Patent ID: 11892766
Assignee: APPOTRONICS CORPORATION LIMITED
Field: Optics (Instruments)
Classification: CPC G  Y | IPC G

Claim 0:
1. A projection screen, comprising:
a microstructure layer comprising a matrix layer and a microstructure unit formed on a surface of the matrix layer,
wherein the microstructure unit comprises triangular pyramid units arranged in an array, wherein each of the triangular pyramid units comprises a light output surface attached to and fixed to the surface of the matrix layer; wherein at least two of the triangular pyramid units that are arranged in a same row are identical to each other; wherein at least two triangular pyramid units of the triangular pyramid units that are arranged in a same column vary gradually; and wherein each of the taper angles forms between a base of one of the at least two triangular pyramid units that has the taper angle and an edge, parallel to a column direction, of the triangular pyramid unit, wherein the base is a surface of the triangular pyramid unit other than the light output surface and two surfaces that intersect to form the edge; and
wherein each of the taper angles of the at least two triangular pyramid units arranged along the column direction satisfy, θ
   =
   
    
     180
     +
     
      arcsin
      ⁢
        
      
       (
       
        
         sin
         ⁢
           
         α
         ⁢
         1
        
        n
       
       )
      
     
     +
     
      arcsin
      ⁢
        
      
       (
       
        
         sin
         ⁢
           
         α
         ⁢
         4
        
        n
       
       )
      
     
    
    2
   
  
  ,
 

where θ denotes the taper angle of one of the at least two triangular pyramid units, α1 denotes an incident angle of image light, α4 denotes an emergent angle of the image light, and n denotes a refractive index of the triangular pyramid unit.