| 摘要 |
PURPOSE:To display an incoming call in a busy mode, by producing an audible signal with a data process carried out by a microprocessor within a key telephone device and delivering the voice through an amplifier and a speaker in the key telephone. CONSTITUTION:When an incoming call arrives at a trunk line, the incoming signal is received at a signal receiving circuit 3. Then the output of reception is fed to a microprocessor 4. In this case, the processor 4 drives an oscillator 5 for a display of an incoming call arrived at the trunk line as long as the extension is not busy. When the extension is busy, the data is fed to a key telephone which is busy to produce an audible signal in a microprocessor 13. As a result, the audible signal is produced in the processor 13 of a key telephone under a busy mode, and this output signal is applied to an amplifier 17 to be delivered through a speaker 18. Thus an incoming call can be audibly displayed at a key telephone regardless of a busy mode of the telephone. |
