Distance measuring system by irradiating a target with light and sensing the reflected light

Claim 1

A DISTANCE MEASURING SYSTEM, COMPRISING IN COMBINATION, A LIGHT SOURCE FOR IRRADIATING A TARGET AND BE REFLECTED THEREBY; AN AUDIO OSCILLATOR TO MODULATE SAID LIGHT SOURCE SO AS TO PRODUCE A LIGHT SIGNAL MODULATED IN PHASE, FREQUENCE AND AMPLITUDE; DETECTOR CELL MEANS WITH REFLECTOR MEANS FOR FOCUSSING SAID REFLECTED LIGHT THEREON, SAID DETECTOR CELL MEANS TRANSLATING SAID DETECTED LIGHT INTO AN AMPLITUDE MODULATED ELECTRIC SIGNAL WHOSE AMPLITUDE AND FREQUENCY CORRESPOND TO THAT OF BOTH THE LIGHT SOURCE AND THE DETECTED SIGNAL BUT WHOSE PHASE CORRESPONDS ONLY TO THE DETECTED SIGNAL; RESOLVER MEANS CONNECTED TO SAID AUDIO OSCILLATOR, RECEIVING A SIGNAL THEREFROM, A CORRESPONDING IN AMPLITUDE TO THAT SUPPLIED BY SAID DETECTOR CELL AND SHIFTING THE PHASE OF SAID SIGNAL THROUGH 360* BY THE ROTATION THEREOF, INCLUDING MOTOR MEANS TO ROTATE SAID RESOLVER MEANS; A MULTIPLIER AVERAGER CIRCUIT TO WHICH IS APPLIED THE OUTPUT FROM THE DETECTOR CELL MEANS AND RESOLVER MEANS, AND MULTIPLYING SAID TWO INPUTS; TRIGGER MEANS RESPONSIVE TO SAID MULTIPLIER AVERAGER CIRCUIT, SAID TRIGGER MEANS BEING ENABLED ONLY WHEN SAID MULTIPLIED PRODUCT IS AT ITS MAXIMUM; AND GATE MEANS, ONE INPUT OF WHICH IS RESPONSIVE TO SAID TRIGGER MEANS; TIMER MEANS CONNECTED BETWEEN SAID RESOLVER MOTOR MEANS, AND THE OTHER INPUT TO SAID AND GATE MEANS, SUPPLYING AN OUTPUT TO ENABLE SAID AND GATE MEANS ONLY THROUGH THOSE ANGLE POSITIONS IN WHICH THE PHASE SHIFT PROVIDED BY A RESOLVER IS BETWEEN 0* AND 180*; POTENTIOMETER MEANS, SAID POTENTIOMETER MEANS BEING LIKEWISE ROTATED BY RESOLVER MOTOR MEANS INCLUDING A LINE FOR CONNECTION TO A VOLTAGE SOURCE; VOLTAGE MEASURING MEANS RESPONSIVE TO THE VOLTAGE FROM A VOLTAGE SOURCE ACROSS SAID POTENTIOMETER MEASURING MEANS; AND SWITCH MEANS ENABLED BY SAID AND GATE MEANS BETWEEN SAID POTENTIOMETER MEANS AND SAID VOLTAGE MEASURING MEANS SO THAT THE INFORMATION PROVIDED BY SAID VOLTAGE MEASURING MEANS CORRESPONDS TO THE DISTANCE BETWEEN SAID LIGHT SOURCE AND SAID TARGET.