Circuit for indicating readable, unreadable or missing characters

Claim 1

A CHARACTER RECOGNITION SYSTEM COMPRISING, A READING MEANS FOR PRODUCING UNIQUE SIGNALS INDICATIVE OF THE CHARACTERS BEING SCANNED, MEANS COUPLED TO SAID READING MEANS FOR UTILIZING SAID UNIQUE SIGNALS TO IDENTIFY THE CHARACTERS BEING SCANNED, SENSING MEANS COUPLED TO SAID LAST NAMED MEANS FOR TESTING FOR THE PRESENCE OR ABSENCE OF A VALID CHARACTER SIGNAL, FIRST GATE MEANS CONNECTED TO SAID SENSING MEANS FOR RECEIVING SIGNALS INDICATIVE OF A VALID CHARACTER, FIRST INDICATOR MEANS CONNECTED TO SAID FIRST GATE MEANS FOR INDICATING THE SCANNING OF A VALID CHARACTER, SECOND GATE MEANS CONNECTED TO SAID SENSING MEANS FOR INDICATING AN INVALID CHARACTER, BISTABLE MEANS COUPLED TO SAID SECOND GATE AND SETTABLE THEREBY, A PAIR OF GATES COUPLED RESPECTIVELY TO THE OUTPUTS OF SAID BISTABLE MEANS, SEPARATE INDICATOR MEANS CONNECTED TO EACH OF SAID PAIR OF GATES TO INDICATE MISSING OR UNREADABLE CHARACTERS RESPECTIVELY, AND MEANS FOR STROBING SAID PAIR OF GATES AND RESETTING SAID BISTABLE MEANS, SAID MEANS FOR STROBING BEING OPERABLE ONLY IN RESPONSE TO A SIGNAL FROM SAID SENSING MEANS INDICATIVE OF THE ABSENCE OF A VALID CHARACTER.