Projection screen and projection device

Abstract

The present invention relates to the technical field of projection display, and provides a projection screen and a projection device. The projection screen comprises a conductive structure (11), a microstructure layer (12), and a conditioning solution (13). A plurality of microstructure cavities (121) are formed in the microstructure layer (12), and the conditioning solution (13) is filled in the plurality of microstructure cavities (121). The conditioning solution (13) comprises a conductive liquid (131) and a reflecting liquid (132), wherein the conductive liquid (131) and the reflecting liquid (132) are not compatible with each other, and the reflecting liquid (132) is used for reflecting projection light. The conductive structure (11) is used for applying a voltage to the conditioning solution (13) in the microstructure cavities (121), so that the reflecting liquid (132) moves relative to the conductive liquid (131), so as to adjust the inclination angle and the inclination direction of the reflective surface of the reflecting liquid (132) relative to the surface of one side of the projection screen.

Description

Projection screen and projection equipment

[0001] This disclosure claims priority to Chinese patent application No. 202311006558.6 filed on August 10, 2023, with the invention name “Fresnel projection screen”, and priority to Chinese patent application No. 202311159570.0 filed on September 8, 2023, with the invention name “A projection screen and projection device”, the entire contents of which are incorporated into this disclosure by reference. Technical Field

[0002] The present disclosure relates to the field of projection display technology, and in particular to a projection screen and a projection device. Background Art

[0003] In the field of projection display technology, projectors are typically used in conjunction with projection screens. Light from the projector is projected onto the projection screen, where it reflects off the screen before reaching the viewer, who then sees the image formed by the light on the surface of the projection screen.

[0004] To enhance the projection effect, projection screens typically include a Fresnel layer, which converges light and increases the gain of the projection screen.

[0005] However, the light converging effect of the Fresnel layer in the related art is poor and cannot meet the needs of users.

[0006] Summary of the Invention

[0007] The present disclosure provides a projection screen and a projection device that can solve the technical problem of poor light convergence effect of the Fresnel layer in the related art. The technical solutions of the projection screen and the projection device are as follows.

[0008] In a first aspect, the present disclosure provides a projection screen. The projection screen comprises a conductive structure, a microstructure layer, and a conditioning solution. The microstructure layer defines a plurality of microstructure cavities, which are filled with a conditioning solution. The conditioning solution comprises a conductive liquid and a reflective liquid, which are mutually incompatible. The reflective liquid is used to reflect projection light. The conductive structure is used to apply a voltage to the conditioning solution within the microstructure cavities, causing the reflective liquid to move relative to the conductive liquid, thereby adjusting the inclination angle and direction of the reflective surface of the reflective liquid relative to a surface of the projection screen.

[0009] In a second aspect, the present disclosure provides a projection device, which includes a projector and the projection screen as described in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG1 is a schematic diagram of the structure principle of a projection screen in a related technical solution;

[0011] FIG2 is a schematic diagram of a projection screen structure provided by an embodiment of the present disclosure;

[0012] FIG3 is a schematic diagram of a surface layer structure provided by an embodiment of the present disclosure;

[0013] FIG4 is a schematic diagram of another surface layer structure provided by an embodiment of the present disclosure;

[0014] FIG5 is a schematic diagram of another surface layer structure provided by an embodiment of the present disclosure;

[0015] FIG6 is a schematic diagram of another surface layer structure provided by an embodiment of the present disclosure;

[0016] FIG7 is a schematic diagram of a Fresnel layer structure provided by an embodiment of the present disclosure;

[0017] FIG8 is a schematic diagram of another Fresnel layer structure provided by an embodiment of the present disclosure;

[0018] FIG9 is a schematic diagram of a diffusion layer structure provided by an embodiment of the present disclosure;

[0019] FIG10 is a schematic diagram of another diffusion layer structure provided by an embodiment of the present disclosure;

[0020] FIG11 is a diagram showing a relationship curve between film thickness and color layer transmittance according to an embodiment of the present disclosure;

[0021] FIG12 is a schematic diagram of the thickness of the colored layer in a wet film state according to an embodiment of the present disclosure;

[0022] FIG13 is a schematic diagram of the thickness of the colored layer in a cured state according to an embodiment of the present disclosure;

[0023] FIG14 is a diagram showing a relationship curve between a first mixing ratio and a transmittance of a coloring layer according to an embodiment of the present disclosure;

[0024] FIG15 is a schematic diagram of a curve showing the relationship between the amount of blue dye and the gain ratio provided in an embodiment of the present disclosure;

[0025] FIG16 is a diagram showing a relationship curve between the amount of red dye and the gain ratio provided by an embodiment of the present disclosure;

[0026] FIG17 is a schematic diagram of a reflective layer structure provided by an embodiment of the present disclosure;

[0027] FIG18 is a schematic diagram of another reflective layer structure provided by an embodiment of the present disclosure;

[0028] FIG19 is a schematic diagram of another reflective layer structure provided by an embodiment of the present disclosure;

[0029] FIG20 is a schematic diagram of another projection screen structure provided by an embodiment of the present disclosure;

[0030] FIG21 is a schematic diagram of another projection screen structure provided by an embodiment of the present disclosure;

[0031] FIG22 is a schematic diagram of another projection screen structure provided by an embodiment of the present disclosure;

[0032] FIG23 is a schematic structural diagram of a Fresnel layer provided by an embodiment of the present disclosure;

[0033] FIG24 is a schematic diagram of a light path of a projection light reflected by a Fresnel layer according to an embodiment of the present disclosure;

[0034] FIG25 is a schematic diagram of a planar structure of a Fresnel layer provided by an embodiment of the present disclosure;

[0035] FIG26 is a schematic diagram of a partial structure of a projection screen provided by an embodiment of the present disclosure;

[0036] FIG27 is a schematic structural diagram of a conductive structure provided by an embodiment of the present disclosure after applying voltage to a regulating solution;

[0037] FIG28 is a schematic structural diagram of a microstructure layer provided by an embodiment of the present disclosure;

[0038] FIG29 is a schematic structural diagram of a microstructure cavity provided by an embodiment of the present disclosure;

[0039] FIG30 is a schematic diagram of light projected by a projector according to an embodiment of the present disclosure and reflected by a microstructure layer to an observation point;

[0040] FIG31 is a schematic diagram of an incident light entering a regulating solution provided by an embodiment of the present disclosure.

[0041] Legend: 100, projection screen, 200, projector, 201, incident light; 11, conductive structure, 111, first electrode layer, 112, second electrode layer, 12, microstructure layer, 121, microstructure cavity, 13, regulating solution, 131, conductive liquid, 132, reflective liquid; 21, surface layer, 22, diffusion layer, 23, coloring layer, 24, Fresnel layer, 241, Fresnel microstructure, 25, reflective layer, 26, substrate layer, 27, lens layer, 28, OCA adhesive layer. DETAILED DESCRIPTION

[0042] FIG1 is a schematic diagram of the structural principle of the projection screen in the related technical solution. Among them, the projection screen can be called a Fresnel projection screen. As shown in FIG1 , the projection screen 100 is generally used in conjunction with an ultra-short-throw laser projector 200. The ultra-short-throw laser projector 200 is generally set at a position on the ground or near the ground to emit light L1 to the Fresnel projection screen 100 at a certain angle, and the light L1 is reflected by the projection screen 100 to the user's perspective, so that the user can view the corresponding content. At the same time, the light L2 on the ceiling (such as the light) is reflected by the projection screen 100 and propagates to the ground. It cannot be reflected to the user's human eye perspective, which can avoid the influence of ambient light on the viewing effect of the human eye.

[0043] Based on the above background, as shown in FIG2 , an embodiment of the present disclosure provides a projection screen 100. The projection screen 100 includes a plurality of functional layers, and one of the functional layers of the projection screen 100 is a coloring layer 23, in which a dye is doped. The coloring layer 23 absorbs ambient light transmitted from the outside to the projection screen 100, and absorbs reflected light reflected by the projection screen 100. Among them, the coloring layer 23 plays the role of absorbing ambient light and improving image contrast. It can be roughly understood that the display effect of the projection screen 100 can be better and less ambient light can be incident on the human eye through the effect of the coloring layer 23. In addition, the coloring layer 23 directly or indirectly affects the optical indicators of the projection screen 100, such as gain and gain ratio.

[0044] In some examples, the film parameters of the coloring layer 23 are maintained within a preset value range, so that the transmittance of the coloring layer 23 is maintained within a target transmittance range. The film parameters include at least the film thickness.

[0045] In some examples, the target transmittance is greater than or equal to 40% and less than or equal to 60%. For example, the transmittance of the colored layer 23 is maintained in a range of greater than or equal to 58% and less than or equal to 60%. The higher the transmittance of the colored layer 23, the more light passes through the colored layer 23 to reach the reflective layer 25 and is reflected by the reflective layer 25, and the brightness of the projection screen 100 is higher.

[0046] Exemplarily, projection screen 100 includes multiple functional layers, including a surface layer 21, a diffusion layer 22, a coloring layer 23, a Fresnel layer 24, and a reflective layer 25, as shown in Figure 2. Surface layer 21 protects projection screen 100 and prevents damage. Diffusion layer 22 increases the viewing angle of projection screen 100, enhances light scattering, and reduces speckle. Fresnel layer 24, the core functional layer of projection screen 100, is used to create Fresnel reflections to reflect ambient light away from the human eye, enhancing the user's viewing experience. Reflective layer 25 increases light reflectivity and utilization.

[0047] Taking the projection screen 100 structure shown in Figure 2 as an example, the light projected by the ultra-short-throw laser projector 200 passes through the surface layer 21, the coloring layer 23, the diffusion layer 22, the Fresnel layer 24 and the reflective layer 25 in sequence. After reaching the reflective layer 25, the light is reflected by the reflective layer 25 and re-emitted from the side where the surface layer 21 is located to the user's human eye perspective.

[0048] FIG3 is a schematic diagram of the structure of a surface layer 21 provided in an embodiment of the present disclosure. The material of the surface layer 21 can be UV adhesive (UV adhesive is a flexible material). As a simple surface layer 21, the surface of the surface layer 21 is flat, and the surface layer 21 can protect the projection screen 100. In other examples, the surface layer 21 can be made of a hard material to form a hard protective layer. For example, the surface layer 21 is made of methyl methacrylate-styrene copolymer (MS).

[0049] FIG4 is a schematic diagram of another surface layer 21 structure provided in an embodiment of the present disclosure. Referring to FIG4 , the surface layer 21 is atomized, and the reflectivity of the light of the atomized surface layer 21 is low. As a result, when the light reaches the surface of the surface layer 21, more light will pass through the surface and enter the interior of the projection screen 100, thereby improving the utilization rate of the light projected by the ultra-short-throw laser projector 200, ensuring the gain of the projection screen 100, and making it difficult for the light projected by the ultra-short-throw laser projector 200 to form a clear image in other places (such as the ceiling), thereby ensuring the user's viewing experience.

[0050] FIG5 is a schematic diagram of another surface layer structure provided by an embodiment of the present disclosure. Referring to FIG5 , a lens (microlens) is provided on the surface layer 21. By providing the microlens, the surface layer 21 is formed into uneven protrusions, thereby increasing the viewing angle of the projection screen 100, while also reducing the surface reflectivity and improving the utilization rate of the light projected by the projector 200. The microlens can be hemispherical in shape.

[0051] Figure 6 is a schematic diagram of another surface layer structure provided in an embodiment of the present disclosure. Referring to Figure 6, the lens set on the surface layer 21 is atomized to form an atomized lens, so as to combine the advantages of the embodiments of Figures 4 and 5 to ensure the gain of the projection screen 100, increase the viewing angle of the projection screen 100, and reduce reflections from other directions (such as the ceiling).

[0052] FIG7 is a schematic diagram of the structure of a Fresnel layer 24 provided in an embodiment of the present disclosure. Referring to FIG7 , the Fresnel layer 24 is used to form Fresnel reflection. When external ambient light passes through the Fresnel layer, it will be reflected to a non-human eye perspective, and the human eye cannot receive the ambient light.

[0053] Figure 8 is a schematic diagram of another Fresnel layer 24 structure provided in an embodiment of the present disclosure. Referring to Figure 8 , microlenses are provided on the surface of the Fresnel layer 24. By providing these microlenses, the viewing angle can be increased and ambient light from a target direction (e.g., the ceiling) can be reduced. It should be noted that in some examples, dyes are added to the microlenses on the surface of the Fresnel layer 24 to form the colored layer 23, thereby reducing the number of functional layers. Because the projection screen 100 has fewer film layers, the thickness of the projection screen 100 is also reduced.

[0054] In some examples, the diffusion layer 22 contains diffusion particles, and the absolute value of the difference in refractive index between the material of the surface layer 21 and the diffusion particles is greater than zero and less than or equal to 0.5. Because light is more likely to refract when passing through two media with different but similar refractive indices, and the higher the refractive index, the higher the proportion of light that is reflected when passing through two media with a large difference in refractive index. Therefore, when light projected by the ultra-short-throw laser projector 200 passes through the diffusion layer 22, the light is diffused due to the difference in refractive index between the diffusion particles in the diffusion layer 22 and the material of the surface layer 21, thereby increasing the viewing angle of the projection screen 100. At the same time, because the absolute value of the difference between the refractive index of the material of the surface layer 21 and the refractive index of the diffusion particles in the diffusion layer 22 is less than or equal to 0.5, i.e., the refractive indices of the two are relatively close, the refractive index of the light projected by the ultra-short-throw laser projector 200 is relatively high. The light is less likely to be reflected and directly exits the projection screen 100 from the surface layer 21. More light can enter the interior of the projection screen 100 and ultimately be reflected into the viewer's eyes, thereby ensuring the gain of the projection screen 100. When the absolute value of the difference between the refractive index of the surface layer 21 and the refractive index of the diffusion particles in the diffusion layer 22 is greater than zero and less than or equal to 0.5, this not only allows light to diffuse, but also increases the transmittance of light passing through the diffusion particles in the diffusion layer 22, thereby improving light utilization and ensuring the gain of the projection screen 100. For example, the absolute value of the difference between the refractive index of the material of the surface layer 21 and the refractive index of the diffusion particles in the diffusion layer 22 can be 0.5, 0.4, 0.3, or 0.2, etc.

[0055] FIG9 is a schematic diagram of the structure of a diffusion layer 22 provided in an embodiment of the present disclosure. Referring to FIG9 , diffusion particles are added to the surface layer 21 to form the diffusion layer 22. Exemplarily, the material of the diffusion particles is silicon dioxide.

[0056] FIG10 is a schematic structural diagram of another diffusion layer 22 provided in an embodiment of the present disclosure. Referring to FIG10 , diffusion particles are added to the Fresnel layer 24 to form the diffusion layer 22 .

[0057] The coloring layer 23 is mixed with dyes. When external ambient light passes through the coloring layer 23 , it can be absorbed by the dyes in the coloring layer 23 , thereby making the projection screen 100 have better resistance to ambient light, that is, the ambient light shielding rate is higher.

[0058] After research, it was found that the film thickness of the coloring layer 23 has a significant impact on the transmittance of the coloring layer 23. The transmittance directly affects the gain and ambient light shielding rate. The higher the transmittance, the more light passes through the coloring layer 23 to the reflective layer 25 and is reflected by the reflective layer 25, and the higher the brightness. The gain is proportional to the brightness and illumination of the diaphragm. Under the same illumination conditions, the higher the transmittance, the higher the brightness of the diaphragm and the higher the gain. The ambient light shielding rate is related to the ability of the layer to absorb ambient light. The more ambient light absorbed, the higher the ambient light shielding rate. The coloring layer 23 is generally made of a mixture of dyes and other materials. The coloring layer 23 can be a separate film layer or the same film layer as other functional layers. The coloring layer 23 mainly relies on the dye in the coloring layer 23 to absorb ambient light. The more dye, the stronger the tinting power, the stronger the light absorption effect, and the higher the ambient light shielding rate.

[0059] Further research revealed that for every 50 μm (unit: micrometer) increase in film thickness, the transmittance of the colored layer 23 decreases by approximately 10%. Figure 11 shows a graph showing the relationship between film thickness and transmittance of the colored layer 23, as provided in an embodiment of the present disclosure. In some examples, the thickness of the colored layer 23 ranges from 10 to 200 μm. The thinner the film thickness, the higher the requirements for the film preparation process, the more difficult it is to control, and the lower the production yield.

[0060] In addition, since the content (or ratio) of the dye in the coloring layer 23 is fixed, an increase in the film thickness of the coloring layer 23 will also lead to an increase in the amount of dye, which in turn leads to an enhanced scattering effect on light, causing the haze of the coloring layer 23 to increase, affecting the viewing effect of the projection screen 100. Generally speaking, the haze of the coloring layer 23 is controlled between 2% and 5%.

[0061] In summary, while the transmittance of the colored layer 23 positively optimizes the gain of the projection screen 100, it also results in a decrease in ambient light shielding, an increase in haze, and increased manufacturing difficulty. By setting a specific film thickness, the transmittance of the colored layer can be maintained between 40% and 60%. It should be noted that the transmittance of the colored layer 23 is affected not only by the film thickness of the colored layer 23 but also by other film parameters. The coordinated effect of the film thickness and other film parameters maintains the transmittance of the colored layer between 40% and 60%.

[0062] In some examples, the coloring layer 23 is formed by mixing a dye and a preset material, and the preset material includes UV glue. That is, the dye and UV glue are mixed according to a first mixing ratio and then applied to the substrate to form the coloring layer 23. At this time, the coloring layer 23 acts as an adhesive layer to adhere the surface layer 21 and the reflective layer 25 together. The coloring layer 23 is applied to the surface of the substrate in a wet film state, and gradually changes from the wet film state to a cured state after coating, and the film thickness also decreases accordingly. Figure 12 is a schematic diagram of the film thickness of the coloring layer 23 in the wet film state provided by an embodiment of the present disclosure, and Figure 13 is a schematic diagram of the film thickness of the coloring layer 23 in the cured state provided by an embodiment of the present disclosure. The film thickness of the coloring layer in the wet film state is H1, and the film thickness of the coloring layer in the cured state is H2. The film thickness H1 of the coloring layer 23 in the wet film state is between 80 and 120 μm, and the film thickness H2 of the coloring layer 23 in the cured state is between 50 and 70 μm. The thickness of the coloring layer 23 directly affects the hardness and rollability of the projection screen 100. A thicker projection screen 100 exhibits higher stiffness and hardness, but lower flexibility. A thinner projection screen 100 exhibits greater flexibility, making it easier to roll and transport, but also prone to deformation. In some examples, to achieve greater flexibility, the thickness of the coloring layer 23 after curing is maintained between 50 and 60 μm. The thickness of the coloring layer 23 after curing is referred to as the thickness of the coloring layer 23.

[0063] Furthermore, for a fixed mass and ratio of dye, the more UV glue used, the greater the dilution effect on the dye and the higher the transmittance. In other words, the higher the first mixing ratio, the higher the transmittance of the coloring layer 23. However, as the transmittance of the coloring layer 23 increases, its ability to absorb ambient light decreases, reducing the ambient light shielding rate. This means that the user can see more ambient light reflected from the projection screen 100, impacting the user experience. Figure 14 shows a graph showing the relationship between the first mixing ratio and the transmittance of the coloring layer 23, as provided in an embodiment of the present disclosure. Generally speaking, a 0.5-fold increase in UV glue increases the transmittance of the coloring layer 23 by 12% to 16% and decreases the ambient light shielding rate by 5% to 8%. In the disclosed embodiment, the first mixing ratio ranges from 150:1 to 170:1. When the first mixing ratio is 150:1, the transmittance of the coloring layer is approximately 45%. In some examples, the first mixing ratio is 150:1, and the film thickness in the wet state is 100 μm, or the film thickness in the cured state is 60 μm. When the thickness of the color layer 23 after curing is maintained between 50 and 60 μm, the first mixing ratio is between 160 and 170:1. In other examples, when the thickness of the color layer 23 is 100 μm, the first mixing ratio is maintained between 170 and 180:1, and when the thickness of the color layer 23 is 200 μm, the first mixing ratio is between 290 and 300:1.

[0064] In some examples, the dye in the coloring layer 23 includes a red dye, a blue dye, and a black dye. The red dye, the blue dye, and the black dye are mixed in a second mixing ratio, wherein the second mixing ratio is a mass ratio of the red dye, the blue dye, and the black dye.

[0065] For example, the evaluation of the gain of the projection screen 100 includes white gain, red gain, green gain, and blue gain. In addition, there is the numerical ratio of the red, green, and blue field gains, called the RGB gain ratio, represented by R:G, R:B, and G:B. The gain ratio affects the hue of the image. The gain ratio is usually adjusted by changing the second mixing ratio. When preparing the coloring layer 23, it is necessary to set a reasonable second mixing ratio to ensure that the RGB gain ratio is within a reasonable range. The dye of the coloring layer 23 is usually composed of black dye, blue dye, and red dye. The black color is usually carbon powder, and the blue and red colors are organic nanoparticles.

[0066] Black dye has a strong light absorption property. When the proportion of black dye is high, the transmittance of the colored layer 23 decreases, reducing the gain value. However, the ambient light shielding rate increases, and the image contrast increases. The proportion of black dye affects red gain, green gain, and blue gain, with the blue gain having the most significant impact, followed by green gain, and the red gain having the least impact. Reducing the proportion of black dye increases the R:G, R:B, and G:B gain ratios, with the R:B ratio increasing most significantly.

[0067] The proportion of blue dye has little effect on the transmittance and ambient light shielding rate of the coloring layer 23, and mainly affects the red gain and blue gain. Under the premise that the proportions of other color dyes remain unchanged, as the proportion of blue dye increases, the red gain gradually decreases and the blue gain gradually increases. For the gain ratio, the R:B, G:B and R:G gain ratios all decrease, with R:B decreasing most significantly, followed by R:G, and G:B the least. Figure 15 is a schematic diagram of the relationship curve between the amount of blue dye and the gain ratio provided in the embodiment of the present disclosure. Among them, the horizontal axis is the amount of blue dye dripped into the coloring layer 23, and each drop of blue dye is about 20 mg. For the coloring layer 23 made of a mixture of UV glue and dye, the mass proportion of blue dye can be between 1‰ and 6‰.

[0068] Generally speaking, the proportion of red dye is the lowest, and the proportion of red dye has a lower impact on transmittance. Under the premise that the proportions of other color dyes remain unchanged, as the proportion of red dye increases, the white gain, green gain, and blue gain all decrease. At the same time, the R:G and R:B gain ratios increase, and the G:B gain ratio slowly decreases. Figure 16 is a schematic diagram of the relationship curve between the amount of red dye and the gain ratio provided in the embodiment of the present disclosure. Among them, the horizontal axis is the amount of red dye dripped into the coloring layer 23, and each drop of red dye is about 18 mg. For the coloring layer 23 made of a mixture of UV glue and dye, the mass proportion of red dye can be between 0.9‰ and 4.5‰.

[0069] After research, it was found that when the ratio range of the second mixing ratio is between 5~8:4~6:1, the RGB gain ratio is optimal.

[0070] In some examples, the coloring layer 23 is made of a mixture of dye and polyethylene terephthalate (PET). For example, the projection screen 100 further includes a substrate layer 26, which is located between the surface layer 21 and the reflective layer 25. The substrate layer 26 can serve as a supporting base for the projection screen 100. In the embodiment of the present disclosure, a dye can also be added to the substrate layer 26 during the preparation process to prepare the coloring layer 23 and the substrate layer 26 as a single film layer, thereby reducing the number of functional layers. Since the projection screen 100 has fewer film layers, the thickness of the projection screen 100 can also be smaller. After the dye is mixed with the PET material, the coloring layer 23 is also made more uniform.

[0071] In some examples, substrate layer 26 is a single layer of PET or a double layer of PET. Using a single layer of PET as substrate layer 26 increases the flexibility of projection screen 100, allows for rollability, and reduces costs. Alternatively, other flexible materials can be used for substrate layer 26, such as thermoplastic polyurethane (TPU), which exhibits elasticity and allows for rollability. Alternatively, PU (polyurethane) can be used. PU exhibits excellent rubber properties and can adapt to bonding substrates with different thermal expansion coefficients, forming a soft-hard transition layer between substrates. This provides strong adhesion and improved integration with other functional layers of the screen. It also provides excellent cushioning and shock absorption, but at a relatively high cost. Alternatively, PVC (polyvinyl chloride) can be used. PVC offers excellent dimensional stability, weather resistance, and low cost, and its hardness can be easily adjusted using plasticizers. Alternatively, PP (polypropylene) can be used. PP is easily dyeable, lightweight, tough, and resistant to both heat and chemicals. Alternatively, PE (polyethylene) is odorless, non-toxic, and offers excellent low-temperature resistance, good chemical stability, resistance to most acids and bases, insoluble in common solvents at room temperature, low water absorption, and excellent electrical insulation. Alternatively, MS is relatively hard and non-curable, but offers excellent flatness. Alternatively, flexible styrenic block copolymers (SBC) are available. SBC is flexible, waterproof, and possesses excellent mechanical properties, with higher tensile strength, tear strength, and ball burst strength than MS. SBC can be freely curled without deformation and is resistant to oxidation, offering excellent water resistance, weathering, chemical resistance, and corrosion resistance. The roughened lower surface of SBC, with its three-dimensional network structure, provides excellent bonding strength with a variety of adhesives and can be blended with materials such as PP (polypropylene), PVC (polyvinyl chloride), and PE (polyethylene) to improve the material's performance and strength.

[0072] In some examples, diffusion particles are added to the substrate layer 26 to form the diffusion layer 22 , such as adding diffusion particles to a single substrate layer, adding diffusion particles to one of a double substrate layer, adding diffusion particles to both layers of a double substrate layer, and so on.

[0073] Figure 17 is a schematic diagram of the structure of a reflective layer 25 provided in an embodiment of the present disclosure. In some examples, a dye is added to the reflective layer 25, so that the colored layer 23 and the reflective layer 25 become a single film layer, thereby improving light utilization and reducing the number of functional layers. Since the projection screen 100 has fewer film layers, the thickness of the projection screen 100 can also be reduced.

[0074] Figure 18 is a schematic diagram of the structure of another reflective layer 25 provided in an embodiment of the present disclosure. In some examples, a powdered aluminum layer is provided on the surface of the reflective layer 25. This layer is finer and less directional. Due to the structure of the reflective layer 25, the light projected by the ultra-short-throw laser projector 200 is mostly reflected directionally out of the projection screen 100, eliminating scattered light reflections. This results in a higher gain for the projection screen 100. The powdered aluminum layer can be prepared using spray printing or vapor deposition techniques.

[0075] FIG19 is a schematic diagram of the structure of another reflective layer 25 provided in an embodiment of the present disclosure. In some examples, a scaly aluminum powder layer is provided on the surface of the reflective layer 25. The scaly aluminum powder layer has larger aluminum powder particles, better adhesion, and is less likely to separate from the reflective layer 25. A spray printing process can be used to prepare the scaly aluminum powder layer.

[0076] In some examples, the reflective material of the reflective layer 25 is silver, or a combination of silver and aluminum, or the like.

[0077] Figure 20 is a schematic diagram of another projection screen structure provided by an embodiment of the present disclosure. Projection screen 100 comprises a surface layer 21, a substrate layer 26, a Fresnel layer 24, and a reflective layer 25, arranged in that order. A dye is added to reflective layer 25 to form a colored layer 23, thereby eliminating one functional layer from the projection screen 100. The advantages of each functional layer have been described in the aforementioned embodiments and will not be further elaborated here.

[0078] Figure 21 is a schematic diagram of another projection screen structure provided by an embodiment of the present disclosure. Projection screen 100 comprises, in order, a surface layer 21, a substrate layer 26, a lens layer 27, an OCA adhesive layer 28, a lens layer 27, a substrate layer 26, a Fresnel layer 24, and a reflective layer 25. A dye is added to reflective layer 25 to form a coloring layer 23, eliminating one functional layer from the projection screen 100. The advantages of each functional layer have been described in the aforementioned embodiments and will not be further elaborated here.

[0079] Figure 22 is a schematic diagram of another projection screen structure provided by an embodiment of the present disclosure. Projection screen 100 comprises, in order, a surface layer 21, a substrate layer 26, an OCA adhesive layer 28, a coloring layer 23, an OCA adhesive layer 28, a substrate layer 26, a Fresnel layer 24, and a reflective layer 25. Coloring layer 23 is a separate functional layer. Surface layer 21 is provided with an atomized lens, and diffusion particles are doped into surface layer 21 to form diffusion layer 22. The advantages of each functional layer have been described in the above embodiments and will not be repeated here.

[0080] The disclosed embodiments do not limit the structure of the Fresnel layer 24. In some examples, as shown in FIG23 , the Fresnel layer 24 comprises a plurality of Fresnel microstructures 241. The Fresnel microstructures 241 are concentrically arranged circular ring-shaped structures. When projection light passes through the Fresnel microstructures 241, the light converges toward the center, resulting in a better viewing experience for the position directly facing the projection screen 100.

[0081] As shown in FIG23 , the individual annular Fresnel microstructures 241 are distributed at different locations on the Fresnel layer 24, and the angle of the inclined surface of the Fresnel microstructures 241 used to reflect light is generally the same at each location. However, the angle of incidence of the projection light projected onto the Fresnel layer 24 varies at different locations. For each Fresnel microstructure 241, only a portion of the projection light is reflected toward the central viewing area, while the majority of the projection light converges onto a larger plane. This results in poor overall convergence of the projection light, and suboptimal image quality.

[0082] As shown in Figure 24, which is a schematic diagram of the optical path of projection light reflected by the Fresnel layer 24, projection light a1 projected onto the central axis of the Fresnel layer 24 can be reflected to the center point O (observation point). However, projection light a2 projected outside the central axis of the Fresnel layer 24 cannot be reflected to the center point after reflection. The reflected light path deviates significantly from the center point O, resulting in a poor light convergence effect.

[0083] For example, as shown in FIG25 , the Fresnel layer 24 is rectangular in shape, and the surface of one side of the Fresnel layer 24 is divided into nine rectangular areas of equal size.

[0084] Next, the center point of each rectangular area is selected as the measurement point to test the angle relationship between the projection light projected by the projector 200 with a projection ratio of 0.25 and an off-axis of 145% onto the above nine points and the light reflected when it is reflected to the center point O (observation point).

[0085] After testing, the relationship between the angles between the actual reflected light after the projection light is projected to the nine points shown in Figure 25 and the angle when it is reflected to the center point O is shown in Table 1.

[0086] Table 1

[0087] As can be seen from Figure 25 and the data in Table 1, the projection light projected onto a point on the central axis of the Fresnel layer 24 can be reflected to the center point O. However, the projection light projected onto other positions outside the central axis of the Fresnel layer 24 deviates from the center point O after reflection, resulting in a poor light convergence effect.

[0088] To improve light convergence, the disclosed embodiments incorporate improvements to the Fresnel layer 24. As shown in Figures 26 and 27 , the projection screen 100 includes a conductive structure 11, a microstructure layer 12, and a conditioning solution 13. These conductive structure 11, microstructure layer 12, and conditioning solution 13 can replace the aforementioned Fresnel layer 24. These conductive structure 11, microstructure layer 12, and conditioning solution 13 can be considered a new type of Fresnel layer 24.

[0089] As shown in Figures 26 and 27, a plurality of microstructure cavities 121 are formed inside the microstructure layer 12, and the adjustment solution 13 is filled in the microstructure cavities 121. The adjustment solution 13 includes a conductive liquid 131 and a reflective liquid 132, which are mutually incompatible. The reflective liquid 132 is used to reflect the projection light.

[0090] Therefore, when the light projected by the projector 200 enters the projection screen 100 and passes through the reflective liquid 132, it is reflected by the reflective liquid 132 and is emitted from the projection screen 100 to the side where the projector 200 is located to the human eye, thereby forming a projection image on the projection screen 100.

[0091] It is understood that in order to achieve a reflective effect, the reflective liquid 132 includes a reflective material. In some examples, the reflective liquid 132 includes aluminum, silver, or a combination of aluminum and silver. Because aluminum and silver have good reflective properties, they can effectively reflect the light projected by the projector 200, ensuring the utilization of the projected light.

[0092] In some examples, as shown in Figures 26 and 27, the conductive structure 11 is used to apply voltage to the regulating solution 13 in the microstructure cavity 121, so that the reflective liquid 132 moves relative to the conductive liquid 131 to adjust the inclination angle and inclination direction of the reflective surface of the reflective liquid 132 relative to the surface of one side of the projection screen 100.

[0093] As shown in Figure 27, Figure 27 is a structural schematic diagram after the conductive structure 11 applies voltage to the regulating solution 13. The relative positions of the reflective liquid 132 and the conductive liquid 131 change under the action of the voltage of the conductive structure 11, thereby causing the relative positions of the reflective liquid 132 and the conductive liquid 131 to change, forming reflective surfaces with different angles.

[0094] In some examples, the conductive structure 11 is used to apply different voltages to the conditioning solution 13 within different microstructure cavities 121, so that different reflective surfaces have different inclination angles and directions relative to a surface on one side of the projection screen, causing portions of projection light projected onto the multiple reflective surfaces to be reflected toward the same observation point. The surface on one side of the projection screen 100 mentioned above refers to the surface of the projection screen 100 on the side closest to or further away from the projector 200.

[0095] Thus, in the projection screen 100 provided by the embodiment of the present disclosure, the conductive structure 11 applies different voltages to the conditioning solution 13 within different microstructure cavities 121, thereby causing the reflective liquid 132 to move relative to the conductive liquid 131 to form reflective surfaces with different inclination angles and directions relative to the surface of one side of the projection screen 100. In this way, the reflective surfaces at various locations on the projection screen 100 can converge portions of the projection light projected onto the reflective surfaces to the same observation point, achieving a better light convergence effect.

[0096] It is understandable that in order to keep the conductive liquid 131 and the reflective liquid 132 relatively fixed in position within the microstructure cavity 121 , the conductive liquid 131 and the reflective liquid 132 may completely fill the microstructure cavity 121 .

[0097] In addition, it is understood that the vertical projection of the observation point on the projection screen 100 can be located at the center of the projection screen 100. In this way, the projection light will converge to a position facing the projection screen 100.

[0098] In some examples, as shown in Figures 26 and 27, the conductive structure 11 includes a first electrode layer 111 and a second electrode layer 112. The first electrode layer 111 is stacked on one side of the microstructure layer 12, and the second electrode layer 112 is stacked on the other side of the microstructure layer 12 away from the first electrode layer 111. The first electrode layer 111 and the second electrode layer 112 each include a plurality of electrodes.

[0099] Thus, different voltages can be applied to the regulating solutions 13 in different microstructure cavities 121 through the multiple electrodes of the first electrode layer 111 and the second electrode layer 112, respectively, so that the reflective liquid 132 in the regulating solution 13 can form reflective surfaces at different angles relative to the conductive liquid 131, so that part of the projection light projected onto different reflective surfaces is partially converged toward the observation point.

[0100] In some examples, the first electrode layer 111 includes multiple electrodes corresponding to the multiple microstructure cavities 121. The second electrode layer 112 includes multiple electrodes corresponding to the multiple microstructure cavities 121. In this way, the first electrode layer 111 and the second electrode layer 112 can independently apply a voltage to each microstructure cavity 121.

[0101] In other examples, the first electrode layer 111 includes multiple electrodes, and each electrode corresponds to multiple microstructure cavities 121. The second electrode layer 112 includes multiple electrodes, and each electrode corresponds to multiple microstructure cavities 121. In this way, each electrode is used to apply a voltage to multiple microstructure cavities 121, which can reduce the number of electrodes.

[0102] In the projection screen 100 provided by the embodiment of the present disclosure, the arrangement of the multiple microstructure cavities 121 formed in the microstructure layer 12 can vary. In some examples, as shown in FIG28 , which is a schematic structural diagram of the microstructure layer 12 provided by the embodiment of the present disclosure, the multiple microstructure cavities 121 are arranged in multiple rows along a first direction X, and each row has multiple microstructure cavities 121 arranged along a second direction Y. The first direction X and the second direction Y are perpendicular to each other, and both the first direction X and the second direction Y are parallel to a surface of one side of the projection screen 100.

[0103] It is understood that the projection screen 100 is generally rectangular in shape. Accordingly, as shown in FIG28 , the microstructure layer 12 is also rectangular in shape. Thus, the first direction X can be the width direction of the microstructure layer 12, and the second direction Y can be the length direction of the microstructure layer 12.

[0104] As shown in Figure 28, part of the microstructure cavity 121 is located outside the central axis of the microstructure layer 12. At this time, the projection light projected into the microstructure cavity 121 located outside the central axis can also be reflected to the observation point, and the light convergence effect is better.

[0105] Through the above arrangement, multiple microstructure cavities 121 are located at different positions of the microstructure layer 12, and part of the projection light projected onto the reflective liquid 132 in the microstructure cavity 121 at each position can be converged to the observation point, ensuring the light convergence effect of the projection screen 100.

[0106] Of course, the multiple microstructure cavities 121 can also be arranged in other ways. For example, in other examples, the multiple microstructure cavities 121 are arranged in a plurality of arcs with a center of a circle, and each arc corresponds to a plurality of microstructure cavities 121. In this case, the multiple microstructure cavities 121 provided in the embodiments of the present disclosure are equivalent to dividing each existing Fresnel microstructure into multiple parts, each part corresponding to a reflective surface with a different tilt direction and tilt angle.

[0107] In this way, the microstructure layer 12 provided by the embodiment of the present disclosure has reflective surfaces with different inclination angles and inclination directions at different positions corresponding to a Fresnel microstructure. When the projection light is projected onto different reflective surfaces, part of the projection light can converge to the observation point, and the light convergence effect is better.

[0108] In some examples, the projection light projected onto the center of the reflective surface formed by the reflective liquid 132 in each microstructure cavity 121 is reflected and converged at the observation point. In this case, the projection light projected onto other positions of the reflective surface is reflected and converged to a position near the observation point, thereby achieving a better light convergence effect.

[0109] Based on the above scheme, when applying voltage to the adjustment solution 13 to form a reflective surface, the inclination angle and inclination direction corresponding to the projection light projected by the projector 200 and reflected to the observation point after passing through the center position of the reflective surface can be calculated first, and then the voltage can be applied to the adjustment solution 13 according to the above inclination angle and inclination direction to obtain the above reflective surface.

[0110] Of course, in other examples, the projection light projected by the projector 200 may also be reflected at other positions of the reflection surface and then converged to the observation point. The specific selection can be made according to actual conditions.

[0111] In some examples, as shown in FIG26 , when the conductive structure 11 does not apply a voltage to the adjustment solution 13 , the conductive liquid 131 may be located on a side of the reflective liquid 132 close to the observation point along the projection direction of the projection light.

[0112] 27 , when the conductive structure 11 applies voltage to the regulating solution 13 , the reflecting liquid 132 moves relative to the conductive liquid 131 , and the reflecting liquid 132 forms a reflecting surface with different tilt directions and angles close to the conductive liquid 131 .

[0113] In some examples, as shown in FIG28 , the shapes of the multiple microstructure cavities 121 can be the same. In this way, when manufacturing the microstructure layer 12 , a mold having a single shape can be used for embossing to form the shape of the microstructure cavities 121 , which can simplify the mold structure and facilitate production.

[0114] For example, when fabricating the microstructure layer 12, the material for fabricating the microstructure layer 12 is first coated on a substrate. A mold with a corresponding microstructure is then used to emboss the surface of one side of the microstructure layer 12 to form the aforementioned microstructure cavities 121. The microstructure cavities 121 are then filled with a conditioning solution 13. Finally, a layer of material is coated on the surface of the side where the microstructure cavities 121 are formed to encapsulate the microstructure cavities 121, thereby completing the fabrication of the microstructure layer 12.

[0115] In some examples, referring to FIG26 , the depth of the microstructure cavity 121 along a direction perpendicular to the surface of one side of the projection screen 100 (i.e., the up-down direction in FIG26 ) is equal to or greater than 3 μm and less than or equal to 100 μm. When the depth of the microstructure cavity 121 is greater than 3 μm, the reflective liquid 132 within the microstructure cavity 121 forms reflective surfaces with varying degrees of inclination under the action of the conductive structure 11. When the thickness of the microstructure cavity 121 is too thin, the angle of the reflective surface that can be formed by the reflective liquid 132 is limited.

[0116] At the same time, since the depth of the microstructure cavity 121 is less than 100 μm, the depth of the microstructure cavity 121 is relatively shallow, thereby making the thickness of the entire microstructure layer 12 relatively thin, thereby meeting the user's thickness requirements for the projection screen 100. It is understandable that when the thickness of the microstructure cavity 121 is thicker, the overall thickness of the projection screen 100 will also increase.

[0117] In some examples, the depth of the microstructure cavity 121 may be 3 μm, 10 μm, 20 μm, 50 μm, or 100 μm.

[0118] In some examples, along the third direction, the size of the microstructure cavity 121 is equal to or greater than 10 μm and less than or equal to 200 μm. The third direction is parallel to the surface of one side of the projection screen 100. In this case, the reflective surface formed by the reflective liquid 132 within a single microstructure cavity 121 can effectively converge light near the observation point, achieving a good convergence effect.

[0119] As can be seen from the above, light reflected from a single point on the reflective surface can converge to the observation point, while light reflected from other locations can converge to a smaller range near the observation point. Thus, when the dimensions of the microstructure cavity 121 along the third direction are larger, the volume of the reflective liquid 132 therein is larger, the area of ​​the reflective surface that can be formed is larger, and the range of light from other locations converging to the observation point is also larger.

[0120] In some examples, the dimension of the microstructure cavity 121 along the third direction may be 10 μm, 50 μm, 100 μm, 150 μm, or 200 μm.

[0121] In some examples, the size of the microstructured cavities 121 along the third direction gradually increases along a direction perpendicular to the surface of one side of the projection screen 100 and close to the observation point. In this way, the volume of the microstructured cavities 121 is relatively small, thereby reducing the amount of the conditioning solution 13 filled in the microstructured cavities 121 and reducing the material consumption of the conditioning solution 13.

[0122] In some examples, the shape of the microstructure cavity 121 is one of a pyramid, a cone, a truncated pyramid, a frustum, and a hemisphere. When the shape of the microstructure cavity 121 is one of the above shapes, the overall shape of the microstructure cavity 121 is relatively simple, and production and manufacturing are more convenient.

[0123] For example, as shown in Figures 26 and 27, the cross-section of the microstructure cavity 121 taken along a plane perpendicular to one surface of the projection screen 100 is triangular. In this case, the microstructure cavity 121 is conical or pyramidal. As shown in Figure 29, which is a schematic diagram of another microstructure cavity 121 provided in an embodiment of the present disclosure, the microstructure cavity 121 is conical.

[0124] When the microstructure cavity 121 is in a pyramidal shape, the microstructure cavity 121 may also have different shapes. As shown in FIG26 , the cross-section of the microstructure cavity 121 taken along a plane parallel to one surface of the projection screen 100 is hexagonal. In this case, the microstructure cavity 121 is a hexagonal pyramid.

[0125] The following provides an exemplary description of the inclination angle and inclination direction of the reflective surface formed by the reflective liquid 132 at various locations in the microstructure layer 12 provided by the embodiments of the present disclosure. As shown in FIG30 , FIG30 is a schematic structural diagram of light projected by a projector 200 when it is reflected from the microstructure layer 12 to an observation point O. The dimensions of the microstructure layer 12 are l*w, the projection ratio of the projector 200 is TR, the off-axis is offset, and the observation point O is positioned relative to the center of the microstructure layer 12 and at a vertical distance of 3*w from the microstructure layer 12.

[0126] Therefore, the horizontal distance D from the projector 200 to the microstructure layer 12 is l*TR, and the vertical distance H from the projector 200 to the microstructure layer 12 is (offset-1)*w / 2. A coordinate system is established with the coordinates of the projector 200 at (0, 0, D), and the coordinates of the observation point O are (0, H+w / 2, 3w).

[0127] The distance between the point with coordinates (x, y, z) on the surface of the microstructure layer 12 and the projector 200 The direction vector of the incident light 201 projected by the projector 200 to the point is Among them, I x =x / L; I y =y / L;I z =(zD) / L.

[0128] As shown in FIG31 , FIG31 is a schematic diagram of the structure when incident light 201 enters the adjustment solution 13. When the incident light 201 reaches the microstructure layer 12, it first enters the interior of the conductive liquid 131, then is reflected by the reflective liquid 132, and finally exits the microstructure layer 12 from the conductive liquid 131. The refractive index of the conductive liquid 131 is n.

[0129] Therefore, the direction vector of the incident light 201 after entering the conductive liquid 131 is Among them, IM x =x / (L*n);IM y =y / (L*n);

[0130] If the reflected light is reflected to the observation point O, the direction vector of the outgoing light is in,

[0131] The direction vector of the emitted light inside the conductive liquid 131 is Among them, RM x =R x / n;RM y =R y / n;

[0132] Therefore, according to as well as The direction vector perpendicular to the reflection surface formed by the reflecting liquid 132 can be calculated. in,

[0133] Thus, the inclination angle and inclination direction of the reflective surface formed by the reflective liquid 132 can be calculated according to S, and then a voltage can be applied to the adjustment solution 13 through the conductive structure 11 to form the reflective surface with the above inclination angle and inclination direction.

[0134] It is understandable that the manner in which the conductive structure 11 applies voltage to the adjustment solution 13 may vary according to actual conditions, as long as different voltages can be applied to different adjustment solutions 13 to form reflective surfaces with different tilt angles and tilt directions.

[0135] Furthermore, it is understood that the projection screen 100 provided by the disclosed embodiment can form a reflective surface with different tilt angles and directions because the conductive structure 11 can apply different voltages to the conditioning solution 13. Thus, for projectors 200 with different throw ratios and off-axis projections, the voltage applied by the conductive structure 11 can be adjusted accordingly to accommodate different types of projectors 200.

[0136] The embodiment of the present disclosure further provides a projection device. As shown in FIG1 and FIG2 , the projection device includes a projector 200 and the projection screen 100 described above.

[0137] In some examples, projector 200 is an ultra-short laser projector.

[0138] In some examples, the projector 200 includes a laser, which is one of a monochromatic laser, a two-color laser, and a three-color laser. The three-color laser emits a blue laser, a red laser, and a green laser. The wavelength of the blue laser emitted by the laser is in the range of 430nm to 460nm, the wavelength of the green laser emitted is in the range of 500nm to 540nm, and the wavelength of the red laser emitted is in the range of 610nm to 650nm. Since the three-color laser has the advantages of color authenticity and a higher color gamut, the laser in the projector 200 provided in the embodiment of the present disclosure can select a three-color laser. Of course, the laser in the projector 200 provided in the embodiment of the present disclosure can also select a monochromatic laser or a two-color laser.

[0139] The above description is merely an exemplary embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A projection screen, characterized in that: The projection screen comprises a conductive structure, a microstructure layer and a conditioning solution; A plurality of microstructure cavities are formed inside the microstructure layer, and the adjustment solution is filled in the plurality of microstructure cavities; The adjustment solution includes a conductive liquid and a reflective liquid, the conductive liquid and the reflective liquid are incompatible with each other, and the reflective liquid is used to reflect the projection light; The conductive structure is used to apply voltage to the adjustment solution in the microstructure cavity, so that the reflective liquid moves relative to the conductive liquid to adjust the inclination angle and inclination direction of the reflective surface of the reflective liquid relative to the surface of one side of the projection screen.

2. The projection screen according to claim 1, characterized in that: The conductive structure is used to apply different voltages to the regulating solutions in different microstructure cavities, so that the different reflecting surfaces have different inclination angles and inclination directions relative to the surface of one side of the projection screen, so that part of the projection light projected onto the multiple reflecting surfaces is reflected to the same observation point.

3. The projection screen according to claim 2, characterized in that: The projection light projected onto the center position of each reflection surface converges toward the observation point after being reflected.

4. The projection screen according to claim 1, characterized in that Along the first direction, the plurality of microstructure cavities are arranged in a plurality of rows, and each row has a plurality of the microstructure cavities arranged along the second direction; The first direction and the second direction are perpendicular to each other, and both the first direction and the second direction are parallel to a surface of one side of the projection screen.

5. The projection screen according to claim 1, characterized in that: Along a direction perpendicular to a surface of one side of the projection screen, a depth of the microstructure cavity is equal to or greater than 3 μm and less than or equal to 100 μm.

6. The projection screen according to claim 1, characterized in that: The size of the microstructure cavity along the third direction is equal to or greater than 10 μm and less than or equal to 200 μm; Wherein, the third direction is parallel to a surface of one side of the projection screen.

7. The projection screen according to claim 1, characterized in that: Along a direction perpendicular to the surface of one side of the projection screen and away from the observation point, the size of the microstructure cavity along the third direction gradually decreases; Wherein, the third direction is parallel to a surface of one side of the projection screen.

8. The projection screen according to any one of claims 1 to 7, characterized in that: The multiple microstructure cavities have the same shape.

9. The projection screen according to any one of claims 1 to 7, characterized in that: The microstructure cavity has a shape of a pyramid, a cone, a prism, a frustum and a hemisphere.

10. The projection screen according to any one of claims 1 to 7, characterized in that: The conductive structure includes a first electrode layer and a second electrode layer; The first electrode layer is stacked on one side of the microstructure layer, and the second electrode layer is stacked on a side of the microstructure layer away from the first electrode layer.

11. The projection screen according to claim 10, characterized in that The first electrode layer and the second electrode layer each include a plurality of electrodes, and the plurality of electrodes are used to apply different voltages to the adjustment solutions in different cavities of the microstructure.

12. The projection screen according to claim 11, characterized in that The plurality of electrodes included in the first electrode layer correspond one-to-one to the plurality of microstructure cavities; The second electrode layer includes a plurality of electrodes corresponding to the plurality of microstructure cavities one by one.

13. The projection screen according to any one of claims 1 to 7, characterized in that: When the conductive structure does not apply a voltage to the adjustment solution, along the projection direction of the projection light, the conductive liquid is located on a side of the reflective liquid close to the observation point.

14. The projection screen according to claim 1, characterized in that The projection screen further comprises a coloring layer, and the coloring layer and the microstructure layer are stacked; The coloring layer is used to absorb ambient light transmitted from the outside to the projection screen, and absorb reflected light reflected by the projection screen, wherein the transmittance of the coloring layer is greater than or equal to 40% and less than or equal to 60%.

15. The projection screen according to claim 14, characterized in that The film thickness of the coloring layer is greater than or equal to 50 μm and less than or equal to 70 μm.

16. The projection screen according to claim 14, characterized in that The coloring layer is converted from a wet film state to a solidified state during the preparation process; The film thickness of the coloring layer in a wet film state is greater than or equal to 80 μm and less than or equal to 120 μm; The film thickness of the coloring layer in a cured state is greater than or equal to 50 μm and less than or equal to 70 μm.

17. The projection screen according to any one of claims 14 to 16, characterized in that: The coloring layer is made by mixing a dye and a preset material, the preset material includes UV glue, and the UV glue and the dye are mixed in a first mixing ratio, wherein the first mixing ratio is a mass ratio between the UV glue and the dye, and the first mixing ratio is greater than or equal to 150:1 and less than or equal to 170:

1.

18. The projection screen according to any one of claims 14 to 16, characterized in that: The coloring layer includes dyes, which include at least red dye, blue dye and black dye. The red dye, the blue dye and the black dye are mixed according to a second mixing ratio, wherein the second mixing ratio is the mass ratio between the red dye, the blue dye and the black dye, and the ratio range of the second mixing ratio is between 5 to 8:4 and 6:

1.

19. The projection screen according to any one of claims 14 to 16, characterized in that: The coloring layer is made by mixing dye and polyethylene terephthalate.

20. A projection device, characterized in that: The projection device comprises a projector and a projection screen according to any one of claims 1-19.

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