Method for manufacture of molding die for Fresnel lens sheet

摘要

A method for the manufacture of a Fresnel lens sheet is disclosed. The Fresnel lens sheet have arranged thereon a multiplicity of sawtooth-like Fresnel lenses composed of a Fresnel lens surface demonstrating a convex lens function and a rise surface located between the adjacent Fresnel lens surfaces. This sheet has a layer containing a light-diffusing material or a light-absorbing material on the rise surfaces. The method comprises the steps of, coating a photoresist on the Fresnel lens surfaces and rise surfaces, and forming the layer containing a light-diffusing material or a light-absorbing material on the rise surfaces by exposing the photoresist at mutually different light exposure doses per unit surface area on the Fresnel lens surfaces and rise surfaces.