The invention relates to a lighting device for installation in a substantially
plane surface, for example, the surface of a runway. The lighting device comprises
at least one lamp unit that emits light essentially in a light direction which
forms an angle with an axis at right angles to the substantially plane
surface. Furthermore, the lighting device comprises at least one light refracting
means having a longitudinal direction coincident with the light direction, an incident
face substantially at right angles to the light direction, and an exit face parallel
to the substantially plane surface. The light refracting means is preferably a
prism grating. The lighting means is characterised in that the light refracting
means is supported by a supporting means that extends along the whole of or a substantial
part of the length of the light refracting means, and which preferably envelops
the side faces of the light refracting means.
