Patent ID: 11960101
Assignee: DAI NIPPON PRINTING CO., LTD.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 6:
7. The optical measurement device according to claim 1, further comprising a mechanism that adjusts at least one of the imaging distance, the focal length of the optical system, and an F-number of the optical system so that the size of the light-emitting region that satisfies equations give below is constant:, [
          
            Math
            .
            
              
            
            ⁢
            2
          
          ]
        
        ⁢
        
          
        
      
    
    
      
        
      
    
  
  
    
      
        S
        =
        
          
            
              
                R
                m
              
              ⁢
              
                M
              
            
            ∝
            
              
                
                  F
                  ⁢
                  
                    #
                    image
                  
                
                m
              
              ⁢
              
                M
              
            
          
          =
          
            
              F
              ⁢
              
                #
                image
              
              ⁢
              
                d
                f
              
              ⁢
              
                M
              
            
            =
            
              F
              ⁢
              
                #
                surface
              
              ⁢
              
                M
              
            
          
        
      
    
    
      
        (
        2
        )
      
    
  
  
    
      
        [
        
          Math
          .
          
            
          
          ⁢
          3
        
        ]
      
    
    
      
        
      
    
  
  
    
      
        M
        =
        
          
            [
            
              
                
                  
                    
                      A
                      c
                    
                    
                      A
                      m
                    
                  
                  ⁢
                  
                    erf
                    ⁡
                    
                      (
                      
                        
                          
                            π
                            ⁢
                            
                              
                            
                            ⁢
                            
                              A
                              m
                            
                          
                          
                            A
                            C
                          
                        
                      
                      )
                    
                  
                
                -
                
                  
                    (
                    
                      
                        A
                        c
                      
                      
                        π
                        ⁢
                        
                          
                        
                        ⁢
                        
                          A
                          m
                        
                      
                    
                    )
                  
                  ⁢
                  
                    {
                    
                      1
                      -
                      
                        exp
                        ⁡
                        
                          (
                          
                            -
                            
                              
                                π
                                ⁢
                                
                                  
                                
                                ⁢
                                
                                  A
                                  m
                                
                              
                              
                                A
                                c
                              
                            
                          
                          )
                        
                      
                    
                    }
                  
                
              
            
            ]
          
          
            -
            2
          
        
      
    
    
      
        (
        3
        )
      
    
  

where,
M is an integral parameter,
S is the size of the light-emitting region,
R is the size of the diffraction limited spot,
m is the magnification of the optical system,
F#image is an F-number of the optical system at an image side,
d is the imaging distance,
f is the focal length of the optical system,
F#surface is an F-number of the optical system at a side facing the measurement surface,
Ac is a size of a coherent region on the two-dimensional sensor array surface,
Am is a size of uniform square detector elements on the two-dimensional sensor array surface, and
erf is a standard error function.