| 摘要 |
PURPOSE:To simplify a modulation and a demodulation circuit when a voice signal is sent by the infrared ray remote controller. CONSTITUTION:A voice signal is subjected to pulse density modulation by a pulse density modulator 7 and a control signal is subjected to other pulse modulation than the pulse density modulation by a remote control modulation section 6. Then a switch of a selection switch section 8 is used to select a signal and an infrared ray signal from a high speed LED 10 is sent. The received control signal is demodulated by a remote control demodulation section 14 and the voice signal is demodulated by a low pass filter 13. Then a main control section 15 controls a switch 17 to set a voice recording reproduction section 18 to the recording start state. |
