Patent ID: 11892355
Assignee: CENTRE SCIENTIFIQUE ET TECHNIQUE DU BÂTIMENT (CSTB)
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 2:
3. The optical device as claimed in claim 1, wherein the reflective surface of the primary mirror and the reflective surface of the secondary mirror each have a radial profile defined by the equation:, z
      ⁡
      
        (
        r
        )
      
    
    =
    
      
        
          c
          ⁢
          
            r
            2
          
        
        
          1
          +
          
            
              1
              -
              
                
                  (
                  
                    1
                    +
                    k
                  
                  )
                
                ⁢
                
                  c
                  2
                
                ⁢
                
                  r
                  2
                
              
            
          
        
      
      +
      
        
          ∑
          
            i
            =
            1
          
          N
        
        ⁢
        
          
            a
            i
          
          ⁢
          
            ρ
            i
          
        
      
    
  
  ,

where z is the height of the profile as a function of the radial distance r to the center of the mirror, p is the normalized radial coordinate and the coefficients N, c, k, αi are constants.