A film lens comprises a light transmitting base having one side and an opposite side, a plurality of concave or convex unit lenses formed on the one side of the light transmitting base, and a plurality of projections formed on the opposite side of the light transmitting base and having a profile height...http://www.google.fr/patents/US5598280?utm_source=gb-gplus-shareBrevet US5598280 - Film lens and a surface light source using the same
Film lens and a surface light source using the same
