Optoelectronic arrangement for detecting objects in monitored region has light transmitter and receiver with near and far elements for light from near and far objects

摘要

The arrangement has at least one light beam transmitter (3,7) and receiver (8,9). Light from far and near objects is directed mainly to the far and near elements respectively. Transmitted light (2,6) is directed to a reference surface (4) in a training process and the difference and/or sum of receiver signals adjusted to a reference value(s) within a defined tolerance band. Object detection signal is produced after training process if a difference occurs between current difference and/or sum from reference value(s).