| 摘要 |
PURPOSE:To enable the new originating even for a telephone under reception of a call signal without giving any answer to an incoming call, by providing a detecting circuit to a line circuit to detect whether or not a push-button is pushed with the telephone. CONSTITUTION:When a telephone TELA is hooked off with a push of a push- button BT, the button BT opens. Thus a diode D is inserted in the adverse polarity direction to inhibit the formation of a DC circuit passing through a relay A. Therefore the relay A is not actuated. A central controller CC scans the scanning points SN0 and SN1 of a line circuit LINE and therefore decides the state of the button BT when the TELA is hooked off. Then the controller CC reads out a state memory of the TELA to analyze the scanning result in a calling mode and decides to give an answer to an incoming call or give a new originating with no answer. |
