Air traffic display system

Claim 1

IN AN AIR TRAFFIC CONTROL ARRANGEMENT HAVING A PLURALITY OF RECEIVING SYSTEMS ARRANGED AT PREDETERMINED POINTS RESPONSIVE TO RADIANT ENERGY TRANSMITTED FROM A CRAFT INDICATIVE OF THE AZIMUTH OF SAID CRAFT, THE COMBINATION COMPRISING MEANS AT EACH POINT FOR RECEIVING SAID RADIANT ENERGY, MEANS COUPLED TO SAID RECEIVER FOR CONVERTING SAID RECEIVED ENERGY INTO A CODE HAVING A PLURALITY OF CODE ELEMENTS, AN INDICATOR SYSTEM COUPLED TO SAID CONVERTING MEANS, SAID INDICATOR SYSTEM COMPRISING A PLURALITY OF CONCENTRICALLY ARRANGED CYLINDERS, THERE BEING ONE CYLINDER PER CODE ELEMENT, EACH OF SAID CYLINDERS HAVING A PREDETERMINED CODE PATTERN OF OPAQUE AND TRANSPARENT ELEMENTS, SAID PATTERN BEING DESIGNED TO PROVIDE A DIFFERENT REGISTRATION OF TRANSPARENT ELEMENTS FOR EACH ANGULAR POSITION OF SAID CRAFT, A SOURCE OF RADIANT ENERGY POSITIONED WITHIN SAID CYLINDERS, MEANS FOR SELECTIVELY AND ANGULARLY DISPLACING SAID CYLINDERS RESPECTIVELY IN ACCORDANCE WITH THE CORRESPONDING CODE ELEMENTS TO A REGISTRATION POSITION OF SAID TRANSPARENT ELEMENTS WHEREBY ENERGY FROM SAID SOURCE WILL BE TRANSMITTED THERETHROUGH IN A DIRECTION CORRESPONDING TO THE ANGULAR POSITION OF SAID CRAFT.