Concentrator fresnel lens with varying draft angle

摘要

The present invention relates to a Fresnel lens and a respective mold, the lens comprising a plurality of draft facets, wherein the draft angle of the draft facets has at least two different angular values for two different draft facets, in particular, wherein the draft angle is bigger for a draft facet closer to the edge of the lens or, respectively, of the mold, than for a draft facet closer to the center of the lens or, respectively, of the mold.