METHOD AND DEVICE FOR DISPLAYING SERVED SERVICE

PURPOSE:To surely inform a subscriber of services for a busy period, such as a busy state in-coming call service. CONSTITUTION:A frequency of a busy state in-coming call tone sent superimposingly onto a voice signal through a telephone line L when the busy state in-coming call service is served is selected by a band pass filter 4, the tone is distinguished from a noise and outputted through level comparison by a level comparator circuit 7 to start a timer 9. After the timer 9 is started, a time limit signal is outputted when a time equal to a signal transmission interval of a busy state in-coming call tone elapses. A gate circuit 11 is set 'through' by the time limit signal and when the in-coming call tone signal is sent again in this case, a display start signal is sent through the gate circuit 11. Thus, a light emission drive circuit 12 is started and a busy state in-coming call is displayed visually on a light emission display device 13 or/and a signal tone drive circuit 14 is started, the signal is sounded from a speaker 15 and the busy state in-coming call is displayed audibly with other means than a receiver and the served service (busy state incoming call) is surely informed to the busy state subscriber.