Photoelectric measuring system

摘要

A photoelectric measuring system includes a graduation field in the form of a phase grid. An outer field is provided for the graduation field, and this outer field is likewise formed as a phase grid. The phase grids of the graduation field and the outer field have different grid constants, so that the diffraction images generated by them impinge in different places on an array of photodetectors which are circuited together antiparallel to one another. In this way a push-pull signal is generated which can be reliably evaluated and is well suited for use as a reference signal.