MICROSCOPE OBJECTIVE HAVING LARGE WORKING DISTANCE

摘要

The invention relates to a microscope objective, in particular for use in microscopic zoom systems, in which an object field which is as large as possible in the minimal zoom position and the use of an aperture which is as large as possible in the maximal zoom position are required with good apochromatic correction and while retaining a large working distance. According to the invention, a microscope objective meeting said requirements consists of three optical members G1, G2 and G3, wherein said members are characterized as follows, proceeding from the objective plane: the first member G1 fulfills the focal length condition f'_Obj f'_G1 3 f'_Obj, the second member G2 fulfills the focal length condition 2.5 * f'_Obj |f'_G2| 8.5 * f'_Obj, and the third member G3 fulfills the focal length condition |f'_G3| 5 * ff'_Obj . According to the invention, the first member G1 first has a positive lens made of a highly refractive material followed by a negative lens having a comparatively lower refractive index.