Character selection device

Claim 1

IN A CHARACTER RECOGNITION SYSTEM FOR RECOGNIZING INDIVIDUAL ONES OF A GROUP OF CHARACTERS OF SELECTED CONFIGURATIONS; A GROUP OF POSITIVE PATTERN AREAS EACH TRANSPARENT EXCEPT FOR AN OPAQUE PATTERN OF A DIFFERENT ONE OF SAID CHARACTERS; A GROUP OF NEGATIVE PATTERN AREA EACH OPAQUE EXCEPT FOR A TRANSPARENT PATTERN OF A DIFFERENT ONE OF SAID CHARACTERS; A MESSAGE-BEARING MEDIUM HAVING THEREON CHARACTERS TO BE RECOGNIZED, SAID CHARACTERS HAVING SUBSTANTIALLY DIFFERENT LIGHT TRANSMISSIVE PROPERTIES THAN THE REMAINDER OF SAID MEDIUM; A READING STATION; A LIGHT SOURCE; A FIRST LENS SYSTEM COMPRISING A DIFFERENT LENS AREA FOR EACH PATTERN AREA OF EACH THE POSITIVE AND NEGATIVE GROUPS; SAID LIGHT SOURCE, READING STATION, MESSAGE-BEARING MEDIUM, FIRST LENS SYSTEM, AND SAID POSITIVE AND NEGATIVE PATTERN GROUPS BEING SO POSITIONED THAT LIGHT RAYS FROM SAID SOURCE PASS THROUGH SAID MESSAGE-BEARING MEDIUM AT SAID READING STATION AND ARE FOCUSED BY SAID FIRST LENS SYSTEM AS AN IMAGE ON EACH OF THE PATTERN AREAS OF BOTH SAID POSITIVE AND NEGATIVE PATTERN GROUPS, SAID IMAGE BEING IN THE SAME PHASE ON BOTH THE POSITIVE AND NEGATIVE PATTERN GROUPS; A SECOND LENS SYSTEM COMPRISING A DIFFERENT LENS AREA FOR EACH PATTERN AREA OF EACH THE POSITIVE AND NEGATIVE GROUPS; A PLURALITY OF PAIRS OF PHOTOCONDUCTIVE DEVICES THE RESISTANCE OF WHICH VARIES AS A FUNCTION OF THE LIGHT IMPRESSED THEREON FOR DEVELOPING ELECTRICAL SIGALS CORRESPONDING TO LIGHT INFORMATION RECEIVED, THERE BEING A DIFFERENT PAIR OF SUCH DEVICES FOR EACH DIFFERENT CHARACTER IN THE GROUP, SAID SECOND LENS SYSTEM AND SAID PAIRS OF PHOTO-CONDUCTIVE DEVICES BEING SO POSITIONED THAT LIGHT RAYS PASSING THROUGH EACH DIFFERENT PATTERN AREA OF BOTH SAID POSITIVE AND NEGATIVE PATTERN GROUPS ARE FOCUSED ON A DIFFERENT ONE OF SAID PHOTO-CONDUCTIVE DEVICES WITH THE LIGHT RAYS WHICH PASS THROUGH THE NEGATIVE AND POSITIVE PATTERN AREAS OF A PARTICULAR CHARACTER BEING FOCUSED SEPARATELY ON ONE AND THE OTHER DEVICE RESPECTIVELY OF A PAIR OF PHOTO-CONDUCTIVE DEVICES; MEANS CONNECTING EACH PAIR OF PHOTO-CONDUCTIVE DEVICES IN SERIES ACROSS A SOURCE OF D.-C. VOLTAGE; ELECTRONIC SWITCHING MEANS HAVING INPUT ELEMENTS AND HAVING CONDUCTIVE AND NON-CONDUCTIVE STATES AS DETERMINED BY THE VOLTAGE APPLIED ACROSS ITS INPUT ELEMENTS; MEANS CONNECTING SAID ONE OF THE PHOTO-CONDUCTIVE DEVICES OF A SERIES PAIR ACROSS SAID INPUT ELEMENTS, SAID SWITCHING MEANS BEING NORMALLY SO BIASED THAT SAID SWITCHING MEANS REMAINS IN THE SAME ONE STATE AND IS ADAPTED TO BE CHANGED TO ITS OTHER STATE ONLY IN RESPONSE TO SUCH A CHANGE IN VOLTAGE ACROSS ITS INPUT TERMINALS AS RESULTS WHEN THE RESISTANCES OF BOTH OF SAID PHOTO-CONDUCTIVE DEVICES OF THE SERIES PAIR CHANGE CONCURRENTLY IN SUCH DIRECTIONS AND TO SUCH EXTENTS THAT THE RESISTANCE OF ONE OF THE DEVICES OF THE PAIR REACHES A MAXIMUM OPERATING VALUE AND THE RESISTANCE OF THE OTHER DEVICE OF THE PAIR REACHES A MINIMUM OPERATING VALUE; AND MEANS FOR DERIVING A CHARACTER-RECOGNITION OUTPUT SIGNAL FROM SAID ELECTRONIC SWITCHING DEVICE WHEN IT CHANGES TO ITS OTHER STATE.