TIME INTERVAL MEASURING INSTRUMENT

PURPOSE:To provide a time interval measuring instrument which readily achieves resolution of several nanoseconds (ns) and less and can be constructed at a low cost. CONSTITUTION:An input portion 11 inputs start signals A, distributing one to a synchronous detection circuit 1 3 and the other to a delay circuit 12. The circuit 12 delays the signals A by different times to provide a signal BNE. A stop signal F is inverted by an inversion circuit 13a into a signal G. An AND circuit 13b-13f ANDs the signals A-E with the signal G. Of the output signals H-L of circuits 13b-13f, a judging circuit 14 detects the signal which is always at a low level. Therefore, the signal whose time difference with the signal F is zero is detected and the time interval between the signals A, F can be determined from known delay time provided by the circuit 12.