LED panel lights of the above-mentioned type are known from the prior art, for which additional measures have to be taken in order to protect the layers of the layer structure and the LEDs from dust or humidity. Usually, the layer structure consists of a reflector layer, a cover glass, and a light guiding layer interposed there between which distributes the light of the LEDs, arranged on the edge of the layer structure, uniformly over the total surface. The layers of the layer structure can, for instance, be glued to one another. It is also possible to glue the LEDs to the layer structure. It is also known to use additional seals for sealing the layer structure. Also, LED panel lights of the above-mentioned type are known whose layer structure is not additionally sealed. In the course of time, these lights are subject to a deposition of dirt and/or condensed water between the individual layers so that the light output and the efficiency of the light are reduced.
An LED panel light is known from DE 103 15 251 B4. This light uses a sealing frame which fully surrounds an optical layer structure along the narrow sides thereof. The structure is formed of a base part, a light guide and a transparent cover. To seal the structure, the sealing frame is formed, in one embodiment, of a hot glue plastic material which permanently glues the base part and the cover together.
It is a drawback of the light known from DE 103 15 251 B4 that the use of a hot glue plastic material prevents an exchange of defect component parts, e.g. the LEDs. A housing frame into which the structure is inserted, and which is sealed by a second seal, is not described.
An illumination device for glazings in vehicles is known from US 2011/0267833 A1. In this device light-emitting diodes are used to illuminate an automotive glazing at the side. The optical layer structure is here formed of one or several transparent sheets which are glued together so as to avoid splintering. LEDs are mounted as illuminants at the side and are embraced by a seal. The seal is formed of a U-shaped metal section which is covered by rubber. Additionally, the region inside the seal, in which the LED is arranged, is filled with a transparent adhesive for sealing purposes.