Patent ID: 7746995

Claim:
A telephone control system comprising: a plurality of telephone sets which are connected to a plurality of lines, each of the telephone sets including: a status setting device capable of setting the telephone set into any of an on-call status, a call holding status and an on-hook status, and capable of releasing any set status; a status discriminator for discriminating status of the plurality of lines to be one of the on-call status, the call holding status and the on-hook status; an incoming-call detector for detecting an incoming call signal from any one of the plurality of lines; a notification device for providing a notification of an incoming call by one or both of tone information and visible information in response to a detection output from the incoming-call detector; and a controller for controlling operations of the status setting device, the status discriminator, the incoming-call detector and the notification device, wherein in a state in which the incoming-call detector has detected a new incoming-call signal from a first line, when the status discriminator discriminates the call holding status for a second line, the controller controls the notification device so that the incoming call is notified by, at least, tone information, and when the status discriminator discriminates the on-call status for the second line, the controller controls the notification device so that the incoming call is notified by, at least, visible information.