Automatic exposure control for camera

Claim 1

IN A CAMERA HAVING A LENS SYSTEM FOR FOCUSING AN IMAGE OF A VIEWED SCENE ONTO A PHOTOSENSITIVE SURFACE; A PHOTOCELL POSITIONED FOR ENERGIZATION BY SAID SCENE; AN ELECTRIC MEASURING INSTRUMENT HAVING A PIVOTED COIL CONNECTED TO SAID CELL AND ENERGIZED THEREBY TO ASSUME AN ANGULAR POSITION AS A FUNCTION OF THE INTENSITY OF SAID LIGHT; A POINTER DRIVEN BY SAID COIL; AN ACTUATING DEVICE ACCESSIBLE TO THE CAMERA OPERATOR; AT LEAST ONE MOVABLE DIAPHRAGM VANE FORMING AN EXPOSURE APERTURE ALIGNED WITH SAID LENS SYSTEM, THE SIZE OF SAID APERTURE BEING A FUNCTION OF THE POSITION OF SAID VANE; AND SENSING MEANS CONNECTED TO SAID VANE FOR MOVEMENT IN A PREDETERMINED PATH TO SENSE THE POSITION OF SAID POINTER UPON MOVEMENT OF SAID VANE, FOR DETERMINING THE SIZE OF SAID APERTURE; AN ARRANGEMENT FOR POSITIONING SAID VANE, COMPRISING: A FIRST SPRING NORMALLY MAINTAINING SAID ACTUATING DEVICE IN AN INITIAL POSITION AND ADAPTED TO BE OVERCOME BY MANUAL MOVEMENT OF SAID DEVICE AWAY FROM SAID INITIAL POSITION; A SECOND SPRING OPPOSED TO SAID FIRST SPRING AND HAVING A FORCE LIGHTER THAN THE FORCE OF SAID FIRST SPRING, FOR MOVING SAID VANE AND FOR MOVING SAID SENSING MEANS INTO ENGAGEMENT WITH SAID POINTER IN RESPONSE TO MOVEMENT OF SAID ACTUATING DEVICE AWAY FROM SAID INITIAL POSITION; OVERRIDE MEANS ADAPTED FOR MOVEMENT INTO THE PATH OF SAID SENSING MEANS FOR INTERCEPTING SAID SENSING MEANS IRRESPECTIVE OF THE POSITION OF SAID POINTER; AND MANUALLY OPERABLE SELECTING MEANS COUPLED TO SAID OVERRIDE MEANS FOR MOVING THE LATTER INTO SAID PATH.