Miniature 2-dimensional encoder readhead using fiber optic receiver channels

摘要: A 2D fiber optic encoder readhead having multiple portions for sensing the two-dimensional displacement of a scale grating is disclosed. The detector channels are respective phase masks. At least two masks have different orientations so as to facilitate detection in at directions. configured detect self-image pattern that results from corresponding on grating. allows In various exemplary embodiments, constructed according design relationships insure robust signal-to-noise ratio. Accordingly, high levels signal interpolation may be achieved. assembled particularly accurate and economical manner provided package with dimensions order 1–2 millimeters, resulting very small overall dimension dependent number incorporated.