An Automatic Rangefinder and Focus Control System

A method has been developed for automatic focusing. A light source emits a very narrow modulated beam of infrared rays toward the subject on which the lens is to be focused. The radiation diffused by the subject is caught by a receiver that forms an annular image, the axial position of which depends on the distance between the diffusing subject and the lens. That position is detected in the classical way by means of a pair of photoresistors tending to establish a state of mutual balance. The contrivance with the two photoresistors is linked to the focusing device of the lens through a simple cam and lever mechanism.

Print ISSN

0361-4573

Published

1969-01

Content type

Original Research

DOI

10.5594/J06972