Three-dimensional display apparatus

Claim 1

A RADAR-OPERATED POSITION INDICATING SYSTEM HAVING, IN COMBINATION, A CATHODE RAY STORAGE TUBE HAVING A STORAGE SCREEN, A WRITING GUN AND A READING GUN, AN ALTITUDE COMPUTER, A RADAR UNIT TO FURNISH SIGNALS TO THE COMPUTER AND RANGE X- AND Y-DEFLECTION SIGNALS TO THE WRITING GUN, SAID SIGNALS CORRESPONDING TO AIRCRAFT POSITIONS, THE COMPUTER HAVING A CIRCUIT TO PRODUCE A SIGNAL CONNECTED TO SAID WRITING GUN TO PRODUCE A CHARGE ON SAID SCREEN WHICH IS VARIABLE IN MAGNITUDE AS A FUNCTION OF THE ALTITUDE OF THE AIRCRAFT, A DISPLAY TUBE HAVING A DISPLAY GUN, A SCREEN OSCILLATING SUBSTANTIALLY IN A DIRECTION NORMAL TO ITS SURFACE AND A Z-PICKUP DEVICE OPERATED BY MOVEMENT OF THE OSCILLATING SCREEN, A SWEEP GENERATOR SYNCHRONOUSLY OPERATING THE SWEEP CIRCUITS OF THE READING AND DISPLAY GUNS, AND A Z-GATE CIRCUIT CONNECTED TO RECEIVE A SIGNAL FROM THE READING GUN CORRESPONDING TO THE AMPLITUDE OF THE CHARGE STORED ON THE STORAGE SCREEN, TO RECEIVE A SIGNAL FROM THE Z-PICKUP DEVICE WHICH VARIES AS A FUNCTION OF THE POSITION OF THE OSCILLATING SCREEN, AND TO GATE THE BEAM OF THE DISPLAY TUBE AT THE MOMENT WHEN THE RECEIVED SIGNALS ARE IN A PREDETERMINED RELATIONSHIP.