Apparatus for plotting contour maps automatically employing a cathode ray tube

Claim 1

IN AN AUTOMATIC CONTOUR PLOTTER AN ARRANGEMENT COMPRISING A CATHODE RAY TUBE HAVING A PHOSPHOR SCREEN, MEANS FOR PROJECTING A BEAM OF ELECTRONS ONTO SAID SCREEN TO PRODUCE A LUMINOUS POINT THEREON, AND MEANS OPERABLE BY THE APPLICATION OF ELECTRIC CURRENTS FOR DEFLECTING SAID BEAM TO SHIFT THE LUMINOUS POINT ON SAID SCREEN; MEANS FOR SCANNING TWO STEREOSCOPICALLY RELATED DIAPOSITIVES OF A TERRAIN INCLUDING A PAIR OF LENSES PLACED TO FOCUS LIGHT RAYS FROM THE LUMINOUS POINT IN A PREDETERMINED RELATION UPON SAID DIAPOSITIVES, AND PHOTOSENSITIVE DEVICES EXPOSED TO THE LIGHT RAYS FOCUSED UPON SAID DIAPOSITIVES TO PRODUCE OUTPUT SIGNALS FLUCTUATING IN PROPORTION TO THE TRANSPARENCY OF THE SPOTS ENCOUNTERED BY THE LIGHT RAYS ON SAID DIAPOSITIVES; FIRST MEANS FOR SUPPLYING SUCH CURRENTS TO SAID BEAM DEFLECTION MEANS TO SHIFT SAID BEAM ACROSS SAID SCREEN; MEANS OPERATIVE IN RESPONSE TO CORRELATION BETWEEN THE OUTPUT SIGNALS OF SAID PHOTOSENSITIVE DEVICES FOR GENERATING SIGNALS INDICATIVE OF THE DISCOVERY OF A SPOT OF THE DESIRED CONTOUR ON THE DIAPOSITIVES; MEANS OPERATIVE IN RESPONSE TO SIGNALS GENERATED BY SAID CORRELATION SIGNAL GENERATING MEANS FOR DISABLING SAID FIRST DEFLECTION CURRENT SUPPLY MEANS; SECOND MEANS FOR SUPPLYING CURRENTS TO SAID BEAM DEFLECTION MEANS FOR DEFLECTING SAID BEAM IN A REPETITIVE SEARCH PATTERN ABOUT A CENTER POINT THEREOF TO CAUSE THE LIGHT RAYS FOCUSED UPON THE DIAPOSITIVES TO SCAN THE AREAS AROUND DISCOVERED CONTOUR SPOTS; MEANS UTILIZING SAID SECOND DEFLECTION CURRENTS AND THE OUTPUT OF SAID CORRELATION SIGNAL GENERATING MEANS FOR GENERATING SERVO CURRENTS EFFECTIVE UPON APPLICATION TO SAID BEAM DEFLECTION MEANS TO CONFINE SAID BEAM TO A POSITION OF DEFLECTION WHEREIN THE LIGHT RAYS FOCUSED UPON THE DIAPOSITIVES IMPINGE UPON CORRESPONDING SPOTS OF THE DESIRED CONTOUR; MEANS FOR APPLYING SAID SERVO CURRENTS TO SAID BEAM DEFLECTION MEANS; AND MEANS UTILIZING SAID SECOND DEFLECTION CURRENTS AND THE OUTPUTS OF SAID CORRELATION SIGNAL GENERATING MEANS FOR SENSING THE DIRECTION OF THE DESIRED CONTOUR AND FOR CURTAILING THE APPLICATION OF SAID SERVO CURRENTS TO SAID BEAM DEFLECTION MEANS SO THAT THE REMAINING SERVO CURRENTS SHIFT THE LIGHT POINT ON THE SCREEN OF SAID TUBE IN SUCH A MANNER THAT THE LIGHT RAYS FOCUSED UPON THE DIAPOSITIVES FOLLOW CORRESPONDING CONTOURS OF SAID DIAPOSITIVES.