发明名称 Signalling system
摘要 A signalling system is provided which can be used to update the prices of goods which are electronically displayed on supermarket shelves (1). The signalling system comprises a first signalling device having an input terminal for receiving electrical message data received from a central computer system (5), a spread spectrum encoder for encoding the received message data and an electroacoustic converter (11) for converting the encoded data into corresponding acoustic signals and for transmitting the acoustic signals into a transmission medium. The signalling system also comprises a second signalling device (3) having means for receiving acoustic signals from said transmission medium and for converting the received acoustic signals into corresponding electrical signals, a spread spectrum decoder for decoding the received signals and a message regenerator for regenerating the message data transmitted by the first signalling device from the signals output by the decoder. <IMAGE>
申请公布号 EP1251648(A1) 申请公布日期 2002.10.23
申请号 EP20020077485 申请日期 1998.01.16
申请人 SCIENTIFIC GENERICS LIMITED 发明人 BARCLAY, MICHAEL JOHN
分类号 G06K17/00;H04B1/707;H04B11/00;H04J13/00 主分类号 G06K17/00
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