MANUFACTURE OF FRESNEL LENS

摘要

PURPOSE:To produce a large quantity of Fresnel lenses excellent in reproducibility and low in cost irrespective of fluidity characteristics of resin by a method wherein a special film is supplied between a metal mold roll and resin composite of lens material and formed in a unitary body. CONSTITUTION:The resin film 6 lower in the melting point than the extruding resin composite that is the lens material 5 supplied from an extrusion forming machine 4 is drawn out of its winding roll 7 and is supplied between a metal mold roll 1 and the lens material 5 and the resin composite and the resin film are combined in a unitary body to form a Fresnel lens. Acryl resin, polycarbonate resin as the resin composite, acryl film, PVC film as the resin film are preferred respectively. EFFECT:It is not necessitated to increase specially the pressure of the metal mold rolls or the pressure of a pushing roll 2.