Photocell arrangement in single-lens reflex camera

Claim 1

A LIGHT METER ARRANGEMENT FOR A REFLEX CAMERA HAVING OBJECTIVE LENS MEANS AND FINDER MEANS, SAID LIGHT METER ARRANGEMENT COMPRISING, IN COMBINATION: (A) A LIGHT-SENSITIVE ELEMENT; (B) A FRAME CARRYING A PARTLY REFLECTIVE BEAM DIVIDER MIRROR, SAID FRAME BEING HINGEDLY MOUNTED ON THE CAMERA FOR PIVOTAL MOVEMENT INTO AND OUT OF AN OPERATIVE POSITION IN WHICH SAID BEAM DIVIDER MIRROR LIES IN THE PATH OF THE LIGHT RAYS COMING THROUGH THE OBJECTIVE LENS MEANS AND REFLECTS PART OF SAID LIGHT RAYS TOWARD THE FINDER MEANS; (C) A CONCAVE MIRROR PIVOTALLY MOUNTED ON SAID FRAME; AND (D) MEANS COACTING WITH SAID FRAME AND SAID CONCAVE MIRROR FOR CAUSING SAID CONCAVE MIRROR, WHEN SAID FRAME IS IN SAID OPERATIVE POSITION THEREOF, TO LIE IN THE PATH OF LIGHT RAYS NOT REFLECTED BY SAID BEAM DIVIDER MIRROR AND TO OCCUPY A POSITION IN WHICH SAID CONCAVE MIRROR REFLECTS THE LIGHT RAYS IT RECEIVES ONTO SAID LIGHT-SENSITIVE ELEMENT;