An electroluminescent display device includes at least two elongated, conductive contacts substantially adjacent to and spaced from each other with at least two substantially coextensive ends. A light-emitting element is electrically coupled between the coextensive ends. An elongated insulating base is formed about and between the contacts with their elongated outer edges extending beyond the elongated sides of the base. The base extends substantially the entire length of the outer edges of the contacts and is substantially integral between such contacts.
The device is fabricated in a lead frame environment, wherein the light-emitting element is bonded to a lead frame. A lens is formed over the light-emitting element. The contacts for the device, which may be slidably engageable, are formed from the lead frame. The base is formed contiguous to the lens and over the lead frame to embed the contacts within the base with edges of the contacts extending laterally beyond the surface of the base.
A current-limiting device such as a voltage-dropping resistor or a current-limiting diode may also be embedded within the base, allowing the device to be used over a wide range of operating voltages. The device is ideally suited for replacing on a one-to-one basis switchboard lamps, illuminated key button lamps or the like.
A protective element may be electrically coupled between the coextensive ends of the contacts, allowing the device to be used for circuit protection purposes. Accordingly, upon the occurrence of an overload condition in a circuit coupled to the contact members, the protective element decouples the contact members, resulting in the energization of the light-emitting element.