Patent ID: 11963760
Assignee: RICOH COMPANY, LTD.
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 0:
1. A measuring device comprising:
a total internal reflection prism having a total reflection plane that an object to be measured contacts;
a light source configured to emit light to make the light having a wavelength equal to or greater than 7 micrometers (μm) and equal to or less than 12 μm incident on the total reflection plane; and
a sensor configured to detect light intensity of the light reflected by the total reflection plane,
wherein an equation, arc
   ⁢
   
    sin
    ⁡
    (
    
     
      n
      ⁢
      2
     
     
      n
      ⁢
      1
     
    
    )
   
  
  <
  
   θ
   ⁢
   c
  
  <
  
   
    arc
    ⁢
    
     sin
     ⁡
     (
     
      
       n
       ⁢
       2
      
      
       n
       ⁢
       1
      
     
     )
    
   
   +
   
    5.
       
    [
    DEG
    ]
   
  
 

is satisfied, where
n1 denotes a refractive index of a base material of the total internal reflection prism for the light having a wavelength of 10 μm,
n2 denotes a refractive index of the object to be measured for the light having the wavelength of 10 μm and n2 takes a value 1.32 or 1.44, and
θc denotes an incident angle of a center of light flux emitted from the light source.