Indexer for magazine shelves of a magazine and wafer-shaped objects contained therein

An indexer for magazine shelves of a magazine and the wafer-shaped objects contained therein, the magazine and a first handling plane for removing and charging the objects being adjustable vertically relative to one another for the processing of such wafer-shaped objects, the indexer having an optoelectronic sensor arrangement for detecting the objects and magazine shelves relative to a reference plane which is in a fixed relationship to the first handling plane,

• the optoelectronic sensor arrangement having a transmitter and a receiver, and wherein at least a part of the optoelectronic sensor arrangement is designed as a distance measuring system for measuring, within a horizontal plane that is perpendicular to a direction of adjustment movement of the magazine, a distance to edges of the wafer-shaped objects and to edges of the magazine shelves relative to the transmitter, and further wherein the transmitter and receiver serve to detect shelf-forming projections.