Linear Fresnel lens sheet, transmissive display device and roll-shaped mold for producing linear Fresnel lens sheet

摘要

A linear Fresnel lens sheet includes: a lens layer having a first surface in which a linear Fresnel lens portion, having a number of lens surfaces arranged in a first direction d1, is formed, and a second surface opposite the first surface; and a diffusion layer disposed on the side of the second surface of the lens layer.

主权项

1. A roll-shaped mold for producing a linear Fresnel lens sheet, having inclined surfaces, arranged in the axial direction, for producing the lens surfaces of the linear Fresnel lens sheet, said mold comprising:
a first annular groove group consisting of first annular grooves arranged in the axial direction and extending circumferentially around the mold, each groove defining a first inclined surface; a second annular groove group consisting of second annular grooves arranged in the axial direction and extending circumferentially around the mold, each groove defining a second inclined surface; and an intermediate portion disposed between the first annular groove group and the second annular groove group, wherein the first inclined surfaces of the first annular groove group are inclined toward one side from a radial direction perpendicular to the axial direction in a cross-section passing through the axis of the roll-shaped mold, and the second inclined surfaces of the second annular groove group are inclined toward the opposite side from the radial direction perpendicular to the axial direction in the cross-section passing through the axis of the roll-shaped mold, and wherein the intermediate portion comprises two or more flat cylindrical portions that define cylindrical surfaces located at different positions in the radial direction.