Photosensitive optical scanning device for meter indicators

Claim 1

AN OPTICAL EXAMINATION DEVICE FOR A METER HAVING A LIGHT FACE AND A PLURALITY OF ANGULARLY ROTATABLE DARK INDICATORS TRAVERSING PREDETERMINED AREAS, SAID INDICATORS OPTICALLY CONTRASTING WITH SAID FACE, SAID EXAMINATION DEVICE INCLUDING A SUBSTANTIALLY LIGHT-TIGHT CASING HAVING AN OPENING ADAPTED TO BE POSITIONED IN CONFRONTING RELATIONSHIP TO THE AREAS OF SAID INDICATORS, AN OPTICAL SYSTEM FOR EACH INDICATOR, EACH OPTICAL SYSTEM INCLUDING A SOURCE OF LIGHT IN SAID CASING, MEANS OPTICALLY ASSOCIATED WITH SAID LIGHT SOURCE TO FORM A SCANNING SPOT OF LIGHT ON ONE OF SAID INDICATOR AREAS AND FOCUSED SUBSTANTIALLY IN THE INDICATOR AREA AND DEFOCUSED AT SAID FACE, MEANS FOR MOVING SAID SPOT OF LIGHT IN AN ORBIT CONCENTRIC WITH SAID MOVABLE INDICATOR, AND PHOTOSENSITIVE MEANS SERVICING MORE THAN ONE INDICATOR AND RESPONDING TO THE TOTAL LIGHT IN SAID LIGHT TIGHT CASING AND POSITIONED TO SENSE THE LIGHT REFLECTED FROM SAID ENTIRE FACE AS SAID SPOT MOVES AND TO EXTRACT POSITIONAL INFORMATION REGARDING SAID INDICATOR BY SENSING THE DECREASE IN TOTAL LIGHT IN SAID CASING AS SAID SPOT SWEEPS ACROSS SAID INDICATOR.