Patent attributes
The present invention provides a Fresnel lens sheet capable of successfully avoiding the “collapse”, “abrasion” and “moiré” problems. A Fresnel lens sheet constitutes, together with a lenticular lens sheet, a rear projection screen, which is mounted in the frame of a rear projection type display. The Fresnel lens sheet includes, on one surface of its substrate, a Fresnel lens part containing a plurality of lenses concentrically formed on one plane. The apexes of the lenses situated in the area between the center and the outer edge of the Fresnel lens part are flattened to give flat faces, and the widths of the flat faces of the lenses on the outer edge side are made greater than the widths of the flat faces of the lenses on the center side. The widths of the flat faces of the lenses are from 0 to 30 μm.
