Photoelectric position-measuring device

摘要

In a method for obtaining scanning signals having a defined zero position in a photoelectric measuring device for measuring the relative position of two objects, the graduation of a scale is scanned by means of a scanning field simultaneously in transmitted light and in reflected light. The scanning field is assigned for this purpose both a photoelement to which transmitted light is applied and a photoelement to which reflected light is applied, which are connected differentially to a pulse shaper stage of an evaluation device. Forming the difference of the two scanning signals supplied by the photoelements provides a zero-symmetrical scanning signal.