MF SIGNAL MIS-DETECTION PREVENTING CIRCUIT

摘要

PURPOSE:To prevent mis-detection of an MF signal by making a voice signal being a cause to mis-detection of the MF signal into a silent state at once and confirming the presence of the MF signal again. CONSTITUTION:An MF signal reception notice section 4 receives an external MF signal and sends a signal present SP as a detection signal representing the presence of the MF signal to a silence data insertion section 3 and an MF data analysis section 5. The silence data insertion section 3 inserts a silence data to a D/A converter section 2 immediately upon the input of the SP, interrupts a voice reproduction transmission path 1 to cause the silence state. On the other hand, the MF data analysis section 5 confirms whether or not the SP is sent even after the silence state and fetches the MF signal from the MF signal reception notice section 4 only when the presence of the SP is confirmed to analyze the MF signal data. Thus, the mis-detection of the MF signal is prevented.