Visual alarm for a communication module

Claim 1

A visual alarm system for a modular telecommunication device comprising: an outer housing for said modular telecommunications device which includes an upper and lower shell sealed to one another and formed of a material which is impervious to moisture and oxygen with at least a portion of said upper shell being transparent to light; an organic electroluminescent display assembly contained within said sealed upper and lower shells which includes, a composite layer of organic electroluminescent material having the characteristic of producing illumination in response to voltage across the material; a first layer of electrically conductive material on one side of said layer of composite organic electroluminescent material, said first layer comprising a plurality of parallel elongate conductive strips separated from one another and connected to an electrical terminal on the outside of said sealed upper and lower shells; a second layer of electrically conductive material on the other side of said layer of composite organic electroluminescent material from said first layer, said second layer comprising a plurality of parallel elongate conductive strips separated from one another and extending in a direction at an angle to the conductive strips in said first layer to define a pixel area within the organic electroluminescent layer between each crosspoint region between an overlying and underlying conductive strip, each of said strips in said second layer also being connected to an electrical terminal on the outside of said sealed upper and lower shells; a circuit for selectively applying electrical power to the electrical terminals connected to selected ones of said separate strips within said first and second conductive layers to illuminate said pixel areas at the crosspoint regions between each underlying and overlying conductive strip to which electrical power is selective applied and allow said illuminated pixels to be visible through portions of said upper and lower shell which are transparent; and means for energizing said circuit in response to the occurrence of an alarm condition within said modular telecommunications device to produce illumination of selected ones of the pixel areas underlying the transparent areas in said outer housing and visually signal to a user the existence of said alarm condition.