Apparatus for detecting motion and objects

Claim 1

APPARATUS FOR DETECTING OBJECTS IN A SELECTED ZONE FOR PRODUCING AN AUDIBLT TONE DISTINCTLY REPRESENTATIVE OF THE RANGE OF SAID OBJECT, COMPRISING A SPECTABLE FRAME HAVING A PAIR OF LENS SPACES, A SOURCE OF ALTERNATING CURRENT, MEANS PERIODICALLY TO FREQENCY MODULATE SAID ALTERNATING CURRENT TO PRODUCE A FIRST SIGNAL WHICH PERIODICALLY SWEEPS DOWNWARDLY IN FREQUENCY OVER A SELECTED RANGE AT A RELATIVELY SLOW RATE AND THEN RETURNS AT A RELATIVELY RAPID RATE, A TRANSMITTING TRANSDUCER AND A RECEIVING TRANSDUCER EACH EXPOSED TO SAID ZONE AND EACH HAVING A LIKE RESONANT FREQUENCY CORRESPONDING TO AN INTERMEDIATE FREQUENCY VALUE IN SAID SELECTED RANGE AND EACH HAVING AN EFFECTIVE BANDWITH SUBSTANTIALLY LESS THAN ANY FREQUENCY IN SAID RANGE AND SUBSTANTIALLY LESS THAN THE EXTENT THE SAID RANGE, THE FREQUECY PASSBAND OF SAID TRANSMITTING TRANDUCER BEING REMOTE FROM THE TERMINAL FREQUENCIES OF SAID RANGE AND THE RESPONSE TIME AND TRANSMITTING TRANSDUCER BEING SLOW RELATIVE TO SAID RETURN TIME OF SAID SWEEP, SID TRANSDUCERS EACH BEIN MOUNTED IN A RESPECTIVE ONE OF SAID LENS SPACES, MEANS TO APPLY SAID FIRST SIGNAL