Optical wave guide telephone set - has automatic switching within each telephone device between transmission and reception modes depending on received speech signals

摘要

The telephone set has at least two identical telephone devices at either end of an optical wave guide (5,6). Each device has transmission and reception stages (1,2) which employ a modulator (10) and a demodulator (14). Batteries are used to supply the operating voltage. An automatic switching device (3) within each telephone device responds to speech signals from the telephone device for blocking the reception stage, or to signals received from the optical wave guide for blocking the transmission stage.