INTERFEROMETER SYSTEM, SIGNAL PROCESSING METHOD IN INTERFEROMETER SYSTEM, AND STAGES USING SIGNAL PROCESSING METHOD CONCERNED

摘要

PROBLEM TO BE SOLVED: To provide an interferometer system and a signal processing method and the like in the interferometer system capable of measuring position information of test objects with high precision.

SOLUTION: Detected signals K1 are digital ones of signals acquired by irradiating the test objects with measuring beam and have no variation of their cycles and pulse width drastically. A flag generating section 22 detects the rise and decay of synchronized signals K2 synchronizing the detected signals K1. A period measuring section 23 generates delayed detection signals K3 by delaying the synchronized signals K2 by one cycle through measuring the pulse cycle and the pulse width of individual pulse included in the synchronous detected signal K2. An edge monitoring section 25 detects the rise position and the like of the delayed detection signals K3, while a complement counter section 24 generates complement signals KC on the basis of the complement on-off signal ST outputted from the edge monitoring section 25 and complements places with pulse anomaly in the delayed detection signals KC.

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