OPTICAL SYSTEM WITH VARIABLE FRONT DISTANCE AND FOCAL DISTANCE

摘要

In an optical system of variable focal and back-focal length for operation microscopes, an objective of fixed focal length is combined with an optical system of variable focal length consisting of two lens groups, the first lens group of which is displaceable. The objective projects a real, virtual, or infinity image of the object and the displaceably arranged lens group of the optical system of variable focal length images the image projected by the objective into the focal point of the second lens group of the system. The second lens group consists of two parts which are displaceable in the direction of their optical axis in order to adjust the focal length of the microscope.