75439311
Feb 24, 1998
Jul 13, 1999
infrared communication system and its individual components, namely, a miniature FM transmitter, operating in the infrared band, which transmits signals conveying signage information to receivers carried by individuals; a miniature FM receiver which receives the signals from the transmitter; and an electronic recording device which records the signage information for transmission by the transmitter to the receiver
Electrical and Scientific Apparatus