Optical assembly used in backlight module

Abstract

An optical assembly for use in a backlight module is disclosed. The optical assembly includes: a first optical film having a first surface; the adhesive layer is provided with a second surface and a third surface opposite to the second surface, and the second surface of the adhesive layer is configured on the first surface of the first optical film; the diffusion sheet is provided with a fourth surface, the fourth surface comprises a plurality of first microstructures and a plurality of second microstructures, each second microstructure extends towards a first direction, and each second microstructure extends towards a second direction; wherein the maximum height of the plurality of second microstructures is greater than the maximum height of the plurality of first microstructures so as to bond the plurality of second microstructures to the third surface of the adhesive layer.

Description

[0001] This application is a divisional application of the invention patent application with the application date of December 7, 2017, application number 201711288140.3, and invention title "Optical Component Used in Backlight Module". Technical Field

[0002] The present invention relates to an optical component, particularly an optical component bonded by an adhesive. Background Art

[0003] Flat display panels (such as liquid crystal displays (LCDs)) are widely used. A liquid crystal display requires a backlight module as a surface light source to provide better light uniformity for the entire screen. Current backlight modules include a light guide plate, a light source disposed near the side surface of the light guide plate and within a light source reflector, a reflective sheet disposed above the lower surface of the light guide plate, and a combination of a diffusion sheet, a prism sheet, and other optical films disposed above the upper surface of the light guide plate.

[0004] Bonding the diffusion sheet to the prism sheet is a way to reduce the total thickness of the optical films in the backlight module. The diffusion sheet is only point-bonded to the adhesive layer on the back of the prism sheet substrate at each of the irregular raised portions of its structured surface. This bonding method results in some unwanted phenomena, such as poor light homogenization, poor flaw-masking, insufficient adhesion, and non-uniform viscosity. Therefore, the present invention proposes an optical component and its manufacturing method to overcome the above-mentioned drawbacks. Summary of the Invention

[0005] The optical component of the present invention can solve problems such as poor light homogenization, poor flaw-masking, insufficient adhesion, and non-uniform viscosity in the bonding process. In addition, due to the periodic design of the plurality of extended bonding microstructures on the structured surface of the diffusion sheet, Moiré patterns can be effectively solved. The optical component of the present invention can also solve problems such as curling, waving, bulging, or denting of a single optical film due to uneven heat absorption. The optical component of the present invention can significantly reduce the total thickness of the optical films in the backlight module while increasing heat resistance to prevent deformation.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] An optical component used in a backlight module, comprising:

[0008] A first optical film having a first surface;

[0009] An adhesive layer having a second surface and a third surface opposite the second surface, wherein the second surface of the adhesive layer is disposed on the first surface of the first optical film; and,

[0010] A diffusion sheet having a fourth surface, wherein the fourth surface includes a plurality of first microstructures and a plurality of second microstructures, wherein each of the second microstructures extends in a first direction, and wherein a maximum height of the plurality of second microstructures is greater than a maximum height of the plurality of first microstructures to bond the plurality of second microstructures to the third surface of the adhesive layer.

[0011] The optical component used in the backlight module, wherein: an average height of the plurality of second microstructures is 3 to 50 micrometers greater than an average height of the plurality of first microstructures.

[0012] The optical component used in the backlight module, wherein: the fourth surface has a first edge and a second edge opposite the first edge, and wherein each of the second microstructures extends from the first edge of the fourth surface to the second edge of the fourth surface.

[0013] The optical component used in the backlight module, wherein: each of the first microstructures does not extend from the first edge of the fourth surface to the second edge of the fourth surface, and an average size of the plurality of first microstructures is smaller than an average size of the plurality of second microstructures.

[0014] The optical component used in the backlight module, wherein: there is a gap between every two adjacent second microstructures, and an average height of the plurality of second microstructures is 3 to 50 micrometers greater than an average height of the plurality of first microstructures on the plurality of gaps.

[0015] The optical component used in the backlight module, wherein: there is a gap between every two adjacent second microstructures, and the plurality of first microstructures are distributed on at least one of the plurality of second microstructures and the plurality of gaps.

[0016] The optical component used in the backlight module, wherein: each of the second microstructures has an upper plane bonded to the third surface of the adhesive layer.

[0017] The optical component used in the backlight module, wherein: a width of the upper plane of each of the second microstructures is 1 to 10 micrometers.

[0018] The optical component used in the backlight module, wherein: the upper plane of each of the second microstructures has a width W and there is a distance P between every two adjacent second microstructures, and 0 < W / P < 0.2.

[0019] An optical component used in a backlight module, comprising:

[0020] A prism sheet having a first surface;

[0021] An adhesive layer having a second surface and a third surface opposite to the second surface, wherein the second surface of the adhesive layer is disposed on the first surface of the prism sheet; and,

[0022] A diffusion sheet having a fourth surface, wherein the fourth surface includes a plurality of adhesive microstructures, each of the adhesive microstructures extending in a first direction, and the plurality of adhesive microstructures of the diffusion sheet are bonded to the third surface of the adhesive layer.

[0023] The optical component used in the backlight module, wherein: there is a gap between every two adjacent adhesive microstructures, the fourth surface of the diffusion sheet further includes a plurality of diffusion microstructures, the plurality of diffusion microstructures are distributed on at least one of the plurality of adhesive microstructures and the plurality of gaps, and the average height of the plurality of adhesive microstructures is 3 to 50 micrometers greater than the average height of the plurality of diffusion microstructures on the plurality of gaps.

[0024] The optical component used in the backlight module, wherein: the fourth surface has a first edge and a second edge opposite to the first edge, and each of the adhesive microstructures extends from the first edge of the fourth surface to the second edge of the fourth surface.

[0025] The optical component used in the backlight module, wherein: there is a gap between every two adjacent adhesive microstructures, the fourth surface of the diffusion sheet further includes a plurality of diffusion microstructures, the plurality of diffusion microstructures are distributed on at least one of the plurality of adhesive microstructures and the plurality of gaps, each of the diffusion microstructures does not extend from the first edge of the fourth surface to the second edge of the fourth surface, and the average size of the plurality of diffusion microstructures is smaller than the average size of the plurality of adhesive microstructures.

[0026] The optical component used in the backlight module, wherein: each of the adhesive microstructures has an upper plane bonded to the third surface of the adhesive layer,

[0027] The optical component used in the backlight module, wherein: the width of the upper plane of each of the adhesive microstructures is 1 to 10 micrometers.

[0028] The optical component used in the backlight module, wherein: the upper plane of each of the adhesive microstructures has a width W and there is a distance P between every two adjacent adhesive microstructures, and 0 < W / P < 0.2.

[0029] The optical component used in the backlight module, wherein: the upper plane of each of the adhesive microstructures has a width W and there is a distance P between every two adjacent adhesive microstructures, where W is at least 1 micron and P is at least 100 microns.

[0030] The optical component used in the backlight module, wherein: the adhesive force between the plurality of adhesive microstructures of the diffusion sheet and the third surface of the adhesive layer is at least 50 g / 25 mm.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: problems such as poor light homogenization, poor concealment, insufficient adhesive force, and uneven adhesiveness in the lamination process are solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A cross-sectional schematic diagram of the optical component used in the backlight module of the present invention;

[0033] Figure 2A A three-dimensional schematic diagram of the diffusion sheet of the optical component of the present invention;

[0034] Figure 2B A true cross-sectional schematic diagram of the diffusion sheet of the optical component of the present invention;

[0035] Figure 2C A true top view of the diffusion sheet of the optical component of the present invention;

[0036] Figure 3 A cross-sectional schematic diagram of the optical component used in the backlight module of another embodiment of the present invention, wherein the upper surface of the second microstructure is a plane (i.e., there is a small platform at the top);

[0037] Figure 4 A schematic diagram of a single second microstructure with an upper plane (the first microstructure on the single second microstructure is omitted);

[0038] Figure 5 A schematic diagram showing that the top height of the second microstructure can vary along the length direction of the second microstructure;

[0039] Figure 6 The height of the upper plane of the second microstructure can vary along the length direction of the second microstructure.

[0040] Explanation of the reference numerals: 100-optical component; 101-first optical film; 101A-first surface; 101B-second surface; 101M-structured layer; 101S-substrate; 102-diffuser; 102A-first surface; 102B-second surface; 102M-light diffusion layer; 102S-substrate; 102X-first edge; 102Y-second edge; 103-adhesive layer; 103A-first surface; 103B-second surface; 111-first microstructure; 112-second microstructure; 112A-upper plane; 112P-raised portion; 112Q-non-raised portion; 113-spacer; 114-air gap; H-height difference; P-distance; W-width. DETAILED DESCRIPTION

[0041] The detailed description of the present invention is described below. The preferred embodiments described here are for the purpose of illustration and description and are not intended to limit the scope of the present invention.

[0042] Figure 1 A cross-sectional schematic diagram illustrating an optical component 100 used in a backlight module according to the present invention. Figure 2A A three-dimensional schematic diagram illustrating the diffuser 102 of the optical assembly 100 of the present invention. Figure 2B A schematic diagram illustrating a true cross-section of the diffuser 102 of the optical component 100 of the present invention. Figure 2CA true top view of the diffuser sheet 102 of the optical component 100 of the present invention is illustrated. The optical component 100 includes a first optical film 101, a diffuser sheet 102, and an adhesive layer 103 between the first optical film 101 and the diffuser sheet 102. The first optical film 101 has a first surface 101A and a second surface 101B opposite to the first surface 101A. The first optical film 101 can be any suitable optical film, such as a brightness enhancement film, a prism sheet, a reflective polarizing brightness enhancement film (DBEF), and so on. Optionally, the first optical film 101 can include a substrate 101S (such as a PET substrate) and a structured layer 101M (such as a prism) disposed on the substrate 101S. The adhesive layer 103 has a first surface 103A and a second surface 103B opposite to the first surface 103A. The first surface 103A of the adhesive layer 103 is disposed on the second surface 101B of the first optical film 101. The diffuser sheet 102 has a first surface 102A and a second surface 102B opposite to the first surface 102A. The first surface 102A of the diffuser sheet 102 is a structured surface including a plurality of first microstructures 111 and a plurality of second microstructures 112. Optionally, the diffuser sheet 102 can include a substrate 102S and a light diffusing layer 102M disposed on the substrate 102S. Another light diffusing layer can be disposed on the second surface 102B of the diffuser sheet 102, but is omitted herein. A single second microstructure 112 can have a linear length, a meandering length, or a waveform length and extends in the length direction of the second microstructure 112 (the length direction of the second microstructure 112 is substantially perpendicular to the width direction of the second microstructure 112 (such as the cross-sectional direction)). For example, each second microstructure 112 is parallel to its adjacent second microstructure 112. The length direction of a single second microstructure 112 of the diffuser sheet 102 is substantially parallel to the length direction of a single prism of the prism sheet 101. The length direction of a single second microstructure 112 of the diffuser sheet 102 is substantially perpendicular (or non-parallel) to the length direction of a single prism of the prism sheet 101 to overcome moiré patterns. Each second microstructure 112 can extend from a first edge 102X of the first surface 102A to a second edge 102Y of the first surface 102A (opposite to the first edge 102X of the first surface 102A). The maximum height (or average height) of the second microstructure 112 is greater than the maximum height (or average height) of the first microstructure 111 to bond the second microstructure 112 to the second surface 103B of the adhesive layer 103. The top of the second microstructure 112 can or cannot penetrate into the adhesive layer 103.

[0043] In one embodiment, the first surface 101A of the first optical film 101 (e.g., a prism sheet) is used to output light and the second surface 102B of the diffusion sheet 102 is used to input light. For example, in a backlight module, light exits the light guide plate and then enters the second surface 102B of the diffusion sheet 102; the diffusion sheet 102 is used to diffuse the light entering the second surface 102B of the diffusion sheet 102 and the prisms of the prism sheet 101 are used to collimate the light exiting the prism surface 101A of the prism sheet 101. In another embodiment, the first surface 101A of the first optical film 101 (e.g., a prism sheet) is used to input light and the second surface 102B of the diffusion sheet 102 is used to output light. For example, in a backlight module, light exits the light guide plate and then enters the prism surface 101A of the prism sheet 101; the diffusion sheet 102 is used to diffuse the light exiting the second surface 102B of the diffusion sheet 102. The latter refers to the technique of applying the adhesive optical component 100 of the present invention to an inverse prism sheet.

[0044] The second microstructure 112 on the first surface 102A of the diffusion sheet 102 is bonded to the second surface 103B of the adhesive layer 103. There is a space 113 between every two adjacent second microstructures 112. The second microstructure 112 can be (or approximate to) a lenticular structure or a cylindrical structure. However, the present invention is not limited to this case; as long as each second microstructure 112 extends in a certain direction, the second microstructure 112 can have any suitable shape. Each second microstructure 112 is higher than the space 113 between its two sides. The first microstructure 111 of the diffusion sheet 102 is mainly used for diffusing light. The average size of the first microstructure 111 is smaller than the average size of the second microstructure 112. Each first microstructure 111 does not extend from the first edge 102X of the first surface 102A to the second edge 102Y of the first surface 102A (relative to the first edge 102X of the first surface 102A). The first microstructure 111 on the first surface 102A of the diffusion sheet 102 can be distributed on at least one of the second microstructure 112 and the space 113. The top of the second microstructure 112 is higher than the top of the first microstructure 111 and has a height difference H so that the second microstructure 112 can be used to bond to the second surface 103B of the adhesive layer 103 and the first microstructure 111 on the space 113 does not bond to the second surface 103B of the adhesive layer 103. Specifically, some of the first microstructures 111 on the second microstructure 112 can also bond to the second surface 103B of the adhesive layer 103. The second microstructure 112 on the first surface 102A of the diffusion sheet 102 is bonded to the second surface 103B of the adhesive layer 103 to increase the rigidity of the overall optical component 100. The first microstructure 111 on the space 113 does not bond to the second surface 103B of the adhesive layer 103, so there is an air gap 114 between the space 113 on the first surface 102A of the diffusion sheet 102 and the adhesive layer 103 to increase the light diffusion effect. Generally, the diffusion sheet is only point-bonded to the adhesive layer on the back of the optical film at each irregular raised part of its structured surface. In the present invention, since each second microstructure 112 on the first surface 102A of the diffusion sheet 102 extends in a certain direction (continuously extends in a straight line direction or continuously extends in a curved line direction, preferably, continuously extends in a straight line direction), the bonding area between the first optical film 100 and the diffusion sheet 102 can be improved to be a one-dimensional bonding or a two-dimensional bonding; therefore, the adhesion between the first optical film 100 and the diffusion sheet 102 can be increased to at least 50 g / 25 mm, preferably at least 100 g / 25 mm. The height difference H between the second microstructure 112 and the first microstructure 111 on the space 113 can be 3 to 50 microns, 5 to 50 microns or 3 to 30 microns.If the height difference H is too small, the size of the air gap 114 will be reduced, resulting in ineffective light diffusion and a decrease in the light diffusion effect (haze) of the diffusion sheet 102. If the height difference H is too large, the thickness of the overall optical component 100 will increase and the size of the overall optical component 100 cannot be reduced. Compared with the commonly used point-bonded method, the present invention can greatly increase the adhesion between the first optical film 100 and the diffusion sheet 102 and at the same time control the air gap 114 between the spacer 113 and the adhesive layer 103 on the first surface 102A of the diffusion sheet 102 to enhance the light diffusion effect.

[0045] The adhesive layer 103 can be made of a single / homogeneous material. Optionally, the single / homogeneous material may or may not contain light-diffusing particles. A thinner adhesive layer 103 (for example, the thickness of the adhesive layer 103 can be less than 2.5 microns, less than 2 microns, less than 1.5 microns, or less than 1 micron) can also reduce the adsorption phenomenon generated on both sides of the second microstructure 112 due to capillary action, so as to increase the light diffusion effect of the first surface 102A of the diffusion sheet 102 and the brightness performance of the overall optical component 100. The second surface 103B of the adhesive layer 103 can be a structured surface as described in U.S. Provisional Application No. 62 / 372,315, the entire text of which is incorporated herein by reference.

[0046] Figure 3 FIG. shows a cross-sectional schematic diagram of an optical component 100 used in a backlight module according to another embodiment of the present invention, wherein the upper surface 112A of the second microstructure 112 is a flat surface (i.e., having a small platform 112A at the top). Figure 4Illustrate a single second microstructure 112 having an upper plane 112A (the first microstructure 111 on the single second microstructure 112 is omitted). Optionally, the upper plane 112A of the second microstructure 112 may or may not penetrate the adhesive layer 103. The upper plane 112A of the second microstructure 112 can increase the area bonded to the adhesive layer 103 to increase the adhesion between the first optical film 101 and the diffusion sheet 102. By contacting the upper plane 112A of the second microstructure 112 with the adhesive layer 103, there can be sufficient adhesion to reduce the adsorption phenomenon generated on both sides of the second microstructure 112 due to capillary action, so as to increase the light diffusion effect of the first surface 102A of the diffusion sheet 102 and the luminance performance of the overall optical component 100. The width W of the upper plane 112A of the second microstructure 112 is at least 1 micron. The distance P between adjacent tops of the second microstructure 112 is at least 100 microns. In one embodiment, the width W is 1 - 10 microns, 1 - 5 microns or 1 - 3 microns. If the width W is too small, the area bonded to the adhesive layer 103 will be reduced, and the adhesion between the first optical film 101 and the diffusion sheet 102 will be reduced. If the width W is too large, the area bonded to the adhesive layer 103 will be increased, and the light diffusion effect (haze) of the diffusion sheet 102 will be reduced. In another embodiment, 0 < W / P < 0.2; if W / P is too small, the area bonded to the adhesive layer 103 will be reduced, and the adhesion between the first optical film 101 and the diffusion sheet 102 will be reduced. If W / P is too large, the area bonded to the adhesive layer 103 will be increased, and the light diffusion effect (haze) of the diffusion sheet 102 will be reduced. The distance P can be 100 - 1000 microns or 100 - 500 microns. If the distance P is too small, the area bonded to the adhesive layer 103 will be increased, and the light diffusion effect (haze) of the diffusion sheet 102 will be reduced. If the distance P is too large, the density of the second microstructure 112 will be too low to effectively support the first optical film 101 and cannot increase the rigidity of the overall optical component 100.

[0047] In one embodiment, the height of the top or the upper plane 112A of the second microstructure 112 may vary along the length direction of the second microstructure 112 (see Figure 5 and Figure 6 ). The top or the upper plane 112A of the second microstructure 112 can also be changed to include a plurality of raised portions 112P (which may have a fixed height) and a plurality of non-raised portions 112Q (which may have a fixed height) alternating with these raised portions 112P, and the raised portions 112P of the top or the upper plane 112A of the second microstructure 112 are bonded to the second surface 103B of the adhesive layer 103. There is an air gap 114 between the non-raised portions 112Q of the top or the upper plane 112A of the second microstructure 112 and the adhesive layer 103 to increase the light diffusion effect.

[0048] A photo-curable material (such as a UV-Type resin) or a thermo-curable material can be used to form the first surface 102A of the diffusion sheet 102. The photo-curable material or the thermo-curable material on the first surface 102A of the diffusion sheet 102 undergoes a first curing reaction to make the photo-curable material or the thermo-curable material on the first surface 102A of the diffusion sheet 102 in a semi-cured state. Then, when the photo-curable material or the thermo-curable material on the first surface 102A of the diffusion sheet 102 adheres to the adhesive layer 103 on the second surface 102B of the first optical film 101, a second curing reaction occurs to make the photo-curable material or the thermo-curable material on the first surface 102A of the diffusion sheet 102 and the adhesive layer 103 on the second surface 102B of the first optical film 101 in a fully cured (hardened) state to increase the adhesion between them. Both the first curing reaction and the second curing reaction can be used to increase the adhesion.

[0049] The chemical formula of the photo-curable material on the first surface 102A of the diffusion sheet 102 can be R1-F1. The main chain R1 can be a long carbon chain, an aromatic group, a benzene ring group, or a soft PU group, etc. The reactive functional group F1 can include one acrylate functional group, two acrylate functional groups, three acrylate functional groups, or multiple acrylate functional groups, etc. The chemical formula of the thermo-curable material on the first surface 102A of the diffusion sheet 102 can be R2-F2. The main chain R2 can be a long carbon chain, an aromatic group, a benzene ring group, or a soft PU group, etc. The reactive functional group F2 can be an epoxy group, an OH group, etc.

[0050] The first micro-structure 111 and the second micro-structure 112 on the first surface 102A of the diffusion sheet 102 can be formed by imprinting with a mold / roller. The fabrication of the mold / roller is described as follows: (a) A plurality of grooves corresponding to the plurality of second micro-structures 112 are first scribed on the surface of the mold / roller with a hard tool. The hard tool can be a small-sized tool installed on a CNC (Computer Numerical Control) machine (such as a turning machine, a milling machine, and a ruling / shaping machine); and a treatment process such as a sand-blasting process is performed on the surface of the mold / roller having the plurality of grooves thereon to form the surface of the mold / roller corresponding to the first micro-structure 111 and the second micro-structure 112.

[0051] Experiment:

[0052] In Embodiment 1 of the present invention, the second microstructure 112 on the first surface 102A of the diffusion sheet 102 is bonded to the second surface 103B of the adhesive layer 103. In the general Comparative Example 1, the diffusion sheet is only point-bonded to the adhesive layer on the back surface of the optical film at each irregular raised portion of its structured surface. The adhesive layer 103 in Embodiment 1 and Comparative Example 1 is made of a material composed of Dipentaerythritol Hexaacrylate (DPHA CNS, manufactured by Sartomer Company), Bisphenol A(EO)30 Dimethacrylate (M2301, manufactured by Miwon Company), and Isodecyl Acrylate (M130, manufactured by Miwon Company). The weight ratio of Dipentaerythritol Hexaacrylate in the material of the adhesive layer 103 is 40%. The weight ratio of Bisphenol A(EO)30 Dimethacrylate in the material of the adhesive layer 103 is 10%. The weight ratio of Isodecyl Acrylate in the material of the adhesive layer 103 is 50%. The light diffusion layer of the diffusion sheet in Embodiment 1 and Comparative Example 1 is made of a material composed of Difunctional Epoxy Acrylate (RV-280, manufactured by Aekyung Chemical Company), Bisphenol A(EO)10 Dimethacrylate (M2101, manufactured by Miwon Company), and Tetrahydrofurfuryl Acrylate (M150, manufactured by Miwon Company). The weight ratio of Difunctional Epoxy Acrylate in the material of the light diffusion layer is 40%. The weight ratio of Bisphenol A(EO)10 Dimethacrylate in the material of the light diffusion layer is 50%. The weight ratio of Tetrahydrofurfuryl Acrylate in the material of the light diffusion layer is 10%. In addition, a photoinitiator 184 is added in each embodiment. After mixing at room temperature for 4 hours, relevant physical property measurements, sample coating, production, and preparation are carried out. The measurement results are listed in Table 1.

[0053] Table 1

[0054] Example 1 Comparative Example 1 Upper plane width (μm) 1～3 None Adhesive thickness (μm) 1.5～2.0 1.5～2.0 Diffuser haze (before lamination) 86.2％ 82.3％ Diffuser haze (after lamination) 84.9％ 70.1％ Luminance (optical gain) 1.48 1.50 Adhesion (g / 25 mm) 86 38 Concealment effect Good Poor

[0055] Embodiment 1

[0056] Use a photo-curable material with adhesive properties (such as an ultraviolet resin) as the material for the light diffusion layer 102M of the diffusion sheet 102. Perform a first curing reaction in the photo-cured light diffusion layer 102M after roller imprinting to make the light diffusion layer 102M have a second microstructure 112 with an upper plane 112A having a width of 1 to 3 micrometers. Use a photo-curable material (such as an ultraviolet resin) as the material for the adhesive layer 103, and apply the material of the adhesive layer 103 to the second surface 101B of the PET substrate 101S of the prism sheet 101. Then, bond the upper plane 112A of the second microstructure 112 of the light diffusion layer 102M to the adhesive layer 103 on the second surface 101B of the PET substrate 101S of the prism sheet 101 by roller imprinting (after drying the solvent in the adhesive layer 103, control the dry film thickness of the adhesive layer 103 to be 1.5 to 2.0 micrometers to achieve an adhesion effect between the upper plane 112A of the second microstructure 112 of the light diffusion layer 102M of the diffusion sheet 102 and the second surface 101B of the PET substrate 101S of the prism sheet 101. Then perform a second curing reaction on the material of the light diffusion layer 102M so that there is also an indirect chemical adhesion between the upper plane 112A of the second microstructure 112 of the light diffusion layer 102M of the diffusion sheet 102 and the second surface 101B of the PET substrate 101S of the prism sheet 101). The adhesion between the upper plane 112A of the second microstructure 112 of the light diffusion layer 102M of the diffusion sheet 102 and the second surface 101B of the PET substrate 101S of the prism sheet 101 can reach 86 g / 25 mm. Since the upper plane 112A of the second microstructure 112 of the light diffusion layer 102M only contacts the adhesive layer 103 and does not penetrate into the adhesive layer 103, the adsorption phenomenon generated on both sides of the second microstructure 112 due to capillary action can be reduced, so as to increase the light diffusion effect of the structured surface 102A of the diffusion sheet 102 and the brightness performance of the overall optical component 100.

[0057] Comparative Example 1

[0058] Use a photo-curable material with adhesive properties (such as an ultraviolet resin) as the material for the adhesive layer, and apply the material of the adhesive layer to the back surface of the PET substrate of the prism sheet. Perform a curing reaction in the irregular / random raised / bulged areas of the light diffusion layer of the diffusion sheet and the material of the adhesive layer to achieve an adhesion effect (spot adhesion). Since the raised / bulged areas of the light diffusion layer are irregular / randomly distributed and the raised / bulged areas of the light diffusion layer only contact the adhesive layer and do not penetrate into the adhesive layer, the adhesion of Comparative Example 1 is lower than that of Example 1, and the adhesion is only 38 g / 25 mm. The haze after lamination is also reduced by 12.2% compared with the haze before lamination, so the concealer performance decreases.

[0059] According to the above experimental results, the adhesion of Example 1 of the present invention is significantly better than that of Comparative Example 1, the difference in haze before and after lamination in Example 1 of the present invention is smaller than the difference in haze before and after lamination in Comparative Example 1, and the concealer effect of Example 1 of the present invention is better than that of Comparative Example 1. Therefore, problems such as poor light homogenization, poor concealer effect, insufficient adhesion, and uneven adhesion in the lamination process are solved.

[0060] Although the present invention is disclosed above in the foregoing preferred embodiments, it is not intended to limit the present invention. Any person skilled in the relevant art can make some modifications and refinements without departing from the spirit and scope of the present invention. Although these possible modifications and substitutions are not fully disclosed in the above description, they should all fall within the protection scope of this application.

Claims

1. An optical component used in a backlight module, characterized in that it comprises: A first optical film having a first surface; An adhesive layer having a second surface and a third surface opposite to the second surface, wherein the second surface of the adhesive layer is disposed on the first surface of the first optical film; and, A diffusion sheet having a fourth surface, wherein the top of the fourth surface comprises a flat surface without any microstructure on its surface, and the flat surface is bonded to the third surface of the adhesive layer.

2. The optical component used in the backlight module according to claim 1, wherein: Wherein the fourth surface further comprises a plurality of first microstructures and a plurality of second microstructures, wherein each of the second microstructures extends in a first direction, and the maximum height of the plurality of second microstructures is greater than the maximum height of the plurality of first microstructures.

3. The optical component used in the backlight module according to claim 2, characterized in that: The fourth surface has a first edge and a second edge opposite to the first edge, wherein each of the second microstructures extends from the first edge of the fourth surface to the second edge of the fourth surface.

4. The optical component used in the backlight module according to claim 3, wherein: Each of the first microstructures does not extend from the first edge of the fourth surface to the second edge of the fourth surface, and the average size of the plurality of first microstructures is smaller than the average size of the plurality of second microstructures.

5. The optical component used in the backlight module according to claim 2, characterized in that: There is a gap between every two adjacent second microstructures, wherein the average height of the plurality of second microstructures is 3 to 50 micrometers greater than the average height of the plurality of first microstructures on the plurality of gaps.

6. The optical component used in the backlight module according to claim 2, wherein: There is a gap between every two adjacent second microstructures, wherein the plurality of first microstructures are distributed on at least one of the plurality of second microstructures and the plurality of gaps.

7. The optical component used in the backlight module according to claim 6, characterized in that: The fourth surface has a first edge and a second edge opposite to the first edge, wherein each of the second microstructures extends from the first edge of the fourth surface to the second edge of the fourth surface.

8. The optical component used in the backlight module according to claim 7, characterized in that: Each of the first microstructures does not extend from the first edge of the fourth surface to the second edge of the fourth surface, and the average size of the plurality of first microstructures is smaller than the average size of the plurality of second microstructures.

9. The optical component used in a backlight module according to claim 6, wherein: Each of the second microstructures has an upper plane bonded to the third surface of the adhesive layer.

10. The optical component used in the backlight module according to claim 9, characterized in that: The width of the upper plane of each of the second microstructures is 1 to 10 micrometers.

11. The optical component used in a backlight module according to claim 9, wherein: The upper plane of each of the second microstructures has a width W and there is a distance P between every two adjacent second microstructures, wherein 0 < W / P < 0.2.

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