| 摘要 |
PROBLEM TO BE SOLVED: To reduce power consumption, while feasibly maintaining a non-ringing incoming call function.SOLUTION: A communication terminal connected to a public line 30 and including a facsimile function comprises: a mechanical relay 14 that switches between a disconnection state for disconnecting an external telephone 20 connected with the communication terminal from the public line 30, and a connection state for connecting the external telephone 20 to the public line 30; a polarity inversion detection circuit 17 that detects whether or not polarity of a signal from the public line 30 has inverted; and a line control unit 11 that controls the mechanical relay 14 to switch from the connection state to the disconnection state, when a non-ringing incoming call function for receiving an incoming call while causing the telephone 20 not to ring to ringing from the public line 30 is configured, and the fact that the polarity of the signal from the public line 30 is inverted is detected. |
