DESCRIZIONE
Invention shows an electro-optical key arrangement comprising for a key of the key arrangement comprises: a transmitter (LED1) arranged (G1,G2,G3) to transmit photon radiation at a wave-length range comprising at least one wave length, into a wave guide forming an optical path, a receiver (LED2) arranged to receive, said photon radiation on said at least one wave length, at least partly from said optical path, and to convert said photon radiation into an electric form to be used for an electric signal, and a detector circuit (D1,D2,D3) arranged to detect changes in said photon radiation received for forming a specific electric signal as a key (Q1,Q2,Q3) specific signal. In said arrangement said transmitter (LED1) and said receiver (LED2) are arranged into the same in-cast molded structure body (KB), that further comprises said optical path, arranged into a geometry (LED1, LED2,F) so that touching (F) of the optical path there between said transmitter (LED1) and said receiver (LED2) as an initiation causes a key specific signal as a response in the detector circuit (D1,D2,D3).