ompos- 
the 
  
he 
on 
Sl, | is named the side slit. 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Fig.17. Width of slit-image 
Fig.16. Plane figure of III- 
type. 
The image of the slit projected on the plane I,namely the point C 
and the slit À S. (because, they are shown in the plane figure) is the 
conjugate each other, and as the distance from the light source-lens to 
the point C is larger than the distance from the lens to the slit, 
the projected image of the slit is magnified by the lens Lg at the 
point C . The magnifying power is ba, : AB is the image of 48, 
me —— 
at C, AB" is the image of 485, 
  
  
  
  
Xe 
c ES | 
after the scanning such as the pivot c I 
0 1s slid from the position C to 
the position/ C'. The angle 
between the lens-axis PC and the 
straight line C'P,is represented 
by 4 , and then the width of the 7 
S 
— Se 
slit image 4 B changes to A'B' si 
2 
  
at thé time that the pivot C ‘is