the two-in-one composite optical film structure.

[0028] Figure 3A A three-dimensional view of a three-in-one composite optical film structure is shown. The structure is formed by laminating a composite multifunctional low-diffusion optical film with a lower prism film and an upper prism film to form a single optical film.

[0029] Figure 3B It shows Figure 3A A cross-sectional view of the three-in-one composite optical film structure.

[0030] Figure 4A shows a three-dimensional view of a two-in-one composite optical film structure in which organic or inorganic beads are added to the laminated adhesive layer.

[0031] Figure 4B shows a cross-sectional view of the two-in-one composite optical film structure in Figure 4A.

[0032] Figure 5A shows a three-dimensional view of a three-in-one composite optical film structure in which organic or inorganic beads are added to the upper photocurable adhesive layer.

[0033] Figure 5B shows a cross-sectional view of the three-in-one composite optical film structure in Figure 5A.

[0034] Figure 6A shows a three-dimensional view of a three-in-one composite optical film structure, in which organic or inorganic beads are added to both the upper and lower photocurable adhesive layers.

[0035] Figure 6B shows a cross-sectional view of the three-in-one composite optical film structure in Figure 6A.

[0036] Explanation of reference numerals in the attached figures: 1-composite optical film; 16-first substrate; 10-reverse prism structure; 12-multifaceted groove structure; 2-lower prism film; 26-second substrate; 20-first adhesive layer; 3-upper prism film; 36-third substrate; 30-second adhesive layer; 40, 5A, 5B-matte adhesive layer. Detailed Implementation

[0037] The invention will be described in detail below. The preferred embodiments described herein are for illustrative and descriptive purposes only and are not intended to limit the scope of the invention.

[0038] The following preferred embodiments of the present invention utilize prism structures with different prism angles on the incident surface of the inverted prism film to determine the optimal prism angle. The exit surface of the inverted prism film has an inverted pyramid microstructure, which acts as a diffuser, thereby forming a multifunctional low-diffusion composite optical film with defect masking and brightness enhancement functions, such as... Figure 1 As shown.

[0039] The exit surface of a multifunctional low-diffusion composite optical film with an inverted pyramid microstructure, i.e., the incident surface of the lower prism film (i.e., the PET surface), is laminated with a photocurable adhesive layer to bond the two optical films together, forming a single two-in-one composite optical film, thus constructing a composite optical film structure, such as... Figure 2A and Figure 2B As shown. Alternatively, the convex surface (i.e., the prism structure surface) of the two-in-one composite optical film can be laminated with a photocurable adhesive layer, and then further laminated with the incident surface (i.e., the PET surface) of the upper prism film, thereby bonding the three optical films together to form a single integrated three-in-one composite optical film, thus constructing a composite optical film structure, such as... Figure 3A and Figure 3B As shown.

[0040] The aforementioned two-in-one composite optical film and three-in-one composite optical film can increase brightness by approximately 10% to 20%. They can effectively reduce the thickness and material cost of backlight modules (backlight units, BLUs) by about one-third to one-half, reduce the number of LEDs required, reduce the heat generated by LEDs in the backlight module, reduce overall power consumption, reduce transportation volume and cost, and simplify BLU assembly, thereby achieving multiple benefits such as thinner and lighter modules, energy saving and emission reduction.

[0041] like Figure 1 As shown, the composite optical film 1 includes an inverted prism structure 10 and a multifaceted groove structure 12. The inverted prism structure 10 is disposed on the lower surface of the first substrate 16, and the multifaceted groove structure 12 is disposed on the upper surface of the first substrate 16. The substrate 16 can be made of materials such as PET, PEN, PAR, PC, or TAC. The inverted prism structure 10 includes a triangular pyramid and a semi-circular pyramid, and the height of the prism tip varies considerably. The prism angle ranges from 50° to 140°, preferably from 65° to 125°. Preferably, the multifaceted groove structure includes an inverted pyramid with a circular or polygonal cone. Based on the isotropic light-gathering principle of the inverted prism structure 10, and using an inverted prism film with a specific prism angle, the light emitted from the light guide plate can be directed upwards, thereby increasing the light utilization rate emitted from the light guide plate by approximately 10% to 30%. Furthermore, by setting an inverted pyramid microstructure as a diffusion layer on the emission surface, brightness uniformity and defect shielding effects can be achieved. Therefore, while maintaining the diffusion function, the overall brightness gain of the composite optical film is effectively improved.

[0042] In one embodiment, the multifaceted groove structure 12 includes a plurality of multifaceted grooves.

[0043] In one embodiment, the multifaceted groove includes at least four side surfaces.

[0044] In one embodiment, multiple faceted grooves are distributed along the length of the substrate and along the width of the substrate, wherein there is no gap between two adjacent faceted grooves.

[0045] In one embodiment, the reverse prism structure 10 includes a plurality of reverse prisms.

[0046] As shown in Figure 1, this composite optical film structure combines the diffusion function provided by the inverted pyramid microstructure with the reverse prism and has the following characteristics: (1) This composite optical film can replace the traditional low diffusion film, so it will not increase the overall thickness of the backlight module; (2) The composite optical film will not have an adverse effect on the overall optical color of the backlight module; (3) The overall brightness of the backlight module can be increased by about 10% to 20%.

[0047] like Figure 2A and Figure 2BAs shown, a composite multifunctional low-diffusion optical film 1 and a lower prism film 2 are laminated to form a two-in-one composite optical film structure. The lower prism film 2 includes a second substrate 26, which can be made of PET, PEN, PAR, PC, or TAC. To reduce the thickness of the composite optical film and simplify its assembly, Figure 2A and Figure 2B The embodiment employs a lamination process in which the convex surface of the multifunctional low-expansion composite optical film (i.e., the inverted pyramid microstructure surface) 12 is laminated to the incident surface of the lower prism film 2 through a first adhesive layer 20, thereby forming a single integrated two-in-one composite optical film structure, such as... Figure 2B As shown. Adhesive layer 20 can be a thermosetting or photocurable adhesive layer.

[0048] Therefore, as Figure 2A and Figure 2B As shown, the composite optical film structure formed by combining the diffusion function provided by the inverted pyramid microstructure with the reverse prism and further laminating it with the lower prism film has the following characteristics: (1) The composite optical film can replace the traditional lower diffusion film and lower prism film, thereby effectively reducing the overall thickness of the backlight module; (2) The composite optical film will not have an adverse effect on the overall optical color of the backlight module; (3) The overall brightness of the backlight module remains basically unchanged; (4) The thickness and material cost of the backlight module (backlight unit, BLU) can be reduced by about one-third to one-half; (5) The transportation volume and related transportation costs can be reduced; (6) The assembly complexity and assembly cost of the BLU can be reduced.

[0049] like Figure 3A and Figure 3B As shown in the figure, a three-in-one composite optical film structure is schematically illustrated. This structure is formed by laminating a composite multifunctional low-diffusion optical film 1, a lower prism film 2, and an upper prism film 3. The lower prism film 2 includes a second substrate 26, which can be made of PET, PEN, PAr, PC, or TAC. Similarly, the upper prism film 3 includes a third substrate 36, which can also be made of PET, PEN, PAr, PC, or TAC. Figure 3A and Figure 3B First, an adhesive layer 20 is used to laminate the exit surface (i.e., the surface of the inverted pyramid microstructure) of the multifunctional low-diffusion composite optical film onto the incident surface of the lower prism film, thereby forming a two-in-one composite optical film. Then, the two-in-one composite optical film is laminated onto the incident surface of the upper prism film using a second adhesive layer 30, thus bonding the three optical films together to form a single, integrated three-in-one composite optical film structure. The second adhesive layer 30 can be a thermosetting or photosetting adhesive layer.

[0050] like Figure 3A and Figure 3BAs shown, by combining the diffusion function provided by the inverted pyramid microstructure with the reverse prism, and further laminating this structure together with the lower prism film and the upper prism film, a single integrated three-in-one composite optical film is formed. This composite optical film structure has the following characteristics: (1) This composite optical film can replace the traditional lower diffusion film, the traditional lower prism film and the traditional upper prism film, thereby effectively reducing the overall thickness of the backlight module; (2) This composite optical film will not have an adverse effect on the overall optical color of the backlight module; (3) The overall brightness of the backlight module can be basically maintained; (4) The thickness and material cost of the backlight module (backlight unit, BLU) can be reduced by about one-third to one-half; (5) The transportation volume and related transportation costs can be reduced; (6) The assembly complexity and assembly cost of the BLU can be reduced.

[0051] In a three-in-one composite prism film, the prism structure of the upper and lower prism films, and / or the lower prism film in a two-in-one composite prism film, can employ prism tips with varying heights, such as H-type or G-type structures, or structures comprising one high prism tip and one low prism tip, or one high prism tip and two low prisms. This structure can effectively reduce adhesion and bonding problems between adjacent optical films.

[0052] Furthermore, the UV-curable adhesive layer for the lower prism film used in laminated multifunctional low-diffusion composite optical films and single-layer two-in-one composite optical films can be a transparent adhesive. Alternatively, a matte adhesive layer 40 with a diffusion effect can also be used. The matte finish may include adding organic or inorganic beads to a thermosetting or UV-curable adhesive, or forming a matte finish through embossing (matte embossing), thereby providing defect masking and anti-mura effects, such as... Figure 4A and Figure 4B As shown. For example, the added beads include diffusion beads selected from organic and inorganic beads, wherein the organic beads include PMMA, PS, or melamine, and the inorganic beads include silicon, SiO2, TiO2, CaCO3, Al2O3, or ZrO2, with a haze range of 2% to 60%, preferably 10%. If the matte adhesive layer 40 is formed into a matte coating by embossing, the haze value ranges from 2% to 60%. Therefore, the lower diffusion film can be omitted, thereby achieving a reduction in thickness and an increase in brightness.

[0053] Furthermore, the curing adhesive layer for the multifunctional low-diffusion composite optical film, lower prism film, and upper prism film used in the lamination of single-sheet three-in-one composite optical films can be a transparent UV adhesive (such as...). Figure 3A and Figure 3B (As shown), it can also be a matte adhesive layer 50A and / or 50B with a diffusion effect. Matte finishing may include adding organic or inorganic beads to a thermosetting or UV-cured adhesive, or forming a matte finish through embossing, thereby providing defect masking and anti-rainbow effect, such as... Figure 5A , Figure 5B , Figure 6A and Figure 6B As shown. For example, the added beads include diffusion beads selected from organic and inorganic beads, wherein the organic beads include PMMA, PS, or melamine, and the inorganic beads include silicon, SiO2, TiO2, CaCO3, Al2O3, or ZrO2, with a haze range preferably of 10%. If the matte adhesive layer 40 is formed by embossing, the haze value ranges from 2% to 60%. Therefore, the upper and lower diffusion films can be omitted, thereby achieving a reduction in thickness and an increase in brightness. Therefore, the upper diffusion film can be omitted to achieve a reduction in thickness and an increase in brightness.

[0054] A single-sheet two-in-one or three-in-one composite optical film, formed by laminating a multifunctional downward diffusion composite optical film with a lower prism film and / or an upper prism film, can achieve a lamination bonding strength greater than 50 g / 25 mm. When using an adhesive containing organic or inorganic beads, the haze of the adhesive layer can be controlled between approximately 1% and 60%.

[0055] Based on the isotropic light-gathering principle of the reverse prism film, and employing methods such as... Figure 1 The inverse prism film with a specific prism angle shown can direct the light emitted from the light guide plate upwards. Therefore, the utilization rate of the light emitted from the light guide plate can be increased by approximately 10% to 30%. Furthermore, the exit surface is provided with an inverted pyramid microstructure with diffusion function, thereby achieving light homogenization and defect masking. Therefore, while maintaining the diffusion function, the overall brightness gain of the composite optical film can be effectively improved.

[0056] To reduce the thickness of the composite optical film and simplify its assembly, this invention employs a lamination technique in which the convex surface (i.e., the inverted pyramid microstructure surface) of the multifunctional low-diffusion composite optical film is laminated onto the incident surface (i.e., the PET surface) of the lower prism film using a photocurable adhesive. Thus, the two optical films are bonded together to form a single two-in-one composite optical film, thereby constructing a... Figure 2A and Figure 2B The composite optical film structure shown.

[0057] Alternatively, the convex surface (i.e., the inverted pyramid microstructure surface) of the multifunctional low-diffusion composite optical film can be laminated onto the incident surface (i.e., the PET surface) of the lower prism film using a photocurable adhesive, thus forming a two-in-one composite optical film. Subsequently, the two-in-one composite optical film is laminated onto the incident surface (i.e., the PET surface) of the upper prism film using a photocurable adhesive, thereby bonding the three optical films together to form a single, integrated three-in-one composite optical film structure, such as... Figure 3A and Figure 3B As shown.

[0058] In summary, the aforementioned composite optical film structure combines the isotropic focusing properties of the reverse prism film with the diffusion and light homogenization functions provided by the inverted pyramid microstructure. It is then laminated with a lower prism film and an optional upper prism film to form a single-piece two-in-one or three-in-one composite optical film, offering the following advantages: 1. Under the same backlight module configuration, using a multifunctional composite diffusion optical film that combines the isotropic focusing properties of the reverse prism film with the diffusion and light homogenization functions of the inverted pyramid microstructure can increase the overall brightness of the module by approximately 10% to 20%. 2. When using an adhesive without added organic or inorganic beads (beads) to laminate the multifunctional composite diffusion optical film with the lower prism film (optional) to form a single-piece two-in-one or three-in-one prism composite optical film, high brightness requirements can be met while effectively reducing the thickness of the backlight module (backlight unit, BLU). 3. It can reduce the number of LEDs required and lower the overall power consumption of the backlight module, thereby achieving the benefits of thinning, energy saving, and carbon emission reduction. 4. When using an adhesive containing added organic or inorganic beads (beads) to laminate a multifunctional composite diffusion optical film with a lower prism film (optional) to form a single-sheet two-in-one or three-in-one prism composite optical film, the upper diffusion film can be replaced, thereby achieving both thinning and high brightness. In this structure, the overall thickness of the backlight module (BLU) can be reduced by approximately one-third to one-half. 5. A single-sheet two-in-one or three-in-one prism composite optical film can further improve the thermal stability and wrinkle resistance of the composite optical film. 6. The composite optical film structure does not adversely affect the overall optical colorimetry of the backlight module. 7. It can reduce transportation volume and related transportation costs, and simplify the assembly complexity of the BLU and reduce assembly costs.

Claims

1. A composite optical film, characterized in that, include: The first substrate has a lower surface and an upper surface; Multiple reverse prisms are disposed on the lower surface of the first substrate; as well as Multiple multifaceted grooves are disposed on the upper surface of the first substrate.

2. The composite optical film according to claim 1, characterized in that, A plurality of first prisms are disposed above the plurality of multifaceted grooves, and the plurality of first prisms are disposed on the upper surface of the second substrate, and the second substrate is attached to the plurality of multifaceted grooves by a first adhesive layer.

3. The composite optical film according to claim 2, characterized in that, The first adhesive layer comprises a thermosetting resin or a photocurable resin.

4. The composite optical film according to claim 3, characterized in that, The first adhesive layer also includes beads for providing a diffusion effect.

5. The composite optical film according to claim 4, characterized in that, The beads are selected from organic materials composed of PMMA, PS and melamine.

6. The composite optical film according to claim 3, characterized in that, The first adhesive layer comprises a matte structure formed by embossing.

7. The composite optical film according to claim 2, characterized in that, A plurality of second prisms are disposed above a plurality of first prisms, the plurality of second prisms are disposed on a third substrate, and the third substrate is adhered to the plurality of first prisms by a second adhesive layer.

8. The composite optical film according to claim 8, characterized in that, The second adhesive layer comprises a thermosetting resin or a photocurable resin.

9. The composite optical film according to claim 9, characterized in that, The second adhesive layer also includes added beads for providing a diffusion effect.

10. The composite optical film according to claim 9, characterized in that, The second adhesive layer comprises a matte structure formed by embossing.

11. The composite optical film according to claim 1, characterized in that, The plurality of multifaceted grooves have an inverted pyramid shape.

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