Patent ID: 7864093

Claim:
A pulse phase difference detecting circuit comprising: a first delay circuit that receives a first pulse signal to output a signal obtained by delaying the first pulse signal as a second pulse signal, and includes a plurality of delay units which have the same delay amount and which are connected in series; a second delay circuit that receives the second pulse signal and includes a plurality of delay units which have the same delay amount and which are connected in series; a first delay adjustment circuit that adjusts a delay amount with respect to the second pulse signal, and outputs the adjusted second pulse signal back to the first delay circuit as a third pulse signal; and a pulse arrival position detecting circuit that detects a pulse arrival position of the first pulse signal based on an output of the delay units of the first delay circuit and based on an output of the delay units of the second delay circuit, the output of the delay units of the first delay circuit being transmitted as the third pulse signal and the output of the delay units of the second delay circuit being transmitted as the second pulse signal.