Camera battery test indicator

Claim 1

IN A PHOTOGRAPHIC CAMERA HAVING A SOURCE OF ELECTRIC POTENTIAL, THE COMBINATION COMPRISING: AN ELECTRIC MEASURING INSTRUMENT HAVING A COIL, A MEMBER DEFLECTABLE IN TWO OPPOSITE DIRECTIONS FROM A PREDETERMINED REFERENCE POSITION, AND FIRST SPRING MEANS FOR RESILIENTLY RESISTING DEFLECTION OF SAID MEMBER IN ONE OF SAID DIRECTIONS FROM SAID REFERENCE POSITION; CLOSED CIRCUIT MEANS INDEPENDENT OF SAID POTENTIAL SOURCE AND INCLUDING SAID COIL AND A PHOTORESPONSIVE ELEMENT ILLUMINATABLE BY SCENE LIGHT FOR NORMALLY CAUSING CURRENT TO FLOW THROUGH SAID COIL IN SUCH SENSE AS TO CAUSE DEFLECTION OF SAID MEMBER IN SAID ONE DIRECTION, AGAINST THE RESISTANCE OF SAID FIRST SPRING MEANS, AND IN ACCORDANCE WITH THE DEGREE OF ILLUMINATION ON SAID PHOTORESPONSIVE ELEMENT; MEANS INCLUDING A MANUALLY ACTUATED SWITCH OPERABLE WHEN SAID SWITCH IS ACTUATED, TO CONNECTED SAID SOURCE OF ELECTRIC POTENTIAL IN CIRCUIT WITH SAID COIL, WITHOUT OPENING SAID CLOSED CIRCUIT, SO AS TO BUCK AND OVERCOME THE NORMAL CURRENT FLOW THERETHROUGH PRODUCED BY SAID FIRST CLOSED CIRCUIT AND TO PRODUCE A RESULTANT CURRENT FLOW THROUGH SAID COIL IN THE OPPOSITE SENSE WHEREBY TO CAUSE DEFLECTION OF SAID MEMBER IN THE OTHER DIRECTION FROM SAID REFERENCE POSITION; AND SECOND SPRING MEANS, STRONGER THAN SAID FIRST SPRING MEANS, FOR RESISTING SUCH DEFLECTION OF SAID MEMBER IN SAID OTHER DIRECTION FROM SAID REFERENCE POSITION.