Evaluation environment
Coaxial tube:  Kohler illumination type    /   Critical illumination type 
Objective lens: PEIR Plan 10X
Camera:BU406M(2048 x 2048, 5um)
Light source: SIS-150-AIR + band pass 1100nm
Inspecting object: Mirror

<Definition of the uniformity>
The average brightness in red square is defined as criteria of 100% uniformity.

 

<Original image /  Kohler illumination type>                                                                                             

 

 

Pixels (2048 ,2048)
Mean of uniformity of 8 blue squares(%)  = 82.20578420281981
Max uniformity of 8 blue squares(%) = 90.36996901226476
Min uniformity of 8 blue squares(%) = 76.87275048736467
Standard deviation= 5.101972294868123

 

 

 

 

<Original image /  Critical illumination type>   

       

Pixels (2048 ,2048)
Mean of uniformity of 8 blue squares(%)  =81.95705301193571
Max uniformity of 8 blue squares(%) = 95.12371239487848
Min uniformity of 8 blue squares(%) =68.47193763278311
Standard deviation=10.292410912360923

 

 

 

 

 

<Gaussian distribution>

This graph shows that the uniformity of Kohler illumination type is so stable comparing Critical illumination type.

 

 

■Kohler illumination type

■Critical illumination type