Low speckle rollable high gain back projection screen and method of making

Abstract

The application provides a low-speckle rollable high-gain back projection screen and a preparation method thereof, which comprises a flexible PET substrate, an optical structure layer and an exit surface scattering layer; the flexible PET substrate is used as a middle layer, an optical structure layer containing an array type micro-prism structure is arranged on an incident surface, and a first AF coating protection and anti-reflection coating is arranged to realize efficient coupling and anti-reflection of incident light and suppression of laser speckle; a scattering layer is arranged on an exit surface to homogenize light. The three-layer composite layer structure has clear function layering, strong optical performance synergy, a film form, a rollable characteristic, no damage in rolling storage, stable optical performance after bending, solves the problems of serious speckle, uneven picture, narrow viewing angle and easy damage of a traditional screen, and can be widely applied to various scenes such as vehicle-mounted and household scenes.

Description

Technical Field

[0001] This invention relates to the field of projection display technology, and in particular to a low-speckle, rollable, high-gain rear projection screen and its manufacturing method. Background Technology

[0002] Rear projection displays are increasingly widely used in automotive, home, and commercial settings due to their advantages such as soft images, eye protection, and strong spatial adaptability. Currently, rear projection screens are mainly divided into two categories: rigid screens and traditional flexible screens. Rigid screens (such as resin-based composite screens and nano-coated glass screens) have stable optical performance, but they cannot be rolled up and stored, resulting in high transportation and installation costs and limited application scenarios. Traditional flexible screens (such as PVC screens) can be rolled up, but they have poor optical performance, low gain, poor color reproduction, and cannot suppress the speckle problem inherent in RGB laser light sources. Flexible screens generally face the contradiction of difficulty in balancing optical performance and rollability. Some high-gain screens exhibit the "sun effect," with excessively high brightness in the center of the image and insufficient brightness at the edges, resulting in poor uniformity.

[0003] Therefore, there is a need to provide a low-speckle, rollable, high-gain rear projection screen and its manufacturing method to solve the above-mentioned technical problems. Summary of the Invention

[0004] This invention provides a low-speckle, rollable, high-gain rear projection screen and its manufacturing method, to solve the technical problem that existing rear projection screens cannot simultaneously achieve low speckle, high gain, wide viewing angle, no solar effect, and rollable storage performance.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is: a low-spot, rollable, high-gain rear projection flexible PET substrate, located in the middle layer of the screen, wherein the flexible PET substrate has an incident surface on one side and an exit surface on the other side; An optical structure layer, disposed on the incident surface, is used to enhance the transmission of incident light and suppress laser speckle; and An exit surface scattering layer is disposed on the exit surface for light homogenization; The optical structure layer includes: A micro-pyramidal lens antireflective layer includes an adhesive layer and micro-pyramidal structures. The adhesive layer is connected to the incident surface, and the micro-pyramidal structures protrude from the adhesive layer on the side away from the flexible PET substrate. Several micro-pyramidal structures are arranged in a uniformly distributed array. The first AF coating is disposed on the side of the micro-pyramidal lens antireflective layer away from the flexible PET substrate, and is used to protect the micro-pyramidal lens antireflective layer.

[0006] In this invention, the sidewalls of the micro-pyramidal structure are optical refractive surfaces, and the top of the micro-pyramidal structure is provided with a vertex structure, which can be any one of a convex lens, a concave lens, a planar structure, or a rough irregular surface.

[0007] In this invention, the micro pyramid structure is a truncated pyramid, and the vertex structure is entirely covered on the top end face of the micro pyramid structure. The ratio of the outer contour dimension of the vertex structure to the bottom end face dimension of the micro pyramid structure is 1 / 3 to 1 / 2.

[0008] The low speckle rollable high-gain rear projection screen of the present invention also includes a second AF coating disposed on the side of the scattering layer away from the flexible PET substrate, and the second AF coating is used to protect the scattering layer of the scattering layer.

[0009] This invention provides a method for preparing a low-speckle, rollable, high-gain rear projection screen, which includes the following steps: S1: Substrate pretreatment Select an optical-grade flexible PET substrate of a preset thickness and perform unwinding pretreatment using a roll-to-roll process; S2: Preparation of UV adhesive, Optical grade acrylic UV optical adhesive is mixed with scattering particles in a predetermined ratio and stirred until the particles are uniformly dispersed to prepare a stable UV optical adhesive system. S3: Prepare the scattering layer at the exit surface. Using a disordered microlens roller mold, the UV optical adhesive system is coated onto the emission surface of a flexible PET substrate through a roll-to-roll coating process, with the dry film thickness controlled to be 10μm to 20μm. After UV curing, the emission surface scattering layer with a disordered microlens structure is formed. S4: Fabrication of the incident optical layer The flexible PET substrate is flipped over, and a micro-pyramidal array roller mold is used to coat the UV optical adhesive system onto the incident surface of the flexible PET substrate. The dry film thickness is controlled to be 15μm to 25μm, and then UV curing is performed to form a micro-pyramidal lens anti-reflection layer. S5: Prepare a protective coating. A 100nm thick fluorine-containing AF coating is deposited on the outer surface of the antireflective layer of the micro-pyramidal lens using a continuous vacuum evaporation process to form the first AF coating. S6: The rolled screen is cut, cleaned, and coated to obtain the finished rear projection screen.

[0010] In this invention, in step S5, a fluorine-containing AF coating is simultaneously deposited on the outer surface of the scattering layer of the emission surface to form a second AF coating, the coating thickness of which is 100 nm.

[0011] In this invention, the scattering particles added to the UV optical adhesive system are composite scattering particles, which are one or more of silicon dioxide scattering particles, acrylic scattering particles, or titanium dioxide scattering particles, and the particle size of the composite scattering particles is controlled to be 3-5 μm.

[0012] In this invention, in step S1, the flexible PET substrate is selected as a high-transmittance optical-grade PET substrate with a thickness of 50-125μm and a light transmittance of ≥90%, and in step S6, the total thickness of the rear projection screen is 100-150μm.

[0013] In this invention, in step S4, the micro-pyramidal lens antireflective layer is provided with an array of micro-pyramidal structures, and the sidewalls of the micro-pyramidal structures are optical refractive surfaces. The micro-pyramidal structure has a vertex structure at its top, which can be any one of a convex lens, a concave lens, a planar structure, or a rough irregular surface, in order to increase the beam splitting surface, disperse the incident laser, and suppress hot spots and solar effects on the screen.

[0014] In this invention, the ratio of the outer contour dimension of the vertex structure to the bottom end face dimension of the micro-pyramidal structure is 1 / 3 to 1 / 2. When the vertex structure is a convex lens, the overall size of a single micro pyramid structure is 30-40 μm, and the circumference of the convex lens is 20 μm.

[0015] Compared to existing technologies, the advantages of this invention are as follows: In the low-speckle, rollable, high-gain rear projection screen and its preparation method, the rear projection screen uses a flexible PET substrate as the middle layer, combined with a micro-pyramidal lens anti-reflection layer and a first AF coating in a composite structure. The overall structure is a thin film, lightweight and stable, adapting to the rollability of the flexible PET substrate, allowing for non-destructive roll-up and storage. The optical performance remains stable after bending, meeting the storage and installation needs of automotive, home, and other scenarios. The micro-pyramidal lens anti-reflection layer on the incident surface, through a uniformly arrayed micro-pyramidal structure, performs multiple physical couplings to enhance the transmission of incident light, reducing light loss and improving light utilization. Simultaneously, the micro-pyramidal lens anti-reflection layer can synergistically disrupt the RGB laser coherence conditions, effectively suppressing laser speckle, significantly reducing speckle contrast, and solving the problem of severe speckle in laser projection images. The micro-pyramidal structure is arranged in a uniform array, which can scatter incident light evenly from multiple surfaces, reduce the light intensity concentration at the center of the image, eliminate the center "hot spot" and solar effect, and balance high gain and wide viewing angle, thereby improving the uniformity of image brightness. The first AF coating has multiple functions, including anti-reflection, anti-fouling, scratch resistance, and anti-fingerprint. On the one hand, it reduces surface reflection and further improves the transmission efficiency of incident light; on the other hand, it protects the anti-reflection layer of the micro-pyramidal lens from damage to the optical structure caused by external stains and scratches, making it suitable for complex use environments and extending its service life.

[0016] The rear projection screen of the present invention adopts a layered design of flexible PET substrate, anti-reflection layer and first AF coating. The structure is simple and clear. It can be mass-produced through mature processes such as roll coating, UV curing and vacuum evaporation. The production process is controllable, the yield is high, the production cost is reduced, and it has good market application value. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments are briefly introduced below. The drawings described below are only the corresponding drawings of some embodiments of the present invention.

[0018] Figure 1 This is a schematic diagram of the overall layered structure of a low-speckle, rollable, high-gain rear projection screen according to a preferred embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the optical structure layer of a preferred embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of a micro pyramidal structure according to a preferred embodiment of the present invention.

[0021] Figure 4 This is a rendering of the vertex of the spherical lens according to a preferred embodiment of the present invention.

[0022] Figure 5a This is a schematic diagram of the light intensity distribution corresponding to the vertex of the spherical lens in a preferred embodiment of the present invention.

[0023] Figure 5b This is a schematic diagram of the illuminance distribution corresponding to the vertex of the sphereless lens in a preferred embodiment of the present invention.

[0024] Figure 6 The preferred embodiment of the present invention features the effect of a spherical lens. Figure 1 .

[0025] Figure 7 The preferred embodiment of the present invention features the effect of a spherical lens. Figure 2 .

[0026] Figure 8 The preferred embodiment of the present invention features the effect of a spherical lens. Figure 3 .

[0027] Figure 9a The preferred embodiment of the present invention features the effect of a spherical lens. Figure 2 The corresponding light intensity distribution diagram.

[0028] Figure 9b The preferred embodiment of the present invention features the effect of a spherical lens. Figure 2 A schematic diagram of the corresponding illuminance distribution.

[0029] Figure 10 This is a schematic diagram illustrating the principle of the first scattering particle suppressing laser speckle in the antireflective layer of the micro-pyramidal lens, which is a preferred embodiment of the present invention.

[0030] Figure 11 This is a schematic diagram illustrating the principle of suppressing laser speckle with overall scattering particles in a low-speckle, rollable, high-gain rear projection screen, which is a preferred embodiment of the present invention.

[0031] Figure 12 This is a schematic diagram of the microlens tightly arranged structure of the scattering layer on the emission surface of the present invention, according to a preferred embodiment of the present invention.

[0032] Figure 13 This is a flowchart illustrating the manufacturing process of a low-speckle, rollable, high-gain rear projection screen according to a preferred embodiment of the present invention.

[0033] Reference numerals: 11, Flexible PET substrate; 12, Optical structure layer; 121, Micro-pyramidal lens antireflective layer; 1211, Adhesive layer; 1212, Micro-pyramidal structure; 1213, Vertex structure; 122, First AF coating; 123, First scattering particle; 13, Outgoing surface scattering layer; 131, Second scattering particle. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the diagram, units with similar structures are represented by the same labels.

[0036] The terms "first" and "second" used in the terminology of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance, nor as limiting the order of events.

[0037] Please refer to Figure 1 and Figure 2 ,in Figure 1 This is a schematic diagram of the overall layered structure of a low-speckle, rollable, high-gain rear projection screen according to a preferred embodiment of the present invention. Figure 2 This is a schematic diagram of the optical structure layer of a preferred embodiment of the present invention.

[0038] The following is a preferred embodiment of a low-speckle, rollable, high-gain rear projection screen and its preparation method that can solve the above-mentioned technical problems provided by the present invention.

[0039] A preferred embodiment of the low-speckle, rollable, high-gain rear projection screen provided by the present invention is as follows: A low-speckle, rollable, high-gain rear projection screen includes a flexible PET substrate 11, an optical structure layer 12, and an exit surface scattering layer 13. The flexible PET substrate 11 is located in the middle layer of the screen, with an incident surface on one side and an exit surface on the other side. The optical structure layer 12 is disposed on the incident surface and is used to enhance the transmission of incident light and suppress laser speckle. The exit surface scattering layer 13 is disposed on the exit surface and is used for light homogenization. This three-layer composite stacked structure has clearly defined functional layers: the incident surface focuses on enhancing transmission and suppressing speckle, the exit surface focuses on light homogenization, and the substrate provides flexible support. From a structural perspective, it simultaneously achieves high light transmittance, low speckle, and high uniformity, resulting in a simple structure and strong synergy in optical performance.

[0040] The optical structure layer 12 includes a micro-pyramidal lens anti-reflection layer 121 and a first AF coating 122. The micro-pyramidal lens anti-reflection layer 121 includes an adhesive layer 1211 and a micro-pyramidal structure 1212. The adhesive layer 1211 is connected to the incident surface. The micro-pyramidal structure 1212 protrudes from the adhesive layer 1211 on the side away from the flexible PET substrate 11. Several micro-pyramidal structures 1212 are provided, and the several micro-pyramidal structures 1212 are arranged in a uniformly distributed array. In this embodiment, the adhesive layer 1211 and the micro-pyramidal structure 1212 are integrally formed.

[0041] The first AF coating 122 is disposed on the side of the micro-pyramidal lens anti-reflection layer 121 away from the flexible PET substrate 11, and is used to protect the micro-pyramidal lens anti-reflection layer 121. Through the composite design of array-type micro-pyramidal optical structure combined with AF protective anti-reflection coating, efficient coupling and anti-reflection of incident light are ensured, while the microstructure can be used to disrupt laser coherence, thus achieving the dual effects of optical anti-reflection and speckle suppression. The array arrangement ensures the consistency of optical performance of the entire screen.

[0042] The low-speckle, rollable, high-gain rear projection screen of this invention uses a flexible PET substrate 11 as the middle layer, combined with a micro-pyramidal lens anti-reflection layer 121 and a first AF coating 122 in a composite structure. The overall structure is a thin film, lightweight and stable, adapting to the rollability of the flexible PET substrate 11, allowing for non-destructive roll-up storage. Its optical performance remains stable after bending, meeting the storage and installation needs of automotive, home, and other scenarios. The micro-pyramidal lens anti-reflection layer 121 is set on the incident surface. Through the uniformly arrayed micro-pyramidal structures 1212, the incident light undergoes multiple physical couplings to enhance light transmission, reducing light loss and improving light utilization. Simultaneously, the micro-pyramidal lens anti-reflection layer 121 can synergistically disrupt the RGB laser coherence conditions, effectively suppressing laser speckle, significantly reducing speckle contrast, and solving the problem of severe speckle in laser projection images. The micro-pyramidal structure 1212 is arranged in a uniform array, which can scatter incident light uniformly from multiple surfaces, reduce the light intensity concentration at the center of the image, eliminate the "hot spot" and solar effect at the center, and balance high gain and wide viewing angle, thereby improving the uniformity of image brightness. The first AF coating 122 has multiple functions, including anti-reflection, anti-fouling, scratch resistance, and anti-fingerprint. On the one hand, it reduces surface reflection and further improves the transmission efficiency of incident light; on the other hand, it protects the anti-reflection layer 121 of the micro-pyramidal lens, preventing external stains and scratches from damaging the optical structure, adapting to complex usage environments, and extending service life.

[0043] The specific structure of the low-speckle, rollable, high-gain rear projection screen in this embodiment is described below: Combination Figure 1 The rear projection screen has an overall organic thin-film structure with a total thickness of 140μm. It can be rolled up and stored without damage, and there are no creases after bending, maintaining stable optical performance. This invention optimizes the overall thickness of the screen to the optimal range of 100-150μm. By matching the thickness of the flexible PET substrate 11 with the optical adhesive layers on both sides, it completely solves the problems of screen edge curling caused by excessive thickness and excessive curling stress and storage difficulties caused by excessive thickness. At the same time, it ensures the flatness of the screen installation, perfectly meeting the dual requirements of flexible roll-up and fixed installation.

[0044] In this embodiment, the flexible PET substrate 11 has a thickness of 100μm. The light transmittance of the flexible PET substrate 11 is ≥92%. The flexible PET substrate 11 is optical-grade flexible PET with an elongation at break of ≥100%, exhibiting excellent flexibility and rollability. One side of the flexible PET substrate 11 is the incident surface, and the other side is the exit surface. The use of a high-transmittance, high-ductility optical-grade PET substrate ensures high light transmittance, reduces basic light loss, and possesses excellent bending resilience, making it resistant to deformation during long-term roll-up and storage, thus ensuring the long-term stability of the screen.

[0045] like Figure 1As shown, the low-speckle, rollable, high-gain rear projection screen in this embodiment also includes a second AF coating. The second AF coating is disposed on the side of the scattering layer 13 on the exit surface away from the flexible PET substrate 11, and is used to protect the rear projection screen. By adding an AF protective coating to the exit surface, the screen achieves full protection on both sides, effectively protecting the microlens optical structure on the exit side, avoiding damage to the optical surface from external friction, stains, and dust, and further improving the screen's weather resistance and service life.

[0046] The structure of the antireflective layer 121 of the micro-pyramidal lens is described below: Combination Figure 1 , Figure 2 and Figure 3 In this embodiment, in order to improve the bonding strength between the micro pyramid structure 1212 and the incident surface of the flexible PET substrate 11, and at the same time ensure the optical matching of the interface and reduce light reflection loss, the optical structure layer 12 also includes an adhesive layer 1211. The adhesive layer 1211 is connected to the incident surface, and the micro pyramid structure 1212 protrudes from the adhesive layer 1211 on the side away from the flexible PET substrate 11.

[0047] In this embodiment, the micro-pyramidal structure 1212 is a circular fixed-point pyramidal lens or a flat fixed-point pyramidal lens, and its sidewalls are optical refractive surfaces. The micro-pyramidal structure 1212 has multi-faceted optical refraction characteristics, which can split and refract incident laser light from multiple angles, effectively disperse concentrated beams, avoid light convergence, suppress hot spots on the screen from the source, and improve the overall brightness uniformity of the screen.

[0048] In this embodiment, the top of the micro pyramid structure 1212 is provided with a vertex structure 1213. The micro pyramid structure 1212 is in the shape of a regular quadrangular frustum. The vertex structure 1213 is any one of a convex lens, a concave lens, a planar structure, or a rough irregular surface. The vertex structure 1213 is used to increase the number of light-splitting surfaces, disperse the incident laser beam, and suppress hot spots and solar effects on the screen.

[0049] By adjusting the size of the vertex structure 1213, the gain value at the center point of the image can be precisely controlled, enabling personalized and precise gain adjustment. It can be customized to meet the optical needs of different scenarios, such as home, automotive, and commercial applications. It is also compatible with rear projection engines of different light sources, including lasers and LEDs, significantly improving optical adaptability. Multiple types of vertex structures 1213 allow for modular and scenario-based optical parameter adjustment, breaking the limitations of fixed gain in traditional screens. This adapts to different light sources and image quality requirements in different scenarios, greatly improving device versatility and adaptability.

[0050] Furthermore, the vertex structure 1213 is a convex lens with a hemispherical structure. The convex lens is set at the top of the micro pyramidal structure 1212. The arc structure of the top surface of the convex lens has excellent light diffusion effect, which can further homogenize the light refracted by the micro pyramidal structure 1212, eliminate strong light at the edges and corners and local light spots, and greatly improve the brightness uniformity of the entire screen.

[0051] The pyramidal lens features multiple vertex structures (1213) to achieve multiple physical coupling and transmission enhancement of incident light, as well as multi-faceted uniform scattering, precisely controlling the gain value at the center of the image. The multi-layered composite microstructure enables multiple coupling and transmission enhancement of light, effectively improving light utilization and screen gain, while precisely controlling center brightness, thus resolving the image quality defects of traditional screens where the center is too bright and the edges are too dark.

[0052] This embodiment compares and verifies the light intensity gain distribution and image uniformity of different vertex structure specifications of the micro pyramid structure 1212. In this experiment, the overall size of the micro pyramid structure 1212 is uniformly defined as 30μm to 40μm, the size of the vertex structure 1213 is 20μm, and the radius of curvature is 8μm. All dimensions here refer to the outer perimeter of the corresponding structure.

[0053] By adjusting the specifications of different vertex structures 1213, the ratio of the outer contour dimension of the vertex structure 1213 to the bottom end face dimension of the micro-pyramidal structure 1212 is kept within the range of 1 / 3 to 1 / 2. This adjusts the front light transmission ratio and beam splitting effect, optimizing the uniformity of image brightness. Furthermore, verification has shown that a 1 / 2 ratio provides the best uniformity of light intensity distribution.

[0054] For the optical effects of the apexless spherical lens structure (apexless structure 1213, micro-pyramidal structure 1212 is a square pyramid), please refer to [link / reference]. Figure 4 The light intensity in the four corner areas (top left, bottom left, top right, and bottom right) of the image is significantly excessive, resulting in obvious uneven brightness. See the corresponding light intensity and illuminance distribution diagrams below. Figure 5a , Figure 5b This allows for direct verification of the defects of concentrated light intensity and poor uniformity at the four corners of the screen under a spherical lens structure.

[0055] Adding a vertex structure 1213 (a convex lens with a hemispherical structure) to the top of the micro-pyramidal structure 1212 effectively improves light divergence and significantly optimizes the uniformity of light intensity in the image. When the ratio of the outer contour size of the vertex structure 1213 to the bottom face size of the micro-pyramidal structure 1212 is 2:5, the relative effective size of the vertex structure 1213 is too small, resulting in insufficient uniformity correction of strong light at the four corners. Weak light spots still exist at the four corners of the image. See [link to specific effects] for details. Figure 6 .

[0056] When the ratio of the outer contour dimension of the vertex structure 1213 to the bottom end face dimension of the micro-pyramidal structure 1212 is 1:2, the multi-coupling anti-reflection effect and multi-angle beam splitting effect of the micro-pyramidal structure are optimally matched. This effectively disperses concentrated light intensity at the edges and corners, eliminates central hot spots, and achieves optimal uniformity in overall illumination and intensity distribution, without obvious light spots or uneven brightness. For specific effects, please refer to [link / reference needed]. Figure 7 .

[0057] When the ratio of the outer contour dimension of vertex structure 1213 to the bottom end face dimension of micro-pyramidal structure 1212 increases to 3:5, the relative size of vertex structure 1213 becomes too large. This causes light to converge excessively in the positive direction, resulting in weak light spots in the four positive positions (top, bottom, left, and right) of the image, disrupting the overall uniformity of the image. See [link to specific effects] for details. Figure 8 , Figure 9a , Figure 9b .

[0058] Multiple comparative tests have verified that the ratio of the outer contour dimension of the vertex structure 1213 to the bottom end face dimension of the micro pyramid structure 1212 is controlled within the preferred range of 1 / 3 to 1 / 2. When the optimal value is 1 / 2, the solar effect, corner glare and front glare can be completely eliminated while ensuring high gain of the screen, thus achieving highly uniform brightness of the entire screen.

[0059] Combination Figure 1 and Figure 10 In this embodiment, the micro-pyramidal lens antireflective layer 121 is cured and formed by a first UV optical adhesive containing first scattering particles 123. The first scattering particles 123 are uniformly dispersed in the bonding layer 1211 and the micro-pyramidal structure 1212. The scattering particles are uniformly dispersed in the micro-pyramidal structure 1212, which can destroy the coherence of the laser beam in all directions, greatly reduce speckle contrast, and at the same time assist in light homogenization, further improving the uniformity of image quality.

[0060] The first UV optical adhesive is an optical-grade acrylic UV adhesive with a light transmittance of ≥92% and flexibility after curing. This highly transparent and flexible UV adhesive material ensures high light transmittance, avoids light loss caused by the adhesive layer, and is compatible with the curling characteristics of the substrate, making it less prone to cracking when bent, thus ensuring the integrity of the optical structure.

[0061] The first scattering particle 123 is a composite particle of silicon dioxide scattering particles and acrylic scattering particles, with a mass ratio of silicon dioxide scattering particles to acrylic scattering particles of 1:1. The particle size of the first scattering particle 123 is 3-5 μm, and its mass accounts for 3% of the mass of the first UV optical adhesive. The first scattering particle 123 is uniformly dispersed within the bonding layer 1211 and the micro-pyramidal structure 1212. The composite scattering particles, combined with precise particle size and doping ratio, can achieve efficient speckle suppression without affecting the screen's light transmission gain. The uniform particle dispersion ensures consistent speckle suppression effect across the entire screen, eliminating local image quality differences.

[0062] The first AF coating 122 of this embodiment will be described as follows: Combination Figure 1 The first AF coating 122 is located on the outermost side of the anti-reflection layer 121 of the micro-pyramidal lens. The outer layer covering structure can fully cover the micro-pyramidal optical structure, comprehensively protect the delicate microstructure from wear and contamination, and ensure the long-term integrity of the optical structure.

[0063] The first AF coating 122 is prepared using a vacuum evaporation process for a fluorine-containing anti-fingerprint coating. Vacuum evaporation produces coatings with high uniformity, strong adhesion, and no coating defects. It can stably achieve both optical anti-reflective and protective functions, and the process is suitable for roll-to-roll mass production.

[0064] The first AF coating 122 has a thickness of 100nm. The nanoscale ultra-thin coating design does not obstruct or interfere with the optical refraction effect of the microstructure, maximizing the preservation of the screen's original optical performance while ensuring protective effects.

[0065] The first AF coating 122 can reduce surface reflection, improve the anti-reflective effect, and at the same time, it is stain-resistant, scratch-resistant, fingerprint-resistant, and protects the optical structure.

[0066] In this embodiment, the AF coating (Anti-Fingerprint Coating) is a functional coating widely used on surfaces such as glass, ceramics, and metals. Its main functions are to reduce fingerprint adhesion, improve surface cleanability, and enhance tactile and optical properties. The following is a detailed explanation of its specific functions: 1. Core functions of fingerprint and stain resistance: The essence of AF coating is a low surface energy coating (usually composed of fluoropolymers, such as perfluoropolyethers and fluorosilanes), whose surface tension is much lower than that of the oils in fingerprints (mainly fatty acids and sweat). When a finger touches the coated surface, oils are difficult to wet or adhere (large contact angle, usually >105°). Even if a slight mark is left, it appears as a bead-like "lotus leaf effect" rather than a diffused, blurry stain, thus significantly reducing visible fingerprints.

[0067] 2. Improved ease of cleaning: Since fingerprints and stains (such as dust, water stains, and oil stains) have very weak adhesion to the AF coating, they can be removed simply by wiping with a soft cloth (or even by blowing with an air blower). There is no need to use strong cleaning agents or wipe repeatedly, reducing the risk of surface wear and tear. It is especially suitable for devices that are frequently touched (such as mobile phone screens, tablets, and smartwatches).

[0068] 3. Optimize smooth touch: The AF coating can reduce the surface friction coefficient (the friction coefficient of uncoated glass is about 0.5~0.7, which can be reduced to 0.1~0.2 after coating), making the touch feel smoother and more fluid, reducing the "gritty" feeling, and improving the comfort of sliding operations (such as screen sliding and button touch), which is also an important reason for its popularity in touch screen devices.

[0069] 4. Improve auxiliary optical performance: Some AF coatings have a certain anti-reflection effect (reducing surface reflection through refractive index matching), which can reduce the reflection of the glass surface and improve the clarity of the screen or mirror (especially under strong light); at the same time, reducing fingerprint residue can also avoid visual interference caused by dirt.

[0070] 5. Protecting the substrate (indirect effect): Although the AF coating itself is extremely thin (usually only nanometers thick, such as 10~50nm), its oleophobic and hydrophobic properties can reduce the direct contact between corrosive stains (such as salt and acidic substances in sweat stains) and the substrate, indirectly delaying the corrosion or aging of the substrate and extending the product's service life.

[0071] The scattering layer 13 at the exit surface of this embodiment will be described in detail: Combination Figure 1 and Figure 11 The scattering layer 13 is disposed on the emitting surface of the flexible PET substrate 11 for light homogenization and speckle suppression. The emitting surface, through secondary light homogenization design, re-uniformly scatters the light optimized on the incident surface, further eliminating residual light spots and brightness differences, maximizing image uniformity, and suppressing laser speckle a second time.

[0072] Combination Figure 11 As shown, the scattering layer 13 on the exit surface is cured and formed by a second UV optical adhesive containing second scattering particles 131. The second scattering particles 131 are the same as the first scattering particles 123, with a particle size of 3–5 μm and a mass percentage of 3%. The parameters of the scattering particles on the entrance and exit surfaces are unified, achieving bidirectional synergistic speckle suppression, high matching degree of scattering effect, no optical deviation, and ensuring the consistency of image quality across the entire screen.

[0073] Combination Figure 12 The scattering layer 13 at the exit surface has a uniformly disordered microlens tightly arranged structure, and the second scattering particles 131 are uniformly dispersed inside and between the microlenses. Figure 12 (Not shown in the image). The disordered microlens array structure can achieve the Lambertian scattering effect, greatly widening the projection viewing angle. At the same time, it works with scattering particles to achieve uniform light across the entire field of view, completely solving the problems of narrow viewing angle and poor edge image quality of traditional screens.

[0074] The second AF coating of this embodiment will be described in detail: The second AF coating (not shown in the figure) is applied to the outside of the scattering layer 13 on the exit surface. It fully covers the microlens structure of the exit surface, protecting the fine, disordered microlens array from wear and contamination, and ensuring the long-term integrity of the uniform light output structure.

[0075] The second AF coating is prepared using a vacuum evaporation process for a fluorine-containing coating, with a thickness of 100 nm. The process and parameters are consistent with the incident surface coating, ensuring consistent double-sided protection performance. This high degree of process standardization facilitates mass production.

[0076] The second AF coating is stain-resistant, scratch-resistant, and fingerprint-resistant, protecting the optical structure of the emission surface.

[0077] Both the incident and exit surfaces are treated with AF process to form a protective coating that is anti-fouling, scratch-resistant, and fingerprint-resistant. This coating is suitable for complex usage environments such as automotive and outdoor applications, preventing damage to the optical structure from the external environment, ensuring the long-term stability of the screen's optical performance, and extending the product's service life.

[0078] This invention, by uniformly dispersing scattering particles of a specific size in the optical structure layer 12 of the incident surface and the scattering layer 13 of the exit surface, can synergistically disrupt the coherence conditions of RGB lasers, significantly reducing the laser speckle contrast from 14% without the addition of scattering particles to below 5%, fundamentally solving the speckle image quality problem brought about by the widespread adoption of laser projection. At the same time, the scattering particles can also synergistically achieve uniform light scattering, further improving image uniformity, thus balancing speckle suppression and optical gain.

[0079] The incident surface is equipped with a micro-pyramidal lens anti-reflection layer 121 to achieve multiple physical coupling and anti-reflection of incident light, reducing light loss and achieving a screen gain of up to 2.5. The multi-faceted beam splitting design eliminates the "hot spot" and solar effect at the center point from the root. The microlens scattering structure on the exit surface further achieves light uniformity, expands the viewing angle, and achieves ultra-high color reproduction with color reproduction ΔU < 0.005 and ΔV < 0.005, solving the problems of "gain and viewing angle cannot be achieved at the same time" and "uniformity and high brightness cannot be achieved at the same time" in traditional rear projection screens.

[0080] Combination Figure 1 as well as Figure 13 As shown, the preparation method of the low-speckle, rollable, high-gain rear projection screen of this embodiment is described below: S1: Substrate pretreatment.

[0081] A 100μm optical-grade flexible PET substrate 11 was selected and unwound from roll to roll. The flexible PET substrate 11 has a light transmittance of ≥92% and an elongation at break of ≥100%, combining high light transmittance with excellent flexible curling performance. It is suitable for roll-to-roll production processes and scene curling and storage requirements, providing a basis for controlling the total thickness within the optimal range of 100-150μm.

[0082] S2: Preparation of UV adhesive.

[0083] Optical grade acrylic UV adhesive is mixed with scattering particles and stirred at high speed until the scattering particles are evenly dispersed to form a stable UV optical adhesive system containing scattering particles. This system is used to prepare both the outgoing surface scattering layer 13 and the incident surface antireflection layer.

[0084] This adhesive serves as both a first UV optical adhesive doped with first scattering particles 123 and a second UV optical adhesive doped with second scattering particles 131, and is used uniformly in the preparation of the scattering layer 13 on the outgoing surface and the antireflection layer on the incoming surface. The optical-grade acrylic UV optical adhesive, after curing, has a light transmittance of approximately 93% and an elongation at break ≥80%, exhibiting excellent flexibility.

[0085] The scattering particles added to the UV optical adhesive system are composite scattering particles, which are one or more of silicon dioxide scattering particles, acrylic scattering particles, or titanium dioxide scattering particles, and the particle size of the composite scattering particles is 3-5 μm.

[0086] In this embodiment, the preferred scattering particles are composite particles of silica and acrylic scattering particles (mass ratio 1:1, particle size 3-5 μm), and the amount of scattering particles added is 3% of the total mass of the UV optical adhesive. This standardizes the adhesive formulation system, simplifies the production process, reduces material costs, and ensures consistent optical performance matching between the incoming and outgoing surfaces, with no optical deviation.

[0087] S3: Prepare the outgoing surface scattering layer 13.

[0088] A high-precision disordered microlens roller mold is used to coat the above-prepared UV optical adhesive system onto the emission surface side of the flexible PET substrate 11 through a roll-to-roll coating process. The dry film thickness is controlled to be 15μm. The film is then cured online by a UV curing machine (wavelength 365nm, light intensity 800mJ / cm²) to form an emission surface scattering layer 13. The emission surface scattering layer 13 is a uniform and disordered microlens tightly arranged structure. Scattering particles are uniformly dispersed inside and between the microlenses to achieve the Lambertian scattering effect.

[0089] S4: Prepare the anti-reflection optical structure layer 12 on the incident surface.

[0090] After the scattering layer 13 on the outgoing surface is prepared, the PET substrate is flipped over, and a high-precision pyramidal lens roller mold is used to coat the prepared UV optical adhesive system onto the incident surface side of the flexible PET substrate 11 using a roll-to-roll coating process. The dry film thickness is controlled to be 25 μm, and then online UV curing is performed to form a micro-pyramidal lens antireflective layer 121. The thickness of the antireflective structure on the incident surface is reasonable, ensuring the light coupling antireflection effect, while not affecting the overall flexibility of the screen, thus balancing optical and structural performance.

[0091] Among them, the micro-pyramidal lens antireflection layer 121 is a uniform and regular flat point micro-pyramidal lens array structure, with scattering particles uniformly dispersed inside the micro-pyramidal lens antireflection layer 121 and between the lenses.

[0092] In this embodiment, the micro-pyramidal lens antireflective layer 121 is provided with an array of micro-pyramidal structures. In this embodiment, the micro-pyramidal structure is a square pyramid, and the sidewalls of the micro-pyramidal structure are optical refractive surfaces. The micro-pyramidal structure 1212 has multi-faceted optical refractive properties, which can split and refract incident laser light from multiple angles, effectively disperse concentrated beams, avoid light convergence, suppress hot spots in the image from the source, and improve the overall brightness uniformity of the image.

[0093] The micro-pyramidal structure 1212 has a vertex structure 1213 at its top. The vertex structure 1213 can be any one of a convex lens, a concave lens, a planar structure, or a rough, irregular surface. The vertex structure 1213 is used to increase the number of light-splitting surfaces, disperse the incident laser beam, and suppress hot spots and solar effects on the image. Furthermore, the vertex structure 1213 is a hemispherical convex lens, and the micro-pyramidal structure 1212 has a size of 30–40 μm, while the convex lens has a circumference of 20 μm.

[0094] The top of the micro pyramid structure 1212 adopts an equivalent spherical lens design, and the vertex is set with a convex lens type vertex structure 1213. The circumference of the convex lens is adjusted to 20μm and the radius of curvature is 8μm. The convex lens type vertex structure 1213 controls the gain value of the center point of the screen to a preset high threshold. The array-type microstructure has high forming precision, and the center gain is controllable and adjustable, stably achieving high gain output, while ensuring uniform optical performance of the entire screen.

[0095] S5: Prepare AF coatings (first AF coating 122, second AF coating) After the optical structures of the incident and exit surfaces are fabricated, a fluorine-containing AF coating is deposited on the surface of the antireflective layer 121 of the micro-pyramidal lens using a continuous vacuum evaporation process. This forms the first AF coating 122, which has a thickness of 100 nm, providing anti-fouling, scratch-resistant, and fingerprint-resistant protection. The continuous vacuum evaporation process results in a uniform coating with strong adhesion and no defects, ensuring high consistency in mass production and stably achieving double-sided optical antireflection and long-term protection.

[0096] A continuous vacuum evaporation process is used to deposit a fluorine-containing AF coating on the surface of the scattering layer 13 on the outgoing surface. After the coating is completed, a second AF coating is formed with a thickness of 100nm, achieving anti-fouling, scratch-resistant, and fingerprint-resistant protection. The double-sided synchronous coating process simplifies the production process, improves production efficiency, and ensures consistent double-sided protection and anti-reflective properties.

[0097] S6: Post-processing The rolled-up screen is then slit, cleaned, and coated to obtain the finished rear projection screen with a total thickness of 140 μm. This embodiment shows the finished rear projection screen. With a total thickness in the optimal range of 100-150μm, there is no curling problem. It can be rolled up and stored without damage with a diameter of ≥10cm. There are no creases after bending and no degradation in optical performance.

[0098] The above completes the preparation of a low-speckle, rollable, high-gain rear projection screen according to the present invention.

[0099] This invention discloses a method for fabricating a low-speck, rollable, high-gain rear projection screen. Using high-transmittance, highly flexible PET as the substrate and employing a uniformly proportioned acrylate UV composite scattering adhesive system, a disordered microlens scattering layer is formed on the substrate's exit surface through a roll-to-roll microstructure molding and curing process. This achieves light homogenization and reduces speckle. A micro-pyramidal lens anti-reflection structure with an array of convex lens vertices (1212) is fabricated on the incident surface to split the laser beam at multiple angles, effectively suppressing solar effects and image hotspots, and precisely enhancing the screen's optical gain. Simultaneously, a 100nm fluorine-containing AF protective coating is deposited on both sides via vacuum evaporation, ensuring the screen's wear resistance and stain resistance. The overall process is simple, suitable for mass production, and the finished screen has controllable thickness and excellent flexibility, allowing for non-destructive roll-up storage. While achieving low speckle, high gain, and highly uniform image quality, it also possesses excellent flexibility and lifespan, perfectly suited for rollable rear projection display scenarios.

[0100] The following describes a variant design of the low-speckle, rollable, high-gain rear projection screen in this embodiment: Example 2: Home Scene Adaptation Variant The difference between this embodiment and Embodiment 1 is that: 1. The flexible PET substrate 11 has a thickness of 125μm and is optical-grade PET. The dry film thickness of the scattering layer 13 on the outgoing surface is 10μm, and the dry film thickness of the optical structure layer 12 on the incident surface is 15μm, resulting in a total finished thickness of 150μm, which is within the optimal thickness range. This further improves the flatness of large-size screens while maintaining excellent roll-up and storage performance, making it suitable for home rear projection scenarios of 100 inches and above.

[0101] 2. The scattering particles are single acrylic scattering particles with a particle size of 2-4μm and an addition amount of 2.5%. While ensuring speckle contrast ≤5%, it further improves color reproduction and meets the high-quality requirements of home audio-visual.

[0102] 3. The micro-pyramidal apex has a planar structure. The micro-pyramidal lens has a planar vertex structure at its apex. By adjusting its size, the gain value at the center point of the image is controlled to 1.8 times, balancing gain and uniformity, and adapting to the dual display needs of dark and bright environments in home living rooms.

[0103] Tests showed that the screen speckle contrast ratio prepared in this embodiment is 4.5%, and the color reproduction ΔU < 0.003 and ΔV < 0.003, which fully meets the high picture quality requirements of home audio-visual systems. It can be rolled up and stored in a custom cabinet, adapting to the flexible installation requirements of home scenarios.

[0104] Example 3: In-vehicle scenario adaptation variant The difference between this embodiment and Embodiment 1 is that: 1. The flexible PET substrate 11 is an ultra-thin flexible PET substrate with a thickness of 75μm. The dry film thickness of the scattering layer 13 on the outgoing surface is 12μm, and the dry film thickness of the optical structure layer 12 on the incident surface is 13μm. The total thickness of the finished product is 100μm, which is at the lower limit of the optimal thickness range. This avoids the problem of curling edges on thin products and achieves better curling performance, enabling smaller diameter curling and storage, which is suitable for the storage needs of small spaces in the car.

[0105] 2. The UV optical adhesive is a high- and low-temperature resistant automotive-grade acrylic UV optical adhesive. The working temperature range of the UV optical adhesive is ~40℃~85℃, which is suitable for the complex temperature and humidity environment of the vehicle.

[0106] 3. The scattering particles are a composite of silica and titanium dioxide, with a particle size of 5-8 μm. The amount added is 4% of the total mass of the UV optical adhesive. While ensuring speckle contrast ≤5%, it improves the ability to resist ambient light interference and is suitable for the display requirements of bright in-vehicle environments.

[0107] 4. Both the first AF coating 122 and the second AF coating are weather-resistant fluorine-containing coatings, which improve anti-aging and scratch resistance and are suitable for vehicle use environments.

[0108] After undergoing vehicle environment reliability testing and optical testing, the screen prepared in this embodiment showed no damage to its optical structure and no performance degradation after high and low temperature cycling and vibration testing. The speckle contrast remained stable at 4.7%, and the gain reached 2.2. It can be adapted to various vehicle application scenarios such as in-vehicle panoramic rear projection, door rear projection, and rear-seat entertainment rear projection. It can be rolled up and stored in the car roof and door interior without taking up interior space.

[0109] Example 4: Variations in Commercial Window / Outdoor Advertising Scenarios The difference between this embodiment and Embodiment 1 is that: 1. The flexible PET substrate 11 is made of high weather-resistant flexible PET with a thickness of 100μm. The dry film thickness of the scattering layer 13 on the outgoing surface is 20μm, and the dry film thickness of the optical structure layer 12 on the incident surface is 25μm. The total thickness of the finished product is 145μm, which is within the optimal thickness range, taking into account both the flatness of large sizes and the needs of outdoor installation and roll transportation.

[0110] 2. The micro-pyramidal lens features a rough, irregular vertex structure to improve scattering uniformity and meet the wide viewing angle requirements of large commercial windows.

[0111] 3. The scattering particles are selected from ternary composite scattering particles of silicon dioxide, acrylic and titanium dioxide, with a particle size of 4 to 6 μm. The addition amount is increased to 5%, and the speckle contrast can be controlled below 4.2%. At the same time, the ambient light anti-interference ability is greatly improved, ensuring the contrast and clarity of the picture in bright environments.

[0112] 4. The AF coating has been upgraded to an outdoor weather-resistant and stain-resistant coating, which has hydrophobic, stain-resistant and graffiti-resistant properties, making it suitable for the use needs of commercial outdoor scenarios.

[0113] The screen prepared in this embodiment can be produced, transported and installed in large rolls without the need for on-site splicing, which greatly reduces the installation cost of commercial windows and outdoor advertising. At the same time, it has excellent speckle suppression, high gain and wide viewing angle display effects, perfectly adapting to the application needs of commercial scenarios.

[0114] Based on the preparation method of the low-speckle rollable high-gain rear projection screen in Example 1, the corresponding process parameters are matched according to different application scenarios: for home use, 2-4 μm single acrylic scattering particles are used with an addition amount of 2.5%, the micro-pyramid top has a planar structure, and the gain is adjusted to 1.8 times; for vehicle use, UV adhesive resistant to high and low temperatures of ~40℃~85℃ is used, 5-8 μm composite scattering particles are used with an addition amount of 4%; for outdoor commercial use, ternary composite scattering particles are used with an addition amount of 5%, and the micro-pyramid top has a rough and irregular surface structure.

[0115] Example 5: This example also provides a rear projection display system using a low-speckle, rollable, high-gain rear projection screen. The rear projection display system includes a rear projection optical engine, a low-speckle, rollable, high-gain rear projection screen, and a light signal receiver. The rear projection optical engine is located on the incident side of the screen and is used to emit an RGB laser projection beam. The low-speckle, rollable, high-gain rear projection screen is located in the output optical path of the rear projection optical engine and is used for coupling and anti-reflection, speckle suppression, uniform scattering, and gain adjustment of the projection beam. The low-speckle, rollable, high-gain rear projection screen is the same as the one prepared in Example 1 and is located in the output optical path of the rear projection optical engine. The beam sequentially passes through a first AF coating 122, a micro-pyramidal lens anti-reflection layer 121, a flexible PET substrate 11, an output surface scattering layer 13, and a second AF coating (optional). The optical signal receiver is located on the output side of the screen to receive the optical signal processed by the screen and output a clear picture.

[0116] System performance: The screen is free of speckle, hotspots, and solar effects; the brightness is uniform; the color reproduction is accurate; and the viewing angle is wide. The screen is rollable and retractable, suitable for in-vehicle, home, shop window, and outdoor advertising applications.

[0117] The low-speckle, rollable, high-gain rear projection screen is the low-speckle, rollable, high-gain rear projection screen prepared in Example 1. The rear projection optical engine is an automotive RGB laser rear projection optical engine, and the optical signal receiver is an automotive optical signal receiver. The rear projection optical engine is embedded in the car roof, and the outgoing light path faces the anti-reflection optical structure layer 12 of the incident surface of the screen. The screen can be rolled up and stored inside the car roof. When in use, it is unfolded and laid flat at the position of the car sunroof. The optical signal receiver is integrated into the vehicle system to receive the optical signal processed by the screen, so as to realize the immersive rear projection display in the car.

[0118] The system has been tested in real vehicles and can achieve large-size laser rear projection display inside the vehicle. The image is free of speckle, hot spots, and solar effects. The brightness is uniform and the color reproduction is accurate. The wide viewing angle allows all seats in the vehicle to obtain excellent viewing effects. When not in use, it can be completely rolled up and stored without taking up any space in the vehicle, perfectly adapting to the usage needs of in-vehicle scenarios.

[0119] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A low-speckle, rollable, high-gain rear projection screen, characterized in that, include: A flexible PET substrate is located in the middle layer of the screen. The flexible PET substrate has an incident surface on one side and an exit surface on the other side. An optical structure layer is disposed on the incident surface to enhance the transmission of incident light and suppress laser speckle; as well as An exit surface scattering layer is disposed on the exit surface for light homogenization; The optical structure layer includes: A micro-pyramidal lens antireflective layer includes an adhesive layer and micro-pyramidal structures. The adhesive layer is connected to the incident surface, and the micro-pyramidal structures protrude from the adhesive layer on the side away from the flexible PET substrate. Several micro-pyramidal structures are arranged in a uniformly distributed array. The first AF coating is disposed on the side of the micro-pyramidal lens antireflective layer away from the flexible PET substrate, and is used to protect the micro-pyramidal lens antireflective layer; The sidewalls of the micro-pyramidal structure are optical refractive surfaces. The micro-pyramidal structure is in the shape of a regular quadrangular frustum. The top of the micro-pyramidal structure is provided with a vertex structure. The vertex structure is any one of a convex lens, a concave lens, a planar structure, or a rough irregular surface. The vertex structure is used to increase the number of light-splitting surfaces, disperse the incident laser beam, and suppress hot spots and solar effects on the screen.

2. The low-speckle, rollable, high-gain rear projection screen according to claim 1, characterized in that, The vertex structure is entirely covered on the top end face of the micro pyramid structure, and the ratio of the outer contour dimension of the vertex structure to the bottom end face dimension of the micro pyramid structure is 1 / 3 to 1 / 2.

3. The low-speckle, rollable, high-gain rear projection screen according to claim 1, characterized in that, It also includes a second AF coating disposed on the side of the emission surface scattering layer away from the flexible PET substrate, the second AF coating being used to protect the emission surface scattering layer.

4. A method for preparing a low-speckle, rollable, high-gain rear projection screen, characterized in that, Includes the following steps: S1: Substrate pretreatment Select an optical-grade flexible PET substrate of a preset thickness and perform unwinding pretreatment using a roll-to-roll process; S2: Preparation of UV adhesive, Optical grade acrylic UV optical adhesive is mixed with scattering particles in a predetermined ratio and stirred until the particles are uniformly dispersed to prepare a stable UV optical adhesive system. S3: Prepare the scattering layer at the exit surface. Using a disordered microlens roller mold, the UV optical adhesive system is coated onto the emission surface of a flexible PET substrate through a roll-to-roll coating process, with the dry film thickness controlled to be 10μm to 20μm. After UV curing, the emission surface scattering layer with a disordered microlens structure is formed. S4: Fabrication of the incident optical layer The flexible PET substrate is flipped over, and a micro-pyramidal array roller mold is used to coat the UV optical adhesive system onto the incident surface of the flexible PET substrate. The dry film thickness is controlled to be 15μm to 25μm, and then UV curing is performed to form a micro-pyramidal lens anti-reflection layer. S5: Prepare a protective coating. A 100nm thick fluorine-containing AF coating is deposited on the outer surface of the antireflective layer of the micro-pyramidal lens using a continuous vacuum evaporation process to form the first AF coating. S6: The rolled screen is cut, cleaned, and coated to obtain the finished rear projection screen.

5. The method for preparing a low-speckle, rollable, high-gain rear projection screen according to claim 4, characterized in that, In step S5, a fluorine-containing AF coating is simultaneously deposited on the outer surface of the scattering layer of the emission surface to form a second AF coating, the thickness of which is 100 nm.

6. The method for preparing a low-speckle, rollable, high-gain rear projection screen according to claim 4, characterized in that, The scattering particles added to the UV optical adhesive system are composite scattering particles, which are one or more of silicon dioxide scattering particles, acrylic scattering particles, or titanium dioxide scattering particles, and the particle size of the composite scattering particles is controlled to be 3-5 μm.

7. The method for preparing a low-speckle, rollable, high-gain rear projection screen according to claim 4, characterized in that, In step S1, the flexible PET substrate is selected as a high-transmittance optical-grade PET substrate with a thickness of 50-125μm and a light transmittance of ≥90%, and the total thickness of the rear projection screen in step S6 is 100-150μm.

8. The method for preparing a low-speckle, rollable, high-gain rear projection screen according to claim 4, characterized in that, In step S4, the micro-pyramidal lens antireflective layer is provided with an array of micro-pyramidal structures, the sidewalls of which are optical refractive surfaces. The micro-pyramidal structure has a vertex structure at its top, which can be any one of a convex lens, a concave lens, a planar structure, or a rough irregular surface, in order to increase the beam splitting surface, disperse the incident laser, and suppress hot spots and solar effects on the screen.

9. The method for preparing a low-speckle, rollable, high-gain rear projection screen according to claim 8, characterized in that, The ratio of the outer contour dimension of the vertex structure to the bottom end face dimension of the micro pyramid structure is 1 / 3 to 1 / 2. When the vertex structure is a convex lens, the overall size of a single micro pyramid structure is 30-40 μm, and the circumference of the convex lens is 20 μm.

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