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

摘要

A linear Fresnel lens sheet (3) includes: a lens layer (10) having a first surface (11) in which a linear Fresnel lens portion (13), having a number of lens surfaces (14) arranged in a first direction d1, is formed, and a second surface (12) opposite the first surface (11); and a diffusion layer (20) disposed on the side of the second surface (12) of the lens layer (10).

主权项

1. A transmissive display device comprising: a linear Fresnel lens sheet comprising a lens layer having a first surface in which a linear Fresnel lens portion, having lens surfaces arranged in a first direction, 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, and
a light source having a projection surface for projecting image light onto the diffusion layer of the linear Fresnel lens sheet, wherein a degree of internal diffusion of the diffusion layer, which is the degree of diffusion of light by the diffusion layer in the linear Fresnel lens sheet as expressed in terms of a haze value, is not less than 70%, and wherein the following relation is satisfied: −α1°+arcsin (1/n)°+arcsin (1/n·sin θi)°≦10° where α1° is the angle of the lens surface, lying farthest from the projection surface of the light source, with respect to a sheet plane of the lens layer, n is a refractive index of the lens layer, and θi° is an angle formed between a normal direction to the sheet plane of the lens layer and an imaginary line connecting the center of the projection surface of the light source with a center of the lens surface lying farthest from the projection surface of the light source.