Patent ID: 7559672

Claim:
A linear luminaire for illuminating a shelf comprising: a first line of compact point light sources emitting upwards and mounted on a first board, the first board being tilted with respect to a bottom of an elongated support structure; and a linear Fresnel lens disposed above the line of point light sources to receive and distribute the light produced by the point light sources, the linear Fresnel lens having an extruded cross-section with a bounded thickness between an interior surface and an exterior surface that is thin relative to a width of the lens, each of the interior and exterior surfaces having instantaneous slopes that form elemental arcuate far-field images of the line of compact point light sources, the exterior surface including a first plurality of refractive facets having a thickness less than half of the bounded thickness and including a first convex lens portion, wherein: each of the first plurality of refractive facets has a close side and an away side with respect to the first convex lens portion, and the away side of each respective facet is longer than the close side of the respective facet; the lens has a first support edge and a second support edge that engage the elongated support structure to position the lens with respect to the point light sources; the first convex lens portion is located proximate the first support edge with none of the first plurality of refractive facets between the convex portion and the first support edge; and the refractive facets have instantaneous slopes selected to reduce non-uniformities in the distribution of the light flux in the far-field images produced by the facets at a target plane parallel to the line of point light sources.