Binocular optical system with automatic focussing

摘要

Binoculars including an automatically focussed optical system in which portions of the two incoming light beams are diverted to an automatic focussing module by two mirrors, one of which is fixed and the other movable. The movable mirror is adjusted until two images on an image screen coincide with one another. The position of the movable mirror is sensed and utilized in a servo control system for positioning the ocular lenses at a focussed position. The distance to the object being viewed is displayed by providing an indicator attached to the ocular lens positioning mechanism.