Composite optical film and backlight module

Abstract

The utility model discloses a composite optical film and a backlight module, and relates to the technical field of optical films. The composite optical film comprises a first prism layer and a second prism layer which are sequentially arranged on one side of a light emitting surface from top to bottom, and a first atomization prism area, a common prism area and a second atomization prism area are sequentially arranged on the upper surface of each of the first prism layer and the second prism layer; a first base material layer and a second base material layer are respectively arranged at the bottoms of the first prism layer and the second prism layer; the top of the first prism layer is provided with a first fitting adhesive layer, and the bottom of the first base material layer is provided with a second fitting adhesive layer. According to the utility model, the problems that the shielding effect at the light incident part of an optical film material is poor, the hotspot phenomenon in front of a lamp is serious, and the cost of redundant parts is increased although lamp socket fireflies and bad tail bright lines can be effectively reduced by using a shading adhesive tape, a diffusion film frame silk screen and a lamp socket small reflector plate in the prior art are solved.

Description

Technical Field

[0001] This utility model relates to the field of optical film technology, and in particular to a composite optical film and a backlight module. Background Technology

[0002] With the continuous development of mobile phone and LCD display technologies, consumers' demands for display quality are constantly increasing, and the design of backlight modules is also constantly being updated. Due to the continuous requirement for thinner mobile electronic products, the uneven bright spots at the edges of edge-lit LED light sources are becoming more prominent, the so-called "hotspot" phenomenon. Therefore, some light-shielding components are used in the module design, which increases the width of the ineffective area at the edge of the display, not only increasing the cost but also affecting the display quality.

[0003] Currently, optical film design only considers issues such as brightness and uniformity. Brightness is improved by brightening films, and uniformity is controlled by diffusion films. Neither has taken into account light leakage from the light source side or the hotspot problem, nor has it proposed corresponding film designs.

[0004] Specifically, the optical film material has poor light-shielding effect at the light-incident area, resulting in severe hotspot phenomenon in front of the lamp. Existing methods, such as using light-shielding tape, screen printing on the diffuser film border, and small reflective sheets at the lamp opening, can effectively reduce the "firefly" effect at the lamp opening (i.e., uneven bright and dark areas on the light-incident side) and the bright line at the tail, but these methods increase the cost of additional components. Currently, no effective solution has been proposed to address these problems. Utility Model Content

[0005] Purpose of the utility model: To provide a composite optical film and a backlight module to at least solve one of the problems existing in the prior art.

[0006] Technical solution: A composite optical film, comprising:

[0007] A first prism layer and a second prism layer are arranged sequentially from top to bottom on one side of the light-emitting surface. The upper surfaces of the first prism layer and the second prism layer are respectively arranged with a first atomizing prism area, a normal prism area and a second atomizing prism area.

[0008] The bottom of the first prism layer and the second prism layer are respectively provided with a first substrate layer and a second substrate layer;

[0009] A first adhesive layer is provided on the top of the first prism layer, and a second adhesive layer is provided on the bottom of the first substrate layer;

[0010] A third substrate layer is disposed on the upper surface of the first adhesive layer, and a diffusion coating is disposed on the upper surface of the third substrate layer;

[0011] In this configuration, a plurality of the first atomizing prism areas are located in the lamp opening area of ​​the composite optical film, a plurality of the second atomizing prism areas are located in the tail area of ​​the composite optical film, and the haze of the first atomizing prism areas and the second atomizing prism areas is greater than the haze of the ordinary prism areas. Furthermore, the second adhesive layer is an atomized adhesive layer to improve the shielding properties at both ends of the composite optical film, thereby enabling the display screen to have uniform high brightness.

[0012] Preferably, a back coating is provided at the bottom of the second substrate layer;

[0013] The haze of the back coating is 1%-5%.

[0014] Preferably, the refractive index of the first prism layer and the second prism layer is 1.5-1.7.

[0015] Preferably, the haze of the diffusion coating is 90%-99%.

[0016] Preferably, the haze of the first atomizing prism area and the second atomizing prism area is 30%-95%.

[0017] Preferably, the first atomizing prism area, the ordinary prism area, and the second atomizing prism area are formed by a single transfer.

[0018] Preferably, the haze of the second adhesive layer is 30%-60%.

[0019] Preferably, the first substrate layer, the second substrate layer, and the third substrate layer are one of PET, PC, or PMMA; and the thickness of the first substrate layer, the second substrate layer, and the third substrate layer is 25-300 μm.

[0020] Preferably, the lamp opening area is covered with at least a diffusion coating, an atomizing adhesive layer and two first atomizing prism areas, the tail area is covered with at least a diffusion coating, an atomizing adhesive layer and two second atomizing prism areas, and the display area is covered with at least a diffusion coating and an atomizing adhesive layer.

[0021] To achieve the above objectives, according to another aspect of this application, a backlight module is also provided.

[0022] The backlight module according to this application includes the aforementioned composite optical film;

[0023] It also includes: a light guide plate disposed on one side of the light incident surface, and a light source disposed at one end of the light guide plate;

[0024] The light source is a side-lit light source.

[0025] Beneficial effects: In this embodiment, a multi-point, multi-layered atomizing prism area is pre-set. Several first atomizing prism areas are located in the lamp opening area of ​​the composite optical film, and several second atomizing prism areas are located in the tail area of ​​the composite optical film. The haze of the first and second atomizing prism areas is greater than that of the ordinary prism areas. Furthermore, the second adhesive layer is atomized adhesive layer. This improves the shielding properties at both ends of the composite optical film, resulting in a uniform and high-brightness display. This achieves high image blur in the lamp opening and tail areas, and reduces the firefly effect at the edges of the luminous surface. The goal is to reduce the number of components, thereby achieving a high degree of uniformity in the overall image. This avoids the use of additional light-shielding tape or black frame printing, reducing material costs and further reducing the ineffective area around the screen, achieving a borderless display effect. This solves the problem of poor light-shielding effect at the light-incident point of optical film materials and serious hotspot phenomenon in front of the lamp. Existing methods, such as using light-shielding tape, screen printing on the diffuser film border, and small reflective sheets at the lamp opening, can effectively reduce the firefly effect (i.e., uneven bright and dark areas on the light-incident side) and the bad effect of bright lines at the tail, but they increase the cost of additional components. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the planar structure of the composite optical film of this utility model; and

[0027] Figure 2 This is a schematic diagram of the prism mold in the composite optical film manufacturing method of this utility model.

[0028] The attached figures are labeled as follows:

[0029] 10. First prism layer;

[0030] 20. Second prism layer;

[0031] 30. First substrate layer;

[0032] 40. Second substrate layer;

[0033] 50. First bonding adhesive layer;

[0034] 60. Second bonding adhesive layer;

[0035] 70. Third substrate layer;

[0036] 80. Diffusion coating;

[0037] 90. Back coating;

[0038] 100. Light guide plate;

[0039] 110. Light source;

[0040] 120. First atomizing prism area;

[0041] 130. Ordinary prism region;

[0042] 140. Second atomizing prism area. Detailed Implementation

[0043] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0044] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0045] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this utility model based on the specific circumstances.

[0046] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0047] like Figure 1-2 As shown, this application relates to a composite optical film and a backlight module. Figure 1As shown, this composite optical film includes: a first prism layer 10 and a second prism layer 20 disposed sequentially from top to bottom on one side of the light-emitting surface. The upper surfaces of both the first prism layer 10 and the second prism layer 20 are sequentially arranged with a first frosting prism area 120, a regular prism area 130, and a second frosting prism area 140. By employing a two-layer prism structure, both located on the light-emitting side of the composite optical film, the light control capability is enhanced through this stacked arrangement. This improves the focusing and guiding efficiency of light, increasing the brightness of the front surface. Simultaneously, the microstructural differences between the upper and lower prism structures can be superimposed to achieve multi-angle supplementary lighting.

[0048] It is important to know that the prism layer includes a prism array, and the prisms in at least two prism layers are arranged in different directions.

[0049] Preferably, the angle between the prism arrangement directions in at least two prism layers is in the range of 80°-100°.

[0050] Preferably, the prism base widths of the prism array can be equal or unequal.

[0051] By functionally dividing the prism structure into three sections horizontally: the lamp base area (first fogging area), the display area (normal area), and the tail area (second fogging area), the fog level is designed according to the differences in light intensity in each area. This enables "regional optimization" of optical performance, improving the overall consistency of the display.

[0052] The bottom of the first prism layer 10 and the second prism layer 20 are respectively provided with a first substrate layer 30 and a second substrate layer 40; this can achieve good fixing and support effects, thereby ensuring the stability of the structure.

[0053] The first prism layer 10 has a first adhesive layer 50 on top and the first substrate layer 30 has a second adhesive layer 60 on bottom; this achieves good bonding effect and ensures a stable interlayer connection.

[0054] A third substrate layer 70 is disposed on the upper surface of the first adhesive layer 50, and a diffusion coating 80 is disposed on the upper surface of the third substrate layer 70. By introducing the diffusion coating 80 at the top, the light emission uniformity of the point light source 110 can be significantly improved. The diffusion coating 80 can effectively disperse the hot spots generated by the LED and reduce the difference between light and dark areas; at the same time, combined with the third substrate layer 70, it ensures the physical protection and dimensional stability of the diffusion layer during the molding or encapsulation process; and improves the softness and consistency of the overall brightness of the light-emitting surface, thereby improving the user's viewing experience.

[0055] In this configuration, a plurality of the first atomizing prism areas 120 are located in the lamp opening area of ​​the composite optical film, a plurality of the second atomizing prism areas 140 are located in the tail area of ​​the composite optical film, and the haze of the first atomizing prism areas 120 and the second atomizing prism areas 140 is greater than the haze of the ordinary prism area 130. Furthermore, the second adhesive layer 60 is an atomized adhesive layer to improve the shielding properties at both ends of the composite optical film, thereby enabling the display screen to have uniform high brightness.

[0056] According to the characteristics of the LED side-lit light source 110, there is an uneven brightness problem between the lamp opening area and the tail area due to differences in distance and reflection.

[0057] The second adhesive layer 60 not only has an adhesive function but also a diffusion function. It forms a "flexible atomized intermediate layer" in the structure, optimizing the light transmission path from the bottom layer upwards; avoiding non-uniform areas caused by direct projection from the light sources 110 at both ends, enhancing boundary light attenuation compensation; and improving the brightness consistency of the entire module in large-size applications.

[0058] By employing a multi-layered structure, regional atomization control, and multi-functional adhesive layer optimization, brightness and uniformity are improved.

[0059] The optical film microstructure of this application can solve the problems of poor light-shielding performance at the light-inlet of the PAD / laptop / MNT side-lit BLU&LCM module, as well as the high levels of hotspot and bright lines on the top side.

[0060] Compared with existing technologies, the advantages of this application are as follows: the light source 110 enters the light guide plate 100 (LGP) from the side and then passes through the entire laminated composite brightness enhancement film. During this process, the enhanced atomized brightness enhancement area contains an upper diffusion layer, an atomized adhesive layer, and a atomized prism area, providing outstanding shielding properties and effectively blocking light leakage at the lamp opening and tail. The general atomized brightness enhancement area contains an upper diffusion layer and an atomized adhesive layer, providing a certain degree of uniform image coverage and imperfection concealment, resulting in a highly optically uniform display image.

[0061] The advantages of the enhanced fogging high-mask area design are: the high fogging design of the lamp opening area and the tail area makes the image in these two areas highly blurred, reduces the firefly effect at the edge of the light-emitting surface, and achieves a high uniformity of the overall image. It avoids the use of additional light-blocking tape or black frame printing methods, reduces material costs, and further reduces the ineffective area around the screen, achieving a borderless display effect.

[0062] This results in a uniform, high-brightness display without edge bright lines, light leakage, or lamp hotspots.

[0063] As can be seen from the above description, this application achieves the following technical effects:

[0064] In this embodiment, a multi-point, multi-layered atomizing prism area is pre-set. Several first atomizing prism areas 120 are located in the lamp opening area of ​​the composite optical film, and several second atomizing prism areas 140 are located in the tail area of ​​the composite optical film. The haze of the first atomizing prism areas 120 and the second atomizing prism areas 140 is greater than the haze of the ordinary prism area 130. Furthermore, the second adhesive layer 60 is an atomized adhesive layer. This improves the shielding properties at both ends of the composite optical film, resulting in a uniform and high-brightness display image. This achieves high image blurring in the lamp opening and tail areas, and reduces the fluorescence at the edges of the luminous surface. The firefly effect can be reduced, thereby achieving a high uniformity of the overall image. This avoids the need for additional light-shielding tape or black frame printing, reducing material costs and further reducing the ineffective area around the screen, achieving a borderless display effect. This solves the problem of poor light-shielding effect at the light-incident point of the optical film and serious hotspot phenomenon in front of the lamp. Existing methods, such as using light-shielding tape, screen printing on the diffuser film border, and small reflective sheets at the lamp opening, can effectively reduce the firefly effect at the lamp opening (i.e., uneven bright and dark areas on the light-incident side) and the bad effect of bright lines at the tail, but they increase the cost of additional components.

[0065] Furthermore, a back coating layer 90 is provided at the bottom of the second substrate layer 40;

[0066] The haze of the back coating 90 is 1%-5%. It is understood that the back coating 90 is located at the bottom of the entire structure, directly covering the bottom of the second substrate layer 40. The addition of the back coating 90 improves the overall durability and protection, effectively preventing moisture or impurities from the external environment from directly contacting the second substrate layer 40, thereby extending the lifespan of the entire optical component. The back coating 90 also has a certain degree of scratch resistance, further protecting the upper structure. The back coating 90 can serve as a reflective layer or an anti-reflective layer, adjusting the reflection or transmission characteristics of light according to specific needs to optimize light utilization efficiency.

[0067] Setting the haze of the back coating 90 to 1%-5% can slightly scatter light while avoiding excessive loss of brightness and eliminating interface reflections (such as Newton's rings) on the back of the substrate, thereby improving display uniformity.

[0068] Adhesion stability: Enhances adhesion to backsheets (such as reflective sheets) and prevents film displacement.

[0069] Furthermore, the refractive indices of the first prism layer 10 and the second prism layer 20 are 1.5-1.7. This range is understood to match common optical polymers (e.g., PET=1.65, PC=1.59, PMMA=1.49), efficiently collecting large-angle light through total internal reflection to enhance frontal brightness.

[0070] Furthermore, the haze of the diffusion coating 80 is 90%-99%. This means it can completely disperse the hot spots of the light source 110, eliminate the printed dots or LED graininess of the light guide plate 100, and achieve a uniform surface light source 110; simultaneously, the high scattering characteristics widen the viewing angle and reduce viewing angle-dependent brightness attenuation; and protect the underlying structure: covering the prism layer to prevent direct contact and damage to the prism from foreign objects.

[0071] Furthermore, the haze of the first atomizing prism area 120 and the second atomizing prism area 140 is 30%-95%. It can be understood that the low haze end (30%-50%) retains the light-gathering ability of the prism and maintains high brightness; the high haze end (80%-95%) enhances scattering and solves local bright spots (such as the lamp mouth area).

[0072] Replacement for independent diffusion layers: Integrate scattering function into prism microstructures to reduce the number of film layers.

[0073] Furthermore, the first atomizing prism area 120, the ordinary prism area 130, and the second atomizing prism area 140 are transferred and formed in one step. This avoids interlayer interfaces caused by multiple forming processes, reducing light loss (approximately 3-5%). Simultaneously, it ensures the positional accuracy of the microstructures in different functional areas (±1μm), preventing moiré patterns caused by misalignment. Additionally, it reduces costs and increases efficiency: a single imprint saves on equipment investment and energy consumption, increasing production efficiency by more than 30%.

[0074] Specifically, such as Figure 2 As shown, the prism layer has a fogging prism area and a general prism area. The fogging prism area is obtained by secondary sandblasting of the prism mold roller. That is, after the general prism mold is processed, a sandblasting process is performed in a preset fixed area to obtain a fogging prism mold with a fogging area.

[0075] Furthermore, the haze of the second adhesive layer 60 is 30%-60%. It is understandable that by replacing the traditional transparent adhesive layer, while ensuring good adhesion, it can also provide additional light uniformity, reduce the need for independent diffusion films, eliminate bubble noise (the hazy adhesive layer can cover up bright spots caused by tiny bonding bubbles or foreign objects), and improve contrast (by scattering ambient light reflection and reducing screen whitening under strong light).

[0076] Furthermore, the first substrate layer 30, the second substrate layer 40, and the third substrate layer 70 are one of PET, PC, or PMMA; and the thickness of the first substrate layer 30, the second substrate layer 40, and the third substrate layer 70 is 25-300 μm. It is understood that all three materials are optically transparent polymer materials with good light transmittance, thermal stability, and processing adaptability; the thickness range covers both thin film and medium-thickness layer applications.

[0077] Setting the thickness of the substrate layer within the aforementioned range can meet the different requirements of various functional layers for mechanical strength and thermal expansion and contraction characteristics; it can also ensure the overall light transmittance and service life of the film.

[0078] Furthermore, the lamp port area is at least covered with a diffusion coating 80, an atomizing adhesive layer, and two first atomizing prism areas 120; the tail area is at least covered with a diffusion coating 80, an atomizing adhesive layer, and two second atomizing prism areas 140; and the display area is at least covered with a diffusion coating 80 and an atomizing adhesive layer. It is understood that different functional areas are covered with different optical layers (such as a diffusion layer, an atomizing adhesive layer, and atomizing prism areas) to achieve regionalized optical control.

[0079] This application also relates to a backlight module, including the aforementioned composite optical film;

[0080] It also includes: a light guide plate 100 disposed on one side of the light incident surface, and a light source 110 disposed at one end of the light guide plate 100;

[0081] The light source 110 is a side-lit light source.

[0082] Specifically, the light source 110 is a side-lit light source. In terms of structural layout, the side-lit light source 110 places the light source 110 assembly on the side of the backlight module, and the light is evenly distributed to the entire module by the guidance of the light guide plate 100. This not only reduces the number and volume of the light source 110 assembly, reducing the overall weight and cost of the module, but also makes the module more compact and flexible in structural design.

[0083] Alternatively, depending on actual needs, the atomizing prism layer can be placed only on a single upper or lower brightening layer. Or, the microstructure orientations of the upper and lower prism layers can be interchanged.

[0084] Depending on the actual needs, the atomized adhesive layer can be placed only on a single upper or lower adhesive layer. Alternatively, both adhesive layers can be made into atomized adhesive layers.

[0085] This application has the following beneficial effects:

[0086] 1. Improves the uniformity of light emission at the light-receiving surface and tail of notebook / MNT products.

[0087] 2. Improve the product's shielding, hotspot protection, and ability to block bright lines from the top and sides.

[0088] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and all such equivalent transformations fall within the protection scope of the present invention.

Claims

1. A composite optical film, characterized in that, include: A first prism layer (10) and a second prism layer (20) are arranged sequentially from top to bottom on one side of the light-emitting surface. The upper surfaces of the first prism layer (10) and the second prism layer (20) are respectively arranged with a first atomizing prism area (120), a normal prism area (130) and a second atomizing prism area (140). The bottom of the first prism layer (10) and the second prism layer (20) are respectively provided with a first substrate layer (30) and a second substrate layer (40); A first adhesive layer (50) is provided on the top of the first prism layer (10), and a second adhesive layer (60) is provided on the bottom of the first substrate layer (30). A third substrate layer (70) is provided on the upper surface of the first adhesive layer (50), and a diffusion coating (80) is provided on the upper surface of the third substrate layer (70); Among them, a plurality of the first atomizing prism areas (120) are located in the lamp opening area of ​​the composite optical film, a plurality of the second atomizing prism areas (140) are located in the tail area of ​​the composite optical film, and the haze of the first atomizing prism areas (120) and the second atomizing prism areas (140) is greater than the haze of the ordinary prism area (130), and the second adhesive layer (60) is an atomizing adhesive layer to improve the shielding at both ends of the composite optical film, so that the display screen has uniform high brightness.

2. The composite optical film according to claim 1, characterized in that, The bottom of the second substrate layer (40) is provided with a back coating layer (90); The haze of the back coating (90) is 1%-5%.

3. The composite optical film according to claim 1, characterized in that, The refractive indices of the first prism layer (10) and the second prism layer (20) are 1.5-1.

7.

4. The composite optical film according to claim 1, characterized in that, The haze of the diffusion coating (80) is 90%-99%.

5. The composite optical film according to claim 1, characterized in that, The haze of the first atomizing prism area (120) and the second atomizing prism area (140) is 30%-95%.

6. The composite optical film according to claim 1, characterized in that, The first atomizing prism area (120), the ordinary prism area (130) and the second atomizing prism area (140) are formed by one-time transfer printing.

7. The composite optical film according to claim 1, characterized in that, The haze of the second adhesive layer (60) is 30%-60%.

8. The composite optical film according to claim 1, characterized in that, The first substrate layer (30), the second substrate layer (40) and the third substrate layer (70) are one of PET, PC or PMMA; and the thickness of the first substrate layer (30), the second substrate layer (40) and the third substrate layer (70) is 25-300 μm.

9. The composite optical film according to claim 1, characterized in that, The lamp port area is at least covered with a diffusion coating (80), an atomizing adhesive layer and two first atomizing prism areas (120), the tail area is at least covered with a diffusion coating (80), an atomizing adhesive layer and two second atomizing prism areas (140), and the display area is at least covered with a diffusion coating (80) and an atomizing adhesive layer.

10. A backlight module, characterized in that, Includes the composite optical film according to any one of claims 1-9; It also includes: a light guide plate (100) disposed on one side of the light incident surface, and a light source (110) disposed at one end of the light guide plate (100); The light source (110) is a side-lit light source.

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