| 摘要 |
PROBLEM TO BE SOLVED: To provide a measuring device which is advantageous to measure a position or displacement of an object with high accuracy.SOLUTION: A measuring device, which measures a position or displacement of an object by calculating phase difference between a reference signal and a measurement signal, includes: demodulation units 10 and 20 for demodulating the measurement signal by a first frequency, and for generating a demodulation signal including a second frequency component, a periodic error component and a harmonic component generated by the demodulation; decimation filters 30 and 50 for removing the harmonic component from the demodulation signal and for outputting a signal including the second frequency component and the periodic error component; and a measurement signal correction unit 300 for detecting and removing the periodic error component included in the output signal. The measurement signal correction unit 300 includes: a detection unit (including an amplitude phase calculation unit 320) for detecting the periodic error component; a signal generation unit 380 for generating a removal signal; removal units 302 and 304 for removing the periodic error component by using the removal signal and for outputting the second frequency component; and a processing delay correction unit for correcting a processing delay in the detection unit and the signal generation unit 380. |
