Collision warning system

Claim 1

A COLLISION WARNING SYSTEM FOR WARNING THE OPERATOR OF A PROTECTED VEHICLE OF AN IMPENDING COLLISION WITH AN INTRUDING VEHICLE COMPRISING A RADAR MOUNTED IN SAID PROTECTED VEHICLE, RECEIVING MEANS IN SAID PROTECTED VEHICLE FOR RECEIVING FIRST INFORMATION FROM SAID INTRUDING VEHICLE IN RESPONSE TO AN INTERROGATION SIGNAL FROM THE RADAR OF SAID PROTECTED VEHICLE WHICH CORRESPONDS TO THE VECTOR COMPONENTS OF SPEED AND DIRECTION OF SAID INTRUDING VEHICLE, MEANS IN SAID PROTECTED VEHICLE FOR PRODUCING SECOND INFORMATION CORRESPONDING TO THE VECTOR COMPONENTS OF SPEED AND DIRECTION OF SAID PROTECTED VEHICLE, TRANSLATION MEANS IN SAID PROTECTED VEHICLE RECEPTIVE OF SAID FIRST AND SECOND INFORMATION FOR TRANSLATING SAID FIRST AND SECOND INFORMATION INTO RESULTANT CONTROL INFORMATION REPRESENTATIVE OF THE VECTOR DIFFERENCE OF THE AFORESAID VECTOR COMPONENTS, A PLAN POSITION INDICATING DEVICE MOUNTED IN SAID PROTECTED VEHICLE AND RECEPTIVE OF ENERGY REFLECTED FROM SAID INTRUDING VEHICLE, CONTROL MEANS RESPONSIVE TO SAID RESULTANT CONTROL INFORMATION FOR DERIVING A CONTROL SIGNAL WHICH ATTAINS A DISTINCTIVE AMPLITUDE DURING A NARROW TIME INTERVAL WHICH IS A FUNCTION OF THE POSITION OF THE VECTOR DIFFERENCE OF SAID VECTOR COMPONENTS, AND MEANS ACTUATED ONLY WHEN SAID CONTROL SIGNAL IS OF SAID DISTINCTIVE AMPLITUDE FOR ILLUMINATING A NARROW SECTOR OF SAID INDICATING DEVICE, THE POSITION OF SAID ILLUMINATED SECTOR BEING DEPENDENT UPON THE RELATIVE ANGULAR POSITION OF SAID PROTECTED AND INTRUDING VEHICLES, SAID INDICATING DEVICE PROVIDING A VISUAL DISPLAY OF ENERGY REFLECTED FROM SAID INTRUDING VEHICLE WITHIN SAID ILLUMINATED SECTOR ONLY WHEN SAID VEHICLES ARE TRAVELING ALONG A COLLISION COURSE.