| 摘要 |
PURPOSE:To display accurate time on a telephone set provided with display device in a key telephone system having an internal clock. CONSTITUTION:This system is provided with a telephone set provided with a display device 11 and a main device 12. The main device 12 is provided with a telephone set interface 13 to which the telephone set provided with display device 11 is connected, a trunk line interface 14 connected to a public line, an automatic call controller 16 having a timer information memory 17, a call destination information memory 18 and a controller 19, a time recognition device 20 having a temporary storage memory 21, a sound pattern memory 22 and a controller 23, and a central processing unit 24. The device 12 automatically makes a call toward time signal service in the public line at every prescribed time, identifies time from the sound of a received time tone and corrects the time of the internal clock 15 in accordance with this time data. |
