FOCUS SERVO DEVICE AND OPTICAL RECORDING/REPRODUCING DEVICE

摘要: PROBLEM TO BE SOLVED: To surely draw a focus servo by measuring the time between two extreme values different in polarities with focal point position of error signal and closing loop based on middle value at this time. SOLUTION: Peak bottom positions an analog FE are detected peak detection circuits 12, 13, set S12 reset S13 sent to counter 14, 14 starts count S12, ends S13, counts prescribed clock frequency, result S14 is averaged averaging circuit 15, turned making timing position, since actuator driven be adjusted, followed without dispersion being affected fluctuation FE.