Device for producing a light barrier

Abstract

A device for producing a light barrier includes a laser unit with at least one vertical cavity surface emitting laser (VCSEL), a photodiode, and a reflector. The reflector is configured to reflect light emitted by the VCSEL, such that a light reflection produced as a result is received by the photodiode, producing a detection signal, from which a direct current signal component is subtracted so that an alternating current component is provided as an evaluation signal. The evaluation signal has a higher signal-to-noise ratio than the detection signal, such that an evaluation device connected to the VCSEL is able to detect an interruption of the light reflection if no self-mixing interference is present.

Dependencies are inferred from the claim text.