TELEPHONE LINE DISPLAY DEVICE AND TELEPHONE SET HAVING IT

摘要

PURPOSE:To identify a holding state and an incoming state of plural telephone lines on one display device by adopting the constitution that a holding current at line holding and a bell current flowing to a ringer means at incoming flow to a display circuit means. CONSTITUTION:A display means (rectifier 23 and its load circuit) connected in series with a telephone line, e.g., 12, a line holding means (rectifier 27 and its load circuit) and a ringer circuit means (rectifier 38 and its load circuit) connected in terms of AC to the line holding means via a capacitor 36 are provided. The holding state is displayed by flowing the holding current to the display circuit means at the line holding. The incoming state is displayed by flowing a bell signal current flowing to the ringer circuit means at incoming into the display circuit means. Thus, the display function of incoming/holding is attained with a comparatively simple circuit corresponding to plural telephone lines and an inexpensive and simple telephone set is attained.