Pulse phase difference encoding circuit

A time difference detecting means for providing a signal indicating a time difference between a first signal and a second signal, comprising:

• a delayed pulse generating means having a plurality of delay elements connected in series to form a series circuit, receiving said first signal, for generating a plurality of delayed pulses while said first signal is passing through the delay elements;
• a detecting means, connected to said delayed pulse generating means and receiving said delayed pulses, for detecting a latest one of said delayed pulses when receiving said second signal a certain time after said first signal and generating a detecting signal indicating a time period elapsed between the time when said first signal is input thereto and the time when said second signal is input thereto;
• means, connected to said delayed pulse generating means, for connecting one end of the series circuit to an other end thereof to repeatedly circulate said delayed pulses from the one end toward the other end through the delay elements of the series circuit;
• counting means, connected to said delayed pulse generating means, for counting a number of times that the delayed pulses circulate in the series circuit;
• and
• means, connected to said detecting means and to said counting means, for combining the detecting signal from the detecting means with the number of times of circulation counted by the counting means, to indicate a time difference between the first and second signals.

A phase difference detecting circuit for detecting a phase difference between a first signal and a second signal subsequent to said first signal, said circuit comprising:

• a series circuit including a plurality of serially-connected delay elements having an end delay element connected to a beginning delay element to form a ring circuit, said first signal being input to any one connecting portion formed between any two delay elements, a delayed signal being produced at each said connecting portion of each said delay element which is sequentially delayed from one connecting portion to another;
• an encoder, connected to said series circuit and to receive said second signal to detect a position of said delayed signal from one of a plurality of said delay elements, at a time when the second signal is input thereto;
• a counter circuit, connected to said series circuit to count a number of times that said delayed signal travels between said end and beginning delay elements;
• and
• detecting means for detecting a phase difference between said first and second signals using a count from said counter circuit and a detected position of said delayed signal detected by said encoder.

A time difference detector for providing a signal indicating a time difference between a first signal and a second signal, comprising:

• a plurality of delay elements connected in series to form a series circuit, receiving said first signal, and generating a plurality of delayed pulses while said first signal is passing through the delay elements;
• an encoder circuit connected to said series circuit to receive said delayed pulses, configured to detect a latest one of said delayed pulses when receiving said second signal a certain time after said first signal, and generating a detecting signal indicating a time between an input of said first signal and an input of said second signal;
• a connecting element connected between one end of the series circuit and an other end thereof, to repeatedly circulate said delayed pulses from the one end toward the other end through the delay elements of the series circuit;
• a counter circuit connected to count a number of times that the delayed pulses circulate in the connecting element of the series circuit;
• and
• means for combining the detecting signal from the encoder with the number of times of circulation counted by the counter, to indicate a time difference between the first and second signals.