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

Claim 5:
6. The optical measurement device according to claim 1, further comprising a mechanism that adjusts at least one of the imaging distance and the focal length of the optical system so that the size of the light-emitting region that satisfies an equation given below is constant:, [
        
          Math
          .
          
            
          
          ⁢
          1
        
        ]
      
    
    
      
        
      
    
  
  
    
      
        S
        =
        
          
            
              R
              m
            
            ∝
            
              
                F
                ⁢
                
                  #
                  image
                
              
              m
            
          
          =
          
            
              F
              ⁢
              
                #
                image
              
              ⁢
              
                d
                f
              
            
            =
            
              F
              ⁢
              
                #
                surface
              
            
          
        
      
    
    
      
        (
        1
        )
      
    
  

where,
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, and
F#surface is an F-number of the optical system at a side facing the measurement surface.