DEVICE MEASURING LINEAR MOVEMENTS Russian patent published in 1995 - IPC

FIELD: measurement technology. SUBSTANCE: in compliance with invention two quadrature interference signals are extracted forming polarization and intensity of interfering beams. Then these signals are converted into electrical ones from which information on value and direction of movement is extracted. Polarization and intensity of interfering beams are so formed that one output interference signal is result of summing of two beams of equal intensity with similar character of polarization and the other one is result of summing of two elliptically polarized beams. In second signal polarization direction at which intensities of interfering beams are equal and change of intensity of interfering signal requires phase shift relative to change of intensity of first signal is extracted. EFFECT: increased authenticity of measurement of linear movements. 3 dwg