Portable teleprinter connected to public switched telephone network - enables deaf people to communicate via this network

摘要

A portable teleprinter is connected to the public switched telephone network to enable deaf people to communicate via this network. The teleprinter has both a keyboard and a paper tape facility. The keyboard can be used to print onto the tape and to feed a coder that allows its output to be passed directly to the telephone line. Incoming signals are decoded and printed out. A suitable acoustic coupler couples the teleprinter to a normal telephone terminal thereby avoiding having to break into the telephone line.