Patent ID: 10042152

Abstract:
An immersion microscope objective includes a first lens group having a positive refractive power, a second lens group having a positive refractive power, and a third lens group having a negative refractive power. The first lens group includes a first lens surface and a second lens surface. The first lens surface is positioned nearest to the object side, and the second lens surface is positioned on an image side of the first lens surface and nearest to the first lens surface. The conditional expression −3≤(rG12/f)×(NAob/ndimm)2≤−1.7 is satisfied, in which rG12 denotes a radius of curvature at the second lens surface, f denotes a focal length of an entire system of the immersion microscope objective, NAob denotes an object-side numerical aperture of the immersion microscope objective, and ndimm denotes a refractive index of an immersion liquid for a d-line.