US Patent 7611648 Method for forming an optical element

The invention relates to a process for forming an optical element. A forming tool is used having a plurality of molding or hot-embossing portions formed on a surface thereof for molding or hot-embossing optical structures onto a substrate. On the surface of the substrate there is formed at least one preformed portion. The substrate is heated to a temperature above a transition temperature and the forming tool and the substrate are pressed against each other for forming an optical element having a plurality of structures having an optical effect, wherein the shape of the structures having an optical effect is given by the respective associated molding or hot-embossing portion.