AUTONOMOUS CONTROL END UNIT

摘要

PROBLEM TO BE SOLVED: To provide a highly accurate end unit insusceptible to working environmental temperature, fixing attitude or aging. SOLUTION: An autonomous control end unit 1 comprises a fixed measuring member 3 at a fixing section 5 and a displacement measuring member 4 at a resilient displacement section 6 being displaced by means of a drive element 12 wherein the interval between inner reflectors 3B, 4B and the measuring optical axis of the mirror with respect to a measuring optical path are kept constantly at a specified position based on measurements from a laser light wave interferometer 20. When the detection phase of the interferometer is kept at an initial set value, the distance between measuring faces and the attitude can be kept at high accuracy even if the working environmental temperature is varied and the effect of aging can be eliminated.