Patent ID: 9195040
Filing Date: 2015-11-24
Classification: G02B

Abstract:
1. An immersion microscope objective comprising, in order from an object side: 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, wherein: the first lens group includes a cemented lens and at least one positive single lens, and the cemented lens includes a positive lens and a meniscus lens, the second lens group changes a divergent light beam to a convergent light beam, the third lens group includes an object-side lens group and an image-side lens group, in the object-side lens group, a surface nearest to an image side is a concave surface which is directed toward the image side, and in the image-side lens group, a surface nearest to the object side is a concave surface which is directed toward the object side, a plurality of lenses having a positive refractive power are provided, at least one lens having a positive refractive power from among the plurality of lenses having a positive refractive power has a cemented surface which is cemented to a lens having a negative refractive power, and the plurality of lenses having a positive refractive power include a lens which satisfies the following conditional expressions (1) and (2), and the following conditional expression (3) is satisfied: where, n n WD denotes a working distance of the immersion microscope objective, and d