Optical position measuring device

摘要

The optical positioning measuring device is used to determine the relative position between two objects movable relative to each other. The device has a light source. It also has a rule scale with definite scale divisions. The device also has at least one scan scale with a definite scale division. Interference capable partial beam bundles are incident on the sample scale. The beam bundles are deflectable in at least four different spatial directions. The scan scale also has a super-structure which can be characterised by predetermined super-structure parameters. The device has four detector elements for detecting signal components corresponding to the interfering partial beam bundles. The scan scale is formed such that the incident beam bundles are deflected on the order of 0, 1 and 2. The four detector elements are arranged in the spatial directions such that they correspond to the deflection orders of 1 and 2. The scale divisions of the scan scale are selected to be double that of the divisions of the rule divisions. The super-structure parameters of the scan scale are selected such that with an order of curvature of 0, 1 and 2, adequate intensity of the signal components is guaranteed. With orders 1 and 2, a sufficient degree of modulation of the signal components results with relative movement of the two scales. The phase and amplitude relationships between the detected signal components enable an addition of non-inverted and inverted signal components such that at least two output signals can be generated with a phase offset of 90 deg.