DETECTING DEVICE FOR DISPLACEMENT

摘要

PROBLEM TO BE SOLVED: To provide a signal of origin in a device for detecting displacement. SOLUTION: Cumulative displacement which is pulse number of an interpolating clock converted from phase difference between the cycle of a phase modulation signal and that of a reference signal is preset into an up-down counter 110, on the other hand, displacement is calculated using difference of the pulse number converted from the cycle of the phase modulation signal and that from the cycle of the reference signal. Clocks of the same number as pulse number obtained by the displacement are supplied to the up-down counter 110 with determining for each clock upward or downward counting according to the direction of displacement. The output when the counting result coincides preset fixed-point information is set to a fixed point output. Finally, a signal of origin is provided by multiplying logically the fixed-point output by an A/B phase signal derived from the output of the up-down counter 110.