Photosensitive line tracing apparatus

Claim 1

A SYSTEM FOR TRACING A PATTERN LINE COMPRISING A ROTATABLE SENSING HEAD HAVING A FRONT-TO-BACK AXIS, SAID SENSING HEAD COMPRISING PHOTOSENSITIVE MEANS HAVING A PLURALITY OF SENSITIVE AREAS, MEANS PROJECTING AN IMAGE OF A DIFFERENT SEGMENT OF THE PATTERN LINE UPON EACH OF THE SENSITIVE AREAS, MEANS FOR SIMULTANEOUSLY MODULATING SAID IMAGES CAST ON SAID SENSITIVE AREAS AT A PREDETERMINED FREQUENCY TO PRODUCE FLUCTUATING OUTPUT SIGNALS THEREFROM, MEANS FOR ROTATING SAID SENSING HEAD WITH RESPECT TO SAID PATTERN LINE, COORDINATE DRIVE MEANS FOR TRANSLATING SAID SENSING HEAD WITH RESPECT TO SAID PATTEN LINE, A RESOLVER FOR ENERGIZING SAID COORDINATE DRIVE MEANS, MEANS PROVIDING A FIRST DRIVE SIGNAL OF SAID PREDETERMINED FREQUENCY AND PHASE CONNECTED TO SAID RESOLVER FOR ENERGIZING SAID COORDINATE DRIVE MEANS TO DRIVE SAID SENSING HEAD IN A FORWARD DIRECTION AT A CONSTANT SPEED, MEANS FOR PRODUCING A SIGNAL PROPORTIONAL TO THE ALGEBRAIC SUM OF SAID FLUCTUATING OUTPUTS, MEANS FOR PRODUCING A SIGNAL PROPORTIONAL TO THE ALGEBRAIC DIFFERENCE OF SAID FLUCTUATING OUTPUTS WHEREBY THE PREDETERMINED FREQUENCY COMPONENTS OF ONE OF SAID SUM AND DIFFERNCE SIGNALS IS INDICATIVE OF THE ANGULAR DISPLACEMENT OF THE FRONT-TO-BACK AXIS OF THE SENSING HEAD FROM THE PATTERN LINE AND THE OTHER OF SAID SUM AND DIFFERENCE SIGNALS IS INDICATIVE OF THE TRANSVERSE DISPLCEMENT, MEANS RESPONSIVE TO ONE OF SAID SUM AND DIFFERNCE SIGNALS FOR ENERGIZING SAID ROTATING MEANS TO ANGULARLY ALIGNT SAID FRONT-TO-BCAK AXIS WITH THE SEGMENTS OF THE LINE BEING SENSED, AND MEANS RESPONSIVE TO THE OTHER OF SAID SUM AND DIFFERNCE SIGNALS FOR PROVIDING A POSITIONAL SIGNAL TO SAID RESOLVER TO POSITIONALLY ALIGN SAID FRONT-TO-BACK AXIS WITH RESPECT TO THE SEGMENTS OF THE LINE BEING SENSED.

Claim 2

A SYSTEM FOR TRACING A PATTERN LINE COMPRISING A ROTATABLE SENSING HEAD HAVING A FRONT-TO-BACK AXIS, SAID SENSING HEAD COMPRISING PHOTOSENSITIVE MEANS HAVING A PLURALITY OF SENSITIVE AREAS, MEANS PROJECTING AN IMAGE OF A DIFFERENT SEGMENT OF THE PATTERN LINE UPON EACH OF THE SENSITIVE AREAS, MEANS FOR SIMULTANEOUSLY MODULATING SAID IMAGES CAST ON SAID SENSITIVE AREAS AT A PREDETERMINED FREQUENCY TO PRODUCE FLUCTUATING OUTPUT SIGNALS THEREFROM, MEANS FOR ROTATING SAID SENSING HEAD WITH RESPECT TO SAID PATTERN LINE, COORDINATE DRIVE MEANS FOR TRANSLATING SAID SENSING HEAD WITH RESPECT TO SAID PATTEN LINE, A RESOLVER FOR ENERGIZING SAID COORDINATE DRIVE MEANS, MEANS PROVIDING A FIRST DRIVE SIGNAL OF SAID PREDETERMINED FREQUENCY AND PHASE CONNECTED TO SAID RESOLVER FOR ENERGIZING SAID COORDINATE DRIVE MEANS TO DRIVE SAID SENSING HEAD IN A FORWARD DIRECTION AT A CONSTANT SPEED, MEANS FOR PRODUCING A SIGNAL PROPORTIONAL TO THE ALGEBRAIC SUM OF SAID FLUCTUATING OUTPUTS, MEANS FOR PRODUCING A SIGNAL PROPORTIONAL TO THE ALGEBRAIC DIFFERENCE OF SAID FLUCTUATING OUTPUTS WHEREBY THE PREDETERMINED FREQUENCY COMPONENTS OF ONE OF SAID SUM AND DIFFERNCE SIGNALS IS INDICATIVE OF THE ANGULAR DISPLACEMENT OF THE FRONT-TO-BACK AXIS OF THE SENSING HEAD FROM THE PATTERN LINE AND THE OTHER OF SAID SUM AND DIFFERENCE SIGNALS IS INDICATIVE OF THE TRANSVERSE DISPLCEMENT, MEANS RESPONSIVE TO ONE OF SAID SUM AND DIFFERNCE SIGNALS FOR ENERGIZING SAID ROTATING MEANS TO ANGULARLY ALIGNT SAID FRONT-TO-BCAK AXIS WITH THE SEGMENTS OF THE LINE BEING SENSED, AND MEANS RESPONSIVE TO THE OTHER OF SAID SUM AND DIFFERNCE SIGNALS FOR PROVIDING A POSITIONAL SIGNAL TO SAID RESOLVER TO POSITIONALLY ALIGN SAID FRONT-TO-BACK AXIS WITH RESPECT TO THE SEGMENTS OF THE LINE BEING SENSED.