A curtain structure and a high-gain white curtain

Abstract

This utility model discloses a screen structure and a high-gain white screen, belonging to the field of projection display technology. The screen structure includes two substrate layers, with a barrier layer bonded between the two substrate layers via an adhesive layer. The substrate layers, adhesive layer, and barrier layer have different refractive indices. The high-gain white screen includes a protective layer, a diffusion layer, and the aforementioned screen structure, arranged sequentially from the incident surface to the back surface. By utilizing the difference in refractive indices between the substrate layer, adhesive layer, and barrier layer, an optical effect similar to mother-of-pearl is created, reducing light penetration and enhancing light reflection and scattering. This improves detail rendering, reduces the loss of dark areas, enhances resistance to external light interference, reduces contrast, reduces color saturation distortion, reduces light loss during propagation, improves overall brightness uniformity, ensures full presentation of high-resolution signal details, and is compatible with more projection devices.

Description

Technical Field

[0001] This utility model relates to the field of projection display technology, and in particular to a screen structure and a high-gain white screen. Background Technology

[0002] In the field of projection display, traditional white screens, as the basic imaging carrier, have long relied on the principle of diffuse reflection to achieve light propagation, with their gain typically maintained between 0.8 and 1.0. This technological state was sufficient for basic use in early small-scale, low-brightness projection scenarios, but as the industry's requirements for display effects and application scenarios continue to upgrade, the inherent defects of traditional white screens have gradually become a bottleneck restricting development.

[0003] In terms of brightness, the diffuse reflection characteristics of traditional white screens cause light to scatter uniformly in all directions, with only a small amount of light being directed into the viewer's field of vision. In use, especially when the projection device has limited brightness (such as portable projectors or low-power engineering projectors), the screen displays insufficient brightness, weak detail, and easily loses depth in dark areas, failing to meet users' demands for high-definition, high-contrast images.

[0004] In terms of ambient light adaptability, traditional white screens have extremely poor resistance to interference from external light. When natural light or indoor ambient light shines on the screen surface, it will superimpose and interfere with the projected light, causing the image to appear "washed out," the contrast to drop significantly, and the color saturation to become distorted. This means that traditional white screens must be used in dark environments with strictly controlled light, greatly limiting their application in open settings such as conference rooms, exhibition halls, and outdoor venues.

[0005] In large-size display scenarios, the shortcomings of traditional white screens are even more pronounced. When the screen size exceeds 100 inches, due to its low gain, the projected light is more easily lost during propagation, resulting in brightness attenuation at the edges of the image (i.e., "dim screen") and poor overall brightness uniformity.

[0006] From the perspective of compatibility with new projection devices, as projection technology develops towards higher resolutions (such as 4K and 8K) and higher refresh rates, the optical performance of traditional white screens can no longer match the output capabilities of new devices. Their surface materials have low light reflection efficiency and poor color reproduction, resulting in the inability to fully reproduce details of high-resolution signals, thus wasting device performance.

[0007] Therefore, there is an urgent need for a high-gain (above 2.0) white screen to improve the significant shortcomings of white screens in terms of brightness, ambient light adaptability, large-size applications, and compatibility with new projection equipment. The industry's demand for white screens with higher gain and better optical performance is becoming increasingly urgent. Utility Model Content

[0008] The purpose of this invention is to solve the aforementioned technical problems by providing a screen structure and a high-gain white screen. Utilizing the difference in refractive index between the substrate layer, adhesive layer, and barrier layer, an optical effect similar to mother-of-pearl is created, reducing light permeability and enhancing light reflection and scattering. This improves detail rendering, reduces the loss of detail in dark areas, enhances resistance to external light interference, reduces contrast, minimizes color saturation distortion, reduces light loss during propagation, improves overall brightness uniformity, ensures full presentation of high-resolution signal details, adapts to high refresh rate development, and is compatible with more types of projection devices.

[0009] To achieve the above objectives, the present invention provides the following solution: The present invention discloses a screen structure, comprising two substrate layers, wherein a barrier layer is bonded between the two substrate layers by an adhesive layer, and the substrate layers, the adhesive layer, and the barrier layer have different refractive indices.

[0010] Preferably, the substrate layer is made of PET substrate.

[0011] Preferably, a whitening agent is added to the substrate layer.

[0012] Preferably, the whitening agent is an inorganic whitening filler or a fluorescent whitening agent.

[0013] Preferably, the adhesive layer is an EVA adhesive layer.

[0014] Preferably, the barrier layer is an EVOH barrier layer.

[0015] Preferably, it includes two barrier layers, with a PA layer disposed between the two barrier layers.

[0016] This utility model also discloses a high-gain white screen, including a protective layer, a diffusion layer and the above-mentioned screen structure, wherein the protective layer, the diffusion layer and the screen structure are arranged sequentially from the incident surface to the back surface.

[0017] Preferably, the protective layer is a scratch-resistant and anti-glare material layer.

[0018] Preferably, the diffusion layer is a microlens array diffusion layer.

[0019] The present invention achieves the following technical advantages over the prior art: This invention utilizes the difference in refractive index between the substrate layer, adhesive layer, and barrier layer to create an optical effect similar to mother-of-pearl, reducing light permeability and enhancing light reflection and scattering. In terms of brightness, it improves detail rendering and reduces the loss of detail in dark areas. Regarding ambient light adaptability, it enhances resistance to external light interference, reduces contrast, and minimizes color saturation distortion. For large-size displays, it reduces light loss during propagation and provides good overall brightness uniformity. In terms of compatibility with new projection devices, the surface material has high light reflection efficiency and good color reproduction, ensuring full presentation of details in high-resolution signals, adapting to high refresh rates, and matching the output capabilities of new devices.

[0020] Compared with the prior art, the other technical solutions of this utility model have also achieved the following technical effects: 1. In this utility model, a whitening agent is added to the substrate layer. The high whiteness and opacity of the whitening agent can enhance the reflectivity of the material to visible light, thereby improving the whiteness. It can also effectively scatter light, reduce light transmittance, make the film material appear uniformly white, and scatter ultraviolet rays, delay the photodegradation of the substrate, and extend its service life.

[0021] 2. In this utility model, a whitening agent is added to the substrate layer. The high whiteness and opacity of the whitening agent can enhance the reflectivity of the material to visible light, thereby improving the whiteness. It can also effectively scatter light, reduce light transmittance, make the film material appear uniformly white, and scatter ultraviolet rays, delaying the photodegradation of PET material and extending its service life.

[0022] 3. In this utility model, the adhesive layer is an EVA adhesive layer, which has excellent optical properties: excellent light transmittance; good weather resistance: resistant to ultraviolet rays and damp heat aging, and does not yellow after long-term outdoor use (such as solar panel encapsulation); good chemical stability: strong resistance to acids and alkalis; it can also effectively bond materials such as PET, PVC (polyvinyl chloride), and PA, with good compatibility and a balance between initial tack and holding power: quick positioning and long-term firmness. It has a low modulus of elasticity: after curing, it forms a flexible film, suitable for flexible materials such as screens; and it has anti-peel properties: avoiding delamination due to thermal expansion and contraction of the material.

[0023] 4. In this utility model, the barrier layer is an EVOH barrier layer, which has extremely low permeability: its barrier performance against gases such as oxygen and carbon dioxide is hundreds of times that of ordinary plastics. It also has high tensile strength, elasticity and wear resistance, further improving the durability of the modified screen (white screen).

[0024] 5. This utility model includes two barrier layers, with a PA layer between the two barrier layers. PA is polyamide, commonly known as nylon. This material further enhances the overall strength and toughness of the screen (white screen), making the screen's tensile strength as high as 200MPa and its impact strength excellent.

[0025] 6. The present invention includes two PET substrate layers, two EVOH barrier layers and a PA layer, which can significantly improve the material strength and tensile properties to meet the higher requirements of large-size screens for material strength and tensile properties. Traditional white screens often use a single substrate, which is prone to deformation due to uneven tension during long-term use, further affecting the flatness of the image and the display effect. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained by analyzing these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of the high-gain white screen (including the screen structure) in an embodiment of this utility model; Figure 2 This is a schematic diagram of the structure of the substrate layer containing TiO2 in an embodiment of this utility model; Figure 3 This is a schematic diagram of the interference of incident light rays at a certain angle in a single film layer in an embodiment of this utility model; Figure 4 This is a schematic diagram illustrating the reflection of light at the interface between two media when light is incident from a medium with a different refractive index onto another medium in this embodiment of the present invention.

[0028] Figure 5 The reflectivity of the single-layer film optical element with perpendicular incident light in this embodiment of the invention. With the refractive index of the film Relationship diagram; Figure 6 This is a graph showing the relationship between the wavenumber width of the high-reflection band and the refractive index of the two film materials constituting the multilayer film in an embodiment of this utility model. Figure 7 This is a diagram showing the overall broadening relationship of the high reflectivity band after the two odd-numbered high reflectivity film stacks are combined in this embodiment of the present invention. Figure 8 This is a schematic diagram illustrating the principle of "averaging" of the neutron beam in the target plane in the diffusion layer of the microlens array in this embodiment of the present invention.

[0029] Explanation of reference numerals in the attached drawings: 1. Protective layer; 2. Diffusion layer; 3. Substrate layer; 4. Adhesive layer; 5. Barrier layer; 6. PA layer. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments analyzed and obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0031] The purpose of this invention is to provide a screen structure and a high-gain white screen to solve the problems existing in the prior art. To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Example 1 like Figures 1 to 8 As shown, this embodiment provides a screen structure including two substrate layers 3, with a barrier layer 5 bonded between the two substrate layers 3 by an adhesive layer 4. The substrate layers 3, adhesive layer 4, and barrier layer 5 have different refractive indices. Utilizing the difference in refractive indices between the substrate layers 3, adhesive layer 4, and barrier layer 5, an optical effect similar to mother-of-pearl is created, reducing light permeability and enhancing light reflection and scattering. In terms of brightness performance, it improves detail rendering and reduces the loss of detail in dark areas. Regarding ambient light adaptability, it improves resistance to external light interference, reduces contrast, and minimizes color saturation distortion. For large-size display scenarios, it reduces light loss during propagation and provides good overall brightness uniformity. In terms of compatibility with new projection devices, the surface material has high light reflection efficiency and good color reproduction, ensuring full presentation of details in high-resolution signals, adapting to high refresh rates, and matching the output capabilities of new devices.

[0033] In one embodiment, the substrate layer 3 is made of PET substrate. PET, short for Polyethylene terephthalate, is commonly known as polyester resin. It has good mechanical properties, with an impact strength 3-5 times that of other films, and good folding endurance. It is resistant to oil, grease, dilute acids, dilute alkalis, and most solvents. It has high transparency, can block ultraviolet rays, and has good gloss. Of course, other suitable materials can also be used if available.

[0034] In one embodiment, a whitening agent is added to the substrate layer 3. The high whiteness and opacity of the whitening agent enhance the material's reflectivity to visible light, thereby increasing whiteness. It also effectively scatters light, reduces light transmittance, and makes the film material appear uniformly white. Furthermore, it scatters ultraviolet light, delaying the photodegradation of PET material and extending its service life.

[0035] In one embodiment, the whitening agent is an inorganic whitening filler or a fluorescent whitening agent, such as titanium dioxide (TiO2), pearl powder (the main component of which is calcium carbonate (CaCO3)).

[0036] In one embodiment, adhesive layer 4 is an EVA adhesive layer. EVA is a copolymer of ethylene and vinyl acetate, with the English chemical name being Ethylene Vinyl Acetate Copolymer. EVA adhesive layers possess excellent optical properties: excellent light transmittance; good weather resistance: resistant to UV radiation and damp heat aging, and does not yellow after long-term outdoor use (e.g., solar panel encapsulation); good chemical stability: strong resistance to acids and alkalis (compliant with RoHS and FDA standards); it can also effectively bond materials such as PET, PVC (polyvinyl chloride), and PA, exhibiting good compatibility and a balance between initial tack and holding power: rapid positioning and long-term firmness. It has a low elastic modulus: after curing, it forms a flexible film, suitable for flexible materials such as screens; and it has peel resistance: preventing delamination due to thermal expansion and contraction of the material.

[0037] In one embodiment, the barrier layer 5 is an EVOH barrier layer. EVOH stands for ethylene-vinyl alcohol copolymer. The EVOH barrier layer has extremely low permeability: its barrier performance against gases such as oxygen and carbon dioxide is hundreds of times that of ordinary plastics (such as PE and PP). It also has high tensile strength (approximately 44 MPa), elasticity, and abrasion resistance, further improving the durability of the modified screen (curtain).

[0038] In one embodiment, the screen includes two barrier layers 5, with a PA layer 6 disposed between the two barrier layers 5. PA stands for polyamide, commonly known as nylon. This material further enhances the overall strength and toughness of the screen (screen), giving it a tensile strength of up to 200 MPa and excellent impact strength.

[0039] In one embodiment, when light shines on the curtain structure, the conventional path of light between the various film layers of the curtain structure is as follows: a portion of the light is reflected from the upper surface of the film layer, while the remaining light is transmitted into the film layer and reflected from the lower surface of the film layer (the interface between the upper and lower film layers). The two reflected waves overlap and interfere with each other, producing constructive or destructive interference based on their phase difference.

[0040] like Figure 3 The image shows film interference caused by incident light rays at a certain angle. Incident light ray (angle) It splits into two paths: one is reflected and refracted from the top surface into the film layer (angle). The light then reflects off the bottom surface and exits the film parallel to the first reflected ray. The refractive index of the film is... Thickness is The refractive index of the surrounding medium is... The optical path difference and phase shift during reflection determine the interference result, which varies with polarization state and wavelength.

[0041] The phase difference (▽Φ) between two reflected waves is defined as: ; in: λ is the wavelength of light in a vacuum; The refractive index of the film; The thickness of the film layer; The angle of refraction within the film layer, according to Snell's law, is related to the angle of incidence. The relationship is: ; This refers to the phase change during reflection. When light is reflected from a medium with a high refractive index, the phase change occurs. Phase shift.

[0042] Constructive interference occurs when a phase difference leads to an enhancement of reflected light. This happens when: ; When light travels from a direction with a refractive index of 1 The medium incident on the refractive index When light passes through another medium, reflection occurs at the interface between the two media. If the medium does not absorb light, the interface is an optical surface, and the light is incident perpendicularly, then the reflectivity is... Transmittance T = 1 - R.

[0043] like Figure 4 As shown: Reflectivity of a single-layer optical element when light is incident perpendicularly From the calculation formula, it can be seen that when The larger, The larger the value, the lower the actual refractive index of the film. The reflectivity is limited; the highest reflectivity achievable with a single-layer film is no more than 50%. By designing multilayer reflective films so that the reflected light beams from all interfaces of the film return to the front surface with the same phase, thus producing constructive interference, it is theoretically possible to obtain a reflectivity close to 100%.

[0044] like Figure 5 As shown: This case uses a high refractive index. Low refractive index An alternating multilayer film design scheme is used, with the outermost layers on both sides of the dielectric film system being high-refractive-index layers, each layer having a thickness of [missing information]. / 4. For the center wavelength The maximum value of the vertical incident reflectivity is: ; It can be known that when The larger the ratio, or the more layers (2S+1) there are, The larger the reflectivity, the closer it can theoretically be to 100%. However, in practice, due to losses from absorption and scattering in the film layers, increasing the number of layers after a certain point will not further improve reflectivity. The refractive index of the material and the design of the film system are also crucial factors ultimately affecting the reflectivity performance of the component.

[0045] like Figure 6 As shown: The wavenumber width of a high-reflectivity band is only related to the refractive indices of the two materials constituting the multilayer film; the greater the difference, the wider the high-reflectivity band. The refractive index of the film materials cannot be infinitely high. For example, among materials with practical value in the visible light region, the highest refractive index is no more than 2.6 and the lowest is no less than 1.35. Therefore, the high-reflectivity bandwidth is finite. There are two methods to broaden the high-reflectivity band: one is to have a regular increase / decrease in the thickness of each layer of the film system; the other is to stack two or more multilayer films with different center wavelengths.

[0046] like Figure 7 As shown: By combining two odd-numbered high-reflectivity film stacks, a very narrow transmission band appears in the overlapping part (at the dashed line C), but the overall high-reflectivity band is broadened.

[0047] Table 1 shows the refractive indices of each film layer in a specific case of this screen structure: Table 1:

[0048] The calculation is based on the above formula: .

[0049] Through rigorous optical film system design and interlayer structure, the overall reflectivity of the screen reaches over 98%, which is more than 1.8 times that of traditional screens, and the gain is increased to over 2.0.

[0050] Example 2 like Figures 1 to 8As shown, this embodiment provides a high-gain white screen, including a protective layer 1, a diffusion layer 2, and the screen structure of Embodiment 1. The protective layer 1, diffusion layer 2, and screen structure are arranged sequentially from the incident surface to the back surface. The incident surface of any substrate layer 3 in the screen structure is bonded to the back surface of the diffusion layer 2. That is, from the incident surface to the back surface, the sequence is: protective layer 1 → diffusion layer 2 → substrate layer 3 → adhesive layer 4 → barrier layer 5 → PA layer 6 → barrier layer 5 → adhesive layer 4 → substrate layer 3. The gain of this high-gain white screen is increased to over 2.0.

[0051] In one embodiment, the protective layer 1 is a scratch-resistant and anti-glare material layer, such as scratch-resistant and anti-glare SiO2.

[0052] In one embodiment, the diffusion layer 2 is a microlens array diffusion layer. The homogenization principle of a microlens array (ML) is: the core is to "divide and conquer" the non-uniform incident light (such as a Gaussian beam, diverging light from a point source, etc.) into uniformly distributed outgoing light on the target plane through beam splitting, direction control, and energy superposition.

[0053] The specific process can be divided into three key steps, which combine structural characteristics to achieve uniform light distribution: I. Structural Basis of Microlens Arrays: Microlens arrays consist of a large number of tiny (typically ranging from a few micrometers to hundreds of micrometers in diameter) and regularly shaped (e.g., circular, hexagonal) microlenses arranged periodically (e.g., rectangular arrays, hexagonal arrays). Each microlens, as an independent optical unit, can individually control the sub-beam incident on its surface.

[0054] II. The core principle of uniform light distribution: segmentation-control-superposition.

[0055] 1. Beam splitting: This involves breaking down incident light into "sub-beams." Incident light typically has a non-uniform intensity distribution (e.g., the Gaussian distribution of laser light: high intensity at the center and low intensity at the edges). The first function of a microlens array is to "split" the incident light into a large number of independent sub-beams—each microlens corresponds to a tiny region of the incident light, receiving only the light energy within that region, thus breaking down the originally concentrated, non-uniform beam into tens to tens of thousands of small-scale sub-beams.

[0056] Example: If the incident light is a Gaussian spot with a diameter of 10 mm, and it passes through an array of 100 microlenses (each lens with a diameter of 1 mm), then each microlens will only receive light from a 1 mm × 1 mm region of the incident light, forming 100 sub-beams.

[0057] 2. Direction Control: By altering the propagation path of the sub-beams, each microlens refracts or focuses the received sub-beams through its own curvature (focal length), changing their propagation direction. The goal is to deflect the high-energy sub-beams, originally concentrated at the center of the incident light, towards the edges, and to deflect the weaker-energy sub-beams at the edges towards the center or other areas, breaking the original "strong at the center, weak at the edges" distribution pattern. Specifically, the focal length of the microlens determines the deflection angle (or focusing position) of the sub-beams. By designing the curvature parameters of the microlenses, each sub-beam can be projected onto different positions on the target plane (such as a screen or detector), avoiding energy concentration.

[0058] 3. Energy Superposition: Sub-beams are "averaged" on the target plane. All sub-beams, after direction modulation, are ultimately superimposed on the target plane (the homogenized beam plane). Because each sub-beam corresponds to a different region of the incident light (the energy at the original center and edge is decomposed) and is dispersed to different positions on the target plane, the original intensity differences are "diluted": the strong energy at the center of the original incident light is dispersed to various positions on the target plane by multiple microlenses; the weak energy at the edge of the original incident light is also dispersed to various positions on the target plane. After superposition, the energy at any point on the target plane is the sum of the energies of the multiple sub-beams, thus achieving uniform intensity distribution. (Reference) Figure 8 As shown.

[0059] III. Key Influencing Factors: 1. Number of microlenses: The more microlenses there are (the smaller the size), the finer the sub-beams are divided, and the better the uniformity after stacking (but the manufacturing difficulty is higher); 2. Arrangement: The hexagonal array provides denser sub-beam coverage than the rectangular array, with no obvious gaps when superimposed, resulting in better uniformity; 3. Focal length matching: The focal length of the microlens must be matched with the incident light divergence angle and the distance to the target plane to ensure that the sub-beams are completely superimposed on the target plane and avoid local energy loss.

[0060] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A curtain structure, characterized by It includes two substrate layers, with a barrier layer bonded between the two substrate layers by an adhesive layer. The substrate layers, the adhesive layer, and the barrier layer have different refractive indices.

2. The curtain structure of claim 1, wherein, The substrate layer is made of PET substrate.

3. The curtain structure according to claim 1 or 2, characterized in that, A whitening agent is added to the substrate layer.

4. The curtain structure according to claim 3, characterized in that, The whitening agent is an inorganic whitening filler or a fluorescent whitening agent.

5. The curtain structure according to claim 2, characterized in that, The adhesive layer is an EVA adhesive layer.

6. The curtain structure according to claim 2, characterized in that, The barrier layer is an EVOH barrier layer.

7. The curtain structure according to claim 1 or 6, characterized in that, It includes two barrier layers, with a PA layer disposed between the two barrier layers.

8. A high-gain white screen, characterized in that, It includes a protective layer, a diffusion layer, and a curtain structure as described in any one of claims 1-7, wherein the protective layer, the diffusion layer, and the curtain structure are arranged sequentially from the incident surface to the back surface.

9. The high-gain white screen according to claim 8, characterized in that, The protective layer is a scratch-resistant and anti-glare material layer.

10. The high-gain white screen according to claim 8, characterized in that, The diffusion layer is a microlens array diffusion layer.

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