Patent ID: 7133212

Claim:
An immersion microscope objective comprising in order from the object plane: a first lens group with a focal length between 2.6-times and 3.1-times the focal length of the objective f and comprising a first lens component and a second lens component, each having a collecting effect, wherein the focal length of the first lens component is between 3-times and 4.5-times the objective focal length and one of the lenses of the first lens component is made of lanthan glass with a refractive index n e >1.72 at a wavelength of 546.07 nm, and wherein a lens of the second lens component is made from a material with a partial dispersion of a first type; a second lens group with a focal length between 8-times and 10.2-times the objective focal length and comprising at least two lenses which are cemented together, one of which is made from a material with a partial dispersion of the first type and has a collecting effect, the other lens being made from a material with a partial dispersion of a second type and having a diverging effect; a third lens group with a focal length whose absolute value is greater than 25-times the objective focal length and comprising at least two lenses which are cemented together, at least one of which is made from a material with a partial dispersion of the first type and has a collecting effect; and a fourth lens group with a focal length greater than 6⅔-times the objective focal length and comprising two meniscus-shaped lenses whose hollow surfaces face one another.