Abstract: A method and apparatus for processing signals from light pulses for use in detecting the presence of objects that intrude between a light source and light receiver. Upon the receiver detecting light pulses emitted from the source, the emitted light pulses are modulated responsive to a modulation signal into an electro-optical signal path having successive periods. Each period has main, minimum and maximum pulses with the signal path providing a linear processing area having upper and lower amplitudes. Within the linear processing area an hysteresis range is set with upper and lower detection levels. Detection is disabled for those light pulses having amplitudes which are above or below the respective upper and lower detection levels. The linear processing area has an offset amplitude and the main pulse is controlled to have an amplitude which is a function of the offset amplitude.