DEVICE FOR DETECTING MOVING SUBSTANCE

摘要

PURPOSE:To detect a moving substance with high accuracy by a device wherein a difference signal obtained from a pair of detectors is used to drive a flip- flop circuit. CONSTITUTION:Upon receiving radiant energy from a moving substance 1, a first detector 31 generates an output signal e1 and a second detector 32 generates an output signal e2 with a lag of short time. A difference of both the signals e1 and e2 is calculated by a subtractor 4 and thus obtained difference signal e3 is taken out. The difference signal e3 is differentiated by a differential circuit 5 to be converted into an output signal e4 including pulse signals with both negative and positive polarities. An RS flip-flop circuit 8 issues from its Q terminal and output signal e7 corresponding to detection of the moving substance and this signal can be taken out from an output terminal 9.