TWO-COORDINATE DISPLACEMENT CENSOR Russian patent published in 2010 - IPC G01B11/00 G01B9/02 

FIELD: physics.

SUBSTANCE: sensor has a two-dimensional diffraction grating with a periodic structure, a coherent radiation source, a photodetector and an even number of reflecting mirrors. The two-dimensional diffraction grating with positive and negative diffraction orders in two perpendicular planes is reflective and is fixed. The coherent radiation source, reflecting mirrors whose reflecting surfaces are at an angle to the diffraction grating and are arranged in pairs on one of the diffraction grating along perpendicular lines, and the photodetector are integrated into one reading unit connected to a moving object. The mirrors are at a tangent to ellipsoids, one of the foci of which coincides with the point of convergence of waves reflected by the mirrors on the diffraction grating, and the other coincides with the diffraction point on the diffraction grating such that, among waves undergoing double diffraction, two waves of selected diffraction orders are isolated and superposed in space and the obtained interference patterns are picked up by the photodetector.

EFFECT: wider range and more accurate measurement.

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