| 摘要 |
PURPOSE: A speaker apparatus unified with microphone is provided to eliminate the howling phenomenon by generating the negative-phase signal of the MIC signal. CONSTITUTION: The microphone(5) is buried to the organic electroluminescent display. The impedance sensing circuit(12) detects signal except for the microphone input(18) from the current signal coming in from micro. In order to delete the MIC signal fed back from the impedance sensing circuit, reverse phase generation circuits(10,11) occur the negative-phase signal of MIC signals(15,16). The low-pass and high pass filters(13,14) filters the MIC signal coming in after the impedance sensing circuit and output as the microphone input(18). |
