Focusing apparatus for cameras and the like

Claim 1

IN A PHOTOGRAPHIC CAMERA, IN COMBINATION, AN OBJECTIVE LENS; A FOCUSING ARRANGEMENT FOR SAID OBJECTIVE LENS COMPRISING A PAIR OF PHOTOELECTRIC MEANS EACH INCLUDING A PHOT-SENSITIVE ELEMENT AND ADAPTED TO CREATE ELECTRICAL IMPULSES THE INTENSITY OF WHICH DEPEND ON VARIATION OF THE INTENSITY OF THE LIGHT REACHING THE RESPECTIVE PHOTO-SENSITIVE ELEMENT, THE PHOTO-SENSITIVE ELEMENT OF AT LEAST ONE OF SAID PHOTOELECTRIC MEANS CONSTRUCTED SO AS TO BE ADAPTED TO CAUSE THE RESPECTIVE PHOTOELECTRIC MEANS TO CREATE DIFFERENT ELECTRICAL IMPULSES DEPENDING NOT ONLY ON THE INTENSITY BUT ALSO THE DISTRIBUTION OF LIGHT REACHING SAID PHOTOSENSITIVE ELEMENT, AND MEANS FOR DIRECTING REAL IMAGES OF THE SAME OBJECT ONTO BOTH OF SAID PHOTO-SENSITIVE ELEMENTS, AT LEAST ONE OF SAID MEANS BEING ADJUSTABLE FOR VARYING THE SHARPNESS OF THE IMAGE ON AT LEAST THE PHOTO-SENSITIVE ELEMENT OF SAID ONE PHOTOELECTRIC MEANS SO THAT THE RESPECTIVE PHOTOELECTRIC MEANS CREATES ELECTRICAL IMPULSES WHICH DEPEND IN INTENSITY UPON VARIATIONS OF THE SHARPNESS OF THE IMAGE ON THE RESPECTIVE PHOTO-SENSITIVE ELEMENT; AND FOCUSING MEANS FOR FOCUSING SAID OBJECTIVE LENS AND BEING ACTUATED BY SAID COMBINED ELECTRICAL IMPULSES OF BOTH SAID PHOTOELECTRIC MEANS ONLY WHEN THE VARIATIONS OF ELECTRICAL IMPULSES OF SAID ONE PHOTOELECTRIC MEANS DUE TO VARIATIONS OF DISTRIBUTION OF LIGHT REACHING THE PHOTOSENSITIVE ELEMENT OF SAID ONE PHOTOELECTRIC MEANS DO NOT COINCIDE WITH VARIATIONS OF THE ELECTRICAL IMPULSES OF THE OTHER OF SAID PHOTOELECTRIC MEANS DUE TO VARIATION OF DISTRIBUTION OF LIGHT REACHING THE PHOTO-SENSITIVE ELEMENT OF THE OTHER OF SAID PHOTOELECTRIC MEANS.