Patent attributes
A condensing optical system, suitable for a scanning confocal optical system (having a composition for scanning a beam spot on a subject surface by swinging a point source of light) and capable of satisfactorily suppressing various aberrations and reducing loss of light quantity, is provided. The condensing optical system, installed in a scanning confocal optical system for obtaining images of a subject surface by scanning a beam emitted from a point source of light by moving the point source which serves as a pinhole for confocal observation, is configured to satisfy the following condition0.1<|m×NA|<0.2where “m” denotes magnification of the condensing optical system and “NA” denotes a numerical aperture of the condensing optical system on its subject surface side.
