Optical tracking system

Claim 1

AN ELECTRO-OPTICAL SYSTEM FOR TRACKING A TARGET COMPRISING: A PHOTOSENSITIVE CELL HAVING AN ACTIVE SURFACE THEREON COMPRISING TWO STRAIGHT PHOTOCONDUCTIVE ELEMENTS JOINED END TO END AS LEGS AT RIGHT ANGLES TO EACH OTHER, CIRCUIT MEANS CONNECTING SAID ELEMENTS TO A SOURCE OF POTENTIAL OUTPUT TERMINAL MEANS, CIRCUIT MEANS COUPLING SAID ELEMENTS TO SAID OUTPUT TERMINAL MEANS, AN OPTICAL SYSTEM FOR COLLECTING RADIATION RECEIVED FROM A RADIATING TARGET, CONCENTRATING SAID COLLECTED RADIATION INTO A BEAM, AND DIRECTING SAID BEAM OF RADIATION FROM SAID TARGET TO THE SURFACE OF SAID CELL TO FORM AN IMAGE OF SAID TARGET THEREON AT A POINT DISPLACED FROM THE JUNCTURE OF SAID ELEMENTS, SAID OPTICAL SYSTEM INCLUDING MEANS FOR ROTATING SAID BEAM TO OBTAIN REPEATED INTERSECTIONS OF SAID IMAGE WITH THE LEGS OF SAID CELL TO THEREBY GENERATE AT SAID OUTPUT TERMINAL MEANS A SERIES OF PULSES RELATED IN TIME TO TRACKING ERROR AND TO THE POSITION ANGLE OF SAID BEAM ROTATION MEANS, A TWO-PHASE GENERATOR, MEANS FOR ROTATING SAID GENERATOR IN SYNCHRONISM WITH SAID BEAM ROTATION MEANS AND MEANS COUPLED TO SAID OUTPUT TERMINAL MEANS AND TO SAID TWOPHASE GENERATOR FOR COMBINING SAID PULSES AND THE OUTPUT OF SAID TWO-PHASE GENERATOR TO SECURE TRACKING ERROR SIGNALS.