Photoelectric position measuring instrument with grids

摘要: A position measuring instrument, comprising a scanning grid, scale grid and an illumination unit, is used to produce two sets of diffracted partial light rays. The defines constant formed by fields, constructed as phase grids, offset one another in the direction 1/4 constant. grids have slat-to-furrow width ratio that deviates from 1:1 ratio. has same but 1:1. cooperate with unit rays several orders. An oppositely deflecting prism allocated each field. first second set are generated, wherein opposite set. photodetector respective selected order corresponding electrical signals.