Parallel system stereoscopic microscope objective lens system, parallel system stereomicroscope

摘要

PROBLEM TO BE SOLVED: To provide an objective lens system for a parallel system stereomicroscope, the lens system which allows realization of excellent focusing performance by suppressing distortion aberration to a degree practically free of problem to secure flatness on an image plane and by appropriately correcting other various aberrations.;SOLUTION: The objective lens system for a parallel system stereomicroscope L_ob comprises: a first lens group G1 including a cemented lens B1 of which the component lenses are lined up in order from the farthest side from an object Ob and which has a negative refractive power, the lens group G1 as a whole having a positive refractive power; a second lens group G2 including a lens having a meniscus shape with the convex surface facing the object side and a negative refractive power, and a cemented lens having a positive refractive power; and a third lens group G3 including at least a single lens having a positive refractive power, and having a positive refractive power as a whole. Where "fB1" is the focal distance of the cemented lens B1 constituting the first lens group G1 and having a negative refraction power and "f" is the focal distance of the objective lens system L_ob as a whole, the condition represented by the formula 1.00(-fB1)/f20.00 is satisfied.;COPYRIGHT: (C)2012,JPO&INPIT