Camera having a focusing device

摘要

A single lens reflex camera including an objective having an optical axis for focusing an image of an object and a device for determining when the objective has properly focused an image at an image plane which is located at a position which is optically equivalent to the location of the film plane, the latter including an image-forming device including a first refracting device for receiving an image from the objective and for providing at least a pair of identical images of the object to be photographed at the image plane, a detecting plane provided along the optical axis having a pair of identical photosensitive detectors, each of which provides an output which varies as the image is moved longitudinally therealong and an image-transmitting device situated at least in part at the image plane which includes a second refracting device for receiving the images from a first refracting device and for participating in the transmission thereof to the detecting plane in a manner according to which the identical images simultaneously move equally in opposite directions along the pair of detectors in response to adjustment of the objective.