Bidirectional signal transmission system using IR light - has identical devices for simultaneous transmission in both directions

摘要

The transmission system allows signals to be transmitted between two identical devices in both directions simultaneously. The propagationn of the IR light between the 2 devices is effected directly or using relfection, refraction or diffraction. Each device has a single stabilised frequency oscillator (4) for both the transmission and reception function, with a low-pass filter (10) determining the frequency spectrum and a bandpass filter defining the reception spectrum. -