/Variable Magnification Optical System, Optical Equipment, And Method For Producing Variable Magnification Optical System
Abstract
A variable magnification optical system comprises, in order from an object side, a first lens group having negative refractive power, a second lens group having positive refractive power, a third lens group and a fourth lens group. Upon varying magnification, respective distances between neighboring lens groups are varied. The first lens group comprises a negative lens at a most object side and a positive lens at a most image side; the second lens group comprises, in order from the object side, a 2a lens group having positive refractive power, a 2b lens group having positive refractive power and a 2c lens group; the 2b lens group comprises a negative lens; and specified conditional expressions are satisfied.
Full Text
What is claimed is:
A variable magnification optical system comprises, in order from an object side, a first lens group having negative refractive power, a second lens group having positive refractive power, a third lens group and a fourth lens group. Upon varying magnification, respective distances between neighboring lens groups are varied. The first lens group comprises a negative lens at a most object side and a positive lens at a most image side; the second lens group comprises, in order from the object side, a 2a lens group having positive refractive power, a 2b lens group having positive refractive power and a 2c lens group; the 2b lens group comprises a negative lens; and specified conditional expressions are satisfied.
Timeline
Filed
06/16/2026Published
10/01/2026Granted
Not AvailableIPC Codes(5)
G02B 15/14:by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
G02B 13/18:with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration
G02B 15/20:having an additional movable lens or lens group for varying the objective focal length