| 摘要 |
PURPOSE:To confirme suitably an incoming call without giving a surprise to a called party by changing sequentially a ring tone from a low recognizing state to a high recognizing state so as to make the confirmation of an incoming call corresponding to the recognizing capability of the called party. CONSTITUTION:An output of an oscillator 1 is fed to a speaker 3 through an amplifier 2 whose amplification factor is changed by a voltage and a ring tone is outputted from the speaker 3. A voltage controlling the amplifier 2 is formed by a controller 5. The controller 5 consists of a CR time constant circuit, for example, and a control voltage is changed sequentially when a call state signal is excited from a call signal receiver 4 is excited. When a reset signal is transmitted from a switch 6, the system is controlled so that the output is disconnected by the controller 5, and the control voltage restores to the initial state. Thus, the incoming call confirmation is attained suitably in response to the recognizing capability of the called party without giving a surprise to the called party in this way. |
