发明名称 Audience survey system
摘要 An incasting system which makes possible an interactive participative broadcasting system is described. A plurality of incasting signal generators are each located at respective ones of a plurality of sources which are connected to a central sink via respective communication paths. Detector means located at the central sink are each responsive to the signal which may appear on any one of a plurality of the communication paths.
申请公布号 US3909536(A) 申请公布日期 1975.09.30
申请号 US19740467267 申请日期 1974.05.06
申请人 NORTHERN ELECTRIC COMPANY LIMITED 发明人 WATSON, DOUGLAS JOHN;PARKINSON, PETER
分类号 H04M11/06;(IPC1-7):H04M11/06 主分类号 H04M11/06
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