TRASMETTIT0RE LUMIN0S0 M0DULAT0A FREQUENZA F0NICA IN APPARECCHI PER TELEC0MUNICAZI0NI

摘要

1503265 Light links SABA SCHWERZWALDER APPARATE-BAU-ANSTALT AUGUST SCHWER SOHNE GmbH 19 March 1976 [30 Aug 1975] 11078/76 Heading G1A [Also in Division H3] A receiver has an audio modulated light transmitter 8 comprising light emitting diodes (12), Fig. 2 (not shown) disposed behind a tuning scale 1 for optical transmission of audio signals derived from the receiver to headphones which have a receiver response to the light signals. For signals of two or more channels, equal but differently modulated light transmitters 8 may be arranged side by side and/or one below the other behind the tuning scale. A dark layer (10) on the tuning scale is omitted at places where each light transmitter is disposed behind a filter plate (11) pervious only to infrared light radiated by the light emitting diodes (12). The layer 10 may be of a material pervious to infrared rays so that the light transmitters 8 remain unseen by an observer.