Patent Publication Number: US-2023161239-A1

Title: Method for manufacturing projection screen and projection screen

Description:
TECHNICAL FIELD 
     The present disclosure relates to a method for manufacturing a projection screen and a projection screen. 
     BACKGROUND 
     Reflective projection screen is a widely used projection screen. In order to eliminate glare, a metal film is usually plated on a surface of the substrate of the conventional projection screen, and a diffusion film is attached to a surface of the metal film, so as to realize the scattering and reflection of incident light. However, in this structure, the angular size of the surface structure of the diffusion film is required to be controlled, and thus the manufacturing process is difficult and costly. 
     SUMMARY 
     To solve the problem that the above manufacturing process of the projection screen is difficult, costly, and is difficult to control the diffusion angle, the present disclosure provides a reflective screen and a manufacturing method thereof, which can be used for movie screens and home screens and have the beneficial effects of simple manufacturing process and low cost. 
     In a first aspect of the present disclosure, a method for manufacturing a projection screen is provided, including:
         step S 1 : preparing a substrate;   step S 2 : under a first preparation condition, forming a reflective layer by vacuum plating above the substrate; and   step S 3 : under a second preparation condition, forming a diffusion layer by the vacuum plating on the reflective layer,   wherein the second preparation condition is different from the first preparation condition, and a sputtering power in the second preparation condition is greater than a sputtering power in the first preparation condition.       

     With the method for manufacturing the projection screen and the structure of the projection screen of the present disclosure, the reflective layer and the diffusion layer are formed of the same material, and integrally form a composite body that can realize a reflective layer having its own concave-convex structure. Accordingly, an additional diffusion film is not required to be attached or formed on the projection screen, a concave-convex structure is not required to be formed on the substrate by sandblasting, etching, etc., and diffusion particles are not required to be doped in the reflective layer. Therefore, the projection screen of the present disclosure has the beneficial effects of simple manufacturing and low cost. 
     In addition, the reflective layer and the diffusion layer of the projection screen of the present disclosure are prepared by the same preparation method, both using vacuum deposition process and the same optical material, which can solve the problem of bonding failure of the diffusion layer and the reflective layer in the prior art due to different materials and different processes thereof. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a side sectional view of a first structure of a projection screen of the present disclosure. 
         FIG.  2    is a side sectional view of a second structure of a projection screen of the present disclosure. 
         FIG.  3    is a surface scanning electron microscope image of a surface of a reflective layer in the projection screen shown in  FIG.  2   . 
         FIG.  4    is a surface scanning electron microscope image of a rough structure on the reflective layer in the projection screen shown in  FIG.  2   . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     There is a structure of a projection screen in the prior art, in which a concave-convex structure is provided on the surface of the substrate, and a reflective layer is plated on a surface of the concave-convex structure, so that the reflected light is scattered. However, the process for manufacturing the concave-convex structure is costly and difficult in this technique. 
     In addition, there is a structure of a projection screen in the prior art, in which a sawtooth microstructure is provided on the surface of the substrate, and a reflective layer and a diffusion layer for reflection and diffusion are formed on the sawtooth microstructure layer. The existing manufacturing method firstly forms a rough surface on the sawtooth micro diffusion layer by etching and sandblasting, i.e., a diffusion layer, and then forms a reflective layer by spray coating, such that the projection light will diffuse at a small angle after passing through the reflective layer. However, the disadvantage of this manufacturing method is in that the sawtooth microstructure layer is easily damaged when forming the rough surface by etching and sandblasting, which greatly reduces the uniformity of the emitted projection light. 
     Another type of projection screen with diffusion forms a reflective layer on the substrate by spray coating and forms an uneven diffusion layer on the reflective layer. However, since the diffusion layer and the reflective layer are made of different materials and formed by different processes, bonding failure of the reflective layer and the diffusion layer is prone to occur, reducing the reliability of the projection screen. 
     Hereinafter, specific embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be emphasized that all the dimensions in the drawings are merely schematic and are not necessarily illustrated in true scale, so they are not restrictive. For example, it should be understood that parameters such as dimensions and proportions of the substrate, reflective layer, diffusion layer and other components in the figures are not shown in accordance with the actual sizes and proportions, but are only for the convenience of illustration and do not intend to limit the specific scope of the present disclosure. 
     &lt;Manufacturing Method of a Projection Screen of the Present Disclosure&gt; 
     Here, the manufacturing method of the projection screen having a first structure as shown in  FIG.  1    will be described. 
     (1) A substrate is prepared. 
     (2) With a low sputtering power of 50 W-150 W, a low pressure of 0.3 Pa-1.3 Pa, and a sputtering temperature that is between room temperature to 100° C., a reflective layer  102  is plated on the substrate  101 . The thickness of the reflective layer  102  is 10 nm-100 nm. 
     (3) With a high sputtering power of 100 W-250 W, a high pressure of 1 Pa-3 Pa, and a sputtering temperature of 80° C.-300° C., a material for forming the reflective layer  102  is grown on a surface of the reflective layer  102  to form a diffusion layer  103 . 
     It should be noted that the room temperature in the above manufacturing method refers to the indoor ambient temperature, at which the vacuum plating process is performed. The indoor ambient temperature is defined to be 20° C.-30° C. under the normal circumstance. 
     The above preparation conditions for forming the reflective layer  102  and the diffusion layer  103  are only exemplary, and do not intend to limit the present disclosure thereto. It should be noted that the emphases in the present disclosure are to firstly form the reflective layer under a first preparation condition, and then form the diffusion layer  103  with the same material as the reflective layer under a second preparation condition different from the first preparation condition. In this case, the sputtering power in the second preparation condition is greater than the sputtering power in the first preparation condition. 
     Based on this, those skilled in the art can adopt different preparation conditions as requirements, rather than being limited to the specific data range described above in the present disclosure. 
     &lt;A First Structure of a Projection Screen of the Present Disclosure&gt; 
       FIG.  1    is a side sectional view of the first structure of the projection screen of the present disclosure. As shown in  FIG.  1   , the projection screen includes a substrate  101 , a reflective layer  102 , and a diffusion layer  103 . The reflective layer  102  is a flat film layer and formed on the substrate  101 . The diffusion layer  103  is formed on the flat reflective layer  102 , and is formed of the same material as the reflective layer  102 . 
     The substrate  101  may be a flexible substrate such as PET, PC, and PVC, or a rigid substrate such as acrylic and glass. 
     The diffusion layer  103  is a rough structure having island-shaped structures, and the size of each of the island-shaped structures and the spacing between two adjacent ones of the island-shaped structures may be achieved by controlling different parameters in the magnetron sputtering process. The size and spacing of the island-shaped structures on the diffusion layer  103  are controlled based on different process parameters, so that the diffusion angle is capable of being easily controlled. 
     Since the diffusion layer  103  and the reflective layer  102  are formed of the same material, in the structure of the projection screen shown in  FIG.  1   , the diffusion layer  103  and the reflective layer  102  are integrally formed without interface therebetween and can be regarded as one layer. The reflective layer and the diffusion layer of the projection screen of the present disclosure are prepared by the same preparation method, both adopting the magnetron sputtering process and the same optical material, which solves the problem of bonding failure of the diffusion layer and the reflective layer in the prior art due to the different materials and different processes thereof 
     &lt;A Second Structure of a Projection Screen of the Present Disclosure&gt; 
       FIG.  2    is a side sectional view of the second structure of the projection screen of the present disclosure. As shown in  FIG.  2   , the projection screen includes a substrate  201 , a microstructure  202 , a reflective layer  203 , and a diffusion layer  204 . The microstructure  202  is formed on the substrate  201 , the reflective layer  203  is formed on the microstructure  202 , and the diffusion layer  204  is formed on the reflective layer  203  and is formed of the same material as the reflective layer  203 . 
     The substrate  201  may be a flexible substrate such as PET, PC, and PVC, or a rigid substrate such as acrylic and glass. 
     The microstructure  202  may be formed of a photocurable resin or a thermal-curable resin. 
     The reflective layer  203  may adopt highly reflective materials such as silver, aluminum, or chromium, and may also adopt a reflective material with a reflection spectrum that meets the requirements. 
     The diffusion layer  204  is formed to have a rough structure of island-shaped structures, and the size of each of the island-shaped structures and the spacing between two adjacent ones of the island-shaped structures can be achieved by controlling different parameters in the magnetron sputtering process. The size and spacing of the island-shaped structures on the diffusion layer  303  are controlled based on different process parameters, so that the diffusion angle is capable of being easily controlled. 
     Since the diffusion layer  204  and the reflective layer  203  are formed of the same material, in the structure of the projection screen shown in  FIG.  2   , the diffusion layer  204  and the reflective layer  203  are integrally formed without interface therebetween, and can be regarded as one layer. The reflective layer and the diffusion layer of the projection screen of the present disclosure are prepared by the same preparation method, both adopting the magnetron sputtering process and the same optical material, which solves the problem of bonding failure of the diffusion layer and the reflective layer in the prior art due to the different materials and different processes thereof 
     &lt;Manufacturing Method of the Second Structure&gt; 
     Hereinafter, a manufacturing method of the projection screen with the second structure as shown in  FIG.  2    will be described. 
     The manufacturing method of the second structure is different from the manufacturing method of the first structure in that the second structure has the reflective layer and the diffusion layer formed on the linear prism microstructure  202 , that is, the substrate structures of the first and second structures are different from each other. 
     (1) A photocurable resin or thermal-curable resin is coated and imprinted on the substrate  201  to form the microstructure  202 . The microstructure  202  is formed by a plurality of linear prism structures, and each linear prism structure is composed of a first surface and a second surface. 
     (2) The reflective layer  203  with a uniform thickness is plated on the microstructure  202  by vacuum plating under a first preparation condition. The thickness of the reflective layer  203  is 20 nm-200 nm. In some embodiments, the thickness of the reflective layer  203  is 40 nm-100 nm. The vacuum plating is, for example, magnetron sputtering, thermal evaporation, electron beam evaporation, or the like. 
     In this embodiment, the first preparation condition is specifically shown in Table 1. 
     
       
         
           
               
               
               
             
               
                   
                   
               
             
            
               
                   
                 Sputtering target 
                 Metal Al (purity: 99.99%) 
               
               
                   
                 Substrate material 
                 PET 
               
               
                   
                 Substrate temperature 
                 Room temperature 
               
               
                   
                 Distance from target to substrate 
                 120 mm 
               
               
                   
                 Working gas 
                 Ar (purity: 99.999%) 
               
               
                   
                 Gas flow rate 
                   30 sccm 
               
               
                   
                 Base vacuum degree 
                 5-10 Pa 
               
               
                   
                 Deposition vacuum degree 
                  0.6 Pa 
               
               
                   
                 Sputtering power 
                   80 W 
               
               
                   
                 Sputtering time 
                    3 min 
               
               
                   
                   
               
            
           
         
       
     
     As shown in the surface scanning electron microscope image in  FIG.  3   , the reflective layer  203  formed on the first surface and the second surface of the microstructure  202  is a flat and dense aluminum film. 
     Therefore, the reflective layer  203  is also formed in a shape of a microstructure that is formed by a plurality of linear prism structures. 
     (3) Under a second preparation condition, the material for forming the reflective layer  203  is grown on the reflective layer  203  by magnetron sputtering to form the diffusion layer  204 . 
     In this embodiment, the second preparation condition is shown in Table 2. 
     
       
         
           
               
               
               
             
               
                   
                   
               
             
            
               
                   
                 Sputtering target 
                 Metal Al (purity: 99.99%) 
               
               
                   
                 Substrate material 
                 PET 
               
               
                   
                 Substrate temperature 
                 100° C. 
               
               
                   
                 Distance from target to substrate 
                 120 mm 
               
               
                   
                 Working gas 
                 Ar (purity: 99.999%) 
               
               
                   
                 Gas flow rate 
                  50 sccm 
               
               
                   
                 Base vacuum degree 
                 5-10 Pa 
               
               
                   
                 Deposition vacuum degree 
                  1.6 Pa 
               
               
                   
                 Sputtering power 
                 200 W 
               
               
                   
                 Sputtering time 
                  3 min 
               
               
                   
                   
               
            
           
         
       
     
     It should be noted that the room temperature in the above manufacturing method refers to the indoor ambient temperature, at which the vacuum plating is performed. The indoor ambient temperature is defined to be 20-30° C. under the normal circumstance. 
     As shown in the surface scanning electron microscope image in  FIG.  4   , the diffusion layer  204  is a rough structure having island-shaped structures, and the size of each of the island-shaped structures and the spacing between two adjacent ones of the island-shaped structures can be achieved by controlling different parameters in the magnetron sputtering process. The size and spacing of the island-shaped structures in the diffusion layer  204  are controlled based on different process parameters, so that the diffusion angle is capable of being easily controlled. 
     In addition, the substantial structure of the diffusion layer  204  is also formed in a shape of a microstructure that is formed by a plurality of linear prism structures, and each prism structure is also composed of two surfaces. 
     In the structure of  FIG.  2   , a light-absorbing layer  205  is formed on the diffusion layer  204  substantially having a microstructure above the first surface of the microstructure  202 . However, in the projection screen of the present disclosure, the light-absorbing layer is not essential. Therefore, the projection screen of the present disclosure may not include a light-absorbing layer. It can be understood that, in other embodiments, the light-absorbing layer  205  may also be disposed on the second surface of the microstructure. 
     The above preparation conditions for forming the reflective layer  203  and the diffusion layer  204  are only exemplary, and do not intend to limit the present disclosure thereto. It should be noted that the emphases in the present disclosure are to firstly form the reflective layer  203  with a uniform thickness on the microstructure under the first preparation condition, and then form the diffusion layer  204  with the same material as the reflective layer under the second preparation condition that is different from the first preparation condition. In this way, the sputtering power in the second preparation condition is greater than the sputtering power in the first preparation condition. 
     Based on this, those skilled in the art can adopt different preparation conditions as requirements, rather than being limited to the specific data range described above in the present disclosure. 
     According to the above projection screen structure and the manufacturing method thereof of the present disclosure, the reflective layer and the diffusion layer are formed of the same material and are integrally formed as a composite body that can realize the reflective layer having its own concave-convex structure. Accordingly, an additional diffusion film is not required to be attached or formed on the projection screen, a concave-convex structure is not required to be formed on the substrate by sandblasting, etching, etc., and diffusion particles are not required to be doped in the reflective layer. Therefore, the projection screen of the present disclosure has the beneficial effects of simple manufacturing and low cost. 
     In addition, the reflective layer and the diffusion layer in the projection screen of the present disclosure are prepared by the same preparation method, both adopting the magnetron sputtering process and the same optical material, which solves the problem of bonding failure of the diffusion layer and the reflective layer in the prior art due to the different materials and different processes thereof. 
     Those skilled in the art should understand that various modifications, combinations, sub-combinations and changes may be made within the scope of the appended claims of the present disclosure or their equivalents according to design requirements and other factors.