Patent ID: 11914119
Assignee: KONICA MINOLTA, INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 5:
6. The ultraviolet optical system according to claim 1, the ultraviolet optical system including a lens surface closest to an object side having a concave shape on the object side, and the ultraviolet optical system satisfying a following conditional expression (2):, φ2
        >
        WD
      
    
    
      
        (
        2
        )
      
    
  

wherein
φ1=φ2+2WD tan Θ holds
when
WD is a distance from a most-object-side position of a most-object-side lens to a measurement area with respect to an ultraviolet light source,
φ2 is an effective diameter of the measurement area with respect to the ultraviolet light source,
φ1 is an effective diameter of a lens surface positioned closest to an object side in an objective lens group, and
Θ is an angle formed by a principal light ray of a light flux having a maximum measurement angle and an optical axis.