DE20119972U1 - Electroluminescent light cord with elastomer tube as the carrier of the light layer structure - Google Patents

Description

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State of the art

Electroluminescent light cords have a metal wire as the first electrode, which is coated with the typical electroluminescent light layer structure in the following order: insulation and reflective layer, electroluminescent light layer, transparent electrically conductive layer, which is fed over the entire length of the light cord with the help of a fine metal wire. A transparent tube covers the light cord for electrical and mechanical protection.

This structural design, which is dictated by physics, is unsuitable for light cords with a larger diameter (10-20 mm). The core, the solid metal wire, essentially determines the diameter of the light cord. The weight of the metal, the relatively high metal costs and, above all, the fact that the flexibility of the light cord decreases with increasing thickness mean that only small diameters can be achieved. The light output is correspondingly low.

Advantages of the invention and its description

The light cord according to the invention has a conductive elastomer tube with a wire drawn in for feeding as a base. In larger light cords, the wire on the inside is coiled and

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ensures that the necessary electric field does not drop even over long lengths. The decisive advantage of this technical solution is that light cords with a diameter of 20 mm and more can be produced, but are still flexible and lightweight. Since commercially available materials can be used, favorable pricing is possible.

An embodiment according to the above claims is explained with reference to the following figure:

An electrically conductive elastomer tube (1) with a drawn-in metal wire (2) is coated with a thin reflective and insulating layer (3). This in turn receives an electroluminescent coating (4) in a further production step. A final transparent, electrically conductive coating (5) completes the structure of the flat capacitor in the special round design. In order to counteract a loss of light over longer lengths due to the limited conductivity of the transparent cover electrode, a wire (7) is inserted into a transparent protective tube (6) when the coated elastomer tube described above is drawn in. This wire ensures a uniform supply and thus illumination over its entire length by making close contact with the surface of the elastomer tube.

Claims (4)

1. Endless electroluminescent light cord, characterized in that an elastomer tube with electrical conductivity and of any cross-section, which surrounds a metal wire as a feed electrode, is built up as a flat capacitor by successive coatings which are typical for electroluminescence, so that after applying an alternating voltage with a certain frequency to the feed electrode in the elastomer tube as well as to the fine wire of any length which endlessly touches the outer transparent, electrically conductive electrode, an electric field is built up and the luminous pigment layer is stimulated to glow. 2. Endless electroluminescent light cord according to protection claim 1, characterized in that the light cord is pulled into a transparent tube with a fine wire for electrical supply to the transparent, electrically conductive cover electrode and for simultaneous mechanical and electrical protection. 3. Endless electroluminescent light cord according to claim 1, characterized in that a wide range of luminous colors is possible due to a translucently colored tube surrounding the light cord. 4. Endless electroluminescent light cord according to claim 1, characterized in that different luminous colors are produced by adding a color pigment to the coating material for the outer, transparent cover electrode, which has the property of being stimulated to glow in its own color by the electroluminescent light underneath.