Apochromatic immersion objective
OwnerJörg SPRENGERinventor
Life of this patent
Estimating the term…
Abstract
An apochromatic immersion objective has a plurality of lenses, which form multiple subsystems with a plurality of lens groups. The first subsystem has an opened-up triplet group with a singlet lens and a cemented doublet element. The absolute value of the radius of curvature of the surface of the singlet lens facing the cemented doublet element is greater than the absolute value of the radius of curvature of the surface of the cemented doublet element facing the singlet lens. A plurality of the lenses form cemented elements. A plurality of the cemented elements have lenses made of glasses with a refractive index difference of more than 0.3. At least two cemented elements have converging cemented surfaces.
Claims20
An objective, comprising:
- a plurality of lenses which define multiple subsystems comprising a first subsystem, each subsystem comprising a plurality of lens groups,
- wherein:
- the first subsystem comprises an opened-up triplet group which comprises a singlet lens and a cemented doublet element;
- an absolute value of a radius of curvature of a surface of the singlet lens facing the cemented doublet element is greater than an absolute value of a radius of curvature of a surface of the cemented doublet element facing the singlet lens;
- a plurality of the lenses define cemented elements;
- a plurality of the cemented elements comprise lenses which comprise glasses with a refractive index difference greater than 0.3;
- at least two cemented elements comprise converging cemented surfaces;
- and
- the objective is an apochromatic immersion objective.
Dependencies are inferred from the claim text.