{TAIL ~ a tenth step} which multiplies the first time ratio with the phase proceeding amount of the speed detection signal and computes {HEAD ~ the phase proceeding amount} of the first speed detection signal after the current reproducing control signal is inputted; and 
{ TAIL ~ a tenth step } which multiplies the first time ratio with the phase proceeding amount of the speed detection signal and computes { HEAD ~ the phase proceeding amount } of the first speed detection signal after the current reproducing control signal is inputted ; and
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH