| 摘要 |
PURPOSE:To transmit traffic information with an identification signal inserted before and after during the transmission of a radio broadcast and to detect the identification signal to output following traffic information by switching the receiving of the radio broadcast in the receiving side. CONSTITUTION:Traffic information interposed between leading identification signal f1 and f2 and trailing identification signal f2 and f1 is transmitted besides an ordinary broadcasting signal from a broadcasting station. In the receiving side, these broadcasting signals are received by an antenna 22, and the ordinary broadcast and traffic information are received selectively by tuners 25 and 26. Leading identification signals f1 and f2 are detected by filters 30 and 31 respectively. Detected signals f1 and f2 are detected by detecting circuits 32 and 33 and are compared with a reference voltage through a level setting circuit 53 and a detecting circuit 54 by comparing circuits 34 and 35. Respective outputs of comparing circuits 34 and 35 are applied to time discriminating circuits 37 and 38, and outputs of discriminating circuits 37 and 38 are applied to monostable circuits 47 and 44 and AND gates 45 and 46. If a prescribed condition is satisfied, a relay 50 is operated to output traffic information. |
